waashk/dblp huggingface dataset:
a novel stable and low-maintenance clustering scheme. clustering is one of the most important features of mobile ad hoc networks (manets), enabling their performance and scalability for a large number of mobile nodes. the design of clustering schemes is quite complex, due to the highly dynamic topology of such networks. until now, a wide variety of clustering schemes has been proposed, focusing different metrics and purposes. in this article a distinct, fully distributed and clusterhead-free, clustering scheme is proposed, named as novel stable and low-maintenance clustering scheme for mobile ad hoc networks (nsloc). the proposed clustering scheme was evaluated by simulation on topologies with up to 1000 nodes and variable node speeds. results showed that the two mains goals of nsloc, namely stability and low-maintenance, were fulfilled, while introducing less overhead than existing clustering solutions.
refinement of models of software components. models of software components at different levels of abstraction, component interfaces, contracts, implementations and publications are important for component-based design. refinement relations among models at the same level and between different levels are essential for model-driven development of components. classical refinement theories mainly focus on verification and put little attention on design. therefore, most of them are not suitable for component-based model-driven development (cb-mdd). to address this issue, in this paper, we propose two refinement relations for cb-mdd, that is a trace-based refinement and a state-based refinement. both are discussed in the framework of rcos, which is a formal model of component and object systems. these refinement relations provide different granularity of abstraction and can capture the intuition that a refined component provides "more" and "better" services to the environment. we also show how to extend these refinement relations to allow us to compare contracts, components and publications with different interfaces by exploiting the primitive operator internalizing over contracts, components and publications.
an evaluation of the sinuosity effect on visualization of rdp simplified maps: an empirical study. the process of line simplification consists of extracting a subset of points whose trend approximates the original line according to a more or less significant tolerance. in spite of the apparent straightforwardness of this concept, the process meant to accomplish this task may result very complex. the goal of the research we are carrying out is to contribute to the automation of the simplification process for visualization purposes by investigating what and how specific map and system properties affect it. to this aim, users' capability to recognize the differences between a map and a simplified version of it, may represent a key factor in evaluating how much a map can be automatically simplified preserving its visual content in terms of features and relationships. in this paper we illustrate the results collected through an empirical experimental study in which we have focused our observation on line sinuosity and users' perception related to its changes. results processed by this study demonstrate that the sinuosity is a relevant factor, whose management may contribute to automate the simplification process for visualization purposes.
towards higher throughput and energy efficiency in dense wireless ad hoc and sensor networks. traditional single-channel mac protocols for wireless ad hoc and sensor networks favor energy-efficiency over throughput. more recent multi-channel mac protocols display higher throughput but less energy efficiency. in this paper we propose namac, a negotiator-based multi-channel mac protocol in which specially designated nodes maintain the sleeping and communication schedules of nodes. negotiators facilitate the assignation of channels and coordination of communications windows, thus allowing individual nodes to sleep and save energy. simulation results show that na-mac, at high network loads, consumes 36% less energy while providing 25% more throughput than comparable state-of-art multi-channel mac protocols for ad hoc networks. additionally, we propose a lightweight version of namac and show that it outperforms (55% higher throughput with 36% less energy) state of art mac protocols for wireless sensor networks.
quality of service for multicasting using nice. to distribute data from one sender to multiple receivers efficiently and concurrently, multicasting is one of the most appropriate mechanisms. application layer multicast (alm), often also referred to as overlay multicast, has been introduced to overcome the limitations of ip multicast. the om-qos (quality of service for overlay multicast) framework aims to enable qos for different alm protocols. we applied the om-qos mechanisms to the overlay multicast protocol nice and performed evaluations in qos environments using resource reservations and measurement based qos. our evaluations show that we can support the qos requirements of all paths in the multicast tree, while introducing an acceptable overhead in terms of delay.
a method for business process decomposition based on the separation of concerns principle. functional decomposition breaks down a business process into a set of progressively more detailed activities. it facilitates the modular design of a system, the reuse of its parts and also contributes to increasing its comprehensibility. but achieving these qualities requires a business process to be decomposed consistently. separation of concerns is the principle of separating a system into distinct features with a minimum of overlapping. this paper proposes using this principle to consistently decompose a business process into its constituent activities. an activity is modelled as a collaboration between role types that are played by entities. the decomposition method successively separates the overlapping roles until an activity is specified by the collaboration of an orthogonal set of role types. this method facilitates the consistent decomposition of a business process and the unambiguous identification of its atomic activities.
sysml-based requirement modeling environment for multicore embedded system. the requirements engineering plays an important role during the lifespan of a complex system development project. the writing of system requirements in system developments process is through the natural language frequently. natural language usually contains uncertainty. additionally, requirements engineer lacks field knowledge and often shows shortages of relevant experiences. all these cause equivocal and wrong requirements analysis of the system requirements specification. in order to avoid these, the appropriate requirements modeling tools and can offer engineer's appropriate mechanism to understand what the customer want, analyze the requirements, assess feasibility, consult the rational solution, clearly point out the solution, confirm the specification, and reduce the possibility that the specific project may fail. we have presented a requirements modeling tool based on sysml. this research copes with model driven approach and requirements definition template for precise, consistent requirements specifications definition. mda offers a procedure of analyzing the requirements to prevent a specific project from procrastinating. it assists users to confirm and improve the exactness of the requirements contents via the "profile" of the requirements. the ocl leads users to write the template of the requirements, and brings in the characteristics of multi-core embedded system in the requirements documents through "profile".
a hardware peripheral for java bytecodes translation acceleration. java has gained great popularity in a wide range of applications. just-in-time compilation is crucial for providing efficient execution of java programs, but it is generally a hard task, not suited for embedded systems. this paper presents a hardware acceleration unit for efficient execution of jit translation in embedded socs. the translation is limited to only first level optimizations, which include translation of java bytecodes to native risc instructions (stack folding). for experimentation, we developed a soc with arm7tdmi processor. in a f 80nm asic technology and 80mhz clock, we measured a speed up of up to 4 times over the software only jit translation.
expressing aspectual interactions in requirements engineering: experiences in the slot machine domain. aspect oriented requirements engineering (aore) provides support for modularizing crosscutting requirements. in the context of an industrial project in the domain of slot machines we needed to perform aore, with a special emphasis on dependencies and interactions among concerns. we were however unable to find any report of large-scale industrial applications of aore approaches that treat dependencies and interactions. we therefore evaluated two aore approaches: theme/doc and mdsocre, to establish their applicability in our setting. in this paper we report on our experience, showing successful uses of both approaches as well as where they fall short. we furthermore propose possible enhancements for both approaches, to address these limitations.
personal identification using periocular skin texture. in this paper, we propose the use of periocular skin texture as a biometric modality. salient skin texture features are extracted and represented using local binary patterns (lbps). matching is performed using cityblock distance as a measure of similarity. we investigate the use of each periocular region separately in addition to their use in conjunction. verification and identification experiments involving over 400 subjects were performed using a datasets constructed from the frgc and feret datasets. reported recognition rates of nearly 90%, demonstrate the effectiveness of this novel technique.
automatic recognition of finger spelling for libras based on a two-layer architecture. different feature extraction techniques have been applied to the problem of automatic finger spelling (and gesture) recognition problem. however, different hand postures and gestures with different complexities have been given the same space representation. our approach tries to get rid off the assumption that one size fits all. a two level architecture was investigated where signs with similar hand postures were grouped together for a preliminary artificial neural network (ann) classification. a second ann was applied to disambiguate the confusions among symbols, using another space representation. our results indicate that it is possible to improve recognition rates with this approach.
energy-efficient real-time scheduling of multimedia tasks on multi-core processors. in recent years, various multi-core architectures have become popular selections for the designs of mobile platforms. with the strong computing demands from many multimedia applications, how to energy-efficiently utilize the computing power of mobile platforms without violations of timing constraints has become a critical design problem. in this paper, a data-partitioning-based approach is proposed to explore the parallelism of multimedia workload processing over multiple cores. dynamic voltage scaling and dynamic power management strategies are both considered in the dynamic scaling of the computing power of cores and the adjustment of the set of active cores, respectively. the practicability and the energy efficiency of the proposed algorithms were evaluated by a series of experiments and simulations, for which we have encouraging results.
using passage-based language model for opinion detection in blogs. in this work, we evaluate the importance of passages in blogs especially when we are dealing with the task of opinion detection. we argue that passages are basic building blocks of blogs. therefore, we use passage-based language modeling approach as our approach for opinion finding in blogs. our decision to use language modeling (lm) in this work is totally based on the performance lm has given in various opinion detection approaches. in addition to this, we propose a novel method for bi-dimensional query expansion with relevant and opinionated terms using wikipedia and relevance-feedback mechanism respectively. we also compare the impacts of two different query terms weighting (and ranking) approaches on final results. besides all this, we also compare the performance of three passage-based document ranking functions (linear, avg, max). for evaluation purposes, we use the data collection of trec blog06 with 50 topics of trec 2006 over trec provided best baseline with opinion finding map of 0.3022. our approach gives a map improvement of almost 9.29% over best trec provided baseline (baseline4).
a semantic web-based approach for personalizing news. hermes is an ontology-based framework for building news personalization services. this framework consists of a news classification phase, which classifies the news, a knowledge base updating phase, which keeps the knowledge base up-to-date, a news querying phase, allowing the user to search the news for concepts of interest, and a results presentation phase, showing the returned news items. the focus of this paper is on how to keep the knowledge base up-to-date. for this purpose, we elaborate on the updating phase that searches for key events in the news. using rules based on patterns and actions, these events can be extracted and the knowledge base is updated. this is a semi-automatic process since user validation is required before updating the knowledge base.
energy efficient program updating for sensor nodes with flash memory. updating sensor node programs is an essential task for maintaining stability and modifying the characteristics of wireless sensor networks. the updating mechanism must consider energy and memory efficiency, because of resource constraints of sensor nodes. in this paper, we propose a novel program updating mechanism, which considers resource constraints of sensor nodes. the proposed mechanism was designed for sensor nodes with the nor flash memory. this is generally used to store program image. it was designed to minimize the number of flash write/erase operations, which consume a great deal of energy, and to provide wear-leveling for the nor flash memory. we set a function as the basic unit of program updating, and partition a function into fixed-sized blocks that can be separately relocated in memory. experimental results show that the proposed mechanism outperforms other mechanisms in terms of energy, memory and wear-leveling for flash memory.
content cloaking: preserving privacy with google docs and other web applications. web office suites such as google docs offer unparalleled collaboration experiences in terms of low software requirements, ease of use, data ubiquity, and availability. when the data holder (google, microsoft, etc.) is not perceived as trusted though, those benefits are considered at stake with important privacy requirements. content cloaking is a lightweight, cryptographic, client-side solution to protect content from data holders while using web office suites and other "web 2.0", ajax-based, collaborative applications.
dual-level defense for networks under ddos attacks. ddos has become one of the thorniest problems in the internet, and aims to deny legitimate users of the services they should have. in this paper, we introduce novel dual - level attack defense against the ddos attacks. the macroscopic level detectors attempt to detect voluminous congestion inducing attacks which cause apparent slowdown in network functionality. the subsequent characterization process identifies these large volumes attacks that have been detected early in transit domain. the microscopic level detectors detect sophisticated attacks that cause network performance to degrade gracefully and remain undetected in transit domain. the subsequent characterization process identifies such attacks that have been detected at border routers in stub domain near the victim. we employ the concepts of change point detection on entropy with time to improve the detection rate. honeypots help achieve high detection and filtering accuracy. in addition to being competitive than other techniques, the defense works well in the presence of different ddos attacks. the compromise of detection and characterization accuracy and time of confirming is a critical aspect and the proposed technique provides the quite demanded solution.
timing analyzing for systems with execution dependencies between tasks. in this paper, a novel approach to timing analysis of complex real-time systems with intricate execution dependencies between tasks, such as asynchronous message-passing and globally shared state variables, is presented. by applying the method to a model taken from a real robotic control system, we show the benefit, in terms of reduced pessimism, when compared to a combination of standard static wcet analysis and response-time analysis.
a cytoscape based framework for efficient sub-graph isomorphic protein-protein interaction motif lookup. study of interactomes requires assembling complex tools, ontologies and online interaction network databases and so on to validate hypotheses and gain insight. one of the major bottlenecks is the discovery of similar or isomorphic subgraphs in very large interactomes and cross referencing the relationships a set of proteins or genes share. these interactomes are so large that most traditional subgraph isomorphism computation tools are unable to handle efficiently as stand alone tool, or as part of systems such as r. in this paper, we present a cytoscape plugin to compute and discover isomorphic subnetworks in large interactomes based on a novel and efficient isomorphic subgraph computation method developed in our laboratory. given an input interactome and a given query subnetwork, the plugin can efficiently compute interactome subnetworks similar to the query network, and cross reference the results from go or other interactome databases with the aid of other available cytoscape plugins such as bingo. we describe the tool with respect to real life applications biologists may want to contemplate.
using interaction requirements to operationalize usability. in the context of today's software development, usability is often seen as a fuzzy concept: although considered important for the overall success of a software product, usability is not taken into account systematically during development, and effective human-computer interaction design depends in many cases on the whim of individual developers. this paper presents inspire, a pragmatic approach to operationalizing particular usability facets by specifying interaction requirements. interaction elements of a use case-based functional specification are identified and categorized. based on this categorization, matching interaction attributes, i.e. patterns of interaction design, are selected from a library of interaction attributes known to improve usability, and are further refined to meet the specific software functionality, user profiles, and context of use. the resulting interaction requirements are both realizable and testable, thus operationalizing usability in a way that allows developers to consider usability aspects explicitly during software design, implementation and test.
monitoring mpi programs for performance characterization and management control. monitoring distributed programs on high performance supercomputers is a challenging task, yet it is essential for the proper administration of the machines and for users to understand what their program is doing on production runs. to this end, we created a flexible monitoring capability for a major class of scientific applications, programs using mpi, that efficiently gathers information from the distributed program and collects it at a central point. this data can then be used to both understand application-centric issues and system-centric issues; and for improvement, administration, and maintenance of both the complex applications producing important scientific results and the complex systems that execute them.
efficient mapping and voltage islanding technique for energy minimization in noc under design constraints. voltage islanding technique in network-on-chip (noc) can significantly reduce the computational energy consumption by scaling down the voltage levels of the processing elements (pes). this reduction in energy consumption comes at the cost of the energy consumption of the level shifters between voltage islands. moreover, from physical design perspective it is desirable to have a limited number of voltage islands. considering voltage islanding during mapping of the pes to the noc routers can significantly reduce both the computational and the level-shifter energy consumptions and the communication energy consumption on the noc links. in this paper, we formulate the problem as an optimization problem with an objective of minimizing the overall energy consumption constrained by the performance in terms of delay and the maximum number of voltage islands. we provide the optimal solution to our problem using mixed integer linear program (milp) formulation. we also propose a heuristic based on random greedy selection to solve the problem. experimental results using e3s benchmark applications and some real applications show that the heuristic finds near-optimal solution in almost all cases in a very small fraction of the time required to achieve the optimal solution.
transport congestion events detection (tced): towards decorrelating congestion detection from tcp. tcp(transmission control protocol) uses a loss-based algorithm to estimate whether the network is congested or not. the main difficulty for this algorithm is to distinguish spurious from real network congestion events. other research studies have proposed to enhance the reliability of this congestion estimation by modifying the internal tcp algorithm. in this paper, we propose an original congestion event algorithm implemented independently of the tcp source code. basically, we propose a modular architecture to implement a congestion event detection algorithm to cope with the increasing complexity of the tcp code and we use it to understand why some spurious congestion events might not be detected in some complex cases. we show that our proposal is able to increase the reliability of tcp newreno congestion detection algorithm that might help to the design of detection criterion independent of the tcp code. we find out that solutions based only on rtt (round-trip time) estimation are not accurate enough to cover all existing cases. furthermore, we evaluate our algorithm with and without network reordering where other inaccuracies, not previously identified, occur.
constraint processing in relational database systems: from theory to implementation. constraint satisfaction problems (csp) are frequently solved over data residing in relational database systems. in such scenarios, the database is typically just used as a data storage back end. however, there exist important advantages, such as the wide availability of database practices and tools for modeling, to having database systems that are capable of natively modeling and solving csps. this paper introduces general concepts and techniques to extend a database system with constraint processing capabilities. input csps are modeled via sql, augmented with a non-deterministic guess operator as introduced by cadoli and mancini (tplp 2007). problems are represented with a combination of internal relations and parse trees, and are translated to a flexible intermediate problem representation that is subsequently translated into several common representations for sat. benchmarks with a prototype system show the feasibility of the approach and demonstrate the promise of a strong integration of csp solvers and database systems.