OpenRaiser/Intern-Atlas huggingface dataset:
A Progressive Network Management Architecture Enabled By Java Technology
Venue: arXiv cs.NI 2010
Year: 2010

This paper proposes a framework based completely on Java technology. The advantages brought about by the use of Java in network management answer some critical problems existing in current systems. With this work we address several factors concerning interoperability and security in heterogeneous network environments. Specifically, we present a manager application and a multithreaded agent engine that make use of a lightweight communication mechanism for message exchange. A MIB parser is introduced to accelerate handling of incoming management requests, and the RSA public-key cryptosystem is implemented to provide both encryption and authentication features. Results, measured in terms of response time, compare favourably with other published work and standard management frameworks.
Performance Study of ETX based Wireless Routing Metrics
Venue: arXiv cs.NI 2010
Year: 2010

Being most popular and IETF standard metric, minimum hop count is appropriately used by Ad hoc Networks, as new paths must rapidly be found in the situations where quality paths could not be found in due time due to high node mobility. There always has been a tradeoff between throughput and energy consumption, but stationary topology of WMNs and high node density of WSN's benefit the algorithms to consider quality-aware routing to choose the best routes. In this paper, we analytically review ongoing research on wireless routing metrics which are based on ETX (Expected Transmission Count) as it performs better than minimum hop count under link availability. Performances over ETX, target platforms and design requirements of these ETX based metrics are high-lighted. Consequences of the criteria being adopted (in addition to expected link layer transmissions & retransmissions) in the form of incremental: (1) performance overheads and computational complexity causing inefficient use of network resources and instability of the routing algorithm, (2) throughput gains achieved with better utilization of wireless medium resources have been elaborated.
Service-Oriented Simulation Framework: An Overview and Unifying Methodology
Venue: arXiv cs.SE 2010
Year: 2010

The prevailing net-centric environment demands and enables modeling and simulation to combine efforts from numerous disciplines. Software techniques and methodology, in particular service-oriented architecture, provide such an opportunity. Service-oriented simulation has been an emerging paradigm following on from object- and process-oriented methods. However, the ad-hoc frameworks proposed so far generally focus on specific domains or systems and each has its pros and cons. They are capable of addressing different issues within service-oriented simulation from different viewpoints. It is increasingly important to describe and evaluate the progress of numerous frameworks. In this paper, we propose a novel three-dimensional reference model for a service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks. In particular, the model inspects the crossover between the disciplines of modeling and simulation, service-orientation, and software/systems engineering. Based on the model, we present a comprehensive survey on several classical service-oriented simulation frameworks, including formalism-based, model-driven, interoperability protocol based, eXtensible Modeling and Simulation Framework (XMSF), and Open Grid Services Architecture (OGSA) based frameworks etc. The comparison of these frameworks is also performed. Finally the significance both in academia and practice are presented and future directions are pointed out.
Semantic Web: Who is who in the field - A bibliometric analysis
Venue: arXiv cs.DL 2010
Year: 2010

The Semantic Web is one of the main efforts aiming to enhance human and machine interaction by representing data in an understandable way for machines to mediate data and services. It is a fast-moving and multidisciplinary field. This study conducts a thorough bibliometric analysis of the field by collecting data from Web of Science (WOS) and Scopus for the period of 1960-2009. It utilizes a total of 44,157 papers with 651,673 citations from Scopus, and 22,951 papers with 571,911 citations from WOS. Based on these papers and citations, it evaluates the research performance of the Semantic Web (SW) by identifying the most productive players, major scholarly communication media, highly cited authors, influential papers and emerging stars.
Multiple-source multiple-sink maximum flow in planar graphs
Venue: arXiv cs.DM 2010
Year: 2010

In this paper we show an O(n^(3/2) log^2 n) time algorithm for finding a maximum flow in a planar graph with multiple sources and multiple sinks. This is the fastest algorithm whose running time depends only on the number of vertices in the graph. For general (non-planar) graphs the multiple-source multiple-sink version of the maximum flow problem is as difficult as the standard single-source single-sink version. However, the standard reduction does not preserve the planarity of the graph, and it is not known how to generalize existing maximum flow algorithms for planar graphs to the multiple-source multiple-sink maximum flow problem.
MiniAgda: Integrating Sized and Dependent Types
Venue: arXiv cs.PL 2010
Year: 2010

Sized types are a modular and theoretically well-understood tool for checking termination of recursive and productivity of corecursive definitions. The essential idea is to track structural descent and guardedness in the type system to make termination checking robust and suitable for strong abstractions like higher-order functions and polymorphism. To study the application of sized types to proof assistants and programming languages based on dependent type theory, we have implemented a core language, MiniAgda, with explicit handling of sizes. New considerations were necessary to soundly integrate sized types with dependencies and pattern matching, which was made possible by concepts such as inaccessible patterns and parametric function spaces. This paper provides an introduction to MiniAgda by example and informal explanations of the underlying principles.
Connectivity statistics of store-and-forward inter-vehicle communication
Venue: arXiv cs.NI 2010
Year: 2010

Inter-vehicle communication (IVC) enables vehicles to exchange messages within a limited broadcast range and thus self-organize into dynamical vehicular ad hoc networks. For the foreseeable future, however, a direct connectivity between equipped vehicles in one direction is rarely possible. We therefore investigate an alternative mode in which messages are stored by relay vehicles traveling in the opposite direction, and forwarded to vehicles in the original direction at a later time. The wireless communication consists of two `transversal' message hops across driving directions. Since direct connectivity for transversal hops and a successful message transmission to vehicles in the destination region is only a matter of time, the quality of this IVC strategy can be described in terms of the distribution function for the total transmission time. Assuming a Poissonian distance distribution between equipped vehicles, we derive analytical probability distributions for message transmission times and related propagation speeds for a deterministic and a stochastic model of the maximum range of direct communication. By means of integrated microscopic simulations of communication and bi-directional traffic flows, we validated the theoretical expectation for multi-lane roadways. We found little deviation of the analytical result for multi-lane scenarios, but significant deviations for a single-lane. This can be explained by vehicle platooning. We demonstrate the efficiency of the transverse hopping mechanism for a congestion-warning application in a microscopic traffic simulation scenario. Messages are created on an event-driven basis by equipped vehicles entering and leaving a traffic jam. This application is operative for penetration levels as low as 1%.
Join-Reachability Problems in Directed Graphs
Venue: arXiv cs.DS 2010
Year: 2010

For a given collection G of directed graphs we define the join-reachability graph of G, denoted by J(G), as the directed graph that, for any pair of vertices a and b, contains a path from a to b if and only if such a path exists in all graphs of G. Our goal is to compute an efficient representation of J(G). In particular, we consider two versions of this problem. In the explicit version we wish to construct the smallest join-reachability graph for G. In the implicit version we wish to build an efficient data structure (in terms of space and query time) such that we can report fast the set of vertices that reach a query vertex in all graphs of G. This problem is related to the well-studied reachability problem and is motivated by emerging applications of graph-structured databases and graph algorithms. We consider the construction of join-reachability structures for two graphs and develop techniques that can be applied to both the explicit and the implicit problem. First we present optimal and near-optimal structures for paths and trees. Then, based on these results, we provide efficient structures for planar graphs and general directed graphs.
A contribution to the conditioning of the total least squares problem
Venue: arXiv cs.NA 2010
Year: 2010

We derive closed formulas for the condition number of a linear function of the total least squares solution. Given an over determined linear system Ax=b, we show that this condition number can be computed using the singular values and the right singular vectors of [A,b] and A. We also provide an upper bound that requires the computation of the largest and the smallest singular value of [A,b] and the smallest singular value of A. In numerical examples, we compare these values and the resulting forward error bounds with existing error estimates.
On the Asymptotic Connectivity of Random Networks under the Random Connection Model
Venue: arXiv cs.NI 2010
Year: 2010

Consider a network where all nodes are distributed on a unit square following a Poisson distribution with known density $ρ$ and a pair of nodes separated by an Euclidean distance $x$ are directly connected with probability $g(\frac{x}{r_ρ})$, where $g:[0,\infty)\rightarrow[0,1]$ satisfies three conditions: rotational invariance, non-increasing monotonicity and integral boundedness, $r_ρ=\sqrt{\frac{\logρ+b}{Cρ}}$, $C=\int_{\Re^{2}}g(\Vert \boldsymbol{x}\Vert)d\boldsymbol{x}$ and $b$ is a constant, independent of the event that another pair of nodes are directly connected. In this paper, we analyze the asymptotic distribution of the number of isolated nodes in the above network using the Chen-Stein technique and the impact of the boundary effect on the number of isolated nodes as $ρ\rightarrow\infty$. On that basis we derive a necessary condition for the above network to be asymptotically almost surely connected. These results form an important link in expanding recent results on the connectivity of the random geometric graphs from the commonly used unit disk model to the more generic and more practical random connection model.
Increasing risk behavior can outweigh the benefits of anti-retroviral drug treatment on the HIV incidence among men-having-sex-with-men in Amsterdam
Venue: arXiv cs.SI 2010
Year: 2010

The transmission through contacts among MSM (men who have sex with men) is one of the dominating contributors to HIV prevalence in industrialized countries. In Amsterdam, the capital of the Netherlands, the MSM risk group has been traced for decades. This has motivated studies which provide detailed information about MSM's risk behavior statistically, psychologically and sociologically. Despite the era of potent antiretroviral therapy, the incidence of HIV among MSM increases. In the long term the contradictory effects of risk behavior and effective therapy are still poorly understood. Using a previously presented Complex Agent Network model, we describe steady and casual partnerships to predict the HIV spreading among MSM. Behavior-related parameters and values, inferred from studies on Amsterdam MSM, are fed into the model; we validate the model using historical yearly incidence data. Subsequently, we study scenarios to assess the contradictory effects of risk behavior and effective therapy, by varying corresponding values of parameters. Finally, we conduct quantitative analysis based on the resulting incidence data. The simulated incidence reproduces the ACS historical incidence well and helps to predict the HIV epidemic among MSM in Amsterdam. Our results show that in the long run the positive influence of effective therapy can be outweighed by an increase in risk behavior of at least 30% for MSM. Conclusion: We recommend, based on the model predictions, that lowering risk behavior is the prominent control mechanism of HIV incidence even in the presence of effective therapy.
Universal regular autonomous asynchronous systems: omega-limit sets, invariance and basins of attraction
Venue: arXiv cs.OH 2010
Year: 2010

The asynchronous systems are the non-deterministic real time-binary models of the asynchronous circuits from electrical engineering. Autonomy means that the circuits and their models have no input. Regularity means analogies with the dynamical systems, thus such systems may be considered to be the real time dynamical systems with a 'vector field' Φ:{0,1}^2 \rightarrow {0,1}^2. Universality refers to the case when the state space of the system is the greatest possible in the sense of the inclusion. The purpose of the paper is that of defining, by analogy with the dynamical systems theory, the ω-limit sets, the invariance and the basins of attraction of the universal regular autonomous asynchronous systems.
Exact Schedulability Test for global-EDF Scheduling of Periodic Hard Real-Time Tasks on Identical Multiprocessors
Venue: arXiv cs.OS 2010
Year: 2010

In this paper we consider the scheduling problem of hard real-time systems composed of periodic constrained-deadline tasks upon identical multiprocessor platforms. We assume that tasks are scheduled by using the global-EDF scheduler. We establish an exact schedulability test for this scheduler by exploiting on the one hand its predictability property and by providing on the other hand a feasibility interval so that if it is possible to find a valid schedule for all the jobs contained in this interval, then the whole system will be stamped feasible. In addition, we show by means of a counterexample that the feasibility interval, and thus the schedulability test, proposed by Leung [Leung 1989] is incorrect and we show which arguments are actually incorrect.
Annotated English
Venue: arXiv cs.CL 2010
Year: 2010

This document presents Annotated English, a system of diacritical symbols which turns English pronunciation into a precise and unambiguous process. The annotations are defined and located in such a way that the original English text is not altered (not even a letter), thus allowing for a consistent reading and learning of the English language with and without annotations. The annotations are based on a set of general rules that make the frequency of annotations not dramatically high. This makes the reader easily associate annotations with exceptions, and makes it possible to shape, internalise and consolidate some rules for the English language which otherwise are weakened by the enormous amount of exceptions in English pronunciation. The advantages of this annotation system are manifold. Any existing text can be annotated without a significant increase in size. This means that we can get an annotated version of any document or book with the same number of pages and fontsize. Since no letter is affected, the text can be perfectly read by a person who does not know the annotation rules, since annotations can be simply ignored. The annotations are based on a set of rules which can be progressively learned and recognised, even in cases where the reader has no access or time to read the rules. This means that a reader can understand most of the annotations after reading a few pages of Annotated English, and can take advantage from that knowledge for any other annotated document she may read in the future.
Exhaustive Verification of Weak Reconstruction For Self Complementary Graphs
Venue: arXiv cs.DM 2010
Year: 2010

This paper presents an exhaustive approach for verification of the weak reconstruction of Self Complementary Graphs up to 17 vertices. It describes the general problem of the Reconstruction Conjecture, explaining the complexity involved in checking deck-isomorphism between two graphs. In order to improve the computation time, various pruning techniques have been employed to reduce the number of graph-isomorphism comparisons. These techniques offer great help in proceeding with a reconstructive approach. An analysis of the numbers involved is provided, along with the various limitations of this approach. A list enumerating the number of SC graphs up till 101 vertices is also appended.
Cluster Evaluation of Density Based Subspace Clustering
Venue: arXiv cs.DB 2010
Year: 2010

Clustering real world data often faced with curse of dimensionality, where real world data often consist of many dimensions. Multidimensional data clustering evaluation can be done through a density-based approach. Density approaches based on the paradigm introduced by DBSCAN clustering. In this approach, density of each object neighbours with MinPoints will be calculated. Cluster change will occur in accordance with changes in density of each object neighbours. The neighbours of each object typically determined using a distance function, for example the Euclidean distance. In this paper SUBCLU, FIRES and INSCY methods will be applied to clustering 6x1595 dimension synthetic datasets. IO Entropy, F1 Measure, coverage, accurate and time consumption used as evaluation performance parameters. Evaluation results showed SUBCLU method requires considerable time to process subspace clustering; however, its value coverage is better. Meanwhile INSCY method is better for accuracy comparing with two other methods, although consequence time calculation was longer.
PERSEUS Technology: New Trends in Information and Communication Security
Venue: arXiv cs.CR 2010
Year: 2010

Using cryptography to protect information and communication has bacically two major drawbacks. First, the specific entropy profile of encrypted data makes their detection very easy. Second, the use of cryptography can be more or less regulated, not to say forbidden, according to the countries. If the right to freely protect our personal and private data is a fundamental right, it must not hinder the action of Nation States with respect to National security. Allowing encryption to citizens holds for bad guys as well. In this paper we propose a new approach in information and communication security that may solve all these issues, thus representing a rather interesting trade-off between apparently opposite security needs. We introduce the concept of scalable security based on computationnally hard problem of coding theory with the PERSEUS technology. The core idea is to encode date with variable punctured convolutional codes in such a way that any cryptanalytic attempt will require a time-consuming encoder reconstruction in order to decode. By adding noise in a suitable way, that reconstruction becomes untractable in practice except for Intelligence services that however must use supercomputers during a significant, scalable amount of time. Hence it limits naturally any will to unduly performs such attacks (eg. against citizens' privacy). On the users' side, encoder and noise parameters are first exchanged through an initial, short HTTPS session. The principles behind that approach have been mathematically validated in 1997 and 2007. We present the PERSEUS library we have developed under the triple GPL/LGPL/MPL licences. This library can be used to protect any kind of data.
Performance Comparison and Analysis of Preemptive-DSR and TORA
Venue: arXiv cs.NI 2010
Year: 2010

The Dynamic Source Routing protocol (DSR) is a simple and efficient routing protocol designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. Preemptive DSR(PDSR) is the modified version of DSR. The main objective of this paper is to analyze and compare the performance of Preemptive DSR and Temporarily Ordered Routing Algorithm(TORA).It discusses the effect of variation in number of nodes and average speed on protocol performance. Simulation results (provided by the instructor) are analyzed to get an insight into the operation of TORA and PDSR in small/large sized networks with slow/fast moving nodes. Results show that PDSR outperforms TORA in terms of the number of MANET control packets used to maintain/erase routes. Also, it is concluded that TORA is a better choice than PDSR for fast moving highly connected set of nodes. It is also observed that DSR provides better data throughput than TORA and that routes can be created faster in PDSR than in TORA. This paper tries to explain the reasons behind the nature of the results.
Redundancy-Related Bounds on Generalized Huffman Codes
Venue: arXiv cs.IT 2010
Year: 2010

This paper presents new lower and upper bounds for the compression rate of binary prefix codes optimized over memoryless sources according to various nonlinear codeword length objectives. Like the most well-known redundancy bounds for minimum average redundancy coding - Huffman coding - these are in terms of a form of entropy and/or the probability of an input symbol, often the most probable one. The bounds here, some of which are tight, improve on known bounds of the form L in [H,H+1), where H is some form of entropy in bits (or, in the case of redundancy objectives, 0) and L is the length objective, also in bits. The objectives explored here include exponential-average length, maximum pointwise redundancy, and exponential-average pointwise redundancy (also called dth exponential redundancy). The first of these relates to various problems involving queueing, uncertainty, and lossless communications; the second relates to problems involving Shannon coding and universal modeling. For these two objectives we also explore the related problem of the necessary and sufficient conditions for the shortest codeword of a code being a specific length.
A simple generalization of the ElGamal cryptosystem to non-abelian groups II
Venue: arXiv cs.CR 2011
Year: 2011

This is a study of the MOR cryptosystem using the special linear group over finite fields. The automorphism group of the special linear group is analyzed for this purpose. At our current state of knowledge, I show that the MOR cryptosystem has better security than the ElGamal cryptosystem over finite fields.
2-State 3-Symbol Universal Turing Machines Do Not Exist
Venue: arXiv cs.OH 2011
Year: 2011

In this brief note, we give a simple information-theoretic proof that 2-state 3-symbol universal Turing machines cannot possibly exist, unless one loosens the definition of "universal".