uk: Комп'ютерні науки

description: Efficient message-passing implementations of shared data types are a vital component of practical distributed systems, enabling them to work on shared data in predictable ways, but there is a long history of results showing that many of the most useful types of access to shared data are necessarily slow. A variety of approaches attempt to circumvent these bounds, notably weakening consistency guarantees and relaxing the sequential specification of the provided data type. These trade behavioral guarantees for performance. We focus on relaxing the sequential specification of a first-in, first-out queue type, which has been shown to allow faster linearizable implementations than are possible for unrelaxed queues. The algorithms which showed these improvements in operation time tracked a complete execution history, storing complete object state at all n processes in the system, leading to n copies of every stored data element. In this paper, we consider the question of reducing the space complexity of linearizable implementations of shared data types, which provide intuitive behavior through strong consistency guarantees. We improve the existing algorithm for a relaxed queue, showing that it is possible to store only one copy of each element in a shared queue, while still having a low amortized time cost. This is one of several important steps towards making these data types practical in real world systems.

uk: вхід без авторизації

name: Concurrent data structures: Fast and Space-Efficient Queues via Relaxation


Armando Castañeda

type: Person

cs: Informatika

de: Informatik

fi: tietojenkäsittelytiede

uk: Комп'ютерні науки

en: Computer Science

fr: Informatique

da: Datalogi

es: Ciencias de la Computación

nl: Informatica

cs: Technické vědy

de: Ingenieurwissenschaften

fi: tekniikka

uk: Інженерія

en: Engineering Sciences

fr: Ingénierie

da: Ingeniørvidenskab

es: Ingeniería

nl: Engineering

description: Considering asynchronous shared memory systems in which any number of processes may crash, this work identifies and formally defines relaxations of queues and stacks that can be non-blocking or wait-free while being implemented using only read/write operations. Set-linearizability and Interval-linearizabilty are used to specify the relaxations formally, and precisely identify the subset of executions which preserve the original sequential behavior. The relaxations allow for an item to be returned more than once by different operations, but only in case of concurrency; we call such a property multiplicity. The stack implementation is wait-free, while the queue implementation is non-blocking. Interval-linearizability is used to describe a queue with multiplicity, with the additional relaxation that a dequeue operation can return weak-empty, which means that the queue might be empty. We present a read/write wait-free interval-linearizable algorithm of a concurrent queue. As far as we know, this work is the first that provides formalizations of the notions of multiplicity and weak-emptiness, which can be implemented on top of read/write registers only.

TIB AV-Portal

type: Service

type: WebContent

type: MediaObject

@language: en

cs: přihlášení není vyžadováno

de: keine Anmeldung erforderlich

uk: вхід без авторизації

en: no login required

nl: geen login vereist

name: Concurrent data structures: Relaxed Queues and Stacks from Read/Write Operations

Opodis

type: Organization

cs: Video

de: Video

fi: Video

uk: Відео

en: Video

fr: Vidéo

da: Video

nl: Video

es: Video


uk: Комп'ютерні науки

description: In this paper, we focus on the uniform bipartition problem in the population protocol model. This problem aims to divide a population into two groups of equal size. In particular, we consider the problem in the context of \emph{arbitrary} communication graphs. As a result, we clarify the solvability of the uniform bipartition problem with arbitrary communication graphs when agents in the population have designated initial states, under various assumptions such as the existence of a base station, symmetry of the protocol, and fairness of the execution. When the problem is solvable, we present protocols for uniform bipartition. When global fairness is assumed, the space complexity of our solutions is tight.

uk: вхід без авторизації

name: Graph algorithms and population protocols: Uniform Bipartition in Population Protocol Model with Arbitrary Communication Graphs


uk: Комп'ютерні науки

description: We study algorithms in the distributed message-passing model that produce secured output, for an input graph G. Specifically, each vertex computes its part in the output, the entire output is correct, but each vertex cannot discover the output of other vertices, with a certain probability. This is motivated by high-performance processors that are embedded nowadays in a large variety of devices. Furthermore, sensor networks were established to monitor physical areas for scientific research, smart-cities control, and other purposes. In such situations, it no longer makes sense, and in many cases it is not feasible, to leave the whole processing task to a single computer or even a group of central computers. As the extensive research in the distributed algorithms field yielded efficient decentralized algorithms for many classic problems, the discussion about the security of distributed algorithms was somewhat neglected. Nevertheless, many protocols and algorithms were devised in the research area of secure multi-party computation problem (MPC or SMC). However, the notions and terminology of these protocols are quite different than in classic distributed algorithms. As a consequence, the focus in those protocols was to work for every function f at the expense of increasing the round complexity, or the necessity of several computational assumptions. In this work, we present a novel approach, which rather than turning existing algorithms into secure ones, identifies and develops those algorithms that are inherently secure (which means they do not require any further constructions). This approach yields efficient secure algorithms for various locality problems, such as coloring, network decomposition, forest decomposition, and a variety of additional labeling problems. Remarkably, our approach does not require any hardness assumption, but only a private randomness generator in each vertex. This is in contrast to previously known techniques in this setting that are based on public-key encryption schemes.

uk: вхід без авторизації

name: Graph algorithms and population protocols: Secured Distributed Algorithms without Hardness Assumptions


uk: Комп'ютерні науки

description: We consider the problem of computing shortest paths in hybrid networks, in which nodes can make use of different communication modes. For example, mobile phones may use ad-hoc connections via Bluetooth or Wi-Fi in addition to the cellular network to solve tasks more efficiently. Like in this case, the different communication modes may differ considerably in range, bandwidth, and flexibility. We build upon the model of Augustine et al. [SODA '20], which captures these differences by a local and a global mode. Specifically, the local edges model a fixed communication network in which O(1) messages of size O(logn) can be sent over every edge in each synchronous round. The global edges form a clique, but nodes are only allowed to send and receive a total of at most O(logn) messages over global edges, which restricts the nodes to use these edges only very sparsely. We demonstrate the power of hybrid networks by presenting algorithms to compute Single-Source Shortest Paths and the diameter very efficiently in sparse graphs. Specifically, we present exact O(logn) time algorithms for cactus graphs (i.e., graphs in which each edge is contained in at most one cycle), and 3-approximations for graphs that have at most n+O(n1/3) edges and arboricity O(logn). For these graph classes, our algorithms provide exponentially faster solutions than the best known algorithms for general graphs in this model. Beyond shortest paths, we also provide a variety of useful tools and techniques for hybrid networks, which may be of independent interest.

uk: вхід без авторизації

name: Graph algorithms and population protocols: Fast Hybrid Network Algorithms for Shortest Paths in Sparse Graphs


uk: Комп'ютерні науки

description: Diameter, radius and eccentricities are fundamental graph parameters, which are extensively studied in various computational settings. Typically, computing approximate answers can be much more efficient compared with computing exact solutions. In this paper, we give a near complete characterization of the trade-offs between approximation ratios and round complexity of distributed algorithms for approximating these parameters, with a focus on the weighted and directed variants. Furthermore, we study bi-chromatic variants of these parameters defined on a graph whose vertices are colored either red or blue, and one focuses only on distances for pairs of vertices that are colored differently. Motivated by applications in computational geometry, bi-chromatic diameter, radius and eccentricities have been recently studied in the sequential setting [Backurs et al. STOC'18, Dalirrooyfard et al. ICALP'19]. We provide the first distributed upper and lower bounds for such problems. Our technical contributions include introducing the notion of approximate pseudo-center, which extends the pseudo-centers of [Choudhury and Gold SODA'20], and presenting an efficient distributed algorithm for computing approximate pseudo-centers. On the lower bound side, our constructions introduce the usage of new functions into the framework of reductions from 2-party communication complexity to distributed algorithms.

uk: вхід без авторизації

name: Graph algorithms and population protocols: Distributed Distance Approximation


uk: Комп'ютерні науки

description: We give efficient distributed algorithms for the minimum vertex cover problem in bipartite graphs in the CONGEST model. From K\H{o}nig's theorem, it is well known that in bipartite graphs the size of a minimum vertex cover is equal to the size of a maximum matching. We first show that together with an existing O(nlogn)-round algorithm for computing a maximum matching, the constructive proof of K\H{o}nig's theorem directly leads to a deterministic O(nlogn)-round CONGEST algorithm for computing a minimum vertex cover. We then show that by adapting the construction, we can also convert an \emph{approximate} maximum matching into an \emph{approximate} minimum vertex cover. Given a (1−δ)-approximate matching for some δ>1, we show that a (1+O(δ))-approximate vertex cover can be computed in time O(D+\poly(lognδ)), where D is the diameter of the graph. When combining with known graph clustering techniques, for any \eps∈(0,1], this leads to a \poly(logn\eps)-time deterministic and also to a slightly faster and simpler randomized O(logn\eps3)-round CONGEST algorithm for computing a (1+\eps)-approximate vertex cover in bipartite graphs. For constant \eps, the randomized time complexity matches the Ω(logn) lower bound for computing a (1+\eps)-approximate vertex cover in bipartite graphs even in the LOCAL model. Our results are also in contrast to the situation in general graphs, where it is known that computing an optimal vertex cover requires ~Ω(n2) rounds in the CONGEST model and where it is not even known how to compute any (2−\eps)-approximation in time o(n2).

uk: вхід без авторизації

name: Graph algorithms and population protocols: Approximating Bipartite Minimum Vertex Cover in the CONGEST model


uk: Комп'ютерні науки

description: This paper provides an algorithmic framework for obtaining fast distributed algorithms for a highly-dynamic setting, in which \emph{arbitrarily many} edge changes may occur in each round. Our algorithm significantly improves upon prior work in its combination of (1) having an O(1) amortized time complexity, (2) using only O(logn)-bit messages, (3) not posing any restrictions on the dynamic behavior of the environment, (4) being deterministic, (5) having strong guarantees for intermediate solutions, and (6) being applicable for a wide family of tasks. The tasks for which we deduce such an algorithm are maximal matching, (degree+1) -coloring, 2-approximation for minimum weight vertex cover, and maximal independent set (which is the most subtle case). For some of these tasks, node insertions can also be among the allowed topology changes, and for some of them also abrupt node deletions.

uk: вхід без авторизації

name: Graph algorithms and population protocols: Fast Deterministic Algorithms for Highly-Dynamic Networks


uk: Комп'ютерні науки

description: We investigate the minimal number of failures that can *partition* a system where processes communicate both through shared memory and by message passing. We prove that this number precisely captures the resilience that can be achieved by algorithms that implement a variety of shared objects, like registers, and solve common tasks, like randomized consensus, approximate agreement and renaming. This has implications for the m&m-model of Aguilera et al., and for the hybrid, cluster-based model of Imbs and Raynal.

uk: вхід без авторизації

name: Consensus Potpourri: Optimal Resilience in Systems that Mix Shared Memory and Message Passing


uk: Комп'ютерні науки

description: Third-state dynamics (Angluin et al. 2008; Perron et al. 2009) is a well-known process for quickly and robustly computing approximate majority through interactions between randomly-chosen pairs of agents. In this paper, we consider this process in a new model with persistent-state catalytic inputs, as well as in the presence of transient leak faults. Based on models considered in recent protocols for populations with persistent-state agents (Dudek et al. 2017; Alistarh et al. 2017; Alistarh et al. 2020), we formalize a Catalytic Input (CI) model comprised of n input agents and m worker agents. For m=Θ(n), we show that computing the PARITY of the input population with high probability requires at least Ω(n2) total interactions, demonstrating a strong separation between the CI and standard population models. On the other hand, we show that the third-state dynamics can be naturally adapted to this new model to solve approximate majority in O(nlogn) total steps with high probability when the input margin is Ω(√nlogn) , which preserves the time and space efficiency of the process in the original model. Moreover we show the robustness of third-state dynamics protocols to the transient leak faults considered by (Alistarh et al. 2017; Alistarh et al 2020). In both the original and CI models, these protocols successfully compute approximate majority with high probability in the presence of leaks occurring at each time step with probability β≤O(√nlognn) . The resilience of these dynamics to adversarial leaks exhibits a subtle connection to previous results involving Byzantine agents.

uk: вхід без авторизації

name: Consensus Potpourri: Approximate Majority With Catalytic Inputs


uk: Комп'ютерні науки

description: An elegant strategy for proving impossibility results in distributed computing was introduced in the celebrated FLP consensus impossibility proof. This strategy is *local* in nature, as at each stage, one configuration of an hypothetical protocol for consensus is considered, together with future valencies of possible extensions. This proof strategy has been used in numerous situations related to *consensus*, leading one to wonder why it has not been used in impossibility results of the two other well-known tasks: *set agreement* and *renaming*. This paper provide an explanation why the proof strategies for showing the impossibility of these tasks have a global nature. We show that *a protocol can always solve such tasks locally*, in the following sense. Given a configuration and all its future valencies, if a single successor configuration is selected, then the protocol can reveal all decisions in this branch of executions, satisfying the task specification. This result is shown for both set agreement and renaming.

uk: вхід без авторизації

name: Consensus Potpourri: Locally Solvable Tasks and the Limitations of Valency Arguments


uk: Комп'ютерні науки

description: We study the rational behaviors of participants in committee-based blockchains. Committee-based blockchains rely on specific blockchain consensus that must be guaranteed in presence of rational participants. We consider a simplified blockchain consensus algorithm based on existing or proposed committee-based blockchains that encapsulates the main actions of the participants: \emph{voting} for a block, and \emph{checking its validity}. Knowing that those actions have costs, and achieving the consensus gives rewards to committee members, we study using game theory how strategic participants behave while trying to maximize their gains. We consider different reward schemes, and found that in each setting, there exist equilibria where blockchain consensus is guaranteed; in some settings however, there can be coordination failures hindering consensus. Moreover, we study equilibria with trembling participants, which is a novelty in the context of committee-based blockchains. Trembling participants are rational that can do unintended actions with a low probability. We found that in presence of trembling participants, there exist equilibria where blockchain consensus is guaranteed; however, when only voters are rewarded, there also exist equilibria where validity can be violated

uk: вхід без авторизації

name: Consensus Potpourri: Rational Behaviors in Committee-Based Blockchains


uk: Комп'ютерні науки

description: This work presents Information Theoretic HotStuff (IT-HS), a new optimally resilient protocol for solving Byzantine Agreement in partial synchrony with information theoretic security guarantees. In particular, IT-HS does not depend on any PKI or common setup assumptions and is resilient to computationally unbounded adversaries. IT-HS is based on the Primary-Backup view-based paradigm. In IT-HS, in each view, each party sends only a constant number of words to every other party. This yields an O(n2) word and message complexity in each view. In addition, IT-HS requires just O(1) persistent local storage and O(n) transient local storage. Finally, like all Primary-Backup view-based protocols in partial synchrony, after the system becomes synchronous, all nonfaulty parties decide on a value in the first view a nonfaulty leader is chosen. Moreover, like PBFT and HotStuff, IT-HS is optimistically responsive: with a nonfaulty leader, parties decide as quickly as the network allows them to do so, without regard for the known upper bound on network delay. Our work improves in multiple dimensions upon the information theoretic version of PBFT presented by Miguel Castro, and can be seen as an information theoretic variant of the HotStuff paradigm.

uk: вхід без авторизації

name: Consensus Potpourri: Information Theoretic HotStuff


uk: Комп'ютерні науки

description: With the emergence of attack-prone cross-organization systems, providing asynchronous state machine replication (SMR) solutions is no longer a theoretical concern. This paper presents \emph{ACE}, a framework for the design of such fault tolerant systems. Leveraging a known paradigm for randomized consensus solutions, ACE wraps existing practical solutions and real-life systems, boosting their liveness under adversarial conditions and, at the same time, promoting load balancing and fairness. Boosting is achieved without modifying the overall design or the engineering of these solutions. ACE is aimed at boosting the prevailing approach for practical fault tolerance. This approach, often named \emph{partial synchrony}, is based on a leader-based paradigm: a good leader makes progress and a bad leader does no harm. The partial synchrony approach focuses on safety and forgoes liveness under targeted and dynamic attacks. Specifically, an attacker might block specific leaders, e.g., through a denial of service, to prevent progress. ACE provides boosting by running \emph{waves} of parallel leaders and selecting a \emph{winning} leader only retroactively, achieving boosting at a linear communication cost increase. ACE is agnostic to the fault model, inheriting it s failure model from the wrapped solution assumptions. As our evaluation shows, an asynchronous Byzantine fault tolerance (BFT) replication system built with ACE around an existing partially synchronous BFT protocol demonstrates reasonable slow-down compared with the base BFT protocol during faultless synchronous scenarios, yet exhibits significant speedup while the system is under attack.

uk: вхід без авторизації

name: Consensus Potpourri: ACE: Abstract Consensus Encapsulation for Liveness Boosting of State Machine Replication


uk: Комп'ютерні науки

description: The Ripple network is one of the most prominent blockchain platforms and its native XRP token currently has the third-largest cryptocurrency market capitalization. The Ripple consensus protocol powers thi s network and is generally considered to a Byzantine fault-tolerant agreement protocol, which can reach consensus in the presence of faulty or malicious nodes. In contrast to traditional Byzantine agreement protocols, there is no global knowledge of all participating nodes in Ripple consensus; instead, each node declares a list of other nodes that it trusts and from which it considers votes. Previous work has brought up concerns about the liveness and safety of the consensus protocol under the general assumptions stated earlier, and there is currently no appropriate understanding of its workings and its properties in the literature. This paper makes two contributions. It first provides a detailed, abstract description of the protocol, which has been derived from the source code. Second, the paper points out that the abstract protocol may violate safety and liveness in several simple executions under relatively benign network assumptions.

uk: вхід без авторизації

name: Blockchain and BFT: Security Analysis of Ripple Consensus


uk: Комп'ютерні науки

description: Modern machine learning architectures distinguish servers and workers. Typically, a d-dimensional model is hosted by a server and trained by n workers, using a distributed \textit{stochastic gradient descent} (SGD) optimization scheme. At each SGD step, the goal is to estimate the gradient of a cost function. The simplest way to do this is to \emph{average} the gradients estimated by the workers. However, averaging is not resilient to even one single Byzantine failure of a worker. Many alternative \emph{gradient aggregation rules} (GARs) have recently been proposed to tolerate a maximum number f of Byzantine workers. These GARs differ according to (1) the complexity of their computation time, (2) the maximal number of Byzantine workers despite which convergence can still be ensured (breakdown point), and (3) their accuracy, which can be captured by (3.1) their angular error, namely the angle with the true gradient, as well as (3.2) their ability to aggregate full gradients. In particular, many are not full gradients for they operate on each dimension separately, which results in a coordinate-wise blended gradient, leading to low accuracy in practical situations where the number (s) of workers that are actually Byzantine in an execution is small ($s<We propose \textsc{Aksel}, a new scalable median-based GAR with an optimal time complexity (O(n)), an optimal breakdown point (n>2f) and the lowest upper bound on the \textit{expected angular error} (O(1)) among \textit{full gradient} approaches. We also study the \textit{actual angular error} of \textsc{Aksel} when the gradient distribution is normal and show that it only grows in O(logn), which is the first logarithmic upper bound ever proven assuming an optimal breakdown point. We also report on an empirical evaluation of \textsc{Aksel} on various classification tasks, which we compare to alternative GARs against state-of-the-art attacks. \textsc{Aksel} is the only GAR reaching top accuracy when there is actually none or few Byzantine workers while maintaining a good defense even under the extreme case (s=f). For simplicity of presentation, we consider a scheme with a single server. However, as we explain in the paper, \textsc{Aksel} can also easily be adapted to multi-server architectures.

uk: вхід без авторизації

name: Blockchain and BFT: Fast Byzantine SGD (Best Student Paper Award)


uk: Комп'ютерні науки

description: In the past few years, many Byzantine-tolerant distributed machine learning (DML) algorithms have been proposed in the point-to-point communication model. In this paper, we focus on a popular DML framework -- the parameter server computation paradigm and iterative learning algorithms that proceed in rounds, e.g., \cite{vaidya-2f-redundancy, Rachid_genuine_BML,Su_BGD}. One limitation of prior algorithms in this domain is the \textit{high communication complexity}. All the Byzantine-tolerant DML algorithms that we are aware of need to send n d-dimensional vectors from worker nodes to the parameter server in each round, where n is the number of workers and d is the number of dimensions of the feature space (which may be in the order of millions). In wireless network, power consumption is proportional to the number of bits transmitted. Consequently, it is extremely difficult, if not impossible, to deploy these algorithms in power-limited wireless devices. %This is because communication of large gradients (or vectors) requires high power consumption. Motivated by this observation, we aim to reduce the \textit{communication complexity} of Byzantine-tolerant DML algorithms in the \textit{single-hop radio network} \cite{Broadcast_SPAA10,Broadcast_Nitin_PODC05,Broadcast_Koo_PODC04}. Inspired by the CGC filter developed by Gupta and Vaidya, PODC 2020 \cite{vaidya-2f-redundancy}, we propose a gradient descent-based algorithm, Echo-CGC. Our main novelty is a mechanism to utilize the \textit{broadcast properties} of the radio network to avoid transmitting the raw gradients (full d -dimensional vectors). In the radio network, each worker can overhear previous gradients that were transmitted to the parameter server. Roughly speaking, in Echo-CGC, %each worker will compute its local stochastic gradient, and if it if a worker agrees'' with a combination of prior gradients, it will broadcast the echo message'' instead of the its raw local gradient. The echo message contains a vector of coefficients (of size at most n) and the ratio of the magnitude between two gradients (a float). In comparison, the traditional approaches need to send n local gradients in each round, where each gradient is typically a vector in a ultra-high dimensional space (d≫n). %Each worker i computes the angle between the received gradients in the current round and its own gradient (on the local cost function). If there exists a linear combination of previous gradients broadcast by other workers whose angle is less than a certain bound α, then worker i broadcasts the echo'' message, which contains a vector of coefficients (of size at most n) and the ratio of the magnitude between two gradients (a float). Compared to the traditional approach that sends the entire raw gradient – which is typically a vector in a ultra-high dimensional space – the echo message contains only a few bytes \qinzi{Is this still true with the Span method?} \lewis{No, we can say it’s in the order of n and will be beneficial when n«d}; hence, Echo-CGC effectively reduces the communication complexity. The improvement on communication complexity of our algorithm depends on multiple factors, including number of nodes, number of faulty workers in an execution, and the cost function. We numerically analyze the improvement, and show that with a large number of nodes, Echo-CGC reduces 80% of the communication under suitable assumptions.

uk: вхід без авторизації

name: Blockchain and BFT: Echo-CGC: A Communication-Efficient Byzantine-tolerant Distributed Machine Learning Algorithm in Single-Hop Radio Network


Blockchain and BFT: Heterogeneous Paxos

uk: Комп'ютерні науки

description: In distributed systems, a group of *learners* achieve *consensus* when, by observing the output of some *acceptors*, they all arrive at the same value. Consensus is crucial for ordering transactions in failure-tolerant systems. Traditional consensus algorithms are homogeneous in three ways: * all learners are treated equally, * all acceptors are treated equally, and * all failures are treated equally. These assumptions, however, are unsuitable for cross-domain applications, including blockchains, where not all acceptors are equally trustworthy, and not all learners have the same assumptions and priorities. We present the first consensus algorithm to be heterogeneous in all three respects. Learners set their own mixed failure tolerances over differently trusted sets of acceptors. We express these assumptions in a novel Learner Graph, and demonstrate sufficient conditions for consensus. We present Heterogeneous Paxos: an extension of Byzantine Paxos. Heterogeneous Paxos achieves consensus for any viable Learner Graph in best-case three message sends, which is optimal. We present a proof-of-concept implementation, and demonstrate how tailoring for heterogeneous scenarios can save resources and latency.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Classical protocols for reliable broadcast and consensus provide security guarantees as long as the number of corrupted parties f is bounded by a single given threshold t. If f>t, these protocols are completely deemed insecure. We consider the relaxed notion of \emph{multi-threshold} reliable broadcast and consensus where validity, consistency and termination are guaranteed as long as f≤tv, f≤tc and f≤tt respectively. For consensus, we consider both variants of (1−ϵ)-consensus and \emph{almost-surely terminating} consensus, where termination is guaranteed with probability (1−ϵ) and 1, respectively. We give a very complete characterization for these primitives in the asynchronous setting and with no signatures: -Multi-threshold reliable broadcast is possible if and only if maxtc,tv+2tt<n . -Multi-threshold almost-surely consensus is possible if maxtc,tv+2tt<n, 2tv+tt<n and tt<n/3. Assuming a global coin, it is possible if and only if maxtc,tv+2tt<n and 2tv+tt<n. -Multi-threshold (1−ϵ)-consensus is possible if and only if maxtc,tv+2tt<n and 2tv+tt<n.

uk: вхід без авторизації

name: Blockchain and BFT: Multi-Threshold Asynchronous Reliable Broadcast and Consensus


uk: Комп'ютерні науки

description: We study the Byzantine lattice agreement (BLA) problem in asynchronous distributed message passing systems. In the BLA problem, each process proposes a value from a join semi-lattice and needs to output a value also in the lattice such that all output values of correct processes lie on a chain despite the presence of Byzantine processes. We present an algorithm for this problem with round complexity of O(logf) which tolerates f<n5 Byzantine failures in the asynchronous setting without digital signatures, where n is the number of processes. This is the first algorithm which has logarithmic round complexity for this problem in asynchronous setting. Before our work, Di Luna et al give an algorithm for this problem which takes O(f) rounds and tolerates f<n3 Byzantine failures. We also show how this algorithm can be modified to work in the authenticated setting (i.e., with digital signatures) to tolerate f<n3 Byzantine failures.

uk: вхід без авторизації

name: Blockchain and BFT: Byzantine Lattice Agreement in Asynchronous Message Systems


uk: Комп'ютерні науки

description: We consider the problem of communicating reliably in a dynamic network in the presence of up to k Byzantine failures. It was shown that this problem can be solved if and only if the dynamic graph satisfies a certain condition, that we call "RDC condition". In this paper, we present the first self-stabilizing algorithm for reliable communication in this setting - that is: in addition to permanent Byzantine failures, there can also be an arbitrary number of transient failures. We prove the correctness of this algorithm, provided that the RDC condition is "always eventually satisfied".

uk: вхід без авторизації

name: Dynamic & Radio Networks: Self-stabilizing Byzantine-resilient communication in dynamic networks


uk: Комп'ютерні науки

description: Modern communication networks support fast path restoration mechanisms which allow to reroute traffic in case of (possibly multiple) link failures, in a completely decentralized manner and without requiring global route reconvergence. However, devising resilient path restoration algorithms is challenging as these algorithms need to be inherently local. Furthermore, the resulting failover paths often have to fulfill additional requirements related to the policy and function implemented by the network, such as the traversal of certain waypoints (e.g., a firewall). This paper presents local algorithms which ensure a maximally resilient path restoration for a large family of product graphs, including the widely used tori and generalized hypercube topologies. Our algorithms provably ensure that even under multiple link failures, traffic is rerouted to the other endpoint of every failed link whenever possible (i.e. detouring failed links), enforcing waypoints and hence accounting for the network policy. The algorithms are particularly well-suited for emerging segment routing networks based on label stacks.

uk: вхід без авторизації

name: Dynamic & Radio Networks: Maximally Resilient Replacement Paths for a Family of Product Graphs


uk: Комп'ютерні науки

description: Broadcast is a primitive which allows a specific party to distribute a message consistently among n parties, even if up to t parties exhibit malicious behaviour. In the classical model with a complete network of bilateral authenticated channels, the seminal result of Pease et al. [JACM'80] shows that broadcast is achievable if and only if t<n/3. There are two generalizations suggested for the broadcast problem -- with respect to the adversarial model and the communication model. Fitzi and Maurer [DISC'98] consider a (non-threshold) general adversary that is characterized by the subsets of parties that could be corrupted, and show that broadcast can be realized from bilateral channels if and only if the union of no three possible corrupted sets equals the entire set of n parties. On the other hand, Considine et al. [JC'05] extend the standard model of bilateral channels with the existence of b-minicast channels that allow to locally broadcast among any subset of b parties; the authors show that in this enhanced model of communication, secure broadcast tolerating up to t corrupted parties is possible if and only if t<b−1b+1n. These generalizations are unified in the work by Raykov [ICALP'15], where a tight condition on the possible corrupted sets is presented such that broadcast is achievable from a complete set of b-minicasts. This paper investigates the achievability of broadcast in general networks, i.e., networks where only some subsets of minicast channels may be available, thereby addressing open problems posed by Jaffe et al. [PODC'12], Raykov [ICALP'15]. To that end, we propose a hierarchy over all possible general adversaries, and identify for each class of general adversaries 1) a set of minicast channels that are necessary to achieve broadcast and 2) a set of minicast channels that are sufficient to achieve broadcast. In particular, this allows us to derive bounds on the amount of b -minicasts that are necessary and that suffice towards constructing broadcast in general b-minicast networks.

uk: вхід без авторизації

name: Dynamic & Radio Networks: On Broadcast in Generalized Network and Adversarial Models


uk: Комп'ютерні науки

description: We study the standard communication problem of broadcast for mobile agents moving in a network. The agents move autonomously in the network and can communicate with other agents only when they meet at a node. In this model, broadcast is a communication primitive for information transfer from one agent, the source, to all other agents. Previous studies of this problem were restricted to static networks while, in this paper, we consider the problem in dynamic networks modelled as an evolving graph. The dynamicity of the graph is unknown to the agents; in each round an adversary selects which edges of the graph are available, and an agent can choose to traverse one of the available edges adjacent to its current location. The only restriction on the adversary is that the subgraph of available edges in each round must span all nodes; in other words the evolving graph is constantly connected. The agents have global visibility allowing them to see the location of other agents in the graph and move accordingly. Depending on the topology of the underlying graph, we determine how many agents are necessary and sufficient to solve the broadcast problem in dynamic networks. While two agents plus the source are sufficient for ring networks, much larger teams of agents are necessary for denser graphs such as grid graphs and hypercubes, and finally for complete graphs at least n−2 agents plus the source are necessary and sufficient. We show lower bounds on the number of agents and provide some algorithms for solving broadcast using the minimum number of agents, for various topologies. These results show how the connectivity of the graph affects the communication capability of a team of mobile agents under the mobile adversarial model.

uk: вхід без авторизації

name: Dynamic & Radio Networks: Broadcasting with mobile agents in dynamic networks


uk: Комп'ютерні науки

description: Reliable broadcast is a communication primitive guaranteeing, intuitively, that all processes in a distributed system deliver the same set of messages. The reason why this primitive is appealing is twofold: \emph{(i)} we can implement it deterministically in a completely asynchronous environment, unlike stronger primitives like consensus and total-order broadcast, and yet \emph{(ii)} reliable broadcast is powerful enough to implement important applications like payment systems. The problem we tackle in this paper is that of \emph{dynamic} reliable broadcast, i.e., enabling processes to join or leave the system. This property is desirable for long-lived applications (aiming to be highly available), yet has been precluded in previous asynchronous reliable broadcast protocols. We study this property in a general adversarial (i.e., Byzantine) environment. We introduce the first specification of a dynamic Byzantine reliable broadcast (\name) primitive that is amenable to an asynchronous implementation. We then present an algorithm implementing this specification in an asynchronous network. Our \name algorithm ensures that if any correct process in the system broadcasts a message, then every correct process delivers that message unless it leaves the system. Moreover, if a correct process delivers a message, then every correct process that has not expressed its will to leave the system delivers that message. We assume that more than 2/3 of processes in the system are correct at all times, which is tight in our context. We also show that if only one process in the system can fail—and it can fail only by crashing—then it is impossible to implement a stronger primitive, ensuring that if any correct process in the system broadcasts (resp., delivers) a message, then every correct process in the system delivers that message—including those that leave.

uk: вхід без авторизації

name: Dynamic & Radio Networks: Dynamic Byzantine Reliable Broadcast (DBRB)


uk: Комп'ютерні науки

description: Broadcasting in wireless networks is vulnerable to adversarial jamming. To thwart such behavior, resource competitive analysis is proposed. In this framework, sending, listening, or jamming on one channel for one time slot costs one unit of energy. The adversary can employ arbitrary strategy to disrupt communication, but has a limited energy budget T. The honest nodes, on the other hand, aim to accomplish broadcast while spending only o(T). Previous work has shown, in a C-channels network containing n nodes, for large T values, each node can receive the message in ~O(T/C) time, while spending only ~O(√T/n) energy. However, these multi-channel algorithms only work for certain values of n and C, and can only tolerate an oblivious adversary. In this work, we provide new upper and lower bounds for broadcasting in multi-channel radio networks, from the perspective of resource competitiveness. Our algorithms work for arbitrary n,C values, require minimal prior knowledge, and can tolerate a powerful adaptive adversary. More specifically, in our algorithms, for large T values, each node’s runtime is O(T/C), and each node’s energy cost is ~O(√T/n). We also complement algorithmic results with lower bounds, proving both the time complexity and the energy complexity of our algorithms are optimal or near-optimal (within a poly-log factor). Our technical contributions lie in using “epidemic broadcast” to achieve time efficiency and resource competitiveness, and employing coupling techniques in the analysis to handle the adaptivity of the adversary. At the lower bound side, we first derive a new energy complexity lower bound for 1-to-1 communication in the multi-channel setting, and then apply simulation and reduction arguments to obtain the desired result.

uk: вхід без авторизації

name: Dynamic & Radio Networks: Broadcasting Competitively against Adaptive Adversary in Multi-channel Radio Networks


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Using scenario planning to enhance coastal resilience to climate change: community futures in the estuarine landscape of Brisbane Waters, Central Coast, Australia

name: Geo-Information for Disaster Management (Gi4DM)

name: Surveying & Spatial Sciences Institute (SSSI)


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Aerial LiDAR technology in support to avalanches prevention and risk mitigation: an operative application at “Colle della Maddalena” (Italy)


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Gi4DM Panel 2: Australian 19/20 Bushfire Season


Gi4DM Panel 1: First Nations

uk: Комп'ютерні науки

description: David Major Founding Director Thirriwirri David is a Yuin Maneroo man and co-founder of Thirriwirri. David has spent twenty five years working in land and heritage management in the ACT, NSW and Victoria, and along with his Thirriwirri co-founder Jason Ardler, are the only First Nations people in Australia to have sat on the executive of a Government land management agency. Thirriwirri supports innovative approaches to partnerships between First Nations communities and Government/Corporates, building shared capacity and capability, and advocating for connection to Country and a primary role for Traditional Owners in the management of their cultural landscapes. Stephen Walker Geospatial Data Analytics and AI Advocate / Supporter - Indigenous Opportunity / Strategist / HealthTech / PropTech As a Certified Indigenous service provider focusing on occupational health, Spartan First promotes indigenous opportunity and welfare, and are leveraging location intelligence to enable increased social, cultural, and economic benefits for indigenous communities. Rohan Fisher is lead satellite-derived fire information analyst for the North Australian Fire Information service at the Darwin Centre for Bushfires research and current PhD candidate Charles Darwin University. Satellite image analyst for 27 years, and subsequently for the Northern Territory government. His current research and training development work is focused on developing Projection Augmented Landscape Models; using low tech tools to create dynamic spatial holograms of country.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Gi4DM Panel 6: COVID 19 and GeoTechnology


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Gi4DM Panel 4: Managing Warming and Cooling Environments


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Gi4DM Panel 5: Remote sensing for disaster management


Gi4DM Panel 3: Education for GeoDM

uk: Комп'ютерні науки

description: More Links: www.hotosm.org www.geochicasosm.org (also we have a Youtube channel) www.up42.com

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Indoor mobile mapping system and crowd simulation to support school reopening because of Covid-19: a case study


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Accuracy analysis of Sentinel 2A and Landsat 8 OLI+ satellite datasets over Kano state (Nigeria) using vegetation spectral indices


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Geographic information system for drought risk mapping in Australia: Drought risk analyser web application


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Transformation to sustainable and resilient urban futures in Southeast Asia


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Cloud-based integration and standardization of address data for disaster management - A South African case study


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Australia-Japan QZSS emergency warning service trial project


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Web-based representation and management of infectious disease data on a city scale, case study of St. Petersburg, Russia


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Volume Estimation of Fuel Load for Hazard Reduction Burning: a voxel approach


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Geospatial analysis of impervious surfaces and their effect on land surface temperature intensity in Abuja, Nigeria


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Teaching geomatics for geohazard mitigation and management in the COVID-19 time


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Integrated GIS system for post-fire hazard assessments with remote sensing

name: Geo-Information for Disaster Management (Gi4DM)


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Multitemporal 3D mapping of post-earthquake recovery phase with UAS: case study Vrisa, Lesvos, Greece

name: Surveying & Spatial Sciences Institute (SSSI)


uk: Комп'ютерні науки

description: Disaster Aware - a global alerting platform for flood events http://www.gi4dm.net/2020/sa/programme/

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Using 3D WebGIS to support the disaster simulation, management and analysis – examples of tsunami and flood


uk: Комп'ютерні науки

description: Exploring spatial parameters to evaluate human walking accessibility of urban green space

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Identifying users’ requirements of geographic information for disaster risk management in the Dominican Republic


uk: Комп'ютерні науки

uk: вхід без авторизації

name: A metadata-based approach for using CCTV to facilitate emergency response


uk: Комп'ютерні науки

uk: вхід без авторизації

name: The role of digitization in post-disaster reconstruction


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Experimental study to compare factors influencing exit choice behaviour in emergency evacuation situations using virtual reality techniques


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Predicting land use/land cover changes using multi-temporal satellite images and multi-layer perceptron Markov model


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Capacity building for disaster management in Mozambique through teaching public participatory GIS and Spatial Data Infrastructure


uk: Комп'ютерні науки

description: Voxel data management and analysis in PostgreSQL/PostGIS under different data layouts

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Analysis of the evolution of gully erosion in olive groves using photogrammetry techniques. Relationships with rainfall regime.


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Socio-economic vulnerability to urban heat in Phoenix, Arizona and Dallas, Texas during June 2020


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Canopy Lidar point cloud data K-means clustering Watershed segmentation method


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Integration of GIS and advanced remote sensing techniques for landslide hazard assessment: A case study of Northwest Syria


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Post-fire hazard detection using ALOS-2 radar and Landsat-8 optical imagery


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Assessment of sentinel-5P performance for ground-level air quality monitoring: preparatory experiments over the COVID-19 lockdown period


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Outdoor AR-application for the digital map table


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Evidence for the development of energy resilience in Fukushima Prefecture since the Great East Japan Earthquake

name: Geo-Information for Disaster Management (Gi4DM)


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Technology and resilience in the reconstruction process.: A case study

name: Surveying & Spatial Sciences Institute (SSSI)


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

en: Information and Library Sciences

de: Geisteswissenschaften

uk: Гуманітарні науки

en: Humanities

@language: de

uk: вхід без авторизації

name: Der Einfluss des Verständnisses von Suchmaschinenwerbung auf das Rechercheverhalten am PC und am mobilen Endgerät: eine Nutzerstudie

Universität Regensburg

addressCountry: DE

addressLocality: Regensburg

addressRegion: Bavaria


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Suchmaschinenoptimierung (SEO) kann einen erheblichen Einfluss auf die Suchergebnisseiten in kommerziellen Suchmaschinen haben. Bisher ist jedoch unklar, welcher Anteil der (Top-)Ergebnisse tatsächlich optimiert wurde und wie dies die Auswahl und das Ranking der angezeigten Treffer bestimmt. Für die Untersuchung über den Einfluss von SEO auf die Suchergebnisse haben wir halb automatische Prozesse und ein Software-Framework entwickelt, das mit einem regelbasierten Klassifikator die Wahrscheinlichkeit von Optimierungsmaßnahmen auf Suchergebnissen zu ermittelt. Der Ansatz basiert auf 20 Merkmalen, zu denen die Analyse über genutzte SEO-Plugins und Analytics Tools, die Auswertung technischer Indikatoren wie die Ladegeschwindigkeit und die Verwendung bestimmter Tags wie zur Description sowie eine manuelle Klassifikation auf Basis von vorab zusammengestellten Listen mit optimierten und nicht optimierten Webseiten gehört. Dieser Ansatz wurde auf drei Datensätzen mit insgesamt 2.043 Suchanfragen und 263.790 Ergebnissen angewendet. Die Ergebnisse zeigen, dass ein großer Teil der in Google gefundenen Seiten zumindest wahrscheinlich optimiert ist, was im Einklang mit Aussagen von SEO-Experten steht, die sagen, dass es sehr schwierig ist, ohne die Anwendung von SEO-Techniken in Suchmaschinen sichtbar zu werden.

uk: вхід без авторизації

name: Den Einfluss der Suchmaschinenoptimierung messbar machen: Ein halb-automatisierter Ansatz zur Bestimmung von optimierten Ergebnissen auf Googles Suchergebnisseiten


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Das SEO Tool ist eine Webanwendung, die die Wahrscheinlichkeit von Suchmaschinenoptimierung (SEO) auf einer Webseite ermittelt. Für die Berechnung der Wahrscheinlichkeit werden insgesamt 20 Merkmale halb automatisch erhoben und in drei Prozessen ausgewertet. Dafür analysiert das Tool zuerst den Quelltext der URL auf Informationen über die Verwendung von SEO-Plugins und Analytics Tools. Zweitens bestimmt es die Kategorie der gegebenen URL anhand manuell klassifizierter Websites, und schließlich berechnet es verschiedene technische und inhaltliche SEO-Indikatoren. Die Ergebnisse aus diesen Prozessen bilden anschließend die Basis für die Einordnung der URL anhand eines regelbasierten Klassifikators. Die Demo des Tools ist unter 5.189.155.20:5000 verfügbar.

uk: вхід без авторизації

name: Ist die Webseite suchmaschinenoptimiert?: Vorstellung eines Online-Tools zur Analyse der Wahrscheinlichkeit der Suchmaschinenoptimierung auf einer Webseite


uk: Комп'ютерні науки

de: Sozialwissenschaften/Soziologie

uk: Суспільні науки та соціологія

en: Social Sciences/Sociology

uk: Бібліотекознавство, документознавство

de: Rechts-, Wirtschafts- und Sozialwissenschaften

uk: Право, економіка та суспільні науки

en: Law, Economics and Social Sciences

uk: Гуманітарні науки

description: In this paper, we present a survey study with 119 participants conducted in German, which investigates respondents’ Facebook behavior. In particular, the survey provides insight into how the individual factors gender, user type and trust in social media influence information behavior with respect to false information on Facebook. Our participants’ Facebook use is predominantly passive, the trust in social media is mediocre and most users claim to encounter false information on a weekly basis. If the truthfulness of information is verified it is mostly done by checking alternative sources and for the most part, users do not react actively to false information on Facebook. Of the different categories of Facebook users studied, more active and intensive users of Facebook (posters and heavy users) encounter false information the most. These users are the only user group to report posts with false information to Facebook or interact with the post. Participants with higher trust in social media tend to check the comments of a post to verify information.

uk: вхід без авторизації

name: Information Behavior towards False Information and “Fake News” on Facebook


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: We present SentText, a web-based tool to perform and explore lexicon-based sentiment analysis on texts, specifically developed for the Digital Humanities (DH) community. The tool was developed integrating ideas of the user centered design process and we gathered requirements via semi-structured interviews. The tool offers the functionality to perform sentiment analysis with predefined sentiment lexicons or self-adjusted lexicons. Users can explore results of sentiment analysis via various visualizations like bar or pie charts and word clouds. It is also possible to analyze and compare collections of documents. Furthermore, we have added a close reading function enabling researchers to examine the applicability of sentiment lexicons for specific text sorts. We report upon the first usability tests with positive results. We argue that the tool is beneficial to explore lexicon-based sentiment analysis in the DH but can also be integrated in DH-teaching.

uk: вхід без авторизації

name: SentText: A Tool for Lexicon-Based Sentiment Analysis in Digital Humanities


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Classifying and categorizing the activities that comprise the digital humanities (DH) has been a longstanding area of interest for many practitioners in this field, fueled by ongoing attempts to define the field both within the academic and public sphere. Several European initiatives are currently shaping advanced research infrastructures that would benefit from an implementation of a suiting taxonomy. Therefore, new humanities and information science collaborations have been formed to provide a service that meets their needs. This working paper presents the transformation of the Taxonomy of Digital Research Activities in the Humanities (TaDiRAH) in order to make it machine-readable and become a formalized taxonomy. This includes the methodology and realization containing a complete revision of the original version, decisions in modelling, the implementation as well as organization of ongoing and future tasks. TaDiRAH addresses a wide range of humanities disciplines and integrates application areas from philologies as well as epigraphy, and musicology to name just a few. For this reason, the decision in favor of SKOS was made purely pragmatically in terms of technology, concept and domains. New language versions can now be easily integrated and low-threshold term extensions can be carried out via Wikidata. The new TaDiRAH not only represents a knowledge organization system (KOS) which has recently been released as version 2.0. According to the FAIR principles this new version improves the Findability, Accessibility, Interoperability, and Reuse of research data and digital assets in the digital humanities.

uk: вхід без авторизації

name: Information Organization and Access in Digital Humanities


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: No existing evaluation infrastructure for shared tasks currently supports both reproducible on- and offline experiments. In this work, we present an architecture that ties together both types of experiments with a focus on reproducibility. The readers are provided with a technical description of the infrastructure and details of how to contribute their own experiments to upcoming evaluation tasks.

uk: вхід без авторизації

name: A Living Lab Architecture for Reproducible Shared Task Experimentation


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: In this paper we investigate the relationship of information science (IS) and the digital humanities (DH) by means of a scientometric comparison of academic journals from the respective disciplines. In order to identify scholarly practices for both disciplines, we apply a recent variant of LDA topic modeling that makes use of additional hierarchical clustering. The results reveal the existence of characteristic topic areas for both IS (information retrieval, information seeking behavior, scientometrics) and DH (computational linguistics, distant reading and digital editions) that can be used to distinguish them as disciplines in their own right. However, there is also a larger shared area of practices related to information management and also a few shared topic clusters that indicate a common ground for – mostly methodological – exchange between the two disciplines.

uk: вхід без авторизації

name: Same same, but different? On the Relation of Information Science and the Digital Humanities.: A Scientometric Comparison of Academic Journals Using LDA and Hierachical Clustering


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Information Behaviour von unbegleiteten, minderjährigen Geflüchteten unter Berücksichtigung der Rolle und Nutzung von Smartphones


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Towards the identification of information needs in conversational search dialogues


uk: Комп'ютерні науки

description: NSU-Watch: Aufklären & Einmischen. Der Podcast über den NSU-Komplex, rechten Terror und Rassismus https://www.nsu-watch.info/podcast/ Das Netzwerk des NSU wurde nicht aufgedeckt und rechtem Terror nicht die Grundlage entzogen. Diese beiden Fakten hatten 2019 massive Konsequenzen und kosteten Menschenleben. Im Juni wurde der Kasseler Regierungspräsident Walter Lübcke von einem Neonazi hingerichtet und im Oktober wurden Jana L. und Kevin S. bei einem antisemitischen und rassistischen Anschlag in Halle ermordet. Recherchen deckten weitere Details zu den rechten Netzwerken in Polizei und Bundeswehr, bekannt unter Namen wie "Nordkreuz" oder "NSU 2.0", auf. Weltweit verloren dutzende Menschen ihr Leben, weil Rassisten einen "Großen Austausch" herbei phantasieren, den sie stoppen wollen. Sie alle werden angeheizt durch eine gesellschaftliche rechte Mobilisierung. Und was wird medial und von Politiker*innen diskutiert? Der Verfassungsschutz soll besser ausgestattet werden und nebenbei kehrte die längst überwunden geglaubte "Killerspiel-Debatte" zurück. Die AfD, auch bekannt als "parlamentarischer Arm des Rechtsterrorismus" sitzt in allen Parlamenten und Talkshows. Im Jahresrückblick des Podcasts "NSU-Watch: Aufklären&Einmischen" wollen wir auf dieses von rechtem Terror geprägte Jahr zurückblicken und auch fragen: Womit haben wir es zu tun? Wie können wir dagegen angehen? Wir blicken auch auf das Jahr 2020, in dem viele dieser Ereignisse weiterhin uns aber auch die Gerichte beschäftigen werden.

uk: вхід без авторизації

name: NSU-Watch: Aufklären & Einmischen: Der NSU-Watch Jahresrückblick 2019


uk: Комп'ютерні науки

description: Nach vielen Jahren Politikunterricht wird Holger und das Publikum nun von Thomas zu den grundlegenden Inhalten geprüft. Der Politikunterricht lief dieses Jahr aus, und bevor Holger versetzt werden kann, muss er eine Lernzielkontrolle über sich ergehen lassen.

uk: вхід без авторизації

name: WRINT Politikunterricht - Die Lernzielkontrolle


Off The Record

uk: Комп'ютерні науки

description: Geheime Einschätzungen des Verfassungsschutzes zur AfD, ungünstiges Framing bei der ARD, intransparente Moderation bei Tiktok: In diesem Jahr haben wir mit so mancher Recherche Schlagzeilen gemacht. Hier wollen wir auf einige interessante Geschichten aus 2019 schauen und einen Blick hinter die Kulissen von netzpolitik.org geben. „Off The Record“ gibt monatlich Einblicke in den Maschinenraum von netzpolitik.org: Die wichtigsten Recherchen, die schönsten Erfolge, die größten Schwierigkeiten und die spannendsten Geschichten hinter den Geschichten. Dieses Mal mit einer Sonderausgabe, in der wir unser Jahr 2019 zusammenkehren.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Von antifeministischen Hasskampagnen bis zu Mental Load, von unangemessenen Preisvergaben bis zu intersektionalen Fragezeichen, von Megan Rapinoe bis zu Greta Thunberg – es gibt viel zu besprechen. Zeit für einen empowernden feministischen Jahresrückblick! „Reichlich Randale“ ist ein Personal-Pöbel-Podcast – inklusive exklusiver Becci-Rants. „Reichlich Randale“ ist feministisch, fußballverliebt, immer unterwegs, cinephil, laut, politisch, offen. Weil ich es bin. „Reichlich Randale“ erzählt euch ein bisschen aus meinem Leben, aber es fühlt sich gleichzeitig nach viel mehr an. Hi, ich bin Becci (@genderbeitrag) und veranstalte mittlerweile traditionell auf dem Congress im Rahmen meines Podcasts „Reichlich Randale“ einen feministischen Jahresrückblick mit tollen Gäst*innen. Von antifeministischen Hasskampagnen bis zu Mental Load, von unangemessenen Preisvergaben bis zu intersektionalen Fragezeichen, von Megan Rapinoe bis zu Greta Thunberg – es gibt viel zu besprechen. Ich freue mich darauf, mich mit euch über empowernde Gedanken und Strukturen auszutauschen. Für intersektionale Solidarität und Freund:innenschaft!

uk: вхід без авторизації

name: Reichlich Randale – Der feministische Jahresrückblick


Aufregen oder Abregen?!

uk: Комп'ютерні науки

description: Der Einmischen Podcast ist für ein paar Rant und sich eher Aufregen bekannt unser Politiklehrer Thomas ist da eher der zynische Pol der Podcastszene. Beide versuchen in dem kleinen Jahresrückblick mal die Aufreger auf ein Minimum zu senken. Unterhaltung garantiert. Der Einmischen Podcast ist für ein paar Rant und sich eher Aufregen bekannt unser Politiklehrer Thomas ist da eher der zynische Pol der Podcastszene. Beide versuchen in dem kleinen Jahresrückblick mal die Aufreger auf ein Minimum zu senken. Unterhaltung garantiert.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: In diesem Talk werden erstmalig Ergebnisse einer Online-Studie mit 653 Podcastproduzierenden vorgestellt. Seitdem vor etwa 15 Jahren die ersten Podcasts im deutschsprachigen Raum produziert und veröffentlicht wurden, ist die Zahl podcastender Personen enorm gestiegen – ein Ende des Wachstums ist nicht abzusehen. Dennoch sind Podcaster_innen bisher kaum Gegenstand psychologischer Forschung geworden. Wie lassen sich deutschsprachige Podcastproduzierende charakterisieren? Was sind die zentralen Motive, die dazu führen, mit dem Podcasten zu beginnen? Gibt es Geschlechterunterschiede? Auf Basis einer Stichprobe von 653 Podcaster_innen sollen diese Fragen erstmals für den deutschsprachigen Raum beantwortet werden.

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name: Mehr als ein Hobby?: Deutschsprachige Podcaster*innen im Fokus psychologischer Forschung.


UA Podcast Berlin

uk: Комп'ютерні науки

description: Im Podcast UA Pod Berlin fassen wir das Sitzungsgeschehen im Untersuchungsausschuss zum Terroranschlag am Breitscheidplatz zusammen. Tagesaktuell binden wir Abgeordneten-Statements zum Geschehen mit ein. Die Kanzlerin versprach den Hinterbliebenen und Opfern Aufklärung. Wir zeigen im Podcast wie weit wir davon entfernt sind. Podcast über den Untersuchungsausschuss zum Anschlag am Breitscheidplatz, Berlin. Diesmal ein offener Podcast mit Diskussion. Wird der Ausschuss wahrgenommen? Wie ist der Eindruck der Behörden? Wieviel Courage braucht eine Zeugin / ein Zeuge?

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Ein gemütlicher Schnack unter Ingenieuren warum die Elektromobilität nicht ins Rollen kommt und warum Wasserstoff noch nicht so richtig in Deutschland explodiert ist. Wir werden aus unseren Erfahrungen mit Elektromobilität, der Freude der Wartezeit auf ein Auto und anderen Problemchen schnacken. Sollten wir nicht von einem E-Roller oder Sofa überfahren worden sein vorher ^^ Wer auch ein E Auto hat oder sich über ERoller aufregen will darf gerne dazukommen. Das große Och Menno Special zur Elektromobilität.

uk: вхід без авторизації

name: Was geht alles schief in der Elektromobilität: Och Menno - Resistor


uk: Комп'ютерні науки

description: Galina Balashova was the main architect and designer for the soviet space programme. She designed the interieurs and visual identity of spacecrafts such as the Soyuz, Buran, and Mir. »Space stations are not only technical structures but architecture built amidst zero gravity.« Galina Balashova (b. 1931) is a self-described "architect-engineer" who spent almost 30 years working in the Soviet Space Programme. She designed the ergonomics, the colours & style and the typography of most soviet spacecrafts, including the Soyuz, the Salyut space stations, the Buran shuttle and the Mir space station. Her pioneering work in the field of zero-gravity architecture is still referenced today in the ISS and other spacecrafts.

uk: вхід без авторизації

name: a home among the stars: Galina Balashova, architect of the soviet space programme


uk: Комп'ютерні науки

description: Kerbal Space Program - Build. Fly. Dream. Einmal ein eigenes Raumfahrtprogramm leiten? Mit KSP ist das möglich.

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name: Build and fly your own rockets in Kerbal Space Program


Was ist Zeit?

uk: Комп'ютерні науки

description: Dort wo sich Physik und Philosophie treffen ist es Zeit, über Zeit zu sprechen.

uk: вхід без авторизації


Standardisation of Open Source Hardware

uk: Комп'ютерні науки

description: Compared to software, the open source approach is relatively new to most actors in the field of (mechanical) hardware. Plus Open Source Hardware faces some special issues. A yet missing definition of its "source code" is one of them (+ patent law, liability, engineers that do not know how to work with git, costly prototyping…). DIN SPEC 3105 will be/is the first official standard for Open Source Hardware and also the first official standard ever published under a free license (CC-BY-SA 4.0; that was a lot of lobby work ;) ). It defines the technology-specific "source" of Open Source Hardware and aims to build a bridge between research institutes, public authority, industry and the worldwide open source community. In this talk I won't explain why Open Source (Hardware) is great. I assume, you all know that (if not, still feel free to ask me in the Q&A part or after the talk). I'll describe what's the standard for, how it works and why its great _for_ Open Source Hardware.

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DOT. The LED Cube

uk: Комп'ютерні науки

description: Ein Würfel der einem Jahre seines Lebens kostet... und hübsch leuchtet... :D Ein Würfel der auf allen Seiten mit LEDs bestückt ist. Mit insgesamt 24.576 davon lassen sich nicht nur coole Animationen anzeigen sondern auch Laufschriften, Grafiken und vieles mehr. Zudem kann man auf dem Würfel Spiele spielen oder Programmieren lernen und seiner Kreativität freien Lauf lassen. Wie entstand die Idee, was steckt alles drin, was könnt ihr damit machen, wo soll's hin gehen, wie könnt ihr mitmachen,... klären wir alles dann. :)

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uk: Комп'ютерні науки

description: SearchWing baut eine Rettungsdrohne für die zivilen Rettungsorganisationen im Mittelmeer wie Sea-Watch, Sea-Eye und Resqship. Wir beschreiben den Aufbau, die Tests auf dem Mittelmeer, die Herausforderungen beim Bau und beim Einsatz des autonomen Flugzeugs und werfen einen Blick auf die verwendeten Bilderkennungsalgorithmen. Wir helfen zivilen Rettungsorganisationen im Mittelmeer bei der Suche nach Schiffbrüchigen. In diesem Talk berichten wir von den Schwierigkeiten und Herausforderungen beim Bau einer autonomen Drohne, die für Einsatz im Mittelmeer geeignet ist. Wenn beispielsweise die Akkus auf dem Flughafen Hamburg im sicheren Schrank verbleiben, weil einer vergessen hat die Akkus für den Flug anzumelden... Wir erläutern den technischen Aufbau mit PixRacer Hardware, Mini Talon EPO Rumpf und den anderen Komponenten. Ungewöhnlich im Vergleich zum klassischen Modellflug ist der Long Range Telemetrie Funk, der große Akku (10000 mAh bei 2kg Fluggewicht) und das ganze Salzwasser :-(. Im Februar 2019 waren wir für Tests auf Malta und im Mai 2019 hat Björn dann den ersten Einsatz im Mittelmeer in Zusammenarbeit mit ResQShip e.V. gemacht. Deshalb können wir auch die Einsatzerfahrungen schildern - wie man das Flugzeug auf dem Schiff startet und landet. Zum Einstieg geben wir auch eine Zusammenfassung der Situation der Seenotrettung im Mittelmeer. Unser Flugzeug sammelt im Flug Bilder, die im Anschluss vom Flugzeug geladen und analysiert werden. Um diese manuelle Bildanalyse zu beschleunigen entwickelen wir auch Computer Vision Algorithmen - auch davon werden wir auf dem Talk einen Überblick geben. Eine Person aus dem Computervision-Team (Petrosilius) hatte bereits letztes Jahr auf der Freifunkbühne dazu einen Vortrag gehalten.

uk: вхід без авторизації

name: SearchWing - Rettungsdrohne im Mittelmeer


uk: Комп'ютерні науки

description: Seit Jahren kämpfen wir um die Haftungsprivilegierung für Freifunker. Als Zugangsvermittler in das Internet hat der Gesetzgeber den Freifunker als Diensteanbieter von Ansprüchen Dritter freigestellt. Nach dem Gesetz ist der Freifunker für die Handlungen Dritter im Internet nicht verantwortlich. Wie die Rechtssprechung die gesetzliche Regelung anwendet, möchte ich Euch in meinem Vortrag berichten. Ich würde gerne den Vortrag in meinen Bericht über die einzelnen Freifunk-Verfahren gegen die Rechteinhaber einbetten. Ich weiß noch nicht recht, wie ich den Zusammenhang gestalte. Mit wem könnte ich darüber sprechen?

uk: вхід без авторизації

name: Die Haftungsprivilegierung des Access-Providers: Vermittler im Sinne des Art. 8 Abs. 3 Infoc-RL im Telemediengesetz


Buying Snacks via NFC with GNU Taler

uk: Комп'ютерні науки

description: ##### Motivation In the digital age the privacy has become an important matter. But with the current digital payment methods the privacy of the user is not guaranteed. To avoid the data sharing, the Taler team implemented a digital form of cash. ##### Project To demonstrate the payment system we developed an interface for a snack machine based on GNU Taler. This implementation allows the customer to pay with a smartphone app via NFC or QR-Code. ##### Team The project was realized by Taler in cooperation with two students from Bern University of Applied Sciences. In the talk the audience will become a little insight into the GNU Taler Project and the aim of the developed Snack Machine Interface. The approach to develop an interface between the Taler Backend and the snack machine will be explained as well as the challenges which come with such a project. Further the implemented hard- and software stacks are presented.

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uk: Комп'ютерні науки

description: About hacking wheelchairs, building custom bicycles, adapters to use e-scooters as outboard motors: Empowering people with disablitities or healthcare needs through Open Hardware. Presentation on experiences and lessons learned in collecting and co-creating open personalized DIY healthcare solutions for replicability and adaptability in Makerspace worldwide. Careables are open source solutions that aim to improve the quality of life for people with unmet particular needs or facing physical limitations. Careables are often co-designed, replicable, accessible, adjustable and shareable online using digital technologies.

uk: вхід без авторизації

name: Hacking health: Improve your life in a makerspace


uk: Комп'ютерні науки

description: Im Internet offerieren diverse Anbieter WiFi Hardware inklusive VPN für 10€. Dieser Talk behandelt, wie sehr sich die verkaufte Hardware sowie Software von den meisten Freifunk Setups unterscheidet.

uk: вхід без авторизації

name: Hotspot Abos: Wie funktionieren diese (und wieviel Freifunk steckt drin)?


uk: Комп'ютерні науки

description: Ein howto für Dummis, Freifunk Infrastruktur selber zu betreiben. Es ist gut, wenn viele Menschen Freifunk Router einrichten können. Doch es ist besser, wenn auch Leute selber einen Super Node betreiben können. Es gibt viele Wege, dies umzusetzen. Ich möchte zeigen, wie ich in letzter Zeit es umgesetzt habe mit mittleren Kenntnissen. Und es wird gezeigt, wie man Provider werden kann.

uk: вхід без авторизації

name: Freifunk Super Node und Firmware Build Server aufsetzen und Provider werden


Ethische Grenzen im Making

uk: Комп'ютерні науки

description: Machbarkeit im Making wird vornehmlich von physikalischen Gesetzen bestimmt. Doch wie sieht es mit ethischen Grenzen aus? Vor allem im Gesundheitsbereich stellt sich die Frage, ob alles das was reverse engineered und selbst gebaut werden kann tatsächlich auch von der maker community diesem Prozess unterzogen werden sollte. Über diese Frage diskutieren Steini und Seb (CADUS). „Tut mir leid, alle von offiziellen Stellen geprüften und zertifizierten Medizingeräte sind kaputt, aber wir überwachen Sie während der OP einfach mit diesem selbst zusammengebauten open source Patienten-Monitor, kein Problem.“ Machbarkeit im Making wird vornehmlich von physikalischen Gesetzen bestimmt. Doch wie sieht es mit ethischen Grenzen aus? Vor allem im Gesundheitsbereich stellt sich die Frage, ob alles das was reverse engineered und selbst gebaut werden kann tatsächlich auch von der maker community diesem Prozess unterzogen werden sollte. Über diese Frage diskutieren Steini und Seb (CADUS).

uk: вхід без авторизації


Autocomplete Texting

uk: Комп'ютерні науки

description: Mitmachspass mit Autocomplete: Entdecke KI-Seele deines Smartphones Ein Spiel mit dem Publikum: Menschen nutzen die Autocomplete/Predict-Funktion ihres Mobilgerätes, um basierend auf einem (wechselnden) vorgegebenen ersten Wort Sätze zu bilden, also immer nur das nächste vorgeschlagene Wort zu bestätigen. Die Ergebnisse werden mehr oder minder live und total willkürlich ausgewählt verlesen. Auch wenn's erstmal sinnlos erscheint: Und auch wenn den Absendenden Anonymität zugesichert wird und im Gegensatz Schummeln verboten ist: Die Art der Sätze, die die trainierte/konditionierte Maschine dabei hervorbringt offenbaren mindestens einen eigenen Charakter oder sagen zumindest etwas über die bevorzugte Nutzung des Gerätes.

uk: вхід без авторизації


Building Nextcloud Flow

uk: Комп'ютерні науки

description: Nextcloud Flow is the overhauled workflow engine in upcoming Nextcloud 18. This talk describes how it evolved, how it works internally, and especially how own components can be built, so you can set up automatized tasks in your Nextcloud.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Richtlinien für den ethischen Einsatz von Algorithmen gibt es langsam wirklich genug. Konzerne und Organisationen übertrumpfen sich geradezu damit zu betonen, dass der Mensch bei allen maschinellen Entscheidungen im Mittelpunkt stehen soll, dass die Systeme fair und nachvollziehbar arbeiten müssen. Aber egal, ob sie nun direkt von Google und IBM stammen, von Normungsorganisationen wie IEEE oder der OECD – gemeinsam ist all diesen Richtlinien: Sie sind rechtlich nicht bindend. Die Frage ist also: Wem dienen solche Ansätze der unternehmerischen und staatlichen Selbstregulierung? Und wollen wir uns auf sie verlassen oder brauchen wir klare gesetzliche Auflagen? Welche Regeln sollten für Unternehmen gelten, welche für den Staat? Und wer soll darüber wachen, dass sie eingehalten werden?

uk: вхід без авторизації

name: “Computer says no”: Worüber sollen Algorithmen entscheiden dürfen


uk: Комп'ютерні науки

description: Der Markt für Mobilgeräte wird dominiert von Android und der Anteil freier Komponenten wird merklich kleiner. Einige Projekte versuchen das zu ändern und bringen GNU/Linux auf Handies und Tablets zu bringen. Wir schauen uns verschiedene solche Projekte an und sprechen über die Notwendigkeit, den aktuellen Stand und die Zukunftsaussichten von GNU/Linux auf Mobilgeräten. Am Beispiel von Ubuntu Touch gehen wir auf besondere Herausforderungen ein.

uk: вхід без авторизації

name: Ubuntu Touch & Co - GNU/Linux in der Hosentasche


uk: Комп'ютерні науки

description: Eine kurze Erzählung von den Anfängen der Protestbewegung bis heute und darüber hinaus. Wenn eine spontan gebildete Menge an Menschen beginnt die Werkzeuge der Demokratie zu nutzen ist das vorläufige Ergebnis eine der größten Petitionen weltweit und über 200.000 kreativ Protestierende auf den Straßen Europas. War es das schon oder kommt da noch etwas? Welche Auswirkungen haben demokratische Werkzeuge wie Petitionen und Demonstrationen? Kann man die nächsten Proteste voraussehen oder wie entstehen Wellen der Aufmerksamkeit? Hat sich eine neue Empörung zum ersten oder zum letzen Mal aufgetan? Von vernetzen Livestreams während der Proteste bis zu Community Aktionen wie Meme-Events und Briefraids.

uk: вхід без авторизації

name: SaveTheInternet - Die Urheberrechtsreform als Zündfunke demokratischer Teilhabe


uk: Комп'ютерні науки

description: After a very quick introduction on Replicant and the smartphones ecosystem, we will look at what affects smartphones' and tablets' lifetime and how to increase it by making Replicant more sustainable.

uk: вхід без авторизації

name: Extending the lifetime of smartphones with Replicant, a fully free Android distribution


uk: Комп'ютерні науки

description: The Independent Solar Mesh System (ISEMS) has a new hardware that will bring the power consumption, space and cost requirements of low cost WiFi relay stations down: FF-ESP32-.OpenMPPT In order to build the cheapest energy autonomous WiFi relay possible, we have designed an update to the previous Freifunk-Open-MPPT-Solarcontroller. It has now integrated WiFi and Bluetooth, so it doesn't need an external WiFi router anymore, but you can still connect one. Technical data is preliminary at the moment, but power consumption will be between ~0.3 at low load and ~0.6 Watt at maximum load. So a 20 Watt Solar panel and a 12V 7Ah battery will be more than enough to keep the system running and relaying traffic all year.

uk: вхід без авторизації

name: FF-ESP32-OpenMPPT - New Freifunk-ISEMS-MPPT-Solar-Controller with integrated WiFi


uk: Комп'ютерні науки

description: We take a quick dive into the Highspeed Amateurradio Multimedia NETwork the wireless backbone of the European Amatuerradio Community. It’s uses mostly commercial hardware on it’s own frequencies beneath the 2,4 and 5 GHz wifi bands. The net is routed with it’s own ipv4 private network consisting of multiple 44.xxx.000.000/16 blocs. A short overview on what the Hamnet is and how it came to be. Not forgetting all the challenges of technical and legal kind that come with running and building the Net.

uk: вхід без авторизації

name: Hamnet – introduction into a wireless backbone


SNAC - The only way to beat Facebook

uk: Комп'ютерні науки

description: The current social media situation is catastrophic. A single megacorporation controls the entire digital life of large parts of the world's population. Together with the rapidly improving methods for processing this data, a power that not only concerns experts is being bundled here. And Facebook's monopoly secures itself. On the one hand, users cannot leave Facebook(/ Instagram/WhatsApp) without being cut off from the social life of their friends. On the other hand, alternatives fail because they can't reach a critical mass. It seems impossible that a single application will ever replace Facebook. The freedom of the Internet is fundamentally threatened. Breaking the power of Facebook is probably one of the greatest challenges of our time. And in order to solve this task, we did come up with a detailed concept that we want to present to the public for the first time at 36c3. SNAC - Social Network Application Cluster - is the name of the protocol used to standardise data exchange between different social media applications. Just as email protocols enable users to choose their provider freely, this protocol should also enable greater diversity in this area. It is easy to see that a single application isn't able to satisfy the needs of every single user. With SNAC we enable a decentralized structure, where each user can choose his server, but also his client application, from a broad spectrum. By developing our pilot application Open Source, we make it easy for other developers to integrate their own applications into the network. But the decentralized Open Source dream alone is not enough to revolutionize the social media world. In order for the new applications emerging in SNAC to be able to run, an appropriate economic environment is needed to cover the operating costs. If the user accesses many different servers while surfing through the decentralized network, the question arises who is responsible for the access costs caused. There is a lack of a corresponding micropayment service with which it is possible to pay very small amounts easy and securely. At first glance, this seems like a project of its own, but it is closely linked to the operation of a decentralised social network. And there are several advantages emerging by linking social networks with a micropayment system. For example, users can donate a few cents to the creators of content they value, which then adds up to a fair reward for the creators. And this is done directly, independently and without forced ads for the users. But the mental alarm bell of data security rightly rings here when one tries to link financial and private communication data. Therefore, it is all the more important to hand over data sovereignty to the user when planning the protocols and to leave the server operators only the task for which they are fairly paid - the operation of the servers. We are currently putting this concept into protocols that enable secure transactions and protect the user's data. The aim is to create an environment where everyone has the chance to honestly and transparently pay the costs they incur instead of filling the pockets of corporations with their data. Our project is quite daring, that is clear to us. And yet we are sure that this is exactly what we want to do in the coming years. Because there is a chance that we will find 15 crazy people who want to develop this utopia together with us. There's a chance we'll find 50,000 people supporting us with an average of 1€ a month to feed our 15 crazy developers. There's a chance that we can create an environment where many small subnets with cool innovative applications can trigger a movement that's going to be so big it will overcome Facebook's monopoly. And above all, we can create an environment where technology benefits people again, rather than the other way around. If 36c3 isn't the right place for a project like this, what else is? We will give a talk in which we will discuss a better world and the difficulties that lie on the path there. We want to encourage listeners to think and participate, but above all we are also there to initiate a discussion. We want to hear all the concerns and mistakes that we overlook and we need the expertise from all the different angles that only the CCC brings together. Hi! We're offering a bit of a different talk, where we want to present a project that might bring a renaissance to the independence and freedom of the internet. We want to dream together of a better world, but then also talk about the concrete steps that need to be done to get there.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Frank Dörner von Ärzte ohne Grenzen und Sebastian Jünemann von CADUS diskutieren die jüngsten Angriffe auf humanitäre Prinzipien in verschiedenen Kontexten, wie beispielsweise während der medizinischen Nothilfe in Nordost-Syrien. Eigentlich sollte es klar sein: Menschen die medizinische Hilfe benötigen sollen sie auch bekommen, Punkt. Doch in Medienkommentaren wird der humanitären Hilfsorganisation CADUS, die ein Feldkrankenhaus im Camp Al Hol in Nordost-Syrien betreibt, längst nicht nur Respekt ausgesprochen. Manche Kommentator*innen schlagen vor, humanitäre Prinzipien auszusetzen sobald es sich bei den Hilfesuchenden um mutmaßliche Angehörige des sogenannten Islamischen Staates (IS) handelt. Schließlich, so die Argumentation, missachte diese Organisation systematisch eben solche Prinzipien. In vielen Konflikten werden humanitäre Grundsätze heute zunehmend missachtet. Helfende werden zu Feinden erklärt und damit legitime Ziele für jedwede Aggression. Krankenhäuser und Ambulanzen können gezielt angegriffen werden, ohne dass es Konsequenzen hat. Afghanistan, Syrien, Yemen – die Liste ist lang. Und aus der jüngsten Geschichte der Seenotrettung wissen wir: auch von staatlichen Stellen werden immer wieder humanitäre Grundsätze mit Füßen getreten. Frank Dörner von Ärzte ohne Grenzen und Sebastian Jünemann von CADUS geben einen Einblick was es bedeutet, in gesellschaftlich und politisch stark umstrittenen Kontexten Hilfe zu leisten, in denen humanitäre Prinzipien immer wieder aus verschiedensten Richtungen angegriffen werden.

uk: вхід без авторизації

name: Treating IS - Humanitäre Prinzipien im Konflikt


uk: Комп'ютерні науки

description: Building a social network on top of net2o, and importing your existing data I've a dream: A peer-to-peer network, where services like search engines or social networks aren't offered by big companies, who in turn need to make money by selling the privacy of their users. Where all data is encrypted, so that access is only possible for people who have the key and really are authorized. Which layman can use without cryptic user interfaces. Where the browser is a platform for running useful applications without the mess of Flash and JavaScript. Without the lag of “buffer bloat” and without the speed problems of a protocol not designed to be assisted by hardware. This dream is coming to reality: This talk will show how far I got, and what challenges still are ahead. The talk is in three parts: 1. a short overview over net2o 2. a demonstration of how the social network stuff looks like 3. and an outlook over what needs to be done to make it a polished product

uk: вхід без авторизації

name: CloudCalypse 2: Social network with net2o [YBTI/wefixthenet session]


uk: Комп'ютерні науки

description: In this talk we present re:claimID, a decentralized, self-sovereign identity management system. re:claimID allows users to reclaim authority over their identities and personal data. The system is built on top if a state-of-the-art, decentralized directory service: The GNU Name System. Built-in cryptographic mechanisms allow users to selectively disclose personal data and the directory service ensures that this data is accessible to authorized parties even if the user is offline. Through OpenID Connect, integration and use of re:claimID is straight-forward and authorization flows are familiar. In this talk, we present the current state of re:claimID as well as a future roadmap. Today, users are often required to share personal data, like email addresses, to use services on the web. As part of normal service operation, such as notifications or billing, services require access to -- ideally fresh and correct -- user data. Sharing attributes in the Web today is often done via centralized service providers to reduce data redundancy and to give services access to current, up-to-date information even if the user is currently offline. Abuse of this power is theoretically limited by local laws and regulations. But, the past has shown that even well-meaning identity providers struggle to keep user data safe as they become major targets for hackers and nation state actors while striving for monetizing anonymized statistics from these data. We advocate for a new, decentralized way for users to manage their identities for the following reasons: * The current state of omniscient identity providers is a significant threat to the users' privacy. * Users must completely trust the service provider with respect to protecting the integrity and confidentiality of their identity in their interest. * The service provider itself is facing substantial liability risks given the responsibility of securely managing potentially sensitive personal data of millions of users. We present re:claimID, a decentralized identity service with the following properties: * Self-sovereign: You manage your identities and attributes locally on your computer. No need to trust a third party service with your data. * Decentralized: You can share your identity attributes securely over a decentralized name system. This allows your friends to access your shared data without the need of a trusted third party. * Standard-compliant: You can use OpenID Connect to integrate reclaim in your web sites.

uk: вхід без авторизації

name: re:claimID - Self-sovereign, Decentralised Identity Management and Personal Data Sharing [YBTI/wefixthenet session]


uk: Комп'ютерні науки

description: With Nextcloud you can sync, share and collaborate on data, but you don't need to put your photos, calendars or chat logs on an American server. Nope, Nextcloud is self-hosted and 100% open source! Thanks to hundreds of apps, Nextcloud can do a lot and in this talk, I will highlight some cool things. Consider this a follow-up from my talk about 200 things Nextcloud can do last year! An update on what's new and some cool new stuff. What, what is `Nextcloud`? Let's see. A private cloud is one way to put it, though that's a contradiction of course. It is a way to share your data, sync your files, communicate and collaborate with others - without giving your data to GAFAM! Keep it on your own server, or something close (like a local hosting provider or data center). Nextcloud is a PHP app that does all that, and more! Easy to use, secure (really) and fully open source of course.

uk: вхід без авторизації

name: A dozen more things you didn't know Nextcloud could do


uk: Комп'ютерні науки

description: We explore the potential of scalable online ethnography to study the rapidly growing phenomenon of participatory culture communities and discuss the potential benefits and challenges of using an online platform in hacker communities. The presentation shares views, with a demo, on how to build participatory online communities from a pilot that focused on the global Burning Man community. The talk is grounded on the collaboration of two high-impact research projects, Burning Stories and Edgeryders. Firstly the aim of Burning Stories, by combining science and arts, is to study the global Burning Man community and seek to explain the processes through which community membership of Burning Man participants evolves across time and space, and how this, in turn, affects the society. By combining the Burning Stories research project with an online ethnography tool from Edgeryders, who use it for multiple Horizon 2020 funded project, the talk aims to present novel ways of disrupting the traditional ways of conducting ethnography in order to understand the emergence of a new cultural phenomenon and apply new, participatory methodology, in order to advance social sciences and community building. The presentation particularly focuses on lessons learnt from these two research projects and with the combination of the projects, explores the potential future use of the co-creative templates for hacker communities.

uk: вхід без авторизації

name: Exploring and empowering participatory culture communities with the use of online ethnography platform


uk: Комп'ютерні науки

description: The Democratic People's Republic of Korea (North Korea) is a hot topic in the media. The peninsula is changing rapidly, but how is that reflected in life on the ground? What is it like to live in Pyongyang? Are the externally reported societal changes and developments in technology also visible in everyday life? This talk will describe modern urban life in Pyongyang, and the recent forces driving change. The talk will particularly focus on observations around the state of youth mindset towards change and technology. For example, what are the future elites' attitudes towards entrepreneurship in an officially communist country? What small signals of changing attitudes can we observe that might influence the opening of the county? Presenting the realities of this environment leads us to the demo of consumer technology, and presented that opportunities for both societal change and technological development might be broader than we often see. We will present this deep dive to North Korea from the perspective of two foreigners who have been spending months at a time in Pyongyang and have been studying it since 2012.

uk: вхід без авторизації

name: Observations on societal and technological changes in the DPRK


Raumfahrtantriebe

uk: Комп'ютерні науки

description: Wie kommt man eigentlich in den Weltraum und was ist an so ein bisschen Schub so kompliziert *? Warum sehen Raumfahrtantriebe so aus wie sie sind und was wird sich mit "New Space" alles ändern? (*)insert rocket science joke here Preview 1. Wie erzeugt man Schub? - Was ist eine Raketenmotor -triebwerk? - Warum fliegen Flaschenraketen mit Wasser höher? 2. Feststoffraketen - Feuerwerk, Modellbau oder Shuttle Booster - Brennprofile 3. Flüssigraketen - Goddards erste Versuche - Komplex, teuer, fehleranfällig und warum wir trotzdem Flüssigtreibstoffe nutzen 3.1. Brennkammer - Aufbau und Eigenschaften 3.2. Turbopumpen - Wie kommt der Treibstoff und Oxidator in die Brennkammer 3.3. Düsen - warum überhaupt Düsen und warum sehen sie so aus wie sie sind - Aerospike 3.4. Treibstoffe - Ein wenig Chemie. Mono-, Bi- und Tritreibstoff 3.5. 5,4 all engines running,2,1,0 lift off - Wie man eine Rakete startet Soyuz, Titan II, Delta 4 und das Space-Shuttle 4. Hybridraketen - Die Komplexität einer Flüssigrakete mit den Nachteilen einer Feststoffrakete 5. Ionenantrieb - Wenig Schub aber hoher Impuls - Aufbau und Eigenschaften 6. Solar Sail - Ein Segel spannen und mit dem Sonnenwind dahingleiten 7. Nuklearantriebe - Ein fliegender Kernreaktor, was kann da schon schief gehen? - in 200 Tagen zum Mars und zurück

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Delta Chat is an e-mail instant messenger that is just becoming available on all platforms. Unlike other offerings, Delta Chat is no platform and operates no own servers. Instead it uses existing SMTP/IMAP servers to send and receive messages. We'll talk about the current development status on all platforms, our new Rust-core based approach, our decentralized e2e-encryption facilities (not requiring keyservers, and safe against active attacks) and how we are generally driving developments from UX and security perspectives. We also aim to showcase "burner accounts", a new concept that we are developing and discussing with activists in eastern european countries and asian cities.

uk: вхід без авторизації

name: Delta Chat: e-mail based messaging, the Rustocalypse and UX driven approach [YBTI/wefixthenet session]


Episode VIII - Die letzten Freifunker?

keywords: Ethics, Society & Politics OpenInfrastructureOrbit

uk: Комп'ютерні науки

description: Freifunk steht für freie Kommunikation in digitalen Datennetzen. Reicht dieser Slogan aus, um die Communities wachsen und die Marke Freifunk bei den Menschen in unserem Land bekannt zu machen? Was können wir tun, um nicht bald die letzten Freifunker zu sein und insbesondere eine engagierte junge Generation anzusprechen, die Informationen ganz anders filtert und verarbeitet als GenX oder Baby Boomers? In diesem interaktiven Talk mit einer Marketingexpertin aus der IT Branche, geht es um die Identität von Freifunk und warum 8 Sekunden entscheidend sind. Freie Kommunikation in digitalen Datennetzen - ein wichtiges Gut, für das Freifunk steht. Aber wie steht es um die Marke Freifunk in Städten, Gemeinden, Kommunen und der Bevölkerung? Gibt es Nachwuchssorgen in den Communities und könnten wir nicht schon viel weiter sein mit unserem 'Netzausbau'? In diesem Talk möchte ich mit Euch gemeinsam einen kritischen Blick auf Freifunk von der Marketingseite her werfen und Ideen entwickeln, wie wir viele Menschen einladen können mitzumachen sodass Freifunk zu einem wichtigen Bestandteil ihres digitalen Lebens wird. Je mehr aktive Mitglieder unsere communities haben, desto eher können wir das umsetzen, worüber Politik und etablierte Wirtschaft primär nur reden: Digitalisierung und digitale Transformation vorantreiben - in Stadt und Land.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Some Initiatives are trying to provide internet access and VoIP dial-out in a user-owned (Commons Economy) or completely open infrastructure. We will present the state of affairs and invite to a discussion on the possible perspectives.

uk: вхід без авторизації

name: Internet access and VoIP as Open/Commons Infrastructure