http://sedici.unlp.edu.ar:80/handle/10915/378 2013-06-19T19:22:31Z 2013-06-19T19:22:31Z López de Teruel Alcolea, Pedro E. http://sedici.unlp.edu.ar:80/handle/10915/9472 2013-01-04T17:36:53Z 2003-01-01T00:00:00Z

Revision Journal of Computer Science & Technology; vol. 3, no. 2 This thesis describes the design and implementation of a mobile robot which is able to perform a structural interpretation of indoor environments, using only visual and proprioceptive sensory information. The desired behaviour is real-time navigation based on this interpretation, instead of a reactive approach. The design is guided by a predictive criterion: the system must anticipate the consequences of its actions, showing a certain predictive understanding of the scene in which it moves.

2003-01-01T00:00:00Z This thesis describes the design and implementation of a mobile robot which is able to perform a structural interpretation of indoor environments, using only visual and proprioceptive sensory information. The desired behaviour is real-time navigation based on this interpretation, instead of a reactive approach. The design is guided by a predictive criterion: the system must anticipate the consequences of its actions, showing a certain predictive understanding of the scene in which it moves. Ramón, Hugo Dionisio http://sedici.unlp.edu.ar:80/handle/10915/9471 2013-01-04T17:37:55Z 2003-01-01T00:00:00Z

Revision Journal of Computer Science & Technology; vol. 3, no. 2 The authors present the Measurement Information Model and the Measurement Process Model, as well as guidelines based on their experience in order to apply these models to specific projects.

2003-01-01T00:00:00Z The authors present the Measurement Information Model and the Measurement Process Model, as well as guidelines based on their experience in order to apply these models to specific projects. Buccella, Agustina Cechich, Alejandra Rodríguez Brisaboa, Nieves http://sedici.unlp.edu.ar:80/handle/10915/9470 2012-05-09T22:00:29Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 The term Federated Databases refers to the data integration of distributed, autonomous and heterogeneous databases. However, a federation can also include information systems, not only databases. At integrating data, several issues must be addressed. Here, we focus on the problem of heterogeneity, more specifically on semantic heterogeneity that is, problems rela ted to semantically equivalent concepts or semantically related/unrelated concepts. In order to address this problem, we apply the idea of ontologies as a tool for data integration. In this paper, we explain this concept and we briefly describe a method for constructing an ontology by using a hybrid ontology approach.

2003-01-01T00:00:00Z The term Federated Databases refers to the data integration of distributed, autonomous and heterogeneous databases. However, a federation can also include information systems, not only databases. At integrating data, several issues must be addressed. Here, we focus on the problem of heterogeneity, more specifically on semantic heterogeneity that is, problems rela ted to semantically equivalent concepts or semantically related/unrelated concepts. In order to address this problem, we apply the idea of ontologies as a tool for data integration. In this paper, we explain this concept and we briefly describe a method for constructing an ontology by using a hybrid ontology approach. Bria, Oscar N. http://sedici.unlp.edu.ar:80/handle/10915/9469 2012-05-09T22:00:30Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 In this paper a slightly modification is proposed to the original Wong and Gotos ATA method for the computation of elementary functions in IEEE 754 single precision. The identification of a trade-off leads to the proposition of a different chunk of the mantissa that in turn brings a reduction in the length of the tables. Results are reported for usual elementary functions based on exhaustive simulations. A mixed framework including VHDL and Matlab R is used for those simulations.

2003-01-01T00:00:00Z In this paper a slightly modification is proposed to the original Wong and Gotos ATA method for the computation of elementary functions in IEEE 754 single precision. The identification of a trade-off leads to the proposition of a different chunk of the mantissa that in turn brings a reduction in the length of the tables. Results are reported for usual elementary functions based on exhaustive simulations. A mixed framework including VHDL and Matlab R is used for those simulations. Moler, Emilce Graciela Blotta, Eduardo Luis Pastore, Juan Ignacio Meschino, Gustavo Ballarín, Virginia Laura http://sedici.unlp.edu.ar:80/handle/10915/9468 2012-05-09T22:00:30Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 In this work an application of image enhancement techniques in fingerprints is presented. Digital Image-processing technology was applied to restored fingerprints with non-uniform contrast. These fingerprints corresponded to unidentified persons who were murdered by Military Forces in 1976. In 1997, after a court decision, Human Right Organisations acceded to the microfilms of the Computer Records Division of the Province of Buenos Aires Police, which contained fingerprints and complementary information from these missing people. Unfortunately most of the fingerprints were taken with a reduction ratio of 41x, they were blurred and their spatial definition was not clear. These features made their classification and comparison very difficult. In this paper a combination of spatial, frequency and morphological enhancement techniques used to restore the fingerprints is presented. Filters had to be combined because the results obtained by applying conventional enhancement techniques were not satisfactory. The resulting images show prominent features in fingerprints that cannot be extracted by other enhancement techniques.

2003-01-01T00:00:00Z In this work an application of image enhancement techniques in fingerprints is presented. Digital Image-processing technology was applied to restored fingerprints with non-uniform contrast. These fingerprints corresponded to unidentified persons who were murdered by Military Forces in 1976. In 1997, after a court decision, Human Right Organisations acceded to the microfilms of the Computer Records Division of the Province of Buenos Aires Police, which contained fingerprints and complementary information from these missing people. Unfortunately most of the fingerprints were taken with a reduction ratio of 41x, they were blurred and their spatial definition was not clear. These features made their classification and comparison very difficult. In this paper a combination of spatial, frequency and morphological enhancement techniques used to restore the fingerprints is presented. Filters had to be combined because the results obtained by applying conventional enhancement techniques were not satisfactory. The resulting images show prominent features in fingerprints that cannot be extracted by other enhancement techniques. Teyseyre, Alfredo Raúl http://sedici.unlp.edu.ar:80/handle/10915/9467 2012-05-09T22:00:30Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 The importance of correctly determining the requirements of a system at the very beginning of the development process it is a well known fact. Experience shows that the incorrect definition of the requirements leads to the development of deficient systems, increases the cost of its development or even causes projects to fail. Therefore it is crucial for the clients to verify that the planned system satisfies their needs. This means that the system must be described in a form that clients can clearly understand it. In this context, visualization techniques appear as a useful tool to help the users in the process of requirements understanding and validation. This work proposes the use of 3D visualization techniques to validate the requirements of a system with the user. The use of these techniques can reduce the communication gap between the clients and the developers resulting in a much more effective process of requirements validation. The approach tries to take advantage of the benefits of the 3D visualization, complementing this with the advantages of formal specifications. A tool, called ReqViz3D, that materializes the proposal was developed. This tool allows to specify the requirements in the formal language Z, define a graphical representation of them, and create a 3D animated visualization of theirs execution through which the users can validate them.

2003-01-01T00:00:00Z The importance of correctly determining the requirements of a system at the very beginning of the development process it is a well known fact. Experience shows that the incorrect definition of the requirements leads to the development of deficient systems, increases the cost of its development or even causes projects to fail. Therefore it is crucial for the clients to verify that the planned system satisfies their needs. This means that the system must be described in a form that clients can clearly understand it. In this context, visualization techniques appear as a useful tool to help the users in the process of requirements understanding and validation. This work proposes the use of 3D visualization techniques to validate the requirements of a system with the user. The use of these techniques can reduce the communication gap between the clients and the developers resulting in a much more effective process of requirements validation. The approach tries to take advantage of the benefits of the 3D visualization, complementing this with the advantages of formal specifications. A tool, called ReqViz3D, that materializes the proposal was developed. This tool allows to specify the requirements in the formal language Z, define a graphical representation of them, and create a 3D animated visualization of theirs execution through which the users can validate them. Campos, Alvaro E. Orellana, Christian Fabián Soto, María Pía http://sedici.unlp.edu.ar:80/handle/10915/9466 2012-05-09T22:00:30Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 Deadlock detection is one of the most discussed problems in the literature. Although several al- gorithms have been proposed, the problem is still open. In general, the correct operation of an algorithm depends on the requirement model being considered. This article introduces a deadlock detection algorithm for the OR model. The algorithm is complete, because it detects all deadlocks, and it is correct, because it does not detect false deadlocks. In addition, the algorithm supports dynamic changes in the wait-for graph on which it works. Once finalized the algorithm, at least each process that causes deadlock knows that it is deadlocked. Using this property, possible extensions are suggested in order to resolve deadlocks.

2003-01-01T00:00:00Z Deadlock detection is one of the most discussed problems in the literature. Although several al- gorithms have been proposed, the problem is still open. In general, the correct operation of an algorithm depends on the requirement model being considered. This article introduces a deadlock detection algorithm for the OR model. The algorithm is complete, because it detects all deadlocks, and it is correct, because it does not detect false deadlocks. In addition, the algorithm supports dynamic changes in the wait-for graph on which it works. Once finalized the algorithm, at least each process that causes deadlock knows that it is deadlocked. Using this property, possible extensions are suggested in order to resolve deadlocks. Ruiz, Anabel Natalia Maldonado, Calixto Martínez Spessot, Cesar Ignacio http://sedici.unlp.edu.ar:80/handle/10915/9465 2012-05-09T22:00:31Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 The studies of Relational Data Base Management Systems and Databases constitute nowadays a main tren of investigation in large businesses and universities of the entire world. The creation of a data base engine keeps being a challenge since there are aspects in which have not been achieved a final solution. Por example, the requeriments of storage of images, video, sound. etc. The purpuse of this project is to implement a Relational Database Manager System (RDBMS) and an Interpreter of Data Query Language that can be utilized in investigation an data processing development of applications. It is important to count on a RDBMS developed in our universities so they can study an do modifications, which is practically impossible with the commercial products due to that does not available neither their Source code neither the documentation detailed neither the necessary training. Our investigation includes the development of innovating algorithms for access and maintenance of the data and procedures; techniques and tools to carry out Datawarehouse and DataMining, offering a good fulfillment as for time of answer and extensive capacity of backup to requeriments such as operational as strategic (Decision Support Systems).

2003-01-01T00:00:00Z The studies of Relational Data Base Management Systems and Databases constitute nowadays a main tren of investigation in large businesses and universities of the entire world. The creation of a data base engine keeps being a challenge since there are aspects in which have not been achieved a final solution. Por example, the requeriments of storage of images, video, sound. etc. The purpuse of this project is to implement a Relational Database Manager System (RDBMS) and an Interpreter of Data Query Language that can be utilized in investigation an data processing development of applications. It is important to count on a RDBMS developed in our universities so they can study an do modifications, which is practically impossible with the commercial products due to that does not available neither their Source code neither the documentation detailed neither the necessary training. Our investigation includes the development of innovating algorithms for access and maintenance of the data and procedures; techniques and tools to carry out Datawarehouse and DataMining, offering a good fulfillment as for time of answer and extensive capacity of backup to requeriments such as operational as strategic (Decision Support Systems). Ibáñez, Francisco S. Díaz Araya, Daniel Forradelas, Raymundo Quilez http://sedici.unlp.edu.ar:80/handle/10915/9464 2012-05-09T22:00:31Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 This paper includes part of the strategies used to solve a scheduling problem developed for a company that produces flexible packaging, presented in a quite general form though. In this problem it is necessary to schedule several jobs that involve four process and for each one of them there is a group of machines available (of similar characteristics). Each activity is performed on just one machine. Besides, for our application, the scheduling must try to verify certain conditions. For each process (and consequently for all the activities that perform this process) there is a list of attributes. The problem is not only to assign each activity to a starting time and to a specific machine, but also to try to verify conditions that depend on the values of the attributes of the activities. Moreover, there are criteria to choose a particular machine. An approach to solve this problem was presented first in [1]. As mentioned there, some due dates could not be fulfilled on time. An approach to decrease the quantity of due dates violations was presented in [2 . This approach generates acceptable results for most of the cases in the real application. However, there were some cases in which the Algorithm did not work properly. The present work includes an Algorithm that improves the results generated in [2 ]for some special cases that arose in the real application.

2003-01-01T00:00:00Z This paper includes part of the strategies used to solve a scheduling problem developed for a company that produces flexible packaging, presented in a quite general form though. In this problem it is necessary to schedule several jobs that involve four process and for each one of them there is a group of machines available (of similar characteristics). Each activity is performed on just one machine. Besides, for our application, the scheduling must try to verify certain conditions. For each process (and consequently for all the activities that perform this process) there is a list of attributes. The problem is not only to assign each activity to a starting time and to a specific machine, but also to try to verify conditions that depend on the values of the attributes of the activities. Moreover, there are criteria to choose a particular machine. An approach to solve this problem was presented first in [1]. As mentioned there, some due dates could not be fulfilled on time. An approach to decrease the quantity of due dates violations was presented in [2 . This approach generates acceptable results for most of the cases in the real application. However, there were some cases in which the Algorithm did not work properly. The present work includes an Algorithm that improves the results generated in [2 ]for some special cases that arose in the real application. Nurcahyo, Gunadi W. Shamsuddin, Siti Mariyam Alias, Rose Alinda Sap, Mohd. Noor Md. http://sedici.unlp.edu.ar:80/handle/10915/9463 2012-05-09T22:00:31Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 We present a study of using fuzzy-based parameters for solving public bus routing problem where demand is uncertain. The fuzzy-based parameters are designed to provide data required by the route selection procedure. The uncertain data are represented as linguistic values which are fully dependent on the users preference. This paper focuses on the selection of the Defuzzification method to discover the most appropriate method for obtaining crisp values which represent uncertain data. We also present a step by step evaluation showing that the fuzzy-based parameters are capable to represent uncertain data replacing the use of exact data which common route selection algorithms usually use.

2003-01-01T00:00:00Z We present a study of using fuzzy-based parameters for solving public bus routing problem where demand is uncertain. The fuzzy-based parameters are designed to provide data required by the route selection procedure. The uncertain data are represented as linguistic values which are fully dependent on the users preference. This paper focuses on the selection of the Defuzzification method to discover the most appropriate method for obtaining crisp values which represent uncertain data. We also present a step by step evaluation showing that the fuzzy-based parameters are capable to represent uncertain data replacing the use of exact data which common route selection algorithms usually use. Kikuti, Daniel Souza, Paulo S. L. Souza, Simone R. S. http://sedici.unlp.edu.ar:80/handle/10915/9462 2012-05-09T22:00:31Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 This paper describes the advances obtained with the XPVM-W95 2.0, a novel monitoring tool for parallel applications that employ PVM-W95 (PVM for Windows) as well as PVM for Linux. The tool provides, at runtime, the appropriate information about parallel virtual machine configuration, parallel applications and workload from each node. The three more important aspects of the XPVM-W95 are: friendly graphical interface, portability and ability to deal with heterogeneity. These items were improved by version 2, mainly when considering the modularity rearrangement. Experiments demonstrate that XPVM-W95 has a stable behavior and reached the objectives proposed. XPVM-W95 allows a great portability of its source code and also allows the monitoring using different metrics. Empirical studies, realized by means of one single application, demonstrated an intrusion of 17,0% on Windows and 0,13% on Linux.

2003-01-01T00:00:00Z This paper describes the advances obtained with the XPVM-W95 2.0, a novel monitoring tool for parallel applications that employ PVM-W95 (PVM for Windows) as well as PVM for Linux. The tool provides, at runtime, the appropriate information about parallel virtual machine configuration, parallel applications and workload from each node. The three more important aspects of the XPVM-W95 are: friendly graphical interface, portability and ability to deal with heterogeneity. These items were improved by version 2, mainly when considering the modularity rearrangement. Experiments demonstrate that XPVM-W95 has a stable behavior and reached the objectives proposed. XPVM-W95 allows a great portability of its source code and also allows the monitoring using different metrics. Empirical studies, realized by means of one single application, demonstrated an intrusion of 17,0% on Windows and 0,13% on Linux. Kretchmar, R. Matthew Feil, Todd Bansal, Rohit http://sedici.unlp.edu.ar:80/handle/10915/9461 2012-05-09T22:00:32Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 Options have been shown to be a key step in extending reinforcement learning beyond low-level reactionary systems to higher-level, planning systems. Most of the options research involves hand-crafted options; there has been only very limited work in the automated discovery of options. We extend early work in automated option discovery with a flexible and robust method.

2003-01-01T00:00:00Z Options have been shown to be a key step in extending reinforcement learning beyond low-level reactionary systems to higher-level, planning systems. Most of the options research involves hand-crafted options; there has been only very limited work in the automated discovery of options. We extend early work in automated option discovery with a flexible and robust method. Acacio Sánchez, Manuel García Carrasco, José Manuel http://sedici.unlp.edu.ar:80/handle/10915/9460 2012-05-09T22:00:32Z 2003-01-01T00:00:00Z

Articulo Journal of Computer Science & Technology; vol. 3, no. 2 Cache-coherent, nonumiform memory acces or cc-NUMA is an attractive architecture for building a spectrum of shared memory multiprocessors (whic are socing widespread use in commercial, technical and scientific applications). Unfortunately, there are some factors which limit the maximun number of processors that can be offered at a good price/perfomance ratio. This paper presents a survey of some of the proposals that have recently appeared focusing on tow of these factors: the increased cost, in terms of hardware overhead that the use of directories entails, and the long cache miss latencies obseved in these designs as a consequence of the indirection introduced by the acces to the directory.

2003-01-01T00:00:00Z Cache-coherent, nonumiform memory acces or cc-NUMA is an attractive architecture for building a spectrum of shared memory multiprocessors (whic are socing widespread use in commercial, technical and scientific applications). Unfortunately, there are some factors which limit the maximun number of processors that can be offered at a good price/perfomance ratio. This paper presents a survey of some of the proposals that have recently appeared focusing on tow of these factors: the increased cost, in terms of hardware overhead that the use of directories entails, and the long cache miss latencies obseved in these designs as a consequence of the indirection introduced by the acces to the directory.