ppxscal/embedding_network huggingface dataset:
An efficient format for nearly constant-time access to arbitrary time intervals in large trace files
Authors: Anthony Chan, William Gropp, Ewing Lusk
Venue: Scientific Programming (2008)

A powerful method to aid in understanding the performance of parallel applications uses log or trace files containing time-stamped events and states (pairs of events). These trace files can be very large, often hundreds or even thousands of megabytes. Because of the cost of accessing and displaying such files, other methods are often used that reduce the size of the tracefiles at the cost of sacrificing detail or other information. This paper describes a hierarchical trace file format that provides for display of an arbitrary time window in a time independent of the total size of the file and roughly proportional to the number of events within the time window. This format eliminates the need to sacrifice data to achieve a smaller trace file size (since storage is inexpensive, it is necessary only to make efficient use of bandwidth to that storage). The format can be used to organize a trace file or to create a separate file of annotations that may be used with conventional trace files. We present an analysis of the time to access all of the events relevant to an interval of time and we describe experiments demonstrating the performance of this file format.
Solving a Telecommunications Feature Subscription Configuration Problem
Authors: David Lesaint, Deepak Mehta, Barry O'Sullivan, Luis Quesada, Nic Wilson
Venue: Proceedings of the 14th international conference on Principles and Practice of Constraint Programming (2008)

Call control features (e.g., call-divert, voice-mail) are primitive options to which users can subscribe off-line to personalise their service. The configuration of a feature subscription involves choosing and sequencing features from a catalogue and is subject to constraints that prevent undesirable feature interactions at run-time. When the subscription requested by a user is inconsistent, one problem is to find an optimal relaxation. In this paper, we show that this problem is NP-hard and we present a constraint programming formulation using the variable weighted constraint satisfaction problem framework. We also present simple formulations using partial weighted maximum satisfiability and integer linear programming. We experimentally compare our formulations of the different approaches; the results suggest that our constraint programming approach is the best of the three overall.
Showing the evolution of the city of Trento across centuries
Authors: Raffaele De Amicis, Gabrio Girardi, Giuseppe Conti
Venue: Proceedings of the 3rd international conference on Digital Interactive Media in Entertainment and Arts (2008)

The paper illustrates the result of an extensive project which has brought to the creation of a vast repository of information of historical interest related to the evolution across history of the town of Trento, in the Italian Alps. The project has brought to the creation of a single point of access to a large set of data such as 3D models, documents, pictures and videos related to the evolution of the town and it has made them available in an interactive form through the use of a popular Geobrowser. Users can navigate the territory across space and time and interact with the system to explore a very large set of documents and information that help them understand how the city has evolved. The resulting application has been accessed by more than two thousand people during an exposition which has lasted for a month and it has been regarded as an essential didactical tool. The work represents a relevant example of how applications originally designed to access geographical information can be adopted, with a different perspective, as effective educational media. Besides being a gateway to information available on a territorial scale the system in fact allowed the superimposition of ancient and modern urban context helping to reduce the gap between ancient and modern urban context whose evolution represents the historical identity of a city.
Identification and application of repetitive biological sequences
Authors: Tamer Kahveci
Venue:  (2007)

Biological sequences are rich in repeats. For example, more than 50% of the human genome consists of repeats and approximately one-quarter of the amino acids are in repeats. Repeats are subsequences of biased composition. They vary in size from less than a hundred bases to tens of kilobases. They are found as either tandem arrays or dispersed throughout the genome. Repeats can generate insertions, deletions, and unequal crossing-over within genomes and affect protein functions. Hence, repeats play important roles in genome evolution. Repeat identification is normally the first step of studying repeats and a critical part of sequence analysis. For protein sequences, some repeats are popularly referred as low complexity regions (LCRs). Although some computational tools have been developed to identify genomic repeats or LCRs, they all are geared towards specific situations and suffer from different problems. We develop novel methods to identify genomic repeats and LCRs, respectively. Genomic repeats and LCRs present difficulties in genome annotation and analyses. Local alignments between repeats cause many false positives to sequence similarity search. These false positives can cause misassembly of genome sequences or misidentification of repeats as gene/protein sequences. Existing sequence similarity search algorithms either ignore the existence of these repeats or completely remove them. The first strategy produces false positives. The second strategy is not desirable, since no LCR-identification tool is 100% accurate. We develop new algorithms that use LCR information wisely to improve the accuracy and efficiency of sequence search.
Simulation of incompressible flows around moving bodies using meshless finite differencing
Authors: Choon Seng Chew, Yeo Khoon Seng, Shu Chang
Venue: Journal of Computational Methods in Sciences and Engineering (2006)

A scheme using the mesh-free generalized finite differencing (GFD) on flows past moving solid bodies is proposed. The aim is to devise a method which can be applied to simulate flows past immersed moving bodies with reduced computational effort by eliminating the need to perform remeshing for every time step and the intense interpolation procedures. The generalized finite difference method (GFD) with weighted least squares approximation was used to solve the incompressible Navier Stokes equations under the arbitrary Lagrangian-Eulerian (ALE) formulation, on a stationary background set of Cartesian nodes and a cloud of nodes following each moving solid boundary to simulate flows near the solid-fluid interface. A combination of standard central-spaced finite differencing and GFD is applied to the background region and cloud region respectively as spatial discretization. The second-ordered Crank Nicolson time discretization is applied in the projection method, which computes an intermediate set of velocities and uses the pressure Poisson equation to obtain the divergence-free velocity field. Test cases were performed for workability and accuracy of the method, and satisfactory results were obtained for the driven cavity, the decaying vortex, the flow past circular cylinder and a flapping elliptic body in a square enclosed space.
Machine Learning Recognition of Otoneurological Patients by Means of the Results of Vestibulo-Ocular Signal Analysis
Authors: Martti Juhola, Heikki Aalto, Timo Hirvonen
Venue: Proceedings of the 2008 21st IEEE International Symposium on Computer-Based Medical Systems (2008)

We distinguished a group of otoneurological patients from healthy subjects on the basis of machine learning methods applied to signal analysis results calculated in our earlier research. We classified them to investigate, which methods are the most efficient to separate the two classes from each other. Decision trees and support vector machines yielded the highest average accuracies of 89.8 % and 89.4 % being 1-5 % better than others.
An agent-based model for secondary use of radio spectrum
Authors: Arnon Tonmukayakul
Venue:  (2007)

Wireless communications rely on access to radio spectrum. With a continuing proliferation of wireless applications and services, the spectrum resource becomes scarce. The measurement studies of spectrum usage, however, reveal that spectrum is being used sporadically in many geographical areas and times. In an attempt to promote efficiency of spectrum usage, the Federal Communications Commission has supported the use of market mechanism to allocate and assign radio spectrum. We focus on the secondary use of spectrum defined as a temporary access of existing licensed spectrum by a user who does not own a spectrum license. The secondary use of spectrum raises numerous technical, institutional, economic, and strategic issues that merit investigation. Central to the issues are the effects of transaction costs associated with the use of market mechanism and the uncertainties due to potential interference. The research objective is to identify the pre-conditions as to when and why the secondary use would emerge and in what form. We use transaction cost economics as the theoretical framework in this study. We propose a novel use of agent-based computational economics to model the development of the secondary use of spectrum. The agent-based model allows an integration of economic and technical considerations to the study of pre-conditions to the secondary use concept. The agent-based approach aims to observe the aggregate outcomes as a result of interactions among agents and understand the process that leads to the secondary use, which can then be used to create policy instruments in order to obtain the favorable outcomes of the spectrum management.
On LP Solvable Models for Portfolio Selection
Authors: Renata Mansini, Włodzimierz Ogryczak, M. Grazia Speranza
Venue: Informatica (2003)

The Markowitz model for single period portfolio optimization quantifies the problem by means of only two criteria: the mean, representing the expected outcome, and the risk, a scalar measure of the variability of outcomes. The classical Markowitz model uses the variance as the risk measure, thus resulting in a quadratic optimization problem. Following Sharpe's work on linear approximation to the mean-variance model, many attempts have been made to linearize the portfolio optimization problem. There were introduced several alternative risk measures which are computationally attractive as (for discrete random variables) they result in solving Linear Programming (LP) problems. The LP solvability is very important for applications to real-life financial decisions where the constructed portfolios have to meet numerous side constraints and take into account transaction costs. This paper provides a systematic overview of the LP solvable models with a wide discussion of their properties.
Ranking fuzzy numbers with an area method using radius of gyration
Authors: Yong Deng, Zhu Zhenfu, Liu Qi
Venue: Computers Mathematics with Applications (2006)

Ranking fuzzy numbers plays an very important role in linguistic decision making and some other fuzzy application systems. Many methods have been proposed to deal with ranking fuzzy numbers. Chu pointed out some shortcomings of the existing distance method and proposed to rank the fuzzy numbers with the area between the centroid point and original point. However, drawbacks are also found in the area method. For example, it cannot rank fuzzy numbers when some fuzzy numbers have the same centroid point. In this paper, we propose a modified area method to rank fuzzy numbers. The modified method can effectively rank various fuzzy numbers and their images. We also used some comparative examples to illustrate the advantage of the proposed method.
Hierarchical Shortest Pathfinding Applied to Route-Planning for Wheelchair Users
Authors: Suling Yang, Alan K. Mackworth
Venue: Proceedings of the 20th conference of the Canadian Society for Computational Studies of Intelligence on Advances in Artificial Intelligence (2007)

Pathfinding on large maps is time-consuming. Classical search algorithms such as Dijkstra's and A* algorithms may solve difficult problems in polynomial time. However, in real-world pathfinding examples where the search space increases dramatically, these algorithms are not appropriate. Hierarchical pathfinding algorithms that provide abstract plans of future routing, such as HPA* and PRA*, have been explored by previous researchers based on classical ones. Although the two hierarchical algorithms show improvement in efficiency, they only obtain near optimal solutions. In this paper, we introduce the Hierarchical Shortest Path algorithm (HSP) and a hybrid of the HSP and A* (HSPA*) algorithms, which find optimal solutions in logarithmic time for numerous examples. Our empirical study shows that HSP and HSPA* are superior to the classical algorithms on realistic examples, and our experimental results illustrate the efficiency of the two algorithms. We also demonstrate their applicability by providing an overview of our Route Planner project that applies the two algorithms proposed in this paper.
Bringing Abstract Concepts Alive. How to Base Learning Success on the Principles of Playing, Curiosity and In-Classroom Differentiation
Authors: Peter Gruber
Venue: Proceedings of the 3rd international conference on Informatics in Secondary Schools - Evolution and Perspectives: Informatics Education - Supporting Computational Thinking (2008)

This article addresses the question which goals a valuable and sustainable learning process should aim at. Meaningful learning activities, emotional commitment and meeting individual needs are identified as core principles. According to these principles, several theories that support the construction of such lesson sequences are discussed. In particular, the importance of knowledge as compared to pure information retrieving is highlighted. From this perspective, the concept of In-Classroom Differentiation is derived. Finally, a concrete example demonstrates how this concept translates from theory into practice. Thus, this article addresses both, the theoretical foundation and the practical implementation.
Cooperative/Competitive Behavior Acquisition Based on State Value Estimation of Others
Authors: Kentaro Noma, Yasutake Takahashi, Minoru Asada
Venue: RoboCup 2007: Robot Soccer World Cup XI (2008)

The existing reinforcement learning approaches have been suffering from the curse of dimension problem when they are applied to multiagent dynamic environments. One of the typical examples is a case of RoboCup competition since other agents and their behaviors easily cause state and action space explosion. This paper presents a method of hierarchical modular learning in a multiagent environment by which the learning agent can acquire cooperative behaviors with its teammates and competitive ones against its opponents. The key ideas to resolve the issue are as follows. First, a two-layer hierarchical system with multi learning modules is adopted to reduce the size of the state and action spaces. The state space of the top layer consists of the state values from the lower level, and the macro actions are used to reduce the size of the action space. Second, the state of the other to what extent it is close to its own goal is estimated by observation and used as a state value in the top layer state space to realize the cooperative/competitive behaviors. The method is applied to 4 (defence team) on 5 (offence team) game task, and the learning agent successfully acquired the teamwork plays (pass and shoot) within much shorter learning time (30 times quicker than the earlier work).
Combining Static and Dynamic Reasoning for the Discovery of Program Properties
Authors: Yannis Smaragdakis
Venue: Proceedings of the 15th international workshop on Model Checking Software (2008)

Combinations of static and dynamic analyses can be profitably employed in tasks such as program understanding, bug detection, behavior discovery, etc. In the past several years, we have explored a particular scheme for improving the quality of bug reports in a sequence of tools: JCrasher, Check 'n' Crash, and DSD-Crasher. We have additionally explored the combination of dynamic and symbolic execution for the purpose of inferring program invariants in the DySy tool. In this talk, we discuss such approaches, while distinguishing the conceptual benefits and drawbacks of each approach from the abilities and shortcomings of the current representative tools.
A Methodology for Sharing Archival Descriptive Metadata in a Distributed Environment
Authors: Nicola Ferro, Gianmaria Silvello
Venue: Proceedings of the 12th European conference on Research and Advanced Technology for Digital Libraries (2008)

This paper discusses how to exploit widely accepted solutions for interoperation, such as the pair OAI-PMH and DC metadata format, in order to deal with the peculiar features of archival description metadata and allow their sharing. We present a methodology for mapping EAD metadata into DC metadata records without losing information. The methodology exploits DLS technologies enhancing archival metadata sharing possibilities and at the same time considers archival needs; furthermore, it permits to open valuable information resources held by archives to the wider context of the cross-domain interoperation among different cultural heritage institutions.
Recognition Algorithm for Diamond-Free Graphs
Authors: Mihai Talmaciu, Elena Nechita
Venue: Informatica (2007)

In this paper we recall the notion of weakly decomposition, we recall some necessary and sufficient conditions for a graph to admit such a decomposition, we introduce the recognition algorithm for the diamond-free graphs which keeps the combinatorial structure of the graph by means of the decomposition, as well as an easy possibility to determine the clique number for the diamond-free graphs.
Image Segmentation Based on Cluster Ensemble
Authors: Zhiwen Yu, Shaohong Zhang, Hau-San Wong, Jiqi Zhang
Venue: Proceedings of the 4th international symposium on Neural Networks: Advances in Neural Networks, Part III (2007)

Image segmentation is a classical problem in the area of image processing, multimedia, medical image, and so on. Although there exist a lot of approaches to perform image segmentation, few of them study the image segmentation by the cluster ensemble approach. In this paper, we propose a new algorithm called the cluster ensemble algorithm (CEA) for image segmentation. Specifically, CEA first obtains two set of segmented regions which are partitioned by EM according to the color feature and the texture feature respectively. Then, it integrates these regions to k segmented regions based on the similarity measure and the fuzzy membership function. Finally, CEA performs the denoise algorithm on the segmented regions to remove the noise. The experiments show that CEA works well during the process of image segmentation.
Analysis of the optimal position of the control vector's switching points for the minimal-time circuit design strategy prediction
Authors: Alexander M. Zemliak, Miguel A. Torres
Venue: Proceedings of the 7th WSEAS International Conference on Microelectronics, Nanoelectronics, Optoelectronics (2008)

The generalized methodology for the electronic networks optimization system was elaborated by means of the optimal control theory approach. The problem of the electronic system design is formulated in this case as a classical problem of functional minimization of the optimal control theory. The minimal time system design algorithm was defined as a controllable dynamic process with an optimal control vector. By this methodology the aim of the system design process with minimal computer time is presented as a transition process of some dynamic system that has the minimal transition time. The optimal position of the control vector switch points was determined as a principal characteristic of the minimal-time system design algorithm. The special function that is a combination of Lyapunov function and its time derivative was proposed to predict the optimal control vector structure to construct a minimal-time system design algorithm.
A New Approach Toward a Modular Multimodal Interface for PDAs and Smartphones
Authors: Giovanni Frattini, Federico Ceccarini, Fabio Corvino, Ivano Furio, Francesco Gaudino, Pierpaolo Petriccione, Roberto Russo, Vladimiro Scotto Di Carlo, Gianluca Supino
Venue: Proceedings of the 10th international conference on Visual Information Systems: Web-Based Visual Information Search and Management (2008)

In this paper we present an innovative approach for exploiting the handheld device hardware increasing power. These results have been achieved in the framework of a larger project aimed to the definition of a platform to build mobile multimodal applications. Such project, called CHAT, has been co-funded by Italian Ministry of Research. Focusing our attention on the system client side, we will show how it is possible to use a thin client approach for building high modular client interfaces, managing asynchronous interactions originated on the server-side, eventually pushing contents using different criteria (e.g. change of the environmental context). We have studied how to build mobile multimodal clients, adopting an innovative approach based on the aggregation of what we have called "multimodal objects" that are able to exploit the benefits of both telecommunication and web protocols to manage input/output processes. Furthermore, we will report some restrictions and constraints coming from the adoption of two different environments: .NET and J2ME. We will highlight our solid experiences in this area and some prelimi-nary results of our research.
Business to employee (B2E) E-business model: a service to employees or organisational management?
Authors: Mohini Singh, Dianne Waddell, Md Mahbubur Rahim
Venue: Proceedings of the 10th WSEAS International Conference on Mathematical Methods and Computational Techniques in Electrical Engineering (2008)

This paper is a discussion of the B2E e-business model from the perspectives of employee services and organisational management. It includes literature to support B2E as employee services and organisational management with benefits to both. Intranets and portals are technologies supporting the implementation of the B2E e-business model which are also discussed. A case study is included to understand the application of the B2E model in a large organisation. Case study analysis indicates that the B2E e-business model is a service to the employees, however, these services are to support organisational efficiencies.
A Summary Structure of Data Cube Preserving Semantics
Authors: Zhibin Shi, Houkuan Huang
Venue: Proceedings of the international conference on Rough Sets and Intelligent Systems Paradigms (2007)

The semantic relations among cells in data cube are more important for efficient query and OLAP. Normally the size of a data cube is very huge and relations among cells are very complicated so the semantic data cube is difficult to be realized. Based on quotient cube, Semantic Data Cube (SDC) structure is put forward in this paper. In SDC the lattice of cells is expressed as tree-hierarchy structure and each cell in lattice is replaced with its upper bound. The SDC depicts the lattice of cells concisely and preserves all the semantic relations among cells. Applying semantics to query answering and maintaining incrementally in SDC, the time of response and the cost of updating can be reduced greatly. Algorithms of constructing SDC, answering a query and maintaining incrementally in SDC are given. The experimental results show that the SDC is effective.