http://sedici.unlp.edu.ar:80/handle/10915/384 2013-05-24T10:49:32Z 2013-05-24T10:49:32Z Tosini, Marcelo Alejandro http://sedici.unlp.edu.ar:80/handle/10915/9538 2013-05-23T18:01:14Z 2007-01-01T00:00:00Z

Revision Journal of Computer Science & Technology; vol. 7, no. 1 This thesis describes the design, implementation and evaluation of FPGA Architecture of a Digital ANN (Artificial Neural Networks) by using four components: data memory, weights memory, neuron module, and control unit. All these components have a generic orthogonal structure in order to facilitate automatic generation from specific parameters. In a particular ANN design all of its components are generated with specific size, depending on two types of parameters: A) Topological (number of inputs and number of hidden neurons) will determine the size of the memories, the neuron processing time and the microprogram size. B) Architectonic (i.e. word size in bits and circuit granularity) will determine the precision of the results and the final ANN performance.

2007-01-01T00:00:00Z This thesis describes the design, implementation and evaluation of FPGA Architecture of a Digital ANN (Artificial Neural Networks) by using four components: data memory, weights memory, neuron module, and control unit. All these components have a generic orthogonal structure in order to facilitate automatic generation from specific parameters. In a particular ANN design all of its components are generated with specific size, depending on two types of parameters: A) Topological (number of inputs and number of hidden neurons) will determine the size of the memories, the neuron processing time and the microprogram size. B) Architectonic (i.e. word size in bits and circuit granularity) will determine the precision of the results and the final ANN performance. Larrea, Martín Leonardo http://sedici.unlp.edu.ar:80/handle/10915/9537 2013-02-19T02:01:35Z 2007-01-01T00:00:00Z

Revision Journal of Computer Science & Technology; vol. 7, no. 1 The goal of this work was centered in the graph visualization. The hope is that the extra dimension would give, literally, more space, and that this would ease the problem of displaying large structures. In spite of their apparent simplicity, the displaying of graphs in 3D can also introduce new problems that can be overcome with the appropriate interactions. So, we have developed a new visualization technique for 3D graph visualization; this includes the design of a new graph layout that we called spherical layout and the set of interactions that can be applied on this representation. This technique allows representing structures to different levels of detail and also can be used as a visualization technique that allows more information to be visualized; based on the universe metaphor, the visualization technique was extended keeping all the time the consistency between the visual representation and the metaphor.

2007-01-01T00:00:00Z The goal of this work was centered in the graph visualization. The hope is that the extra dimension would give, literally, more space, and that this would ease the problem of displaying large structures. In spite of their apparent simplicity, the displaying of graphs in 3D can also introduce new problems that can be overcome with the appropriate interactions. So, we have developed a new visualization technique for 3D graph visualization; this includes the design of a new graph layout that we called spherical layout and the set of interactions that can be applied on this representation. This technique allows representing structures to different levels of detail and also can be used as a visualization technique that allows more information to be visualized; based on the universe metaphor, the visualization technique was extended keeping all the time the consistency between the visual representation and the metaphor. Salvatelli, Adrián Caropresi, José Delrieux, Claudio Izaguirre, María F. Casco, Víctor http://sedici.unlp.edu.ar:80/handle/10915/9536 2012-12-21T11:38:56Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 Segmentation in biological images is essential for the determination of biological parameters that allow the construction of models of several biological problems. This helps to establish clear relationships between those models and the parameter estimation, and for elaboration of key experiments that give support to biological theories. Segmentation is the process of qualitative or quantitative information extraction (shape, texture, physical and geometric properties, among others). These quantities are needed to compute the biological descriptors for further classification (v.g., cell counting, development stage assessment, and many others). This process is almost always supervised (i.e., human assisted), since the quality of the images that are produced with classic microscopy technologies have defects that in general disallow the application of unsupervised segmentation techniques. In this paper we investigate the use of the a local fractal dimension estimation as an image descriptor for microscopy images. This local descriptor appears to be robust enough to perform unsupervised or semisupervised segmentations, specifically in our study. We applied this technique on microscopy images of amphibian embryos' skin in which, using immunofluorescence techniques, we have labeled the cell adhesion molecule E-Cadherin. This molecule is one of the key factors of the Ca²⁺- dependent cell-cell adhesion. Segmentation of the cellular outlines was performed using a processing workflow, which can be repeatedly applied to a set of similar images, from which information is extracted for characterization and eventual quantification purposes.

2007-01-01T00:00:00Z Segmentation in biological images is essential for the determination of biological parameters that allow the construction of models of several biological problems. This helps to establish clear relationships between those models and the parameter estimation, and for elaboration of key experiments that give support to biological theories. Segmentation is the process of qualitative or quantitative information extraction (shape, texture, physical and geometric properties, among others). These quantities are needed to compute the biological descriptors for further classification (v.g., cell counting, development stage assessment, and many others). This process is almost always supervised (i.e., human assisted), since the quality of the images that are produced with classic microscopy technologies have defects that in general disallow the application of unsupervised segmentation techniques. In this paper we investigate the use of the a local fractal dimension estimation as an image descriptor for microscopy images. This local descriptor appears to be robust enough to perform unsupervised or semisupervised segmentations, specifically in our study. We applied this technique on microscopy images of amphibian embryos' skin in which, using immunofluorescence techniques, we have labeled the cell adhesion molecule E-Cadherin. This molecule is one of the key factors of the Ca²⁺- dependent cell-cell adhesion. Segmentation of the cellular outlines was performed using a processing workflow, which can be repeatedly applied to a set of similar images, from which information is extracted for characterization and eventual quantification purposes. Mendoza Alric, Cristian Herrera, Norma Edith http://sedici.unlp.edu.ar:80/handle/10915/9535 2012-05-03T13:13:39Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 The metric spaces model formalizes the similarity search concept in nontraditional databases. The goal is to build an index designed to save distance computations when answering similarity queries later. A large class of algorithms to build the index are based on partitioning the space in zones as compact as possible. Each zone stores a representative point, called center, and a few extra data that allow to discard the entire zone at query time without measuring the actual distance between the elements of the zone and the query object. The way in which the centers are selected affects the performance of the algorithm. In this paper, we introduce two new center selection techniques for compact partition based indexes. These techniques were evaluated using the Geometric Near-neighbor Access Tree (GNAT). We experimentally showed that they achieve good performance.

2007-01-01T00:00:00Z The metric spaces model formalizes the similarity search concept in nontraditional databases. The goal is to build an index designed to save distance computations when answering similarity queries later. A large class of algorithms to build the index are based on partitioning the space in zones as compact as possible. Each zone stores a representative point, called center, and a few extra data that allow to discard the entire zone at query time without measuring the actual distance between the elements of the zone and the query object. The way in which the centers are selected affects the performance of the algorithm. In this paper, we introduce two new center selection techniques for compact partition based indexes. These techniques were evaluated using the Geometric Near-neighbor Access Tree (GNAT). We experimentally showed that they achieve good performance. Rancan, Claudio Pesado, Patricia García-Martínez, Ramón http://sedici.unlp.edu.ar:80/handle/10915/9534 2012-05-03T13:13:40Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 This paper presents a proposal for an architecture that integrates knowledge discovery systems (automatic acquisition) and knowledge based systems (experts systems). This work formulates considerations over the viability of the implementation of this architecture according to the advance of the technologies involved.

2007-01-01T00:00:00Z This paper presents a proposal for an architecture that integrates knowledge discovery systems (automatic acquisition) and knowledge based systems (experts systems). This work formulates considerations over the viability of the implementation of this architecture according to the advance of the technologies involved. Delía, Lisandro Cáseres, Germán Ramón, Hugo Dionisio Thomas, Pablo Javier Bertone, Rodolfo Alfredo http://sedici.unlp.edu.ar:80/handle/10915/9533 2012-05-03T13:13:40Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 Any system interacting with a data base requires modules capable of operating data stored in it. Its development times generally vary between 50 to 60 % of the time used for the application life cycle. The present paper describes the architecture and characteristics of a Framework for the agile generation of Web Applications, called PHP4DB. Its main objectives are to drastically reduce the job time, minimize errors, and tuning, as well as respect a homogeneous interface between each module. These characteristics allow the development team to focus and make emphasis on the tasks particular to the application domain. For a better understanding of its advantages, some of the projects in which the Framework has been used are presented together with the respective analysis of the results obtained.

2007-01-01T00:00:00Z Any system interacting with a data base requires modules capable of operating data stored in it. Its development times generally vary between 50 to 60 % of the time used for the application life cycle. The present paper describes the architecture and characteristics of a Framework for the agile generation of Web Applications, called PHP4DB. Its main objectives are to drastically reduce the job time, minimize errors, and tuning, as well as respect a homogeneous interface between each module. These characteristics allow the development team to focus and make emphasis on the tasks particular to the application domain. For a better understanding of its advantages, some of the projects in which the Framework has been used are presented together with the respective analysis of the results obtained. Ferrández, Antonio Rojas, Yenory Peral, Jesús http://sedici.unlp.edu.ar:80/handle/10915/9532 2013-02-22T11:54:39Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 In this paper, a novel model for monolingual Information Retrieval in English and Spanish language is proposed. This model uses Natural Language Processing techniques (a POStagger, a Partial Parser, and an Anaphora Resolver) in order to improve the precision of traditional IR systems, by means of indexing the "entities" and the "relations" between these entities in the documents. This model is evaluated on both the Spanish and English CLEF corpora. For the English queries, there is a maximum increase of 35.11% in the average precision. For the Spanish queries, the maximum increase is 37.18%.

2007-01-01T00:00:00Z In this paper, a novel model for monolingual Information Retrieval in English and Spanish language is proposed. This model uses Natural Language Processing techniques (a POStagger, a Partial Parser, and an Anaphora Resolver) in order to improve the precision of traditional IR systems, by means of indexing the "entities" and the "relations" between these entities in the documents. This model is evaluated on both the Spanish and English CLEF corpora. For the English queries, there is a maximum increase of 35.11% in the average precision. For the Spanish queries, the maximum increase is 37.18%. Torchinsky, Matías Hanzich, Mauricio Hernández Budé, Porfidio Luque Fadón, Emilio Giné de Solà, Francesc Solsona Theás, Francesc Lérida, Josep L. http://sedici.unlp.edu.ar:80/handle/10915/9531 2013-02-19T11:13:58Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 In this work, we present an integral scheduling system for non-dedicated clusters, termed CISNE-P, which ensures the performance required by the local applications, while simultaneously allocating cluster resources to parallel jobs. Our approach solves the problem efficiently by using a social contract technique. This kind of technique is based on reserving computational resources, preserving a predetermined response time to local users. CISNE-P is a middleware which includes both a previously developed space-sharing job scheduler and a dynamic coscheduling system, a time sharing scheduling component. The experimentation performed in a Linux cluster shows that these two scheduler components are complementary and a good coordination improves global performance significantly. We also compare two different CISNE-P implementations: one developed inside the kernel, and the other entirely implemented in the user space.

2007-01-01T00:00:00Z In this work, we present an integral scheduling system for non-dedicated clusters, termed CISNE-P, which ensures the performance required by the local applications, while simultaneously allocating cluster resources to parallel jobs. Our approach solves the problem efficiently by using a social contract technique. This kind of technique is based on reserving computational resources, preserving a predetermined response time to local users. CISNE-P is a middleware which includes both a previously developed space-sharing job scheduler and a dynamic coscheduling system, a time sharing scheduling component. The experimentation performed in a Linux cluster shows that these two scheduler components are complementary and a good coordination improves global performance significantly. We also compare two different CISNE-P implementations: one developed inside the kernel, and the other entirely implemented in the user space. Romero, Diego Seijas, Leticia Ruedín, Ana M. C. http://sedici.unlp.edu.ar:80/handle/10915/9530 2012-05-03T13:13:40Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 The recognition of handwritten numerals has many important applications, such as automatic lecture of zip codes in post offices, and automatic lecture of numbers in checknotes. In this paper we present a preprocessing method for handwritten numerals recognition, based on a directional two dimensional continuous wavelet transform. The wavelet chosen is the Mexican hat. It is given a principal orientation by stretching one of its axes, and adding a rotation angle. The resulting transform has 4 parameters: scale, angle (orientation), and position (x,y) in the image. By fixing some of its parameters we obtain wavelet descriptors that form a feature vector for each digit image. We use these for the recognition of the handwritten numerals in the Concordia University data base. We input the preprocessed samples into a multilayer feed forward neural network, trained with backpropagation. Our results are promising.

2007-01-01T00:00:00Z The recognition of handwritten numerals has many important applications, such as automatic lecture of zip codes in post offices, and automatic lecture of numbers in checknotes. In this paper we present a preprocessing method for handwritten numerals recognition, based on a directional two dimensional continuous wavelet transform. The wavelet chosen is the Mexican hat. It is given a principal orientation by stretching one of its axes, and adding a rotation angle. The resulting transform has 4 parameters: scale, angle (orientation), and position (x,y) in the image. By fixing some of its parameters we obtain wavelet descriptors that form a feature vector for each digit image. We use these for the recognition of the handwritten numerals in the Concordia University data base. We input the preprocessed samples into a multilayer feed forward neural network, trained with backpropagation. Our results are promising. Escarza, Sebastián Castro, Silvia Mabel Martig, Sergio R. http://sedici.unlp.edu.ar:80/handle/10915/9529 2012-05-03T13:13:40Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no1. Interactions become essential in Visualization because they enable users to adapt the visual representation to their own needs allowing them to explore the underlying information space. By using non-conventional devices, they face a wider fan of interaction possibilities to explore their data. But, there is still not an agreed base theory to describe the processes involved in the visualization pipeline data transformation and, from the interaction viewpoint, it does not exist an interaction classification that allows presenting them under a unified perspective. The objective this work is to contribute to develop a Graph Visualization base classifying and defining the most representative interactions in the field. On this basis, it will be intended to lay the foundations to obtain a systematic development of interactive visualization tools using non-conventional devices. Then, an interaction over graphs' taxonomy is proposed, all their categories are placed in the reference model context and the most relevant aspects to design visualizations using this kind of devices, are analyzed.

2007-01-01T00:00:00Z Interactions become essential in Visualization because they enable users to adapt the visual representation to their own needs allowing them to explore the underlying information space. By using non-conventional devices, they face a wider fan of interaction possibilities to explore their data. But, there is still not an agreed base theory to describe the processes involved in the visualization pipeline data transformation and, from the interaction viewpoint, it does not exist an interaction classification that allows presenting them under a unified perspective. The objective this work is to contribute to develop a Graph Visualization base classifying and defining the most representative interactions in the field. On this basis, it will be intended to lay the foundations to obtain a systematic development of interactive visualization tools using non-conventional devices. Then, an interaction over graphs' taxonomy is proposed, all their categories are placed in the reference model context and the most relevant aspects to design visualizations using this kind of devices, are analyzed. Casalini, María Clara Estevez, Elsa Clara Janowski, Thomas http://sedici.unlp.edu.ar:80/handle/10915/9528 2013-03-04T20:02:57Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 The paper presents a formal model for a knowledge repository shared by members of a Virtual Community of Practice (VCPs), describes how the repository can be used to underpin collaborative problem solving, and how to build computer support for such processes. The repository comprises the resources used and developed by VCPs particularly through problem solving. As a case study, the paper illustrates how the problem solving process and the underlying repository can be applied in disaster prevention and handling. The repository and the process are formally described using the RAISE Specification Language.

2007-01-01T00:00:00Z The paper presents a formal model for a knowledge repository shared by members of a Virtual Community of Practice (VCPs), describes how the repository can be used to underpin collaborative problem solving, and how to build computer support for such processes. The repository comprises the resources used and developed by VCPs particularly through problem solving. As a case study, the paper illustrates how the problem solving process and the underlying repository can be applied in disaster prevention and handling. The repository and the process are formally described using the RAISE Specification Language. Molina, Silvia Leguizamón, Mario Guillermo Alba, Enrique http://sedici.unlp.edu.ar:80/handle/10915/9527 2012-05-03T13:13:41Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 The Ant Colony Optimization (ACO) metaheuristic is a bio-inspired approach for hard combinatorial optimization problems for stationary and non-stationary environments. In the ACO metaheuristic, a colony of artificial ants cooperate for finding high quality solutions in a reasonable time. An interesting example of a non-stationary combinatorial optimization problem is the Multiple Elevators Problem (MEP) which consists in finding a sequence of movements for each elevator to perform in a building so that to minimize, for instance, the users waiting average time. Events like the arrival of one new user to the elevator queue or the fault of one elevator dynamically produce changes of state in this problem. A subclass of MEP is the the so called Single Elevator Problem (SEP). In this work, we propose the design of an ACO model for the SEP that can be implemented as an Ant Colony System (ACS). Keywords: Ant Colony Optimization, Single Elevator Problem, Non-stationary Problems, Ant Colony System design.

2007-01-01T00:00:00Z The Ant Colony Optimization (ACO) metaheuristic is a bio-inspired approach for hard combinatorial optimization problems for stationary and non-stationary environments. In the ACO metaheuristic, a colony of artificial ants cooperate for finding high quality solutions in a reasonable time. An interesting example of a non-stationary combinatorial optimization problem is the Multiple Elevators Problem (MEP) which consists in finding a sequence of movements for each elevator to perform in a building so that to minimize, for instance, the users waiting average time. Events like the arrival of one new user to the elevator queue or the fault of one elevator dynamically produce changes of state in this problem. A subclass of MEP is the the so called Single Elevator Problem (SEP). In this work, we propose the design of an ACO model for the SEP that can be implemented as an Ant Colony System (ACS). Keywords: Ant Colony Optimization, Single Elevator Problem, Non-stationary Problems, Ant Colony System design. De Giusti, Laura Cristina Chichizola, Franco Naiouf, Marcelo Ripoll, Ana De Giusti, Armando Eduardo http://sedici.unlp.edu.ar:80/handle/10915/9526 2012-05-03T13:13:41Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 This paper discusses automatic mapping methods for concurrent tasks to processors applying graph analysis for the relation among tasks, in which processing and communicating times are incorporated. Starting by an analysis in which processors are homogeneous and data transmission times do not depend on the processors that are communicating (a typical case in homogeneous clusters), we progress to extend the model to heterogeneous processors having the possibility of different communication levels, applicable to a multicluster. Some results obtained with the model and future work lines are presented, particularly, the possibility of obtaining the required optimal number of processors, keeping a constant efficiency level.

2007-01-01T00:00:00Z This paper discusses automatic mapping methods for concurrent tasks to processors applying graph analysis for the relation among tasks, in which processing and communicating times are incorporated. Starting by an analysis in which processors are homogeneous and data transmission times do not depend on the processors that are communicating (a typical case in homogeneous clusters), we progress to extend the model to heterogeneous processors having the possibility of different communication levels, applicable to a multicluster. Some results obtained with the model and future work lines are presented, particularly, the possibility of obtaining the required optimal number of processors, keeping a constant efficiency level. Cristina, Federico Dapoto, Sebastián H. Russo, Claudia Cecilia http://sedici.unlp.edu.ar:80/handle/10915/9525 2012-05-08T22:00:33Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 The present paper poses a new method for computing the rotation of a ball in sport training situations, when the ball is approaching the goal line. The proposed method significantly reduces the hardware requirements associated to the capture, as well as the computational complexity necessary to obtain the results. The system's objective is to improve the player's technique and training methodology, and it is treated within the scope of the Institute's research line on signal and image processing areas. Experimental results will be presented using digitally generated images.

2007-01-01T00:00:00Z The present paper poses a new method for computing the rotation of a ball in sport training situations, when the ball is approaching the goal line. The proposed method significantly reduces the hardware requirements associated to the capture, as well as the computational complexity necessary to obtain the results. The system's objective is to improve the player's technique and training methodology, and it is treated within the scope of the Institute's research line on signal and image processing areas. Experimental results will be presented using digitally generated images. Costa, Genaro Morajko, Anna Margalef, Tomás Luque Fadón, Emilio http://sedici.unlp.edu.ar:80/handle/10915/9524 2012-05-03T13:13:41Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 The computational resources need by the scientific community to solve problems is beyond the current available infrastructure. Performance requirements are needed due constant research progress, new problems studies or detail increase of the current ones. Users create new wide distributed systems such as computational Grids to achieve desired performance goals. Grid systems are generally built on top of available computational resources as cluster, parallel machines or storage devices distributed within different organizations and those resources are interconnected by a network. Application tuning on Grid environment is a hard task due system characteristics like multi-cluster job distribution among different local schedulers and dynamic network bandwidth behavior. We had a Monitoring, Analysis and Tuning Environment (MATE) that allows dynamic performance tuning applications within a cluster. Due to the many software layers present on the grid, similar job submission may execute on different places. To tune application jobs, our tool needs to locate and follow the jobs execution within the system. We call this a process tracking problem. This paper presents MATE integration to the Grid and the two process tracking approaches implemented in order to solve the process tracking problem within Grid systems.

2007-01-01T00:00:00Z The computational resources need by the scientific community to solve problems is beyond the current available infrastructure. Performance requirements are needed due constant research progress, new problems studies or detail increase of the current ones. Users create new wide distributed systems such as computational Grids to achieve desired performance goals. Grid systems are generally built on top of available computational resources as cluster, parallel machines or storage devices distributed within different organizations and those resources are interconnected by a network. Application tuning on Grid environment is a hard task due system characteristics like multi-cluster job distribution among different local schedulers and dynamic network bandwidth behavior. We had a Monitoring, Analysis and Tuning Environment (MATE) that allows dynamic performance tuning applications within a cluster. Due to the many software layers present on the grid, similar job submission may execute on different places. To tune application jobs, our tool needs to locate and follow the jobs execution within the system. We call this a process tracking problem. This paper presents MATE integration to the Grid and the two process tracking approaches implemented in order to solve the process tracking problem within Grid systems. Roger, Sandra Ferrández, Sergio López Moreno, Pilar Peral, Jesús http://sedici.unlp.edu.ar:80/handle/10915/9523 2013-03-11T21:08:41Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 This work describes an inference mechanism applied to AliQAn Question Answering System for Spanish in open domain. AliQAn is based fundamentally on the use of syntactic patterns to identify the possible answers. An inference mechanism is applied to the questions set of economic type. In this way, our system improves the accuracy of this question type from 33% to 57%.

2007-01-01T00:00:00Z This work describes an inference mechanism applied to AliQAn Question Answering System for Spanish in open domain. AliQAn is based fundamentally on the use of syntactic patterns to identify the possible answers. An inference mechanism is applied to the questions set of economic type. In this way, our system improves the accuracy of this question type from 33% to 57%. Tissera, Pablo Printista, Alicia Marcela Errecalde, Marcelo Luis http://sedici.unlp.edu.ar:80/handle/10915/9522 2012-05-03T13:13:42Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 Computer simulations using Cellular Automata (CA) have been applied with considerable success in diferent scientific areas, such as chemistry, biochemistry, economy, physics, etc. In this work we use CA in order to specify and implement a simulation model that allows to investigate behavioral dynamics for pedestrians in an emergency evacuation. In particular, we will concentrate on those cases that involve the forced evacuation of a large number of people due to the threat of the fire, within a building with a specific number of exits. The work includes a brief introduction to the main concepts of CA that were considered for implementing the simulation model. As support of the model, a new simulation system named EVAC is presented which allows to design, construct, execute, visualize and analyze different configurations of the building to be evacuated. The experimental work allows to identify important safety aspects to be considered at the time of designing a building, to detect the strengths of the CA approach when used as simulation tool and to suggest possible extensions that would allow to represent some particularities of the problem in a more suitable way.

2007-01-01T00:00:00Z Computer simulations using Cellular Automata (CA) have been applied with considerable success in diferent scientific areas, such as chemistry, biochemistry, economy, physics, etc. In this work we use CA in order to specify and implement a simulation model that allows to investigate behavioral dynamics for pedestrians in an emergency evacuation. In particular, we will concentrate on those cases that involve the forced evacuation of a large number of people due to the threat of the fire, within a building with a specific number of exits. The work includes a brief introduction to the main concepts of CA that were considered for implementing the simulation model. As support of the model, a new simulation system named EVAC is presented which allows to design, construct, execute, visualize and analyze different configurations of the building to be evacuated. The experimental work allows to identify important safety aspects to be considered at the time of designing a building, to detect the strengths of the CA approach when used as simulation tool and to suggest possible extensions that would allow to represent some particularities of the problem in a more suitable way. Rodríguez Brisaboa, Nieves Fariña, Antonio Pedreira, Óscar Reyes, Nora Susana http://sedici.unlp.edu.ar:80/handle/10915/9521 2013-03-11T18:14:30Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 Similarity search is a fundamental operation for applications that deal with unstructured data sources. In this paper we propose a new pivot-based method for similarity search, called Sparse Spatial Selection (SSS). The main characteristic of this method is that it guarantees a good pivot selection more efficiently than other methods previously proposed. In addition, SSS adapts itself to the dimensionality of the metric space we are working with, without being necessary to specify in advance the number of pivots to use. Furthermore, SSS is dynamic, that is, it is capable to support object insertions in the database efficiently, it can work with both continuous and discrete distance functions, and it is suitable for secondary memory storage. In this work we provide experimental results that confirm the advantages of the method with several vector and metric spaces. We also show that the efficiency of our proposal is similar to that of other existing ones over vector spaces, although it is better over general metric spaces.

2007-01-01T00:00:00Z Similarity search is a fundamental operation for applications that deal with unstructured data sources. In this paper we propose a new pivot-based method for similarity search, called Sparse Spatial Selection (SSS). The main characteristic of this method is that it guarantees a good pivot selection more efficiently than other methods previously proposed. In addition, SSS adapts itself to the dimensionality of the metric space we are working with, without being necessary to specify in advance the number of pivots to use. Furthermore, SSS is dynamic, that is, it is capable to support object insertions in the database efficiently, it can work with both continuous and discrete distance functions, and it is suitable for secondary memory storage. In this work we provide experimental results that confirm the advantages of the method with several vector and metric spaces. We also show that the efficiency of our proposal is similar to that of other existing ones over vector spaces, although it is better over general metric spaces. Acosta Nelson Tosini, Marcelo Alejandro Mezzanotte, Martín F. Tommasi, M. Carolina http://sedici.unlp.edu.ar:80/handle/10915/9520 2012-05-03T13:13:42Z 2007-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 7, no. 1 This work develops a system to visualize the information for radar systems interfaces. It is a flexible, portable software system that allows to be used for radars that have different technologies and that is able to be adapted to the specific needs of each aplication domain in an eficient way. Replacing the visualization and processing units on existing radar platforms by this new system, a practical and inexpensive improvement is achieved.

2007-01-01T00:00:00Z This work develops a system to visualize the information for radar systems interfaces. It is a flexible, portable software system that allows to be used for radars that have different technologies and that is able to be adapted to the specific needs of each aplication domain in an eficient way. Replacing the visualization and processing units on existing radar platforms by this new system, a practical and inexpensive improvement is achieved.