OpenRaiser/Intern-Atlas huggingface dataset:
The Distributed Network Processor: a novel off-chip and on-chip interconnection network architecture
Venue: arXiv cs.AR 2012
Year: 2012

One of the most demanding challenges for the designers of parallel computing architectures is to deliver an efficient network infrastructure providing low latency, high bandwidth communications while preserving scalability. Besides off-chip communications between processors, recent multi-tile (i.e. multi-core) architectures face the challenge for an efficient on-chip interconnection network between processor's tiles. In this paper, we present a configurable and scalable architecture, based on our Distributed Network Processor (DNP) IP Library, targeting systems ranging from single MPSoCs to massive HPC platforms. The DNP provides inter-tile services for both on-chip and off-chip communications with a uniform RDMA style API, over a multi-dimensional direct network with a (possibly) hybrid topology.
SPARQL for a Web of Linked Data: Semantics and Computability (Extended Version)
Venue: arXiv cs.DB 2012
Year: 2012

The World Wide Web currently evolves into a Web of Linked Data where content providers publish and link data as they have done with hypertext for the last 20 years. While the declarative query language SPARQL is the de facto for querying a-priory defined sets of data from the Web, no language exists for querying the Web of Linked Data itself. However, it seems natural to ask whether SPARQL is also suitable for such a purpose. In this paper we formally investigate the applicability of SPARQL as a query language for Linked Data on the Web. In particular, we study two query models: 1) a full-Web semantics where the scope of a query is the complete set of Linked Data on the Web and 2) a family of reachability-based semantics which restrict the scope to data that is reachable by traversing certain data links. For both models we discuss properties such as monotonicity and computability as well as the implications of querying a Web that is infinitely large due to data generating servers.
Requirements Engineering Methods: A Classification Framework and Research Challenges
Venue: arXiv cs.SE 2012
Year: 2012

Requirements Engineering Methods (REMs) support Requirements Engineering (RE) tasks, from elicitation, through modeling and analysis, to validation and evolution of requirements. Despite the growing interest to design, validate and teach REMs, it remains unclear what components REMs should have. A classification framework for REMs is proposed. It distinguishes REMs based on the domain-independent properties of their components. The classification framework is intended to facilitate (i) analysis, teaching and extension of existing REMs, (ii) engineering and validation of new REMs, and (iii) identifying research challenges in REM design. The framework should help clarify further the relations between REM and other concepts of interest in and to RE, including Requirements Problem and Solution, Requirements Modeling Language, and Formal Method.
Bisimilarity Enforcing Supervisory Control for Deterministic Specifications
Venue: arXiv cs.SY 2012
Year: 2012

This paper investigates the supervisory control of nondeterministic discrete event systems to enforce bisimilarity with respect to deterministic specifications. A notion of synchronous simulation-based controllability is introduced as a necessary and sufficient condition for the existence of a bisimilarity enforcing supervisor, and a polynomial algorithm is developed to verify such a condition. When the existence condition holds, a supervisor achieving bisimulation equivalence is constructed. Furthermore, when the existence condition does not hold, two different methods are provided for synthesizing maximal permissive sub-specifications.
Enhancement Techniques for Local Content Preservation and Contrast Improvement in Images
Venue: arXiv cs.CV 2012
Year: 2012

There are several images that do not have uniform brightness which pose a challenging problem for image enhancement systems. As histogram equalization has been successfully used to correct for uniform brightness problems, a histogram equalization method that utilizes human visual system based thresholding(human vision thresholding) as well as logarithmic processing techniques were introduced later . But these methods are not good for preserving the local content of the image which is a major factor for various images like medical and aerial images. Therefore new method is proposed here. This method is referred as "Human vision thresholding with enhancement technique for dark blurred images for local content preservation". It uses human vision thresholding together with an existing enhancement method for dark blurred images. Furthermore a comparative study with another method for local content preservation is done which is further extended to make it suitable for contrast improvement. Experimental results shows that the proposed methods outperforms the former existing methods in preserving the local content for standard images, medical and aerial images.
Degraded Broadcast Diamond Channels with Non-Causal State Information at the Source
Venue: arXiv cs.IT 2012
Year: 2012

A state-dependent degraded broadcast diamond channel is studied where the source-to-relays cut is modeled with two noiseless, finite-capacity digital links with a degraded broadcasting structure, while the relays-to-destination cut is a general multiple access channel controlled by a random state. It is assumed that the source has non-causal channel state information and the relays have no state information. Under this model, first, the capacity is characterized for the case where the destination has state information, i.e., has access to the state sequence. It is demonstrated that in this case, a joint message and state transmission scheme via binning is optimal. Next, the case where the destination does not have state information, i.e., the case with state information at the source only, is considered. For this scenario, lower and upper bounds on the capacity are derived for the general discrete memoryless model. Achievable rates are then computed for the case in which the relays-to-destination cut is affected by an additive Gaussian state. Numerical results are provided that illuminate the performance advantages that can be accrued by leveraging non-causal state information at the source.
Optimal control of end-user energy storage
Venue: arXiv cs.NI 2012
Year: 2012

An increasing number of retail energy markets show price fluctuations, providing users with the opportunity to buy energy at lower than average prices. We propose to temporarily store this inexpensive energy in a battery, and use it to satisfy demand when energy prices are high, thus allowing users to exploit the price variations without having to shift their demand to the low-price periods. We study the battery control policy that yields the best performance, i.e., minimizes the total discounted costs. The optimal policy is shown to have a threshold structure, and we derive these thresholds in a few special cases. The cost savings obtained from energy storage are demonstrated through extensive numerical experiments, and we offer various directions for future research.
Restricted Isometry Property in Quantized Network Coding of Sparse Messages
Venue: arXiv cs.IT 2012
Year: 2012

In this paper, we study joint network coding and distributed source coding of inter-node dependent messages, with the perspective of compressed sensing. Specifically, the theoretical guarantees for robust $\ell_1$-min recovery of an under-determined set of linear network coded sparse messages are investigated. We discuss the guarantees for $\ell_1$-min decoding of quantized network coded messages, using the proposed local network coding coefficients in \cite{naba}, based on Restricted Isometry Property (RIP) of the resulting measurement matrix. Moreover, the relation between tail probability of $\ell_2$-norms and satisfaction of RIP is derived and used to compare our designed measurement matrix, with i.i.d. Gaussian measurement matrix. Finally, we present our numerical evaluations, which shows that the proposed design of network coding coefficients result in a measurement matrix with an RIP behavior, similar to that of i.i.d. Gaussian matrix.
Math world: A game-based 3D Virtual Learning Environment (3D VLE) for second graders
Venue: arXiv cs.CY 2012
Year: 2012

This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE) to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educational attributes such as mentality change, emotional fulfillment, knowledge enhancement, thinking skills development, and bodily coordination are evaluated to ensure learning effectiveness. Also, game playability measured in terms of game plays, story, mechanics and interface usability are examined for its educative design. With an aggregate of these enhanced indices, results attest that objectives were met while making mathematics an interesting, motivating and enjoyable subject, hence VLE a significant tool to complement the conventional approaches of teaching.
Design and modelling of different SRAM's based on CNTFET 32nm technology
Venue: arXiv cs.ET 2012
Year: 2012

Carbon nanotube field-effect transistor (CNTFET) refers to a field-effect transistor that utilizes a single carbon nanotube or an array of carbon nanotubes as the channel material instead of bulk silicon in the traditional MOSFET structure. Since it was first demonstrated in 1998, there have been tremendous developments in CNTFETs, which promise for an alternative material to replace silicon in future electronics. Carbon nanotubes are promising materials for the nano-scale electron devices such as nanotube FETs for ultra-high density integrated circuits and quantum-effect devices for novel intelligent circuits, which are expected to bring a breakthrough in the present silicon technology. A Static Random Access Memory (SRAM) is designed to plug two needs: i) The SRAM provides as cache memory, communicating between central processing unit and Dynamic Random Access Memory (DRAM). ii) The SRAM technology act as driving force for low power application since SRAM is portable compared to DRAM, and SRAM doesn't require any refresh current. On the basis of acquired knowledge, we present different SRAM's designed for the conventional CNTFET. HSPICE simulations of this circuit using Stanford CNTFET model shows a great improvement in power saving.
Secure and reliable routing in mobile adhoc networks
Venue: arXiv cs.NI 2012
Year: 2012

The growing diffusion of wireless-enabled portable devices and the recent advances in Mobile Ad-hoc NETworks (MANETs) open new scenarios where users can benefit from anywhere and at any time for impromptu collaboration. However, energy constrained nodes, low channel bandwidth, node mobility, high channel error rates, channel variability and packet loss are some of the limitations of MANETs. MANETs presents also security challenges. These networks are prone to malicious users attack, because any device within the frequency range can get access to the MANET. There is a need for security mechanisms aware of these challenges. Thus, this work aims to provide a secure MANET by changing the frequency of data transmission. This security approach was tested, and the results shows an interesting decreased of throughput from malicious node when the number of frequency used is increased, that way the MANET will not waste it's resources treating malicious packets. The other contribution of this work is a mobility aware routing approach, which aims to provide a more reliable routing by handling effectively the nodes mobility.
Relativized Propositional Calculus
Venue: arXiv cs.CC 2012
Year: 2012

Proof systems for the Relativized Propositional Calculus are defined and compared.
Performance Evaluation of Realistic Vanet Using Traffic Light Scenario
Venue: arXiv cs.NI 2012
Year: 2012

Vehicular Ad-hoc Networks (VANETs) is attracting considerable attention from the research community and the automotive industry to improve the services of Intelligent Transportation System (ITS). As today's transportation system faces serious challenges in terms of road safety, efficiency, and environmental friendliness, the idea of so called "ITS" has emerged. Due to the expensive cost of deployment and complexity of implementing such a system in real world, research in VANET relies on simulation. This paper attempts to evaluate the performance of VANET in a realistic environment. The paper contributes by generating a real world road Map of JNU using existing Google Earth and GIS tools. Traffic data from a limited region of road Map is collected to capture the realistic mobility. In this work, the entire region has been divided into various smaller routes. The realistic mobility model used here considers the driver's route choice at the run time. It also studies the clustering effect caused by traffic lights used at the intersection to regulate traffic movement at different directions. Finally, the performance of the VANET is evaluated in terms of average delivery ratio, packet loss, and router drop as statistical measures for driver route choice with traffic light scenario. This experiment has provided insight into the performance of vehicular traffic communication for a small realistic scenario.
Optimal Node Selection using Estimated Data Accuracy Model in Wireless Sensor Networks
Venue: arXiv cs.NI 2012
Year: 2012

One of the major task of wireless sensor network is to sense accurate data from the physical environment. Hence in this paper, we develop an estimated data accuracy model for randomly deployed sensor nodes which can sense more accurate data from the physical environment. We compare our results with other information accuracy models and shows that our estimated data accuracy model performs better than the other models. Moreover we simulate our estimated data accuracy model under such situation when some of the sensor nodes become malicious due to extreme physical environment. Finally using our estimated data accuracy model we construct a probabilistic approach for selecting an optimal set of sensor nodes from the randomly deployed maximal set of sensor nodes in the network.
System on Programable Chip for Performance Estimation of Loom Machine
Venue: arXiv cs.OH 2012
Year: 2012

System on programmable chip for the performance estimation of loom machine, which calculates the efficiency and meter count for weaved cloth automatically. Also it calculates the efficiency of loom machine. Previously the same was done using manual process which was not efficient. This article is intended for loom machines which are not modern.
Analog network coding in general SNR regime: Performance of a greedy scheme
Venue: arXiv cs.IT 2012
Year: 2012

The problem of maximum rate achievable with analog network coding for a unicast communication over a layered relay network with directed links is considered. A relay node performing analog network coding scales and forwards the signals received at its input. Recently this problem has been considered under certain assumptions on per node scaling factor and received SNR. Previously, we established a result that allows us to characterize the optimal performance of analog network coding in network scenarios beyond those that can be analyzed using the approaches based on such assumptions. The key contribution of this work is a scheme to greedily compute a lower bound to the optimal rate achievable with analog network coding in the general layered networks. This scheme allows for exact computation of the optimal achievable rates in a wider class of layered networks than those that can be addressed using existing approaches. For the specific case of Gaussian N-relay diamond network, to the best of our knowledge, the proposed scheme provides the first exact characterization of the optimal rate achievable with analog network coding. Further, for general layered networks, our scheme allows us to compute optimal rates within a constant gap from the cut-set upper bound asymptotically in the source power.
Technical support for Life Sciences communities on a production grid infrastructure
Venue: arXiv cs.DC 2012
Year: 2012

Production operation of large distributed computing infrastructures (DCI) still requires a lot of human intervention to reach acceptable quality of service. This may be achievable for scientific communities with solid IT support, but it remains a show-stopper for others. Some application execution environments are used to hide runtime technical issues from end users. But they mostly aim at fault-tolerance rather than incident resolution, and their operation still requires substantial manpower. A longer-term support activity is thus needed to ensure sustained quality of service for Virtual Organisations (VO). This paper describes how the biomed VO has addressed this challenge by setting up a technical support team. Its organisation, tooling, daily tasks, and procedures are described. Results are shown in terms of resource usage by end users, amount of reported incidents, and developed software tools. Based on our experience, we suggest ways to measure the impact of the technical support, perspectives to decrease its human cost and make it more community-specific.
On-Board Visual Tracking with Unmanned Aircraft System (UAS)
Venue: arXiv cs.CV 2012
Year: 2012

This paper presents the development of a real time tracking algorithm that runs on a 1.2 GHz PC/104 computer on-board a small UAV. The algorithm uses zero mean normalized cross correlation to detect and locate an object in the image. A kalman filter is used to make the tracking algorithm computationally efficient. Object position in an image frame is predicted using the motion model and a search window, centered at the predicted position is generated. Object position is updated with the measurement from object detection. The detected position is sent to the motion controller to move the gimbal so that the object stays at the center of the image frame. Detection and tracking is autonomously carried out on the payload computer and the system is able to work in two different methods. The first method starts detecting and tracking using a stored image patch. The second method allows the operator on the ground to select the interest object for the UAV to track. The system is capable of re-detecting an object, in the event of tracking failure. Performance of the tracking system was verified both in the lab and on the field by mounting the payload on a vehicle and simulating a flight. Tests show that the system can detect and track a diverse set of objects in real time. Flight testing of the system will be conducted at the next available opportunity.
An ISP Level Solution to Combat DDoS Attacks using Combined Statistical Based Approach
Venue: arXiv cs.CR 2012
Year: 2012

Disruption from service caused by DDoS attacks is an immense threat to Internet today. These attacks can disrupt the availability of Internet services completely, by eating either computational or communication resources through sheer volume of packets sent from distributed locations in a coordinated manner or graceful degradation of network performance by sending attack traffic at low rate. In this paper, we describe a novel framework that deals with the detection of variety of DDoS attacks by monitoring propagation of abrupt traffic changes inside ISP Domain and then characterizes flows that carry attack traffic. Two statistical metrics namely, Volume and Flow are used as parameters to detect DDoS attacks. Effectiveness of an anomaly based detection and characterization system highly depends on accuracy of threshold value settings. Inaccurate threshold values cause a large number of false positives and negatives. Therefore, in our scheme, Six-Sigma and varying tolerance factor methods are used to identify threshold values accurately and dynamically for various statistical metrics. NS-2 network simulator on Linux platform is used as simulation testbed to validate effectiveness of proposed approach. Different attack scenarios are implemented by varying total number of zombie machines and at different attack strengths. The comparison with volume-based approach clearly indicates the supremacy of our proposed system.
An Optimal Algorithm for Conflict-Free Coloring for Tree of Rings
Venue: arXiv cs.DS 2012
Year: 2012

An optimal algorithm is presented about Conflict-Free Coloring for connected subgraphs of tree of rings. Suppose the number of the rings in the tree is |T| and the maximum length of rings is |R|. A presented algorithm in [1] for a Tree of rings used O(log|T|.log|R|) colors but this algorithm uses O(log|T|+log|R|) colors. The coloring earned by this algorithm has the unique-min property, that is, the unique color is also minimum.
A Probabilistic Transmission Expansion Planning Methodology based on Roulette Wheel Selection and Social Welfare
Venue: arXiv cs.AI 2012
Year: 2012

A new probabilistic methodology for transmission expansion planning (TEP) that does not require a priori specification of new/additional transmission capacities and uses the concept of social welfare has been proposed. Two new concepts have been introduced in this paper: (i) roulette wheel methodology has been used to calculate the capacity of new transmission lines and (ii) load flow analysis has been used to calculate expected demand not served (EDNS). The overall methodology has been implemented on a modified IEEE 5-bus test system. Simulations show an important result: addition of only new transmission lines is not sufficient to minimize EDNS.
Modeling and Evaluating Enhancements in Expanding Ring Search Algorithm for Wireless Reactive Protocols
Venue: arXiv cs.NI 2012
Year: 2012

In case of high dynamic topology, reactive routing protocols provide quick convergence by faster route discoveries and route maintenance. Frequent roadcasts reduce routing efficiency in terms of broadcast cost; Bk, and expected time cost; E[t]. These costs are optimized using different mechanisms. So, we select three reactive routing protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR), and DYnamic Manet On-demad (DYMO). We model expanding Ring Search (ERS); an optimization mechanism in the selected protocols to reduce Bk and E[t]. A novel contribution of this work is enhancement of default ERS in the protocols to optimize Bk and E[t]. Using NS-2, we evaluate and compare default-ERS used by these protocols; AODV-ERS1, DSR-ERS1 and DYMO-ERS1 with enhanced-ERS; AODVERS2, DSR-ERS2 and DYMO-ERS2. From modeling and analytical comparison, we deduce that by adjusting Time-To-Live (T TL) value of a network, efficient optimizations of Bk and E[t] can be achieved.
Animal-Inspired Agile Flight Using Optical Flow Sensing
Venue: arXiv cs.SY 2012
Year: 2012

There is evidence that flying animals such as pigeons, goshawks, and bats use optical flow sensing to enable high-speed flight through forest clutter. This paper discusses the elements of a theory of controlled flight through obstacle fields in which motion control laws are based on optical flow sensing. Performance comparison is made with feedback laws that use distance and bearing measurements, and practical challenges of implementation on an actual robotic air vehicle are described. The related question of fundamental performance limits due to clutter density is addressed.