waashk/dblp huggingface dataset:
using constraint techniques for a safe and fast implementation of optimality-based reduction. optimality-based reduction attempts to take advantage of the known bounds of the objective function to reduce the domain of the variables, and thus to speed up the search of a global optimum. however, the basic algorithm is unsafe, and thus, the overall process may no longer be complete and may not reach the actual global optimum. recently, kearfott has proposed a safe implementation of optimality-based reduction. unfortunately, his method suffers from some limitations and is rather slow. in this paper, we show how constraint programming filtering techniques can be used to implement optimality-based reduction in a safe and efficient way.
a scalable overlay framework for internet anycasting service. this study presents ias, a scalable and efficient global overlay routing framework for internet anycasting service. we introduce a new routing group concept and adopt the overlay network mechanism to achieve scalable and efficient inter-domain anycast routing. we show that the routing table size of an anycast router can be bounded by o(&radic;n), where n denotes the number of anycast groups. we conduct simulations on a as topology to verify this bound and show that routes found by ias are very close to the shortest path when the size of anycast group is reasonably large.
structural similarity in geographical queries to improve query answering. the paper proposes a method for query approximation in geographic information systems. in particular, the problem of matching a query with imprecise or missing data is analyzed and an approach for the relaxation of query constraints is proposed. query approximation is performed by relaxing structural constraints, according to an extension of a previous proposal for evaluating concept similarity in an ontology management system [1] inspired by the maximum weighted matching problem in bipartite graphs. in our approach, we start from a weighted hierarchy of geographical objects evaluated using wordnet, a lexical database for the english language available on the internet. if a concept contained in a query has no match in the database, the query is approximated using a structural similarity graph that connects all geographical concepts by the lowest structural distance. the aim of the proposed methodology is to relax structural query constraints, in order to obtain meaningful answers for imprecise or missing data.
a framework for corba interoperability in ad hoc networks. the increasing popularity of wireless-enabled pdas, laptops and smart mobile phones, in addition to an explosion in the number of mobile services and networks, makes necessary the use of supporting frameworks to assist the development of distributed applications in ad hoc networks. starting from omg's standards on wireless access in mobile environments, this paper focuses on additional architectural requirements for adapting and extending corba's interoperability model so that it can be used to transparently handle giop message exchanges among objects across ad hoc networks. the proposed architecture, based on federations of specialized name servers, is described along with a strategy for routing the messages. finally, implementation details and strategies along with performance and scalability issues are discussed.
directed filter for dominant direction fuzzy set in content-based image retrieval. this paper presents a new directed filter that is performed on the dominant directions. the dominant directions are computed by the cluster algorithm and fuzzy set theory. the dominance of those dominant directions is computed and used for similarity measurement. the experiments show that the proposed filter fits for particular image domains very much.
certain trust: a trust model for users and agents. one of the challenges for ubiquitous computing and p2p systems is to find reliable partners for interactions. we believe that this problem can be solved by assigning trust values to entities and allowing them to state opinions about the trust-worthiness of others. in this paper, we develop a new trust model, called certain trust, which can easily be interpreted and adjusted by users and software agents. a key feature of certain trust is that it is capable of expressing the certainty of a trust opinion, depending on the context of use. we show how the trust values can be expressed using different representations (one for users and one for software agents) and present an automatic mapping to change between the representations.
enhancing adaptive random testing in high dimensional input domains. adaptive random testing (art) is an enhancement of random testing (rt). it can detect failures more effectively than rt when failure-causing inputs are clustered. having test cases both randomly selected and evenly spread is the key to the success of art. recently, it has been found that the dimensionality of the input domain could have an impact on the effectiveness of art. the effectiveness of some art methods may deteriorate when the dimension is high. in this paper, we work on one particular art method, namely fixed-sized-candidate-set art (fscs-art) and show how it can be enhanced for high dimensional domains. since the cause of the problems for fscs-art may also be valid for some other art methods, our solutions to the high dimension problems of fscs-art may be applicable for improving other art methods.
energy-efficient disk replacement and file placement techniques for mobile systems with hard disks. mobile systems have usually used hard disks as the secondary storage devices because of their high capacity per cost and high i/o throughput. however, their high power consumption is the main limiting factor for extending their adoptions in mobile systems. in this paper, we propose enhanced file placement techniques for mobile platforms with multiple smaller disks (instead of a single large disk). we investigate that how many smaller disks are necessary to obtain energy saving while maintaining the required performance using both a simplified energy model and a realistic trace-based simulator under the proposed multiple disk configurations. we also propose energy-efficient file placement techniques, which aggregate files with common attributes the same set of disks. by skewing i/o operations, the proposed techniques achieve additional energy saving. experimental results show that the proposed techniques can reduce the energy consumption by up to 43% when eight 1" disks are used instead of a single 2.5" disk with an acceptable increase in the average response time.
instance-based retrieval by analogy. this work presents a method for retrieval in knowledge bases expressed in description logics, founded in the instance-based learning. the procedure implements the disjunctive version space approach exploiting a notion of semantic difference. the method can be employed both to answer to class-membership queries, even though the answers are not logically entailed by the knowledge base, e.g. there are some inconsistent assertions due to heterogeneous sources. in addition, it may also predict/suggest new assertions the method has been implemented and tested in an experimentation, where we show that it is sound and effective.
an approach for indexing, storing and retrieving domain knowledge. in this short paper, we present our solution to index, store and retrieve the domain knowledge. the main principle exploits lucene to index the domain knowledge under guide of the domain schema. the method to map domain knowledge structure into lucene index structure, store and update the indices, and to transfer rdf-based query into lucene's query are presented.
automatic classification of digestive organs in wireless capsule endoscopy videos. wireless capsule endoscopy (wce) allows a physician to examine the entire small intestine without any surgical operation. with the miniaturization of wireless and camera technologies the ability comes to view the entire gestational track with little effort. although wce is a technical break-through that allows us to access the entire intestine without surgery, it is reported that a medical clinician spends one or two hours to assess a wce video, it limits the number of examinations possible, and incur considerable amount of costs. to reduce the assessment time, it is critical to develop a technique to automatically discriminate digestive organs such as esophagus, stomach, small intestinal (i.e., duodenum, jejunum, and ileum) and colon. in this paper, we propose a novel technique to segment a wce video into these anatomic parts based on color change pattern analysis. the basic idea is that the each digestive organ has different patterns of intestinal contractions that are quantified as the features. we present the experimental results that demonstrate the effectiveness of the proposed method.
why do successful search systems fail for some topics. this paper describes and evaluates the vector-space and probabilistic ir models used to retrieve news articles from a corpus written in the french language. based on three clef test-collections and 151 queries, we classify the poor retrieval results of difficult topics under 6 categories. the explanations we obtain from this analysis differ from those suggested a priori by our students. we use the web to manually or automatically find related search terms to the original query. we evaluate these two query expansion strategies in order to improve mean average precision (map) and to reduce the number of topics for which no pertinent responses are listed among the top ten references returned.
a clustering entropy-driven approach for exploring and exploiting noisy functions. linear, gaussian, fitness proportional, clustering, and rosca entropies are succinct measures of diversity that have been applied to balance exploration and exploitation in evolutionary algorithms. in previous studies, an entropy-driven approach using linear entropy explicitly balances and/or searches optimal solutions for the selected unimodal and multimodal functions excluding noisy functions. this paper investigates the reasons for such an exception and introduces a clustering entropy-driven approach to solve the problem. such an approach provides a coarse-grained diversity measure that filters the noise of functions, varies cluster size and categorizes individuals at the genotype level. the experimental results show that the clustering entropy-driven approach further improves the searching results of noisy functions by one more degree.
sesame: space-efficient stack allocation mechanism for multi-threaded sensor operating systems. this paper proposes a sesame, which is a space-efficient stack allocation mechanism for multi-threaded sensor operating systems. it adaptively adjusts the stack size by allocating or releasing additional stack frame based on the amount of each function's stack usage information. our experimental results show that the sesame significantly minimizes spatial overhead of thread's stacks with tolerable time overhead compared with fixed stack allocation mechanism of the multi-threaded sensor operating systems.
nl sampler: random sampling of web documents based on natural language with query hit estimation. random sampling of documents is a substantial supporting function for research in information science, content-related research (like content adaptation), or social sciences. looking for an appropriate method to get a random sample of microsoft office files for research on presentation sharing applications, we found out, that the two main approaches random walk and random search are not appropriate to find formatted documents. both approaches are designed for the purpose of large scale web analysis and do not fit more special requirements. in this paper, we adopt and extend the random search approach first described by bharat and broder to a more universal random sampling method based on natural language lexica called nl sampler, that can be used in a wide range of application domains. it supports parameters like file type or dns domain restrictions while preserving representativeness. we implemented and evaluated the approach and found a zipf-like distribution of average hits per query which enables estimation of query hits for a certain set of parameters and thus can be used in a lot more application areas than the approaches previously published. estimation functions are given for microsoft word and powerpoint documents.
effects of inconsistently masked data using rpt on cf with privacy. randomized perturbation techniques (rpt) are applied to perturb the customers' private data to protect privacy while providing accurate referrals. in the rpt-based collaborative filtering (cf) with privacy schemes, proposed so far, users disguise their ratings in the same way to achieve consistently perturbed data. however, since users might have different levels of concerns about their privacy, the customers might decide to perturb their private data differently, which causes inconsistently masked data. how, then, can e-companies present referrals using such data and how can inconsistent data disguising affect accuracy and privacy?
hybrid retrieval from the unified web. the goal of semantic web initiative is to make the semantics of web content accessible to machines. the semantic web has been evolving into a web of data separate from the existing html web. our work focuses on establishing and exploiting connections between the two webs, especially hyperlink connections from the html web pages to the semantic web nodes, so as to enhance both data and document retrieval. we propose the unified web model to integrate the two webs, and a hybrid query language to retrieve data and documents from the unified web. specifically, the query language amalgamates graph-based reasoning over rdf with keyword-based search.
on efficient wear leveling for large-scale flash-memory storage systems. flash memory won its edge over many other storage media for embedded systems, because it provides better tolerance to the extreme environments which embedded systems are exposed to. in this paper, techniques referred to as wear leveling for the lengthening of flash-memory overall lifespan are considered. this paper presents the dual-pool algorithm, which realizes two key ideas: to cease the wearing of blocks by storing cold data, and to smartly leave alone blocks until wear leveling takes effect. the proposed algorithm requires no complicated tuning, and it resists changes of spatial locality in workloads. extensive evaluation and comparison were conducted, and the merits of the proposed algorithm are justified in terms of wear-leveling performance and resource conservation.
a customizable multi-agent system for distributed data mining. we present a general multi-agent system framework for distributed data mining based on a peer-to-peer model. agent protocols are implemented through message-based asynchronous communication. the framework adopts a dynamic load balancing policy that is particularly suitable for irregular search algorithms. a modular design allows a separation of the general-purpose system protocols and software components from the specific data mining algorithm. the experimental evaluation has been carried out on a parallel frequent subgraph mining algorithm, which has shown good scalability performances.
adaptive broadcast by distributed protocol switching. adaptation is a desirable requirement in a distributed system since it helps the system to perform gracefully under different scenarios. there are many adaptive algorithms for different problems. however the techniques are often application specific. in many distributed systems it may happen that the same problem has multiple protocols, each of which performs differently under different environments. in such cases adaptation can be achieved by dynamically switching between them as the environment changes. in this paper we illustrate the idea of designing adaptive distributed system using protocol switching by presenting an adaptive broadcast protocol that uses either a bfs tree or a dfs tree depending on the load of the system, both trees being rooted at the broadcast source. at low load a bfs tree is used as it reduces the broadcast delay (since the distance of any node from the root is always minimum in a bfs tree) while still keeping the load on any one node low. however at higher load a dfs tree is used to reduce the load on any one node since the degree of a node in a dfs tree is generally lower than that in a bfs tree. so the broadcast adapts to the network load by dynamically switching between a bfs tree and a dfs tree. in the proposed scheme, the switching is done by a middleware layered below the broadcast protocol. this separates the adaptation from the application and no change is needed in the application. we also ensure the application layer property that every broadcast message is correctly delivered to all the nodes, including messages sent when the switching is in progress. we assume the asynchronous model of distributed system with reliable but non-fifo channels. also it is assumed that no failure occurs during the switching. the message complexity of the algorithm that switches to a dfs tree is o(|e|) and is presented in the next section. the algorithm that switches to a bfs tree needs o(|v||e|) messages and is omitted in this paper due to lack of space.
exploiting the efficiency of generational algorithms for hardware-supported real-time garbage collection. generational garbage collectors are more efficient than their non-generational counterparts. unfortunately, however, generational algorithms require both write barriers and write barrier handlers and therefore degrade worst-case performance. in this paper, we present novel hardware support for generational garbage collection. in contrast to previous work, we introduce a hardware write barrier that does not only detect inter-generational pointers, but also executes all related book-keeping operations entirely in hardware. for the first time, write barrier detection and handling occur completely in parallel to instruction execution, so that the runtime overhead of generational garbage collection is reduced to near zero. for evaluation purposes, we extended a system with hardware-supported real-time garbage collection with our hardware support for generational garbage collection. measurements of java programs on an fpga-based prototype show that the generational extensions reduce the total duration of garbage collection activities by a factor of 5 and the memory traffic caused by the collector by a factor of 4 on average.
scalable coordination for sensor networks in challenging environments. in sensor networks, the unpredictable dynamics caused by the disruption of communication in harsh environments, the depletion of battery resources, and node mobility make coordination between sensor nodes more challenging than coordination between nodes in typical wired and wireless networks. while the literature is rich in coordination protocols for sensor networks and routing protocols for ad-hoc wireless networks, they assume relatively static environments. using these protocols in highly dynamic environments leads to increased coordination traffic, high energy-consumption, increased event loss, and excessive latency in reporting events. in this paper we propose swift, a coordination protocol that reacts to changes in nodes' connectivity with a local repair process, significantly reducing the coordination traffic. swift eliminates routing loops through a combination of avoidance and detection mechanisms; and does not require gps support, which cannot be used in closed environments and consumes significant energy resources. experimental results reveal that swift outperforms existing protocols and achieves significant energy efficiency, reduces event loss, and the latency in reporting events under various network dynamics.
a metadata-based architectural model for dynamically resilient systems. designing open and distributed systems that can dynamically adapt in a predictable way to unexpected events is a challenging issue still not solved. achieving this objective is a very complex task since it implies reasoning at run-time, explicitly and in a combined way, on a system's functional and non-functional characteristics. this paper proposes a service-oriented architectural model allowing the dynamic enforcement of formally expressed metadata-based resilience policies. it also describes preliminary dynamic resilience experiments acting as proof of concept.
software reengineering with architecture decomposition. software reengineering involves the activities of studying target system's architecture. however, enterprise legacy software systems tend to be large and complex. the analysis of system architecture therefore becomes a difficult task. to solve the problem, we propose an approach that decomposes software architecture to reduce the complexity associated with analyzing large scale architecture artifacts. our study has shown that architecture decomposition is an efficient way to limit the complexity and risk associated with the re-engineering activities of a large legacy system. it divides the system into a collection of meaningful modular parts with low coupling, high cohesion, and minimizes the interface, thus to facilitate the incremental approach to implement the progressive software re-engineering process. to fulfill this goal, we have developed two major techniques to decompose legacy system architecture. in this paper, we present them in detail. the approach is also supported by our automated reverse engineering tools, and the preliminary experimental result shows our approach is very promising.
extending reusable asset specification to improve software reuse. even though many approaches for reuse have been introduced, software engineers are still hesitating to reuse existing software components. two problems are the root cause of this situation. one is the difficulty in knowing whether the required software components are available. the other is the lack of information as to how to reuse the acquired components. to solve this problem, we introduce an extension to reusable asset specification (ras) and a process for supporting efficient reuse. we explain the process with a case study and evaluate through feedback from software engineers participating the case study.
towards semantic tuplespace computing: the semantic web spaces system. in this paper we introduce semantic web spaces, a middleware for coordinating knowledge processes on the semantic web. co-ordination is an important aspect of any type of interaction between computer agents, but we find especially so on the semantic web in which the communication contains knowledge rather than data and correct inferences can only be made when the right knowledge is available at the right time. because of this we have identified tuplespace computing as a relevant paradigm for agent communication on the semantic web and have prototypically realized a system based on a linda-inspired coordination model and on core semantic technologies such as rdf, ontologies and reasoning.
an edit operation-based approach to the inclusion problem for dtds. xml documents on a database should be revalidated whenever a dtd is updated, since the documents may no longer be valid against the dtd. solving the inclusion problem for dtds is essential to avoiding such an expensive revalidation, but the problem is shown to be pspace-complete. in this paper, we propose a subproblem of the inclusion problem in terms of edit operations to regular expressions, and show a polynomial-time algorithm for solving the subproblem. then we consider the recognizability of the algorithm.