waashk/dblp huggingface dataset:
approaches to comprehension-preserving graphical reduction of program visualizations. past research efforts on the educational effectiveness of software animations agree in the necessity of active involvement of users, i.e. students and teachers. however, one of the main obstacles is the technical difficulty to produce them. our approach seeks to generate software animations analogously to the generation of documents in office applications. the availability of static visualizations allows the user to define animations friendly; thus, he/she can select the most relevant ones to illustrate meaningfully the algorithm. the selection is facilitated if (ideally) all the static visualizations are simultaneously shown to the user. this sets a novel problem: reducing the size of visualizations while preserving their comprehensibility. in this paper we describe the problem and identify the main difficulties. we think that there is no single solution to the problem. we describe several approaches to this problem, as well as our first, qualitative findings.
planning spatial workflows to optimize grid performance. in many scientific workflows, particularly those that operate on spatially oriented data, jobs that process adjacent regions of space often reference large numbers of files in common. such workflows, when processed using workflow planning algorithms that are unaware of the application's file reference pattern, result in a huge number of redundant file transfers between grid sites and consequently perform poorly. this work presents a generalized approach to planning spatial workflow schedules for grid execution based on the spatial proximity of files and the spatial range of jobs. we evaluate our solution to this problem using the file access pattern of an astronomy application that performs co-addition of images from the sloan digital sky survey. we show that, in initial tests on grids of 5 to 25 sites, our spatial clustering approach eliminates 50% to 90% of the file transfers between grid sites relative to the next-best planning algorithms we tested that were not "spatially aware". at moderate levels of concurrent file transfer, this reduction of redundant network i/o improves the application execution time by 30% to 70%, reduces grid network and storage overhead and is broadly applicable to a wide range of spatially-oriented problems.
evolutionary image enhancement with user behaviour modeling. in this paper we present a novel method for image enhancement of gray-scale images based on the simulation of evolution. our method employs genetic algorithms to evolve the shape of the contrast curve in the image, while attempting to partially automate the subjective process of image evaluation (e.g. user behavior) by performing multiple regression on fitness values. results obtained show the robustness and efficiency of the evolutive method for image enhancement. for several images in the test set our method obtains better results than the classical histogram equalization technique. extensive statistics performed, shows that multiple regression can be effectively applied to model the user behavior.
handheld devices for cooperative educational activities. this paper presents a framework that aims to support several steps of learning activities. working either on mobile and non-mobile devices, test-it, allows users to learn ubiquitously and to proceed with their work at any time and place. it approaches both teaching and learning activities, allowing teachers and students to cooperate using common mobile devices to transfer information between each other.we describe the requirements for using such tool on mobile devices and comment some of the current approaches. the design process and the framework's components, focusing particularly on the user interface and usability issues, are addressed.we also focus on the flexibility provided by test-it, allowing users to create specific applications, according to their field or subject of expertise.
fsm-hume: programming resource-limited systems using bounded automata. hume is a novel domain-specific programming language targeting resource-bounded computations, such as real-time embedded systems or mobile code. it is based on generalised concurrent automata, controlled by transitions characterised by pattern matching on inputs and (recursive) function generation on outputs. this paper discusses trade-offs between expressibility and decidability in the design of fsm-hume, a subset of hume (or hume layer) based on generalised linear bounded automata with statically determinable time and space use. we illustrate our approach with reference to space costing of a simple real-time simulation of a line-following automous vehicle.
contentions-conscious dynamic but deterministic scheduling of computational and communication tasks. real time operating systems (rtos) for multiprocessor system-on-chip (mpsoc) are not well tackling with the scheduling of communication load between the tasks running on different processors. traditionally communications and computations are considered separately leading to a great complexity in the analysis of the system behavior. we have explicitly scheduled the inter-processor communication (ipc) on the shared medium considering all the parameters affecting its cost i.e. link contention, node contention and synchronization overhead. we have proposed a dynamic but deterministic communication model and have embedded it with the scheduling of the tasks on processors (rtos kernel services) to get the deterministic behavior of the application.
distributed context management in a mobility and adaptation enabling middleware (madam). as computing devices are getting smaller, we tend to bring them everywhere. consequently the operating conditions of the devices are constantly changing (e.g. changing user requirements, change in the system context and environment context). in order to be usable and dependable, applications and services need to self-adapt to changes in context. this work describes a context management approach for reducing the complexity of context aggregation and utilisation. the context manager is a core component in the madam (mobility and adaptation enabling middleware) project.
how to reuse exisiting interactive applications in ubiquitous computing environments? in ubiquitous computing environments, we will access various devices and appliances from a variety of mobile devices such as mobile phones, pdas and wearable devices.however, we need to reuse existing interactive applications that adopt traditional gui toolkits that assume to use mouses and keyboards, and these applications should be operated from the mobile interaction devices.our approach enables us to use existing gui-based interactive applications although a variety of interaction devices can be adopted to control the applications. therefore, the approach allows us to use traditional gui toolkits to build ubiquitous computing applications that choose appropriate interaction devices dynamically. the paper describes the design and implementation of our middleware to realize the approach. we also present some examples to show the effectiveness of our approach.
fuzzy approach to outsourcing of information technology services. the paper proposes a new approach for tackling the uncertainty and imprecision in outsourcing and evaluating information technology services. identifying suitable outsourcing options, evaluating them and choosing the best one are regarded as multiple decision criteria decision making problems under uncertainty, where the imprecise decision-maker's judgments are represented as fuzzy numbers. a fuzzy modification of the analytic hierarchy process is applied as an evaluation technique. unlike the known fuzzy prioritization techniques, the proposed method derives crisp weights from consistent and inconsistent fuzzy comparison matrices, which eliminates the need of additional aggregation and ranking procedures. a detailed numerical example, illustrating the application of our approach to outsourcing evaluation and selection is given.
handling run-time updates in distributed applications. the server side of business software systems is commonly implemented today by an ensemble of java classes distributed over several hosts. in this scenario, it is often necessary, for performance tuning or bug fixing, to update the code or change the location of some classes. since business systems must typically stay on-line 24 hours a day, changes and updates should be made without stopping system execution.this paper proposes a distributed software architecture which clearly separates the functionalities of the server-side application from its on-line adaptation capabilities. as a result, developers are freed from considering adaptation concerns, which are instead provided by separate, application-independent, transparently integrated components. the latter analyse data related to the operational conditions of the application, and, based on available statistics and expected behaviour, trigger changes on the application classes.the bytecode of classes expected to need on-line updating is modified at load time, so as to insert hooks that will support run-time changes. no tampering with class files is required. particular care has been taken to ensure the type-compatibility of classes thus manipulated.
the inheritance anomaly: ten years after. the term inheritance anomaly was coined in 1993 by matsuoka and yonezawa [15] to refer to the problems arising by the coexistence of inheritance and concurrency in concurrent object oriented languages (cools). the quirks arising by such combination have been observed since the early eighties, when the first experimental cools were designed [3]. in the nineties cools turned from research topic to widely used tools in the everyday programming practice, see e.g. the java [9] experience. this expository paper extends the survey presented in [15] to account for new and widely used cools, most notably java and c# [19]. specifically, we illustrate some innovative approaches to cool design relying on the aspect oriented programming paradigm [13] that aim at better, more powerful abstraction for concurrent oop, and provide means to fight the inheritance anomaly.
user adaptive content delivery mechanism on the world wide web. to reduce the user-perceived latency in web content delivery, many techniques have been proposed. one is a transmission time control mechanism that automatically adjusts the quality of inline objects, such as images on a web page, according to the client network bandwidth. another is a transmission order control mechanism that can transmit inline objects in a specified order preferred by users. in this paper, we describe the development of a user adaptive content delivery mechanism that integrates transmission time control and transmission order control. based on the user's preference profile, it dynamically prioritizes inline objects in terms of content quality and delivery order, and provides user with adapted inline objects. a prototype system has been implemented in java, and gives an example of adapted content delivery.
alternative source coding model for mobile text communication. this paper presents a new source coding model for the efficient transmission of mobile text messages. unlike conventional text messages, which are sent in the form of character sequences, the proposed method uses key-code sequences that reflect the user's typing history for authoring the message. the key-code representation can be as efficient as 4 bits per key-code by utilizing existing dictionary-based text entry systems and mobile phones equipped with the standard reduced keyboard. experiments that use an optimal dictionary show that the key-code representation can save 2.95 bits per character compared to the conventional ascii representation. further, computation of the entropy shows that the optimal code-word length of the ascii representation in kth-order approximation, where probability distributions of blocks of k symbols are given, cannot be comparable to that of the key-code in (k-l)-order approximation.
synchronization analysis for decentralizing composite web services. web services are emerging as the standard mechanism for making information and software available programmatically via the internet, and as building blocks for applications. a composite web service may be built using multiple component web services. once its specification has been developed, the composite service may be orchestrated either using a centralized engine or in a decentralized fashion. decentralized orchestration improves scalability and concurrency. dynamic binding coupled with decentralized orchestration adds high availability and fault tolerance to the system. in this paper, we categorize different forms of concurrency and provide an algorithm to identify these forms in a composite service specification. we also consider the impact of dynamic binding and faults on synchronization constructs.
pointer analysis of multithreaded java programs. this paper presents a context-sensitive and path-sensitive, intra-thread and inter-thread solution to combined pointer analysis, escape analysis and data dependence analysis of multithreaded java programs which uses a sparse representation. we build and maintain a complete static single assignment (ssa) form even for fields variables. we show how to compute inter-thread dependencies for multithreaded programs with structured fork-join constructs, open-ended threads, recursively generated threads, monitors, and wait-notify synchronization. we have implemented our algorithm in a slicer for java programs. our experimental results show that a sparse representation improves the analysis time and strong updates on field variables improves the precision.
a framework for collaborative control of applications. highly interactive applications are increasingly being used in decision support systems. highly interactive applications are increasingly being used in decision support systems. frequently these applications are run in collaborative environments in which interdisciplinary working groups participate to define scenarios, run simulations, and visualize the results. it is most expeditious if participants are able to simply "grab hold" of an application running in the shared environment to make some sort of basic adjustment, query, etc. without the need to move around the room to get to the keyboard and mouse. in this paper we describe the "remote application controller" (rac), a java-swing application running on a personal device that can launch, communicate with, and control a shared set of interactive applications running on various machines in a network. jini is used for application discovery and to establish basic communication between the rac and an application. to participate fully in the shared environment, an application is written using the remote user interface (rui) toolkit, a simple c++-based toolkit that creates standard gui controls on the host device, if appropriate, as well as a platform-independent xml-based description that is exported to requesting personal input devices. we describe the overall architecture of the system, the specifics of the rui toolkit, and then illustrate the system by describing some sample applications.
a service-oriented customizable digital library. web services represent the new methodological and technological challenge in the area of web-based systems, but they raise problems of discovery, interoperability, security. in this paper we address the problem of web service interoperability, proposing a digital library system that allows for the integration of services offered by different providers. farthermore, the services provided to the digital library user community can be customized according to user profiles. the proposed system represents a prototype example of a service-oriented integration architecture dynamically evolving as new services become available to be integrated.
communication delay in hypercubic networks with lrd traffic. realistic network traffic can exhibit the long-range dependent (lrd) feature which is characterised by a hyperbolically decaying correlation function and has strong effects on the performance of communication networks. as the convergence of simulations to a steady state under lrd workloads is often very slow, analytical models become cost-effective and versatile tools that can help designers to investigate system performance. this paper designs an analytical performance model for computing communication delay in adaptively routed hypercubic networks in the presence of lrd traffic. the model is derived in the context of pipelined circuit switching. the tractability and reasonable accuracy of the analytical model make it a practical and cost-effective evaluation tool to study the performance behaviour of hypercubic networks under lrd traffic.
color-based image retrieval using binary signatures. we propose two variations of a new image abstraction technique based on signature bit-strings as well as an appropriate similarity metric for color-based image retrieval. performance evaluation on a heterogeneous database of 20,000 images demonstrated that the proposed technique outperforms well-known approaches while still saving substantial amount of storage space, making it possible to store/search an image database of reasonable size using a few megabytes of main memory (e.g., 4 mbytes for 100,000 images).
performance prediction of wormhole switching in hypercubes with bursty traffic pattern. wormhole switching has been extensively deployed in the current-generation of high-end parallel systems. the performance of wormhole switching in hypercubes has been primarily investigated under the assumption that traffic load follows a poisson arrival process. however, many studies have shown that traffic in parallel computation environments can exhibit a high degree of burstiness and the poisson arrival process is unable to model the behaviour of bursty traffic. this paper proposes a new analytical model for wormhole-switched hypercubes under bursty traffic. simulation experiments demonstrate that the proposed model exhibits a good degree of accuracy under various operating conditions.
verification of a scheduler in b through a timed automata specification. this paper proposes a methodology for specifying and verifying schedulers using the b method. it is based on the refinement mechanism. the specification must manage time through clocks, whereas the natural modeling of schedulers exploits only stopwatches.
a relatedness-based data-driven approach to determination of interestingness of association rules. the presence of unrelated or weakly related item-pairs can help in identifying interesting association rules (ars) in a market basket. we introduce three measures for capturing the extent of mutual interaction, substitutive and complementary relationships between two items. item-relatedness, a composite of these relationships, can help to rank interestingness of an ar. the approach presented, is intuitive and can complement and enhance classical objective measures of interestingness.
efficient evaluation of relevance feedback for multidimensional all-pairs retrieval. new retrieval applications support flexible comparison for all-pairs best match operations based on a notion of similarity or distance. the distance between items is determined by some arbitrary distance function. users that pose queries may change their definition of the distance metric as they progress. the distance metric change may be explicit or implicit in an application (e.g., using relevance feedback). recomputing from scratch the results with the new distance metric is wasteful. in this paper, we present an efficient approach to recomputing the all-pairs best match (join) operation using the new distance metric by re-using the work already carried out for the old distance metric. our approach reduces significantly the work required to compute the new result, as compared to a naive re-evaluation.
looking for monotonicity properties of a similarity constraint on sequences. constraint-based mining techniques on sequence databases have been studied extensively the last few years and efficient algorithms enable to compute complete collections of patterns (e.g., sequences) which satisfy conjunctions of monotonic and/or anti-monotonic constraints. studying new applications of these techniques, we believe that a primitive constraint which enforces enough similarity w.r.t a given reference sequence would be extremely useful and should benefit from such a recent algorithmic breakthrough. a non trivial similarity constraint is however neither monotonic nor anti-monotonic. therefore, we have studied its definition as a conjunction of two constraints which satisfy the desired monotonicity properties: a pattern is called similar to a reference pattern x when its longest common subsequence with x (lcs) is large enough (i.e., a monotonic part) and when the number of deletions such that it becomes the lcs is small enough (i.e., an anti-monotonic part). we provide an experimental validation which confirms the added value of this approach on a biological database. classical issues like scalability and pruning efficiency are discussed.
using object-level run-time metrics to study coupling between objects. in this paper we present an investigation into the run-time behaviour of objects in java programs, using specially adapted coupling metrics. we identify objects from the same class that exhibit non-uniform coupling behaviour when measured dynamically.we define a number of object level run-time metrics, based on the static chidamber and kemerer coupling between objects (cbo) measure. these new metrics seek to quantify coupling at different layers of granularity, that is at class-class and object-class level. we outline our method of collecting such metrics and present a study of the programs from the jolden benchmark suite as an example of their use.a number of statistical techniques, principally agglomerative hierarchical clustering analysis, are used to facilitate the identification of such objects.
an architecture for supporting vicarious learning in a distributed environment. existing software systems designed to support learning do not adequately provide for vicarious learning in a cross-institutional collaborative environment. we have developed an architecture based on role-based access control, which provides the necessary security, robustness, flexibility, and explicit formulation of policy. such an architecture is general enough to be used in a variety of educational institutions and settings, yet flexible enough to allow a wide range of policies within a single system.
design and development of a multiversion olap application. this paper proposes a temporal version mapping concept and a sql query rewriting technique to support the olap query analysis in multidimensional database (mdb) systems modeled on multiversion schema. based on our proposed model, an integration solution of mdb schema change and multiversion olap query analysis performed over the changed database schema are taken into account. in addition, we present the system design and implementation of our prototype system to demonstrate our research idea.