waashk/dblp huggingface dataset:
a distributed protocol for ensuring replicated database consistency in mobile computing environments. a mobile replicated database is comprised of several mobile and fixed servers and clients interconnected through a wireless network. in order to ensure data consistency in mobile replicated databases, several replication control protocols have been proposed. however, most of them reveal relevant limitations, such as: possessing a single failure point and flooding the network with messages exchange. in this paper we introduce a protocol which guarantees data consistency of replicated databases in mobile computing. the proposed approach is completely distributed, avoids the existence of a single failure point, uses a read-any/write-any replication scheme, increases data availability, and reduces the number of messages exchanged among the replicated servers. furthermore, it allows the user to choose a transaction isolation level (degree in which the execution of a given transaction is isolated from all other concurrent transactions). experimental results show the potential efficiency of the proposed approach.
a supervisory control approach for safe behavior of service robot case study: friend. this paper presents an approach based on supervisory control theory for design of a safety controller in service robot system. as case study we focus on friend system and develop a discrete event controller for safety requirements, related to a part of the whole task to be accomplished by robot. the controller will be implemented in a safety module parallel to the system and by enabling the admissible sequences of events, keep the system safe and working according to the specifications.
secret interest groups (sigs) in social networks with an implementation on facebook. in this paper we present the first framework that allows the creation of secret interest groups (sigs) in online social networks; sigs are self managed groups formed outside of the social network, around secret, sensitive or private topics. members exchange credentials that can be used inside the social network to authenticate upon friendship requests or to secure user-generated content. to this end we present a set of cryptographic algorithms leveraging on well-studied primitives, and we describe a java implementation of the framework for facebook.
blade geometry design with kinematic ruled surface approximation. a blade geometry design method is proposed in this paper, which adopts a novel kinematic ruled surface approximation algorithm. the algorithm is applied to approximate a free-form blade surface as a ruled surface in order to reduce the manufacturing cost. by applying klein mapping and study mapping, a ruled surface in euclidean space is transformed to a curve on a dual unit sphere (dus). the kinematic ruled surface approximation algorithm is set up based on the novel definition of a spline on the dus and the corresponding spline interpolation algorithm. this representation of ruled surface links directly to the manufacture procedure.
towards lightweight self-configuration in wireless sensor networks. this paper proposes a new algorithm called sds for solving distributed constraint satisfaction problems in wireless sensor networks. it introduces minimal overhead by using piggybacking for information dissemination and is naturally insusceptible against message loss. partitioning into coordinating cliques has been used to demonstrate the feasibility of our approach.
proposal of an improved motion estimation module for svc. in october 2007 itu-t and mpeg organizations published the scalable video coding (svc) specification as an addendum to the h.264 standard. basically svc enables h.264 video encoders to support temporal, spatial and snr scalability. this new functionalities lead to more flexibility on bandwidth management and robustness against packet losses. it is therefore more suitable for heterogeneous multimedia applications like iptv and mobile networks. however implementations of svc specification are still limited due the augmented computational complexity. one of the most critical svc algorithms is the motion estimation module, which allows identification of extra intra and inter-layer redundancies. the great computation demand of this module is responsible for the large svc encoder latency time, restraining its use in real-time applications. we propose in this paper a new motion estimation approach specially designed to reduce memory accesses and data comparisons in order to increase performance. experimental results prove significant gains in speed (up to 6 times faster) with small effects on quality (less than 0.2 db).
botzilla: detecting the "phoning home" of malicious software. hosts infected with malicious software, so called malware, are ubiquitous in today's computer networks. the means whereby malware can infiltrate a network are manifold and range from exploiting of software vulnerabilities to tricking a user into executing malicious code. monitoring and detection of all possible infection vectors is intractable in practice. hence, we approach the problem of detecting malicious software at a later point when it initiates contact with its maintainer; a process referred to as "phoning home". in particular, we introduce botzilla, a method for detection of malware communication, which proceeds by repetitively recording network traffic of malware in a controlled environment and generating network signatures from invariant content patterns. experiments conducted at a large university network demonstrate the ability of botzilla to accurately identify malware communication in network traffic with very low false-positive rates.
an incremental algorithm for efficient unique signature discoveries on dna databases. dna signatures are distinct short nucleotide sequences that can be used to detect the presence of certain organisms and to distinguish that organisms from all other species. the signatures provide valuable information for many applications, such as pcr primer designs and microarray experiments. in practice, we use a discovery algorithm to discover unique signatures from dna databases, and then apply the signatures to microarray experiments. if the discovered result is not satisfying, we will change the parameter settings of the algorithm to get a new result. the process of changing parameter settings may be consecutively performed until a satisfying result is obtained, which is called consequtively multiple discoveries. the situation occurs frequently especially when we handle unfamiliar dna databases. the challenge is how to accomplish every new discoveries efficiently. the needs of consequtively multiple discoveries are not considered in existing discovery algorithms. in this paper, we propose an incremental algorithm specifically for consecutively multiple discoveries. the algorithm is designed based on the observations on the properties of the signatures. our algorithm finds out the new result by employing the previously discovered results as candidates rather than performing complete discoveries on the whole database. since the candidates in the incremental discovery are reduced and limited to the discovered signatures, the discovery process accelerates. compared with the typical discovery algorithms that perform complete discoveries on a whole database, our incremental algorithm saves at most 87% of the execution time in our experiments.
load balancing for structured p2p networks using the advanced finger selection algorithm (afsa). structured peer-to-peer (p2p) networks, such as networks based on distributed hash tables (dhts), can be enhanced by using load balancing mechanisms. current load balancing mechanisms are either trying to achieve even distribution of objects among nodes, make the address space as evenly populated as possible, or both. however, we have taken a different approach to load balancing in this paper and we have defined the advanced finger selection algorithm (afsa) which is not focused on balancing the objects among the nodes and does not require evenly populated address space. afsa is an algorithm which changes the way how nodes are selected as fingers to the overlay routing tables in structured p2p networks. we implemented the afsa algorithm for both chord and bamboo and we evaluated it with simulations.
dealing with anonymity in wireless sensor networks. nowadays wireless sensor networks (wsn) are used in many application contexts. data handled by wsn are required to be protected for privacy reasons since they can be directly or indirectly related to individuals. the problem of preventing the identification of individuals starting from their data, known as anonymity, is a fundamental requirement for privacy aware systems. this paper proposes a solution to guarantee anonymity for a wide spread type of wsn by means of privacy policies. the solution is based on a uml model that introduces the conceptual elements and guidelines that are needed to build privacy policies for wsn.
adsandbox: sandboxing javascript to fight malicious websites. we present adsandbox, an analysis system for malicious websites that focusses on detecting attacks through javascript. since, in contrast to java, javascript does not have any built-in sandbox concept, the idea is to execute any embedded javascript within an isolated environment and log every critical action. using heuristics on these logs, adsandbox decides whether the site is malicious or not. in contrast to previous work, this approach combines generality with usability, since the system is executed directly on the client running the web browser before the web page is displayed. we show that we can achieve false positive rates close to 0% and false negative rates below 15% with a performance overhead of only a few seconds, what is a bit high for real time application, but supposes a great potential for future versions of our tool.
comparison of enterprise service buses based on their support of high availability. in this paper, we compare and evaluate four enterprise service buses -- fuse, mule, openesb and artix -- based on their support of high availability. we rate artix first, followed by fuse, mule and openesb. these rates are based on the fault tolerance test results as well as the published documentation from providers.
rationale visualization of software architectural design decision using compendium. the justification for software architectural design decisions made throughout the architecting process is necessary for understanding, (re)using, communicating, and modifying an architecture design. although there are many existing tools to capture, store, manage, and share the architectural design decisions explicitly, there still remains a need to visualize and explore architectural design decisions and their underlying rationale. this paper investigates how compendium tool can be employed to visualize architectural design decisions and their rationale, in order to improve the understandability and promote the communication of architectural design decisions.
avoiding to dispense with accuracy: a method to make different dtds documents comparable. the italian regulations about web content accessibility impose html 4.01 strict, xhtml 1.0 strict or superior grammar validity. such markup constraints are complied by a low percentage of public institution sites. in order to include the largest amount of not strict dtd sites on a synthetic, realistic representation of accessibility degree, this paper presents an experimental approach to set up parameters for making validity measures uniform, despite they are taken from evaluating different grammars. the proposed method allows for effectiveness in computing and storing information which otherwise will be quite unfeasible. finally, the generalization of such an approach is shown to be suited for markup quality evaluations, beyond explicit law requirements.
mode independent session directory service architecture: a unified approach for asm and ssm multicast networks. in this paper we describe architectural changes incorporated into dns aware multicast session directory (mdns) that enable it to co-exist in both any source multicast (asm) and source specific multicast (ssm) environments. mdns is a distributed, global, scalable and hierarchical approach that allows multicast sessions to be searched based on multiple parameters including keywords, session-type, geo-locality, etc. mdns design being tightly coupled with existing domain name service (dns) enables sessions to be assigned a uniform resource locator (url) that can be book-marked for future access. we also describe the caching strategy added to mdns and present arguments on its possible benefits. afterwards, we will discuss the slight search strategy alteration required by caching and its security implications. this paper also describes our simulation design. we describe how we automated our experiments. the integration of fully implemented mdns software and our "simulated" network hierarchy will be explained. we provide simulation results and explain their significance with respect to network topography.
a tool for rapid development of ws-bpel applications. we present blitec, a software tool we have developed for supporting a rapid and easy development of ws-bpel applications. blitec translates service orchestrations written in blite, a formal language inspired to but simpler than ws-bpel, into executable ws-bpel programs. we illustrate our approach by means of an example borrowed from the official specification of ws-bpel.
intensional changes: modularizing crosscutting features. feature-oriented programming (fop) targets the encapsulation of software building blocks as features which better match the specification of requirements. as a result, programmers find it easier to design and compose different variations of their systems. change-based fop (cfop) proposes to specify features as sets of first-class change objects which can add, modify or delete building blocks to or from a software system. first, we show how cfop supports the modularization of crosscutting functionality. afterwards, we expose a weakness of cfop which is a consequence from features holding extensional sets of changes. we elaborate on a solution for that weakness which is based on intensional changes: descriptions that can evaluate to an extension of changes.
variable ranges in linear constraints. we introduce an extension of linear constraints, called linear- range constraints, which allows for (meta-)reasoning about the approximation width of variables. semantics for linear- range constraints is provided in terms of parameterized linear systems. we devise procedures for checking satisfiability and for entailing the maximal width of a variable. an extension of the constraint logic programming language clp(r) is proposed by admitting linear-range constraints.
virus dna-fragment classification using taxonomic hidden markov model profiles. in most viral metagenomic studies, genetic material from a diversity of organisms is sampled from the environment and sequenced using sanger or 454 sequencing. this process typically results in dna-fragments that need to be assembled into contigs and annotated before any inferences or conclusions can be drawn from the data in hand. however, one problem subsists: both the relatively short length of the sequenced dna-fragments and the high level of diversity present in a viral community result in a large number of unassembled and unannotated dna-fragments. this problem limits our capability to better understand the viral community under study. we present the preliminary results of a new annotation method, targeting the virus sequences highly likely to be left unannotated by conventional methods. the resulting system, called anacle, gives a taxonomic annotation for virus sequences excluded by a pre-screening with blast. anacle uses an automated method relying a) on the markov clustering (mcl) of all protein sequences belonging to the same taxon and b) on constructing each taxon's genetic variations (skeletons) using hidden markov model (hmm) profiles. the taxonomic annotation consists of comparing each unannotated dna-fragment to all the skeletons, and labeling them as belonging to the taxon associated with the best similarity score. we have evaluated anacle's performance on a simulated metagenomes dataset with 100 and 700 base pairs. the results show that anacle can taxonomically annotate viruses dna-fragments with high precision and specificity. it indicates that the proposed method can provide valuable taxonomic information about dna-fragments that could be left unannotated by other methods. we also present anacle's performance on a small sargasso sea dataset.
recovering uncertain mappings through structural validation and aggregation with the moto system. we present an automated ontology matching methodology, supported by various machine learning techniques, as implemented in the system moto. the methodology is two-tiered. on the first stage it uses a meta-learner to elicit certain mappings from those predicted by single matchers induced by a specific base-learner. then, uncertain mappings are recovered passing through a validation process, followed by the aggregation of the individual predictions through linguistic quantifiers. experiments on benchmark ontologies demonstrate the effectiveness of the methodology.
dealing with application requirements and energy consumption in wireless sensor networks: a novelty detection approach for quality of query services. this paper presents an approach for adapting query processing in wireless sensor networks (wsn) based on the notions of quality of query services (qoqs) and novelty detection (nd). while the former concept captures the idea of possibly having different queries serviced in different ways by the same wsn, the second relates to a machine learning technique embedded in the wsn components that allows them to modify their query processing behavior in a dynamic fashion. this approach aims at the intelligent consumption of the limited resources available in these networks while still trying to deliver the data quality as expected by their client applications. in this context, four classes of qoqs (coqos) have been specified having in mind distinct levels of requirements in terms of accuracy and temporal behavior of the sensed data. moreover, a new nd-based algorithm, named as adaquali (after adaptive quality control for query processing in wsn), is introduced in detail as a way to control the sensor node activities through the adjustment of their rates of data collection and transmission. for validation purposes, experiments with a simulation prototype have been conducted over real data, and the results achieved so far point to gains in terms of energy consumption reduction that vary from 1.73% to 42.99% for different coqos.
resource partitioning for real-time processing on a multicore architecture. this paper presents an approach to the execution of real-time applications on a multicore architecture which is based on the partitioning of computing resources among different operating systems at core level. this means that different operating systems are assigned to different cores where they run in parallel. a working implementation based on the linux kernel and the s. ha.r.k. real-time kernel is described. in this implementation, the linux kernel is configured to use one core only, so that the s. ha.r.k. real-time kernel can be started to run independently in the remaining cores.
cloudxplor: a tool for configuration planning in clouds based on empirical data. configuration planning for modern information systems is a highly challenging task due to the implications of various factors such as the cloud paradigm, multi-bottleneck workloads, and green it efforts. nonetheless, there is currently little or no support to help decision makers find sustainable configurations that are systematically designed according to economic principles (e.g., profit maximization). this paper explicitly addresses this shortcoming and presents a novel approach to configuration planning in clouds based on empirical data. the main contribution of this paper is our unique approach to configuration planning based on an iterative and interactive data refinement process. more concretely, our methodology correlates economic goals with sound technical data to derive intuitive domain insights. we have implemented our methodology as the cloudxplor tool to provide a proof of concept and exemplify a concrete use case. cloudxplor, which can be modularly embedded in generic resource management frameworks, illustrates the benefits of empirical configuration planning. in general, this paper is a working example on how to navigate large quantities of technical data to provide a solid foundation for economical decisions.
dynamic optimization of power and performance for virtualized server clusters. in this paper we present an optimization solution for power and performance management in a platform running multiple independent applications. our approach assumes a virtualized server environment and includes an optimization model and strategy to dynamically control the cluster power consumption, while meeting the application's workload demands.
towards in-network data prediction in wireless sensor networks. researches in wireless sensor networks (wsn) have been focused on saving power in sensor nodes. an efficient strategy to achieve this goal is to reduce the amount of data sent through the network, in this work, we propose an efficient strategy that predicts data in wsns aiming at reducing the data traffic in wsns and thus maximizing the network lifetime. the proposed prediction strategy, denoted adaga-p, is based on a linear regression model, using data acquired from one or several sensors. adaga-p is executed in an in-network fashion by several sensors geographically distributed in a wsn. furthermore, in adaga-p the regression model is adjusted dynamically, if any sensor in the wsn senses an "outlier". experimental results are presented using real data. these results show that the proposed strategy reduces energy consumption in wsns.
constraint-based ln-curves. we consider the design of parametric curves from geometric constraints such as distance from lines or points and tangency to lines or circles. we solve the hermite problem with such additional geometric constraints. we use a family of curves with linearly varying normals, ln curves, over the parameter interval [0, u]. the nonlinear equations that arise can be of algebraic degree 60. we solve them using the gpu on commodity graphics cards and achieve interactive performance. the family of curves considered has the additional property that the convolution of two curves in the family is again a curve in the family, assuming common gauss maps, making the class more useful to applications. we also remark on the larger class of ln curves and how it relates to b&eacute;zier curves.
spatiotemporal sampling for trajectory streams. in this paper, we present a summarization technique adapted to trajectory streams. the spatiotemporal stream sampling (stss) algorithm is a single-pass sampling technique that takes advantage of both the spatial and temporal dimensions inherent to these streams in order to reduce their processing and storage costs.