OpenRaiser/Intern-Atlas huggingface dataset:
Linear-Complexity Overhead-Optimized Random Linear Network Codes
Venue: arXiv cs.IT 2013
Year: 2013

Sparse random linear network coding (SRLNC) is an attractive technique proposed in the literature to reduce the decoding complexity of random linear network coding. Recognizing the fact that the existing SRLNC schemes are not efficient in terms of the required reception overhead, we consider the problem of designing overhead-optimized SRLNC schemes. To this end, we introduce a new design of SRLNC scheme that enjoys very small reception overhead while maintaining the main benefit of SRLNC, i.e., its linear encoding/decoding complexity. We also provide a mathematical framework for the asymptotic analysis and design of this class of codes based on density evolution (DE) equations. To the best of our knowledge, this work introduces the first DE analysis in the context of network coding. Our analysis method then enables us to design network codes with reception overheads in the order of a few percent. We also investigate the finite-length performance of the proposed codes and through numerical examples we show that our proposed codes have significantly lower reception overheads compared to all existing linear-complexity random linear network coding schemes.
A Structured Prediction Approach for Missing Value Imputation
Venue: arXiv cs.LG 2013
Year: 2013

Missing value imputation is an important practical problem. There is a large body of work on it, but there does not exist any work that formulates the problem in a structured output setting. Also, most applications have constraints on the imputed data, for example on the distribution associated with each variable. None of the existing imputation methods use these constraints. In this paper we propose a structured output approach for missing value imputation that also incorporates domain constraints. We focus on large margin models, but it is easy to extend the ideas to probabilistic models. We deal with the intractable inference step in learning via a piecewise training technique that is simple, efficient, and effective. Comparison with existing state-of-the-art and baseline imputation methods shows that our method gives significantly improved performance on the Hamming loss measure.
Review of the Use of Electroencephalography as an Evaluation Method for Human-Computer Interaction
Venue: arXiv cs.HC 2013
Year: 2013

Evaluating human-computer interaction is essential as a broadening population uses machines, sometimes in sensitive contexts. However, traditional evaluation methods may fail to combine real-time measures, an "objective" approach and data contextualization. In this review we look at how adding neuroimaging techniques can respond to such needs. We focus on electroencephalography (EEG), as it could be handled effectively during a dedicated evaluation phase. We identify workload, attention, vigilance, fatigue, error recognition, emotions, engagement, flow and immersion as being recognizable by EEG. We find that workload, attention and emotions assessments would benefit the most from EEG. Moreover, we advocate to study further error recognition through neuroimaging to enhance usability and increase user experience.
A Semi-automated Peer-review System
Venue: arXiv cs.DL 2013
Year: 2013

A semi-supervised model of peer review is introduced that is intended to overcome the bias and incompleteness of traditional peer review. Traditional approaches are reliant on human biases, while consensus decision-making is constrained by sparse information. Here, the architecture for one potential improvement (a semi-supervised, human-assisted classifier) to the traditional approach will be introduced and evaluated. To evaluate the potential advantages of such a system, hypothetical receiver operating characteristic (ROC) curves for both approaches will be assessed. This will provide more specific indications of how automation would be beneficial in the manuscript evaluation process. In conclusion, the implications for such a system on measurements of scientific impact and improving the quality of open submission repositories will be discussed.
Volumetric Reconstruction Applied to Perceptual Studies of Size and Weight
Venue: arXiv cs.CV 2013
Year: 2013

We explore the application of volumetric reconstruction from structured-light sensors in cognitive neuroscience, specifically in the quantification of the size-weight illusion, whereby humans tend to systematically perceive smaller objects as heavier. We investigate the performance of two commercial structured-light scanning systems in comparison to one we developed specifically for this application. Our method has two main distinct features: First, it only samples a sparse series of viewpoints, unlike other systems such as the Kinect Fusion. Second, instead of building a distance field for the purpose of points-to-surface conversion directly, we pursue a first-order approach: the distance function is recovered from its gradient by a screened Poisson reconstruction, which is very resilient to noise and yet preserves high-frequency signal components. Our experiments show that the quality of metric reconstruction from structured light sensors is subject to systematic biases, and highlights the factors that influence it. Our main performance index rates estimates of volume (a proxy of size), for which we review a well-known formula applicable to incomplete meshes. Our code and data will be made publicly available upon completion of the anonymous review process.
Verifiable Source Code Documentation in Controlled Natural Language
Venue: arXiv cs.SE 2013
Year: 2013

Writing documentation about software internals is rarely considered a rewarding activity. It is highly time-consuming and the resulting documentation is fragile when the software is continuously evolving in a multi-developer setting. Unfortunately, traditional programming environments poorly support the writing and maintenance of documentation. Consequences are severe as the lack of documentation on software structure negatively impacts the overall quality of the software product. We show that using a controlled natural language with a reasoner and a query engine is a viable technique for verifying the consistency and accuracy of documentation and source code. Using ACE, a state-of-the-art controlled natural language, we present positive results on the comprehensibility and the general feasibility of creating and verifying documentation. As a case study, we used automatic documentation verification to identify and fix severe flaws in the architecture of a non-trivial piece of software. Moreover, a user experiment shows that our language is faster and easier to learn and understand than other formal languages for software documentation.
A priori estimation of a time step for numerically solving parabolic problems
Venue: arXiv cs.NA 2013
Year: 2013

This work deals with the problem of choosing a time step for the numerical solution of boundary value problems for parabolic equations. The problem solution is derived using the fully implicit scheme, whereas a time step is selected via explicit calculations. The selection strategy consists of the following steps. First, using the explicit scheme, we calculate the solution at a new time level. Next, we employ this solution in order to obtain the solution at the previous time level (the implicit scheme, explicit calculations). This solution should be close to the solution of our problem at this time level with a prescribed accuracy. Such an algorithm leads to explicit formulas for the calculation of the time step and takes into account both the dynamics of the problem solution and changes in coefficients of the equation and in its right-hand side. The same formulas for the evaluation of the time step we get using a comparison of two approximate solutions, which are obtained using the explicit scheme with the primary time step and the step that is reduced by half. Numerical results are presented for a model parabolic boundary value problem, which demonstrate the robustness of the developed algorithm for the time step selection.
A Fuzzy AHP Approach for Supplier Selection Problem: A Case Study in a Gear Motor Company
Venue: arXiv cs.AI 2013
Year: 2013

Suuplier selection is one of the most important functions of a purchasing department. Since by deciding the best supplier, companies can save material costs and increase competitive advantage.However this decision becomes compilcated in case of multiple suppliers, multiple conflicting criteria, and imprecise parameters. In addition the uncertainty and vagueness of the experts' opinion is the prominent characteristic of the problem. therefore an extensively used multi criteria decision making tool Fuzzy AHP can be utilized as an approach for supplier selection problem. This paper reveals the application of Fuzzy AHP in a gear motor company determining the best supplier with respect to selected criteria. the contribution of this study is not only the application of the Fuzzy AHP methodology for supplier selection problem, but also releasing a comprehensive literature review of multi criteria decision making problems. In addition by stating the steps of Fuzzy AHP clearly and numerically, this study can be a guide of the methodology to be implemented to other multiple criteria decision making problems.
Simple Tabulation, Fast Expanders, Double Tabulation, and High Independence
Venue: arXiv cs.DS 2013
Year: 2013

Simple tabulation dates back to Zobrist in 1970. Keys are viewed as c characters from some alphabet A. We initialize c tables h_0, ..., h_{c-1} mapping characters to random hash values. A key x=(x_0, ..., x_{c-1}) is hashed to h_0[x_0] xor...xor h_{c-1}[x_{c-1}]. The scheme is extremely fast when the character hash tables h_i are in cache. Simple tabulation hashing is not 4-independent, but we show that if we apply it twice, then we get high independence. First we hash to intermediate keys that are 6 times longer than the original keys, and then we hash the intermediate keys to the final hash values. The intermediate keys have d=6c characters from A. We can view the hash function as a degree d bipartite graph with keys on one side, each with edges to d output characters. We show that this graph has nice expansion properties, and from that we get that with another level of simple tabulation on the intermediate keys, the composition is a highly independent hash function. The independence we get is |A|^{Omega(1/c)}. Our space is O(c|A|) and the hash function is evaluated in O(c) time. Siegel [FOCS'89, SICOMP'04] proved that with this space, if the hash function is evaluated in o(c) time, then the independence can only be o(c), so our evaluation time is best possible for Omega(c) independence---our independence is much higher if c=|A|^{o(1)}. Siegel used O(c)^c evaluation time to get the same independence with similar space. Siegel's main focus was c=O(1), but we are exponentially faster when c=omega(1). Applying our scheme recursively, we can increase our independence to |A|^{Omega(1)} with o(c^{log c}) evaluation time. Compared with Siegel's scheme this is both faster and higher independence. Our scheme is easy to implement, and it does provide realistic implementations of 100-independent hashing for, say, 32 and 64-bit keys.
Polar Codes for Arbitrary DMCs and Arbitrary MACs
Venue: arXiv cs.IT 2013
Year: 2013

Polar codes are constructed for arbitrary channels by imposing an arbitrary quasigroup structure on the input alphabet. Just as with "usual" polar codes, the block error probability under successive cancellation decoding is $o(2^{-N^{1/2-ε}})$, where $N$ is the block length. Encoding and decoding for these codes can be implemented with a complexity of $O(N\log N)$. It is shown that the same technique can be used to construct polar codes for arbitrary multiple access channels (MAC) by using an appropriate Abelian group structure. Although the symmetric sum capacity is achieved by this coding scheme, some points in the symmetric capacity region may not be achieved. In the case where the channel is a combination of linear channels, we provide a necessary and sufficient condition characterizing the channels whose symmetric capacity region is preserved by the polarization process. We also provide a sufficient condition for having a maximal loss in the dominant face.
Local Event Boundary Detection with Unreliable Sensors: Analysis of the Majority Vote Scheme
Venue: arXiv cs.CG 2013
Year: 2013

In this paper we study the identification of an event region $X$ within a larger region $Y$, in which the sensors are distributed by a Poisson process of density $λ$ to detect this event region, i.e., its boundary. The model of sensor is a 0-1 sensor that decides whether it lies in $X$ or not, and which might be incorrect with probability $p$. It also collects information on the 0-1 values of the neighbors within some distance $r$ and revises its decision by the majority vote of these neighbors. In the most general setting, we analyze this simple majority vote scheme and derive some upper and lower bounds on the expected number of misclassified sensors. These bounds depend on several sensing parameters of $p$, $r$, and some geometric parameters of the event region $X$. By making some assumptions on the shape of $X$, we prove a significantly improved upper bound on the expected number of misclassified sensors; especially for convex regions with sufficiently round boundary, and we find that the majority vote scheme performs well in the simulation rather than its theoretical upper bound.
Comparative Study of QOS Parameters of SIP protocol in 802.11a and 802.11b Network
Venue: arXiv cs.NI 2013
Year: 2013

Present day, the internet telephony growth is much faster than previous. Now we are familiar with digitized packet of voice stream. So, we have required VOIP communication. SIP is one type of VOIP protocol. This one has a SIP proxy. There have one of the important communication environment Wireless LAN (WLAN). WLAN have different radio link standard. Here I am comparing SIP protocol in two radio link standard 802.11a and 802.11b environment. The first one have maximum transmission rate of 54Mbps and second one have maximum transmission rate of 11Mbps. In this paper I want to show the results in a comparative plot. These comparisons include server /client throughput, packet drops, end to end delay etc.
Current Services In Cloud Computing: A Survey
Venue: arXiv cs.OH 2013
Year: 2013

Due to the fast development of the Cloud Computing technologies, the rapid increase of cloud services are became very remarkable. The fact of integration of these services with many of the modern enterprises cannot be ignored. Microsoft, Google, Amazon, SalesForce.com and the other leading IT companies are entered the field of developing these services. This paper presents a comprehensive survey of current cloud services, which are divided into eleven categories. Also the most famous providers for these services are listed. Finally, the Deployment Models of Cloud Computing are mentioned and briefly discussed.
Impact of Limpware on HDFS: A Probabilistic Estimation
Venue: arXiv cs.OS 2013
Year: 2013

With the advent of cloud computing, thousands of machines are connected and managed collectively. This era is confronted with a new challenge: performance variability, primarily caused by large-scale management issues such as hardware failures, software bugs, and configuration mistakes. In our previous work we highlighted one overlooked cause: limpware - hardware whose performance degrades significantly compared to its specification. We showed that limpware can cause severe impact in current scale-out systems. In this report, we quantify how often these scenarios happen in Hadoop Distributed File System.
Integrated Expert Recommendation Model for Online Communities
Venue: arXiv cs.SI 2013
Year: 2013

Online communities have become vital places for Web 2.0 users to share knowledge and experiences. Recently, finding expertise user in community has become an important research issue. This paper proposes a novel cascaded model for expert recommendation using aggregated knowledge extracted from enormous contents and social network features. Vector space model is used to compute the relevance of published content with respect to a specific query while PageRank algorithm is applied to rank candidate experts. The experimental results show that the proposed model is an effective recommendation which can guarantee that the most candidate experts are both highly relevant to the specific queries and highly influential in corresponding areas.
Subsiding routing misbehavior in MANET using "Mirror Model"
Venue: arXiv cs.NI 2013
Year: 2013

Noncooperation or failure to work together is a big challenge that surely degrades the performance and reliability of Mobile Adhoc Networks. In MANETs, nodes have dual responsibilities of forwarding and routing, that's why it needs unison with nodes. To sort out non-cooperation a real life behavior should be implemented, so that misbehavior is nullified. In this paper, we present the "Mirror Model" that strictly enforces cooperation due to its punishment strategy. Node's behavior is watched by its neighbors in PON mode, to update the NPF, NPRF values for a threshold time. After the expiry of the threshold time each node calculates the PFR and broadcasts its neighbors. Similarly all neighbors broadcasted PFR is received and processed by the node to define the 'G' and 'BP' values. The G value is used to isolate selfish nodes from the routing paths and BP denotes the amount of packets to be dropped by an honest node against a selfish node in spite of its misbehavior/packet drops. Cooperation within the neighbors, certainly result in subsiding misbehavior of selfish nodes, therein enhancing cooperation of the whole MANET. This model ensures honesty and reliability in MANET because it does not eliminate a node, but it behaves in the same way as the node behaved. Therefore, it justifies its name, after all mirrors reflects the same. We have implemented the model in "GloMoSim" on top of the DSR protocol, resulting its effectiveness, as compared to the DSR protocol when the network is misconducting for its selfish needs.
SAT-Based Synthesis Methods for Safety Specs
Venue: arXiv cs.LO 2013
Year: 2013

Automatic synthesis of hardware components from declarative specifications is an ambitious endeavor in computer aided design. Existing synthesis algorithms are often implemented with Binary Decision Diagrams (BDDs), inheriting their scalability limitations. Instead of BDDs, we propose several new methods to synthesize finite-state systems from safety specifications using decision procedures for the satisfiability of quantified and unquantified Boolean formulas (SAT-, QBF- and EPR-solvers). The presented approaches are based on computational learning, templates, or reduction to first-order logic. We also present an efficient parallelization, and optimizations to utilize reachability information and incremental solving. Finally, we compare all methods in an extensive case study. Our new methods outperform BDDs and other existing work on some classes of benchmarks, and our parallelization achieves a super-linear speedup. This is an extended version of [5], featuring an additional appendix.
Wireless Computing and IT Ecosystems
Venue: arXiv cs.OH 2013
Year: 2013

We have evolved an IT system that is ubiquitous and pervasive and integrated into most aspects of our lives. Many of us are working on 4th and 5th level refinements in efficiency and functionality. But, we stand on the shoulders of those who came before and this restricts our freedom of action. The prior work has left us with an ecosystem which is the living embodiment of our state-of-the-art. While we work on integration, refinement, broader application and efficiency, the results must move seamlessly into the ecosystem. Fundamental concepts are being researched in the lab and may rebuild the world we all live in, until that happens, we must work within the ecosystem.
Variability and Evolution in Systems of Systems
Venue: arXiv cs.SE 2013
Year: 2013

In this position paper (1) we discuss two particular aspects of Systems of Systems, i.e., variability and evolution. (2) We argue that concepts from Product Line Engineering and Software Evolution are relevant to Systems of Systems Engineering. (3) Conversely, concepts from Systems of Systems Engineering can be helpful in Product Line Engineering and Software Evolution. Hence, we argue that an exchange of concepts between the disciplines would be beneficial.
Determination of Multipath Security Using Efficient Pattern Matching
Venue: arXiv cs.CR 2013
Year: 2013

Multipath routing is the use of multiple potential paths through a network in order to enhance fault tolerance, optimize bandwidth use, and improve security. Selecting data flow paths based on cost addresses performance issues but ignores security threats. Attackers can disrupt the data flows by attacking the links along the paths. Denial-of-service, remote exploitation, and other such attacks launched on any single link can severely limit throughput. Networks can be secured using a secure quality of service approach in which a sender disperses data along multiple secure paths. In this secure multi-path approach, a portion of the data from the sender is transmitted over each path and the receiver assembles the data fragments that arrive. One of the largest challenges in secure multipath routing is determining the security threat level along each path and providing a commensurate level of encryption along that path. The research presented explores the effects of real-world attack scenarios in systems, and gauges the threat levels along each path. Optimal sampling and compression of network data is provided via compressed sensing. The probability of the presence of specific attack signatures along a network path is determined using machine learning techniques. Using these probabilities, information assurance levels are derived such that security measures along vulnerable paths are increased.
Splitting schemes for poroelasticity and thermoelasticity problems
Venue: arXiv cs.NA 2013
Year: 2013

In this work, we consider the coupled systems of linear unsteady partial differential equations, which arise in the modeling of poroelasticity processes. Stability estimates of weighted difference schemes for the coupled system of equations are presented. Approximation in space is based on the finite element method. We construct splitting schemes and give some numerical comparisons for typical poroelasticity problems. The results of numerical simulation of a 3D problem are presented. Special attention is given to using hight performance computing systems.
Integrating Inspection and Test Processes Based on Context-Specific Assumptions
Venue: arXiv cs.SE 2013
Year: 2013

Inspections and testing are two of the most commonly performed software quality assurance processes today. Typically, these processes are applied in isolation, which, however, fails to exploit the benefits of systematically combining and integrating them. In consequence, tests are not focused based on early defect detection data. Expected benefits of such process integration include higher defect detection rates or reduced quality assurance effort. Moreover, when conducting testing without any prior information regarding the system's quality, it is often unclear how to focus testing. A systematic integration of inspection and testing processes requires context-specific knowledge about the relationships between inspections and testing. This knowledge is typically not available and needs to be empirically identified and validated. Often, context-specific assumptions can be seen as a starting point for generating such knowledge. Based on the In2Test approach, which uses inspection data to focus testing, we present in this article how knowledge about the relationship between inspections and testing can be gained, documented, and evolved in an analytical or empirical manner. In addition, this article gives an overview of related work and highlights future research directions.