waashk/dblp huggingface dataset:
using semi-lagrangian formulations with automatic code generation for environmental modeling. an import issue for numerical weather prediction modes (nwp) is the time it takes to produce a valid forecast. one factor, which greatly influences this simulation time is the size of the time step. however, time step size is often limited by the numerical stability of the used advection schemes. available schemes include semiimplicit eulerian and semi-lagrangian schemes. in principal, semi-lagrangian formulations result in irregular communications on parallel architectures. in this paper we describe automatic code generation for a semi-implicit scheme with a semi-lagrangian formulation. we describe how code can be generated from a mathematical specification of the advection model, the embedding of the formulations in the ctadel code generation tool and we show the parallelization of the code. finally, we show results from preliminary experiments we have conducted with the generated code and the reference code from a production nwp on a number of different architectures.
a method for the dynamic generation of virtual versions of evolving documents. document evolution is usually performed by creating a new document which explicitly details changes to specific paragraphs inside other document content. obtaining (virtual) document versions corresponding to its state at a specific date is left to document users, who manually extract from library collections, and compose, the pieces of text needed to obtain the desired version. but this can be a very tedious and difficult task when changes are numerous. we propose a solution to dynamically generate virtual document versions on user demand, respecting the library documents integrity. references to other documents and modification relationships can be automatically detected and are modelled as typed links -modelled with xlink- in a relationship graph. in this paper, we focus on the version generation process, consisting in a dynamic document composition based on a graph traversal. this solution has already shown its adequacy with a legislative digital library.
estimating manifold dimension by inversion error. video and image datasets can often be described by a small number of parameters, even though each image usually consists of hundreds or thousands of pixels. this observation is often exploited in computer vision and pattern recognition by the application of dimensionality reduction techniques. in particular, there has been recent interest in the application of a class of nonlinear dimensionality reduction algorithms which assume that an image dataset has been sampled from a manifold.from this assumption, it follows that estimating the dimension of the manifold is the first step in analyzing an image dataset. typically, this estimate is obtained either by using a priori knowledge, or by applying one of the various statistical and geometrical methods available. once an estimate is obtained, it is used as a parameter for the nonlinear dimensionality reduction algorithm.in this paper, we consider reversing this approach. instead of estimating the dimension of the manifold in order to obtain a low dimensional representation, we consider producing low dimensional representations in order to estimate of the dimensionality of the manifold. by varying the dimensionality parameter, we obtain different low dimensional representations of the original dataset. the dimension of the best representation should then correspond to the actual dimension of the manifold.in order to determine the best representation, we propose a metric based on inversion. in particular, we propose that a good representation should be invertible, in that we should be able to reverse the reduction algorithm's transformation to obtain the original dataset. by coupling this metric with any reduction algorithm, we can estimate the dimensionality of an image manifold. we apply our method in the context of locally linear embedding (lle) and isomap to six frequently used examples and two image datasets.
browsing image databases with galois' lattices. we divide image querying paradigms into three categories: formal querying, interactive search, and browsing. the first two paradigms have been largely investigated in the literature, whereas the last one has not been as much studied. we propose a browsing technique based on concept lattices. the result is a kind of hypertext of images that mixes classification and visualisation issues in a high-dimensionnality space.
identification of parameters and restoration of motion blurred images. this paper proposes a technique for restoring the motion blurred images. restoration of blurred images is very important problem in tracking and identification of criminals, where image of a human face or number plate of a running vehicle taken in hit and run situation gets blurred due to relative motion between the imaging system and object/face. for restoration of motion blurred images, knowledge of the point spread function (psf) is very important. the motion blur psf is characterized by two parameters, namely blur direction and blur length. this paper also presents a method to identify the parameters of the psf from the blurred and noisy images using the log spectrum of the blurred images. these parameters are used to restore the images. the experimental results demonstrate that the image can successfully be restored from the image with substantial amount of natural and artificial blur.
language identification in web pages. this paper discusses the problem of automatically identifying the language of a given web document. previous experiments in language guessing focused on analyzing "coherent" text sentences, whereas this work was validated on texts from the web, often presenting harder problems. our language "guessing" software uses a well-known n-gram based algorithm, complemented with heuristics and a new similarity measure. both fast and robust, the software has been in use for the past two years, as part of a crawler for a search engine. experiments show that it achieves very high accuracy in discriminating different languages on web pages.
morphogenetic constraint-satisfaction based approach for organizational engineering. organizations are modeled using several approaches namely behavioral-science approach, design-science approach [march and smith 1995], classification approach [zachman 1993], etc. can all these different approaches be consistently reconciled? can this reconciliation be systemic, based on principles that support analyses of organizations? we present a solution to these questions through a morphogenetic constraint-satisfaction based approach.in our view, the hallmark of this approach is that it systemically unifies the functional, cross-functional and behavioral views of organizations.
stability vs. optimality tradeoff in game theoretic mechanisms for qos provision. we study noncooperative games whose players are selfish, distributed users of a network and the game's objective is to optimize quality of service (qos). our classes of games are based on generally accepted realistic microeconomic market models of qos provision, and unlike most other games that have been recently studied in this context, stability is not guaranteed for our class of games. stability here refers to whether the game reaches a nash equilibrium. optimality is a measure of how close a nash equilibrium is to optimizing a given objective function defined on game configuration. the overall goal is to determine a minimal set of static game rules based on pricing that result in stable and optimal qos provision. the combination of stability and optimality opens an interesting direction of investigation. we give a new and general technique to establish stability and demonstrate a close trade-off between stability and optimality for our game classes. additionally, these results directly give a simple, computationally efficient, self-organizing mechamism for stable and optimal qos provision in natural cases.
a multi-agent system for e-barter including transaction and shipping costs. an e-barter multi-agent system consists of a set of agents exchanging goods. in contrast to e-commerce systems, transactions do not necessarily involve the exchange of money. agents are equipped with a utility function to simulate the preferences of the customers that they are representing. they are grouped into local markets, according to the localities of the corresponding customers. once these markets are saturated (i.e. no more exchanges can be performed) new agents, representing those local markets, are generated and combined into new markets. by reiteratively applying this process we finally get a global market.even though a formalism to define e-barter architectures has been already introduced, that framework had a strong drawback: neither transaction nor shipping costs were considered. in this paper we extend that framework to deal with systems where fees have to be paid to the owner of the system. these fees depend on the goods involved in the corresponding exchanges. in addition, shipping costs have also to be paid. these modifications complicate the setting because the utility that customers receive after exchanging goods is not directly given by the original utility function. that is, the returned utility after an exchange is performed has to be computed as a combination of the former utility and the derived costs. in particular, some exchanges may be disallowed because those costs exceed the increase of utility returned by the new basket of goods.
health care information systems. health care information systems (hcis) have provided the opportunity and tools to estimate, interpret, observe and better understand newest health care problems. in this way, information and communication technologies permit researchers to sustain greater benefits such as decision support systems, protecting sensitive patient data, integration of complex health care data, 3d visualization of anatomical structures, etc.
encouraging knowledge exchange in discussion forums by market-oriented mechanisms. discussion forums are one of the simplest, while successful, internet-based systems to promote the spread of knowledge. unfortunately, they sometimes lack appropriate incentives to encourage users participation. in this paper we discuss a simple market-oriented mechanism to promote the knowledge exchange activity in discussion forums. the proposed solution departs from other market-oriented approaches since the scarce resource we deal with, the effort to create information, has important peculiarities which must be taken into account. in addition to the basic framework, we have also developed a method to dynamically improve the performance of the system. this method uses statistics about users behavior in order to minimize the reponse time in which questions are satisfactorily answered.
optimizing subset queries: a step towards sql-based inductive databases for itemsets. storing sets and querying them (e.g., subset queries that provide all supersets of a given set) is known to be difficult within relational databases. we consider that being able to query efficiently both transactional data and materialized collections of sets by means of standard query language is an important step towards practical inductive databases. indeed, data mining query languages like mine rule extract collections of association rules whose components are sets into relational tables. post-processing phases often use extensively subset queries and cannot be efficiently processed by sql servers. in this paper, we propose a new way to handle sets from relational databases. it is based on a data structure that partially encodes the inclusion relationship between sets. it is an extension of the hash group bitmap key proposed by morzy et al. [8]. our experiments show an interesting improvement for these useful subset queries.
performance evaluation for text processing of noisy inputs. we investigate the problem of evaluating the performance of text processing algorithms on inputs that contain errors as a result of optical character recognition. a new hierarchical paradigm is proposed based on approximate string matching, allowing each stage in the processing pipeline to be tested, the error effects analyzed, and possible solutions suggested.
experiments on using fuzzy quantified sentences in adhoc retrieval. in this work we implement and evaluate a fuzzy approach to information retrieval whose query language incorporates fuzzy quantifiers. fuzzy quantified sentences are suitable for imposing additional restrictions in the retrieval process which are not typical in classic information retrieval. moreover, fuzzy quantifiers can be implemented in different relaxed ways leading to a wide range of methods for combining query terms. the large-scale evaluation conducted here shows clearly the practical benefits obtained in terms of retrieval performance. these empirical results strengthen previous theoretical works that already advanced the adequacy of fuzzy quantifiers for modeling information needs.
query reformulation for an xml-based data integration system. the main objective of a mediator-based data integration system is to provide a unified view of several distributed and heterogeneous data sources. this view, called mediation schema, corresponds to a set of elements computed from data available on the local data sources. one of the biggest challenges facing a data integration system consists in answering a user query submitted in terms of the mediation schema given that the data is at the sources. this problem consists mainly in reformulating the query in terms of the source schemas and in integrating the corresponding answers. in this paper we address the problem of query reformulation in the context of an xml-based data integration system. our solution is based on algorithms that generate a set of source queries considering a given user query and a set of mappings between the mediation schema and the data source schemas.
evolutionary segmentation of yeast genome. segmentation algorithms differ from clustering algorithms with regard to how to deal with the physical location of genes throughout the sequence. therefore, segments have to keep the original positions of consecutive genes, which is not a constraint for clustering algorithms. it has been proven that exist functional relations among neighbour-genes, so the localization of the boundaries between these functionally similar groups of genes has turned out an important challenge. in this paper, we present an evolutionary algorithm to segment the yeast genome.
devopt: a distributed architecture supporting heuristic and metaheuristic optimization methods. this paper presents a distributed software architecture that allows the cooperation among research institutions in the field of combinatorial optimization --- devopt: distributed evolutionary optimization centers. it has as main aims to share existing algorithms for optimization problems, to allow the easy testing of these algorithms with existing instances, to provide fast and better ways to design new algorithms, and to share computational power among the cooperating institutions. this is achieved respecting the autonomy and heterogeneity of the cooperating institutions. the distributed architecture is discussed here and also a case study of a parallel memetic algorithm to solve the asymmetric traveling salesman problem (atsp) running on this environment is analyzed.
a precise schedulability test algorithm for scheduling periodic tasks in real-time systems. rate monotonic analysis (rma) has been shown to be effective in the schedulability analysis of various types of system. this paper focuses on reducing the run time of each rma-tested system. based on a new concept of tasks, denoted by the lift-utilization tasks, we propose a novel method to reduce the number of iterative calculations in the derivation of the worst-case response time of each task in its rma test. the capability of the proposed method was evaluated and compared to related work, which revealed that our method produced savings of 26-33% in the number of rma iterations.
cooperative active contour model and its application to remote sensing. we propose a decentralized cooperative processing applied to the active contour model "snake", which applies multiple snakes to a single region, to improve its detection accuracy. we verify the effectiveness of our proposal in the cases of multi-snakes with different parameter sets and multi-snakes applied to rgb-decomposed images. we then apply it to multi-spectral remote sensing, and show that multi-snakes detected the boundary with enough accuracy.
pollock: automatic generation of virtual web services from web sites. as the usage of web services proliferates dramatically, new tools to help quickly generate web services are needed. in this paper, we propose a methodology that helps to automatically generate web services from the form-based query interfaces of a web site. since the majority of web data are rather "hidden" behind such a form interface, we believe turning such a human-oriented query interface into machine-oriented web services is an important problem. toward this goal, we adopt the wrapper technology successfully developed and deployed in database community, and demonstrate how to generate web services components (e.g., wsdl, uddi, soap) automatically. we present the overall architecture of our developed prototype and a few showcases based on real web sites.
fgka: a fast genetic k-means clustering algorithm. in this paper, we propose a new clustering algorithm called fast genetic k-means algorithm (fgka). fgka is inspired by the genetic k-means algorithm (gka) proposed by krishna and murty in 1999 but features several improvements over gka. our experiments indicate that, while k-means algorithm might converge to a local optimum, both fgka and gka always converge to the global optimum eventually but fgka runs much faster than gka.
feature-based distributed object search using signatures in peer-to-peer environments. peer-to-peer (p2p) technology has attracted a lot of attention in recent years. efficient object search is an important research issue in p2p environments, especially in those without centralized global indexes. although a number of hash-based basic object search schemes are known to alleviate the problem, they cannot provide flexible feature-based object searches. this paper proposes a novel object search method using distributed frame sliced signatures, and looks at an appropriate choice of parameters to adapt the configuration to the object search and registration workload. it shows object search and registration schemes that take into account the number of messages and response times. effectiveness of these schemes is evaluated through simulation experiments.
implementation of fast rsa key generation on smart cards. although smart cards are becoming used in an increasing number of applications, there is small literature of the implementation issues for smart cards. this paper describes the issues and considerations that need to be taken into account when implementing the key generation step of a cryptographic algorithm widely used nowadays, rsa.smart cards are used in many applications that require a tamper resistant area. therefore, smart cards that use cryptography have to provide encryption, decryption, as well as key generation inside its security perimeter. rsa key generation is a concern for on-card implementation of rsa cryptosystem, as it usually takes a long time. in this paper, two simple but efficient key generation algorithms are evaluated, in addition to a simple but not very efficient algorithm. the paper discusses in detail how to build fast implementations for the three algorithms presented, using smart cards with crypto-coprocessor.
security considerations for active messages. messages are generally regarded as passive since they merely act as a conveyance for information. an active message triggers processing activities at each of its recipients. a discussion is provided on the different classes of processing activities that can occur for active messages. a mechanism for ensuring the security of an active message and its associated processing operations is also outlined.
wssecspaces: a secure data-driven coordination service for web services applications. web services standards and protocols (wsdl, uddi, soap, etc.) are the basis of a novel technology supporting web based applications. web services are components offering ports at which service invocations can be sent using xml-based protocols. the tools currently proposed for specifying and programming the interdependencies among web services (bpel, biztalk, etc.) support the description of the flow of service invocation needed among collaborating web services in order to complete a specific task. in this paper we discuss the design and the implementation of a higher-level interaction model for web services that follows the tradition of data-driven coordination: web services do not coordinate via direct service invocation, but their interaction is mediated by a coordination space where shared data are stored and retrieved. moreover, our proposal extends the traditional data-driven coordination model with a more sophisticated pattern matching mechanism that supports a controlled access to the shared data.
enforcing path uniqueness in internet routing. often an ip network administrator will desire to provision unique paths for traffic demands while avoiding network congestion. under destination based shortest path protocols this must be achieved indirectly via careful selection of link metrics. we demonstrate that current approaches to metric optimisation cannot reliably produce such unique-path routings. we present two methods of enhancing the capability of local search algorithms for optimising these metrics to produce unique-path solutions: a more intelligent move operator and adaptive penalisation schemes. these approaches are evaluated on four real-world ip backbones, and are shown to reliably produce unique-path routings. by appropriate choice of parameters, unique-path solutions may be found either quicker or of better quality than those produced by fixed penalty schemes.
learning system to introduce gis to civil engineers. a web-based e-learning system to facilitate the integration of geographical information systems (gis) into the civil engineering curriculum is described in this paper. the principal learning goal is to encourage students to apply and integrate foundational knowledge in the solution of "real world" comprehensive civil engineering problems. sharable content objects, designed in accordance with the adl/scorm standards, contain basic knowledge components in the form of web-viewable hypermedia coupled with an assessable learning outcome thereby forming a learning object.
medic: mobile diagnosis for improved care. hospitals everywhere are taking advantage of the flexibility and speed of wireless computing to improve the quality and reduce the cost of healthcare. caregivers equipped with mobile computers now have levels of interaction at the bedside not possible with traditional paper charts, and they can access accurate real-time information (patient records, medication and medical imagery) at the point-of-care to make decisions, diagnose and treat patients with greater speed and efficiency. greater and more immediate information access, however, is giving rise to challenges in how to effectively select and present the most relevant aspects for given patient care tasks, as well as how to take advantage of the collaborative opportunities afforded by medical community connection. we propose a system that enables doctors to efficiently query, analyse and annotate patient information, in particular medical imagery, using current mobile technologies. the system allows entire profiles with known diagnoses to be retrieved and can be used to compare diagnosis and treatments for patients with similar symptoms or care records. the application can be employed by caregivers either working in the hospital setting or working remotely and off-site as well as a useful tool to facilitate education and training of medical staff.