waashk/dblp huggingface dataset:
optimal placement of nak-suppressing agents for reliable multicast: a partial deployment case. in reliable multicast, receivers use negative acknowledgments (naks) to inform the sender about their packet loss. the growth in the number of nak messages received by the sender results in the well-known feedback (or nak) implosion problem. therefore, one important issue for reliable multicast protocols is to utilize an effective mechanism to collect nak messages from the receivers. one way to avoid feedback implosion at the sender site is to place nak-suppression agents on the internal nodes (routers) of the network. these agents will forward a single copy of the incoming nak messages toward the sender site and will suppress additional redundant copies coming from the receivers.in this paper, we consider an agent placement (activation) problem for reliable multicast. first, we assume a network environment where a number of internal nodes (routers) have nak-suppression capabilities. then, we try to select a subset of these nodes for nak suppression task for a given reliable multicast application. our main selection criteria is to choose a minimum number of such nodes for the task and have a notion of load-balancing among them. in this context, we study two agent activation problems: the load-balanced agent activation problem (lbaap) and the budgeted agent activation problem (baap) and present efficient algorithms for optimal activation of agents. the problems that we consider in this paper are generalized versions of the respective problems introduced by daescu et al. [3].
design and evaluation of catpa: curation and alignment tool for protein analysis. we present a new application for experimental biologists, the curation alignment tool for protein analysis (catpa), that allows for the efficient and effective creation, storage, management, querying, and visualizing of experimentally curated protein families. protein families in general include paralogs having diverged from a duplication and orthologs. there is more than two decades worth of biological information and more data emerging, but there has not yet been an effective means of dealing with this data. it is our contention that an information system could be created whose appearance was suitable to the visual nature-particularly through alignments-of the information while the underpinnings were formal and followed standard software engineering principles. thus, biologists can interact with the system easily because the data is in the form that they are accustomed to, but they can be assured that there is a sound data model underneath. it is our hope that this will allow biologists to spend more time on the biological science and less time on the information science. in order to help evaluate the utility of this system, we have performed a formal quantitative and qualitative usability study. usability evaluation of catpa was performed to compare the performance of catpa with a similar tool, and users were found to to significantly more efficient using catpa for a number of different types of tasks.
circle: design and implementation of a classifier based on circuit minimization. we present circle, a classification algorithm based on the priciples of boolean function minimization. this classification process uses a recursive method to generate a set of implicants (or rules). the novelty of this algorithm is in the fact that the rules generated contain information about not only presence of features, but also their absence in determining class values. although function minimization is inherently exponential on the number of attributes, we introduce several optimization techniques to reduce the complexity.
on the verification of open distributed systems. a logic and proof system is introduced for specifying and proving properties of open distributed systems. key problems that are addressed include the verification of process networks with a changing interconnection structure, and where new processes can be continuously spawned. to demonstrate the results in a realistic setting we consider a core fragment of the erlang programming language. roughly this amounts to a first-order actor language with data types, buffered asynchronous communication, and dynamic process spawning. our aim is to verify quite general properties of programs in this fragment. the specification logic extends the first-order $\mu$-calculus with erlang-specific primitives. for verification we use an approach which combines local model checking with facilities for compositional verification. we give a specification and verification example based on a billing agent which controls and charges for user access to a given resource.
architectural issues for a location-aware role-based access control system. an increasingly important category of location-based services (lbs) responding to the demands of mobility in organizations is represented by enterprise lbs (e-lbs). e-lbs pose challenging requirements, including the need of selective access to the services based on the position of mobile users and spatially-bounded organizational functions. to address these requirements a general architectural framework for an access control system based on location-aware roles is introduced.
re-classification and multi-threading: . in this paper we consider re-classification in the presence of multi-threading. to this aim we define a multi-threaded extension of the language fickle, that we call ficklemt. we define an operational semantics and a type and effect system for the language. each method signature carries the information on the possible effects of the method execution. the type and effect system statically checks this information. the operational semantics uses this information in order to delay the execution of some threads when this could cause messagenotunderstood errors. we prove that in the execution of a well-typed expression such delays do not produce deadlock.
a method for assessing the reusability of object-oriented code using a validated set of automated measurements. a method for judging the reusability of c++ code components and for assessing indirect quality attributes from the direct attributes measured by an automated tool was demonstrated. the method consisted of two phases. the first phase identified and analytically validated a set of measurements for assessing direct quality attributes based on measurement theory. an automated tool was used to compute actual measures for a repository of c++ classes. a taxonomy relating reuse, indirect quality attributes, and measurements identified and validated during the first part of this research was defined. the second phase consisted of identifying and validating a set of measurements for assessing indirect quality attributes. a case study of the feasibility of applying direct measurements to assess the indirect quality attributes was conducted. the comparison and analysis of indirect quality attributes measured by human analysis with direct quality attributes measured by the automated tool provided empirical evidence that the two sets of quality attributes, direct and indirect, do correlate.
on the computational limits of infinite satisfaction. we study the computational limits of constraint satisfaction problems (csp's) allowing infinitely, or unboundedly, many indexed variables as in, e.g., xi > xi+2 for each i = 1, 2,.... we refer to these csp's as infinite csp's (icsp's). these problems arise in contexts in which the number of variables is unknown a priori as well as in optimization problems wrt the number of variables satisfying a given finite set of constraints.in particular, we investigate the decidability of the satisfiability problem for icsp's wrt (a) the first-order theory specifying the indices of variables and (b) the dimension of the indices. we first show that (1) if the indices are one-dimensional and specified in the theory of the natural numbers with linear order (the theory of (n, 0, succ, <)) then the satisfiability problem is decidable. we then prove that, in contrast to (1), (2) if we move to the two-dimensional case then the satisfiability problem is undecidable for indices specified in (n, 0, succ, <) and even in (n, 0, succ). finally, we show that, in contrast to (1) and (2), already in the one-dimensional case (3) if we also allow addition, we get undecidability. i.e., if the one-dimensional indices are specified in presburger arithmetic (i.e., the theory of (n, 0, succ, <, +)) then satisfiability is undecidable.
quantum versions of k-csp algorithms: a first step towards quantum algorithms for interval-related constraint satisfaction problems. in data processing, we input the results xi of measuring easy-to-measure quantities xi and use these results to find estimates y = f (x1, . . ., xn) for difficult-to-measure quantities y which are related to xi by a known relation y = f(x1, . . ., xn). due to measurement inaccuracy, the measured values xi are, in general, different from the (unknown) actual values xi of the measured quantities, hence the result y of data processing is different from the actual value of the quantity y.in many practical situations, we only know the bounds &delta;i on the measurement errors &delta;xi [equation] xi - xi. in such situations, we only know that the actual value xi belongs to the interval [xi - &delta;i, xi + &delta;i], and we want to know the range of possible values of y. the corresponding problems of interval computations are np-hard, so solving these problems may take an unrealistically long time. one way to speed up computations is to use quantum computing, and quantum versions of interval computations algorithms have indeed been developed.in many practical situations, we also know some constraints on the possible values of the directly measured quantities x1, . . ., xn. in such situations, we must combine interval techniques with constraint satisfaction techniques. it is therefore desirable to extend quantum interval algorithms to such combinations. as a first step towards this combination, in this paper, we consider quantum algorithms for discrete constraint satisfaction problems.
reliability analysis of mobile agent-based systems. in this paper we propose an algorithm for estimating the reliability of mobile agent systems, based on the conditions of the underlying computer network. we use the concept of restricted random walks in graph theory for generating a random static route strategy for mobile agents. the complexity of the mobile agent networks makes it hard to obtain the reliability of the system theoretically; instead we estimate it using the monte carlo approach. we assume that the system consists of a number of independent agents operating simultaneously. the results we have achieved demonstrate the robustness of the proposed algorithm.
an approach to integrating semi-formal and formal notations in software specification. in this paper the integration of graphical, semi-formal modeling languages with formal notations for software specification purposes is discussed and a proposal for a procedural frame based on the combined use of uml and z++ is presented. this procedural frame, organized in stages and steps, provides the methodological basis for a pragmatic and rigorous object-oriented modeling approach aimed at the construction of larger software systems, including real-time systems. within the proposed frame a regular flow of modeling activities is suggested and alternative modeling scenarios are considered. a brief presentation of the harmony integrated specification environment, a tool designed to support the proposed approach, is also included in the paper.
effects of changing requirements: a tracking mechanism for the analysis workflow. managing the effects of changing requirements remains one of the greatest challenges of enterprise software development. the iterative and incremental model provides an expedient framework for addressing such concerns. this paper presents a set of metrics - mutation index, component set, dependency index - and a methodology to measure the effects of requirement changes in the analysis workflow from one iteration to another. results from a sample case study are included to highlight a usage scenario. future directions of our work based on this mechanism are also discussed.
a simple and energy-efficient routing protocol for radio networks. a radio network (rn) is a distributed system where each node is a small hand-held commodity device called a station, running on batteries. each station spends energy while transmitting or receiving a message i.e., when the station is awake. a station conserves power by going into a sleep mode. since it is not possible to recharge batteries when the stations are on a mission, it is extremely important that the stations spend energy only when it is necessary. in this paper, we design an energy-efficient protocol for permutation routing on a single-hop radio network, where each station is within the transmission range of all other stations. an instance of the permutation routing problem involves p stations of an rn, each storing n/p packets. each packet has a unique destination address which is the identity of the destination station to which the packet should be sent. our goal is to route all the packets to their destinations while spending as little energy as possible. from simulation results, it is clear that our protocol performs better than an existing protocol by nakano et al. [12], when each station routes packets with random destination addresses. we also assume that k &laquo; p &laquo; n, where, n, p and k are respectively the number of packets, number of stations and number of channels in the network.
comparing approaches to predict transmembrane domains in protein sequences. there are today several systems for predicting transmembrane domains in membrane protein sequences. as they are based on different classifiers as well as different pre- and post-processing techniques, it is very difficult to evaluate the performance of the particular classifier used. we have developed a system called memmic for predicting transmembrane domains in protein sequences with the possibility to choose between different approaches to pre- and post-processing as well as different classifiers. therefore it is possible to compare the performance of each classifier in a certain environment as well as the different approaches to pre- and post-processing. we have demonstrated the usefulness of memmic in a set of experiments, which shows, e.g., that the performance of a classifier is very dependent on which pre- and post-processing techniques are used.
a multi-agent system architecture for coordination of just-in-time production and distribution. a multi-agent system architecture for coordination of just-in-time production and distribution is presented. the problem to solve is twofold: first the right amount of resources at the right time should be produced, then these resources should be distributed to the right consumers. in order to solve the first problem, which is hard when the production and&#x002f;or distribution time is relatively long, each consumer is equipped with an agent that makes predictions of future needs that it sends to a production agent. the second part of the problem is approached by forming clusters of consumers within which it is possible to redistribute resources fast and at a low cost in order to cope with discrepancies between predicted and actual consumption. redistribution agents are introduced (one for each cluster) to manage the redistribution of resources. the suggested architecture is evaluated in a case study concerning management of district heating systems. results from a simulation study show that the suggested approach makes it possible to control the trade-off between quality of service and degree of surplus production. we also compare the suggested approach to a reference control scheme (approximately corresponding to the current approach to district heating management), and conclude that it is possible to reduce the amount of resources produced while maintaining the quality of service. finally, we describe a simulation experiment where the relation between the size of the clusters and the quality of service was studied.
armed e-bunny: a selective dynamic compiler for embedded java virtual machine targeting arm processors. this paper presents a new selective dynamic compilation technique targeting arm 16/32-bit embedded system processors. this compiler is built inside the j2me/cldc (java 2 micro edition for connected limited device configuration) platform [8]. the primary objective of our work is to come up with an efficient, lightweight and low-footprint accelerated java virtual machine ready to be executed on embedded machines. this is achieved by implementing a selective arm dynamic compiler called armed e-bunny into sun's kilobyte virtual machine (kvm) [9]. in this paper, we present the motivations, the requirements, the architecture, the design, the implementation and debugging issues of armed e-bunny. the modified kvm is ported on an embedded-linux pda and is tested using standard j2me benchmarks. the experimental results on its performance demonstrate that a speedup of 360% over the last version of sun's kvm is accomplished with a footprint overhead that does not exceed 119kb.
automatic extraction of informative blocks from webpages. search engines crawl and index webpages depending upon their informative content. however, webpages --- especially dynamically generated ones --- contain items that cannot be classified as the "primary content", e.g., navigation side-bars, advertisements, copyright notices, etc. most end-users search for the primary content, and largely do not seek the non-informative content. a tool that assists an end-user or application to search and process information from webpages automatically, must separate the "primary content blocks" from the other blocks. in this paper, two new algorithms, contentextractor, and featureextractor are proposed. the algorithms identify primary content blocks by i) looking for blocks that do not occur a large number of times across webpages and ii) looking for blocks with desired features respectively. they identify the primary content blocks with high precision and recall, reduce the storage requirement for search engines, result in smaller indexes and thereby faster search times, and better user satisfaction. while operating on several thousand webpages obtained from 11 news websites, our algorithms significantly outperform the entropy-based algorithm proposed by lin and ho [7] in both accuracy and run-time.
supervised term weighting for automated text categorization. the construction of a text classifier usually involves (i) a phase of term selection, in which the most relevant terms for the classification task are identified, (ii) a phase of term weighting, in which document weights for the selected terms are computed, and (iii) a phase of classifier learning, in which a classifier is generated from the weighted representations of the training documents. this process involves an activity of supervised learning, in which information on the membership of training documents in categories is used. traditionally, supervised learning enters only phases (i) and (iii). in this paper we propose instead that learning from training data should also affect phase (ii), i.e. that information on the membership of training documents to categories be used to determine term weights. we call this idea supervised term weighting (stw). as an example, we propose a number of "supervised variants" of t f idf weighting, obtained by replacing the idf function with the function that has been used in phase (i) for term selection. we present experimental results obtained on the standard reuters-21578 benchmark with one classifier learning method (support vector machines), three term selection functions (information gain, chi-square, and gain ratio), and both local and global term selection and weighting.
reflective middleware for wireless sensor networks. wireless sensor networks (wsns) are distributed systems whose main goal is to collect and deliver data to applications. this paper proposes a reflective, service-oriented middleware for wsn. the middleware provides an abstraction layer between applications and the underlying network infrastructure and it also keeps the balance between application qos requirements and the network lifetime. it monitors both network and application execution states, performing a network adaptation whenever it is needed. simulation results show that the network residual energy can be increased in more than 100% when adopting an adaptation strategy, while the application qos requirement is respected.
a portable virtual machine for program debugging and directing. directors are reactive systems that monitor the run-time environment and react to the emitted events. typical examples of directors are debuggers and tools for program analysis and software visualization. in this paper we describe a cross-platform virtual machine that provides advanced facilities for implementing directors with low effort.
branchless cycle prediction for embedded processors. modern embedded processors access the branch target buffer (btb) every cycle to speculate branch target addresses. such accesses, quite often, are unnecessary as there is no branch instruction among those fetched.in this work we introduce branchless cycle prediction (blcp) to exploit this design inefficiency. blcp uses a simple power efficient structure to predict cycles where there is no branch instruction among those fetched, at least one cycle in advance. we avoid accessing btb during such cycles.we show that, by using blcp, it is possible to reduce btb power dissipation by 32% while paying a negligible performance cost (average: 0.2%).
patterns for blended, person-centered learning: strategy, concepts, experiences, and evaluation. within the last few years, e-learning has become a focal point in several universities and organizations. while much research has been devoted to producing e-content, describing it with metadata, and to constructing e-learning platforms, less attention has been paid to using technology to improve the learning process in terms of depth and scope. our research is targeted at filling this gap by considering learning support from a technical as well as socio-psychological perspective. we investigate how these two worlds can be brought together to result in maximum cross-fertilization. in this paper we focus on conceptual modeling of successful blended learning processes, their semi-formal description as patterns, and on the use of patterns as sources for the derivation of web-based templates. we report on experiences and evaluations of employing patterns in the context of blended, person-centered learning in technical subjects. our major conclusion is that blended learning has added value only if designed thoughtfully and accompanied by high interpersonal skills of instructors.
a probability analysis for candidate-based frequent itemset algorithms. this paper explores the generation of candidates, which is an important step in frequent itemset mining algorithms, from a theoretical point of view. important notions in our probabilistic analysis are success (a candidate that is frequent), and failure (a candidate that is infrequent). for a selection of candidate-based frequent itemset mining algorithms, the probabilities of these events are studied for the shopping model where all the shoppers are independent and each combination of items has its own probability, so any correlation between items is possible. the apriori algorithm is considered in detail; for ais, eclat, fp-growth and the fast completion apriori algorithm, the main principles are sketched. the results of the analysis are used to compare the behaviour of the algorithms for a variety of data distributions.