DSpace Community:
http://hdl.handle.net/2117/3971
Tue, 28 Apr 2015 19:55:03 GMT2015-04-28T19:55:03Zwebmaster.bupc@upc.eduUniversitat Politècnica de Catalunya. Servei de Biblioteques i DocumentaciónoEvolutionary computation and case-based reasoning interoperation in IEDSS through GESCONDA
http://hdl.handle.net/2117/27635
Title: Evolutionary computation and case-based reasoning interoperation in IEDSS through GESCONDA
Authors: Sánchez Marrè, Miquel; Gibert Oliveras, Karina; Vinayagam, Radha K.; Sevilla Villanueva, BeatrizTue, 28 Apr 2015 18:23:00 GMThttp://hdl.handle.net/2117/276352015-04-28T18:23:00ZSánchez Marrè, Miquel; Gibert Oliveras, Karina; Vinayagam, Radha K.; Sevilla Villanueva, BeatriznoOn the complexity of exchanging
http://hdl.handle.net/2117/27400
Title: On the complexity of exchanging
Authors: Molinero Albareda, Xavier; Olsen, Martin; Serna Iglesias, María José
Abstract: We analyze the computational complexity of the problem of deciding
whether, for a given simple game, there exists the possibility of rearranging the participants in a set of j given losing coalitions into a set of j winning coalitions. We also look at the problem of turning winning coalitions into losing coalitions. We analyze the problem when the simple game is represented by a list of wining, losing, minimal winning or maximal loosing coalitions.Thu, 16 Apr 2015 17:13:57 GMThttp://hdl.handle.net/2117/274002015-04-16T17:13:57ZMolinero Albareda, Xavier; Olsen, Martin; Serna Iglesias, María JosénoTradeness of Simple Games, Computational ComplexityWe analyze the computational complexity of the problem of deciding
whether, for a given simple game, there exists the possibility of rearranging the participants in a set of j given losing coalitions into a set of j winning coalitions. We also look at the problem of turning winning coalitions into losing coalitions. We analyze the problem when the simple game is represented by a list of wining, losing, minimal winning or maximal loosing coalitions.Bounded-width QBF is PSPACE-complete
http://hdl.handle.net/2117/27300
Title: Bounded-width QBF is PSPACE-complete
Authors: Atserias Peri, Albert; Oliva Valls, Sergi
Abstract: Tree-width and path-width are two well-studied parameters of structures that measure their similarity to a tree and a path, respectively. We show that QBF on instances with constant path-width, and hence constant tree-width, remains PSPACE-complete. This answers a question by Vardi. We also show that on instances with constant path-width and a very slow-growing number of quantifier alternations (roughly inverse-Ackermann many in the number of variables), the problem remains NP-hard. Additionally, we introduce a family of formulas with bounded tree-width that do have short refutations in Q-resolution, the natural generalization of resolution for quantified Boolean formulas.Tue, 14 Apr 2015 08:29:15 GMThttp://hdl.handle.net/2117/273002015-04-14T08:29:15ZAtserias Peri, Albert; Oliva Valls, SerginoTree-width, Path-width, Quantified Boolean formulas, PSPACE-completeTree-width and path-width are two well-studied parameters of structures that measure their similarity to a tree and a path, respectively. We show that QBF on instances with constant path-width, and hence constant tree-width, remains PSPACE-complete. This answers a question by Vardi. We also show that on instances with constant path-width and a very slow-growing number of quantifier alternations (roughly inverse-Ackermann many in the number of variables), the problem remains NP-hard. Additionally, we introduce a family of formulas with bounded tree-width that do have short refutations in Q-resolution, the natural generalization of resolution for quantified Boolean formulas.A boolean rule-based approach for manufacturability-aware cell routing
http://hdl.handle.net/2117/27267
Title: A boolean rule-based approach for manufacturability-aware cell routing
Authors: Cortadella Fortuny, Jordi; Petit Silvestre, Jordi; Gómez Fernández, Sergio; Moll Echeto, Francisco de Borja
Abstract: An approach for cell routing using gridded design rules is proposed. It is technology-independent and parameterizable for different fabrics and design rules, including support for multiple-patterning lithography. The core contribution is a detailed-routing algorithm based on a Boolean formulation of the problem. The algorithm uses a novel encoding scheme, graph theory to support floating terminals, efficient heuristics to reduce the computational cost, and minimization of the number of unconnected pins in case the cell is unroutable. The versatility of the algorithm is demonstrated by routing single-and double-height cells. The efficiency is ascertained by synthesizing a library with 127 cells in about one hour and a half of CPU time. The layouts derived by the implemented tool have also been compared with the ones from a commercial library; thus, showing the competitiveness of the approach for gridded geometries.Mon, 13 Apr 2015 09:46:45 GMThttp://hdl.handle.net/2117/272672015-04-13T09:46:45ZCortadella Fortuny, Jordi; Petit Silvestre, Jordi; Gómez Fernández, Sergio; Moll Echeto, Francisco de BorjanoCell generation, Design for manufacturability, Detailed routing, Satisfiability, Regular logic-bricks, Combinatorial optimization, Design, Layout, Lithography, CircuitsAn approach for cell routing using gridded design rules is proposed. It is technology-independent and parameterizable for different fabrics and design rules, including support for multiple-patterning lithography. The core contribution is a detailed-routing algorithm based on a Boolean formulation of the problem. The algorithm uses a novel encoding scheme, graph theory to support floating terminals, efficient heuristics to reduce the computational cost, and minimization of the number of unconnected pins in case the cell is unroutable. The versatility of the algorithm is demonstrated by routing single-and double-height cells. The efficiency is ascertained by synthesizing a library with 127 cells in about one hour and a half of CPU time. The layouts derived by the implemented tool have also been compared with the ones from a commercial library; thus, showing the competitiveness of the approach for gridded geometries.Area-optimal transistor folding for 1-D gridded cell design
http://hdl.handle.net/2117/27265
Title: Area-optimal transistor folding for 1-D gridded cell design
Authors: Cortadella Fortuny, Jordi
Abstract: The 1-D design style with gridded design rules is gaining ground for addressing the printability issues in subwavelength photolithography. One of the synthesis problems in cell generation is transistor folding, which consists of breaking large transistors into smaller ones (legs) that can be placed in the active area of the cell. In the 1-D style, diffusion sharing between differently sized transistors is not allowed, thus implying a significant area overhead when active areas with different sizes are required. This paper presents a new formulation of the transistor folding problem in the context of 1-D design style and a mathematical model that delivers area-optimal solutions. The mathematical model can be customized for different variants of the problem, considering flexible transistor sizes and multiple-height cells. An innovative feature of the method is that area optimality can be guaranteed without calculating the actual location of the transistors. The model can also be enhanced to deliver solutions with good routability properties.Mon, 13 Apr 2015 09:20:30 GMThttp://hdl.handle.net/2117/272652015-04-13T09:20:30ZCortadella Fortuny, JordinoCell generation, Design for manufacturability, Linear programming, Transistor folding, Transistor sizingThe 1-D design style with gridded design rules is gaining ground for addressing the printability issues in subwavelength photolithography. One of the synthesis problems in cell generation is transistor folding, which consists of breaking large transistors into smaller ones (legs) that can be placed in the active area of the cell. In the 1-D style, diffusion sharing between differently sized transistors is not allowed, thus implying a significant area overhead when active areas with different sizes are required. This paper presents a new formulation of the transistor folding problem in the context of 1-D design style and a mathematical model that delivers area-optimal solutions. The mathematical model can be customized for different variants of the problem, considering flexible transistor sizes and multiple-height cells. An innovative feature of the method is that area optimality can be guaranteed without calculating the actual location of the transistors. The model can also be enhanced to deliver solutions with good routability properties.Making smart cities smarter using artificial intelligence techniques for smarter mobility
http://hdl.handle.net/2117/27240
Title: Making smart cities smarter using artificial intelligence techniques for smarter mobility
Authors: Vázquez Salceda, Javier; Álvarez Napagao, Sergio; Tejeda Gómez, José Arturo; Oliva Felipe, Luis Javier; Garcia Gasulla, Dario; Gómez Sebastià, Ignasi; Codina Busquet, Víctor
Abstract: The term Smart City is tipically applied to urban and metropolitan areas where Information and Communication Technologies provide ways to enable social, cultural and urban development, improving social and political capacities and/or efficiency. In this paper we will show the potential of Artificial Intelligence techniques for augmenting ICT solutions to both increase the cities competiveness but also the active participation of citizens in those processes, making Smart Cities smarter. As example we will describe the usage of Artificial Intellgence techniques to provide Smart Mobility in the context of the SUPERHUB Project.Fri, 10 Apr 2015 09:42:37 GMThttp://hdl.handle.net/2117/272402015-04-10T09:42:37ZVázquez Salceda, Javier; Álvarez Napagao, Sergio; Tejeda Gómez, José Arturo; Oliva Felipe, Luis Javier; Garcia Gasulla, Dario; Gómez Sebastià, Ignasi; Codina Busquet, VíctornoArtificial intelligence, Semantic data interpretation, Smart mobility, User profiling, User recommendationThe term Smart City is tipically applied to urban and metropolitan areas where Information and Communication Technologies provide ways to enable social, cultural and urban development, improving social and political capacities and/or efficiency. In this paper we will show the potential of Artificial Intelligence techniques for augmenting ICT solutions to both increase the cities competiveness but also the active participation of citizens in those processes, making Smart Cities smarter. As example we will describe the usage of Artificial Intellgence techniques to provide Smart Mobility in the context of the SUPERHUB Project.When is Menzerath-Altmann law mathematically trivial? A new approach
http://hdl.handle.net/2117/27198
Title: When is Menzerath-Altmann law mathematically trivial? A new approach
Authors: Ferrer Cancho, Ramon; Hernández Fernández, Antonio; Baixeries i Juvillà, Jaume; Debowski, Lukasz; Macutek, Jan
Abstract: Menzerath’s law, the tendency of Z (the mean size of the parts) to decrease as X (the number of parts) increases, is found in language, music and genomes. Recently, it has been argued that the presence of the law in genomes is an inevitable consequence of the fact that Z = Y/X, which would imply that Z scales with X as Z~1/X. That scaling is a very particular case of Menzerath-Altmann law that has been rejected by means of a correlation test between X and Y in genomes, being X the number of chromosomes of a species, Y its genome size in bases and Z the mean chromosome size. Here we review the statistical foundations of that test and consider three non-parametric tests based upon different correlation metrics and one parametric test to evaluate if Z~1/X in genomes. The most powerful test is a new non-parametric one based upon the correlation ratio, which is able to reject Z~1/X in nine out of 11 taxonomic groups and detect a borderline group. Rather than a fact, Z~1/X is a baseline that real genomes do not meet. The view of Menzerath-Altmann law as inevitable is seriously flawed.Thu, 09 Apr 2015 09:05:34 GMThttp://hdl.handle.net/2117/271982015-04-09T09:05:34ZFerrer Cancho, Ramon; Hernández Fernández, Antonio; Baixeries i Juvillà, Jaume; Debowski, Lukasz; Macutek, JannoMenzerath-Altmann law, Power-lawsMenzerath’s law, the tendency of Z (the mean size of the parts) to decrease as X (the number of parts) increases, is found in language, music and genomes. Recently, it has been argued that the presence of the law in genomes is an inevitable consequence of the fact that Z = Y/X, which would imply that Z scales with X as Z~1/X. That scaling is a very particular case of Menzerath-Altmann law that has been rejected by means of a correlation test between X and Y in genomes, being X the number of chromosomes of a species, Y its genome size in bases and Z the mean chromosome size. Here we review the statistical foundations of that test and consider three non-parametric tests based upon different correlation metrics and one parametric test to evaluate if Z~1/X in genomes. The most powerful test is a new non-parametric one based upon the correlation ratio, which is able to reject Z~1/X in nine out of 11 taxonomic groups and detect a borderline group. Rather than a fact, Z~1/X is a baseline that real genomes do not meet. The view of Menzerath-Altmann law as inevitable is seriously flawed.Partially definable forcing and bounded arithmetic
http://hdl.handle.net/2117/27193
Title: Partially definable forcing and bounded arithmetic
Authors: Atserias Peri, Albert; Müller, Moritz
Abstract: We describe a method of forcing against weak theories of arithmetic and its applications in propositional proof complexity.Thu, 09 Apr 2015 07:48:00 GMThttp://hdl.handle.net/2117/271932015-04-09T07:48:00ZAtserias Peri, Albert; Müller, MoritznoBounded arithmetic, Forcing, Proof complexity, Propositional proof systems, Depth frege proofs, Pigeonhole principle, Complexity gap, Resolution, SizeWe describe a method of forcing against weak theories of arithmetic and its applications in propositional proof complexity.Clearance for diversity of agents’ sizes in navigation meshes
http://hdl.handle.net/2117/27159
Title: Clearance for diversity of agents’ sizes in navigation meshes
Authors: Oliva Martínez, Ramon; Pelechano Gómez, Núria
Abstract: There are two frequent artifacts in crowd simulation caused by navigation mesh design. The first appears when all agents attempt to traverse the navigation mesh and share the same way points through portals, thus increasing the probability of collisions with other agents or queues forming around portals. The second is caused by way points being assigned at locations where clearance is not guaranteed, which causes the agents to either walk too close to the static geometry, slide along walls or get stuck. To overcome this we use the full length of the portal and propose a novel method for dynamically calculating way points based on current trajectory, destination, and clearance, therefore guaranteeing that agents in a crowd will have different way points assigned.
To achieve collision free paths we propose two novel techniques: the first provides the computation of paths with clearance for cells of any shape (even with concavities) and the second presents a new method for calculating portals with clearance, so that the dynamically assigned way points will always guarantee collision free paths relative to the static geometry. In this paper, we extend our previous work by describing a new version of the algorithm that is suitable for a larger number of navigation meshes, while further improving performance. Our results show how the combination of portals with exact clearance and dynamic way points improve local movement by reducing the number of collision between agents and the static geometry. We evaluate our algorithm with a variety of scenarios and compare our results with traditional way points to show that our technique also offers better use of the space by the agents.Wed, 08 Apr 2015 11:17:50 GMThttp://hdl.handle.net/2117/271592015-04-08T11:17:50ZOliva Martínez, Ramon; Pelechano Gómez, NúrianoClearance, Navigation meshes, Dynamic way pointsThere are two frequent artifacts in crowd simulation caused by navigation mesh design. The first appears when all agents attempt to traverse the navigation mesh and share the same way points through portals, thus increasing the probability of collisions with other agents or queues forming around portals. The second is caused by way points being assigned at locations where clearance is not guaranteed, which causes the agents to either walk too close to the static geometry, slide along walls or get stuck. To overcome this we use the full length of the portal and propose a novel method for dynamically calculating way points based on current trajectory, destination, and clearance, therefore guaranteeing that agents in a crowd will have different way points assigned.
To achieve collision free paths we propose two novel techniques: the first provides the computation of paths with clearance for cells of any shape (even with concavities) and the second presents a new method for calculating portals with clearance, so that the dynamically assigned way points will always guarantee collision free paths relative to the static geometry. In this paper, we extend our previous work by describing a new version of the algorithm that is suitable for a larger number of navigation meshes, while further improving performance. Our results show how the combination of portals with exact clearance and dynamic way points improve local movement by reducing the number of collision between agents and the static geometry. We evaluate our algorithm with a variety of scenarios and compare our results with traditional way points to show that our technique also offers better use of the space by the agents.Trustworthiness in P2P: performance behaviour of two fuzzy-based systems for JXTA-overlay platform
http://hdl.handle.net/2117/27102
Title: Trustworthiness in P2P: performance behaviour of two fuzzy-based systems for JXTA-overlay platform
Authors: Spaho, Evjola; Sakamoto, Shinji; Barolli, Leonard; Xhafa Xhafa, Fatos; Ikeda, Makoto
Abstract: Peer-to-peer (P2P) networks, will be very important for future distributed systems and applications. In such networks, peers are heterogeneous in providing the services and they do not have the same competence of reliability. Therefore, it is necessary to estimate whether a peer is trustworthy or not for file sharing and other services. In this paper, we propose two fuzzy-based trustworthiness system for P2P communication in JXTA-overlay. System 1 has only one fuzzy logic controller (FLC) and uses four input parameters: mutually agreed behaviour (MAB), actual behaviour criterion (ABC), peer disconnections (PD) and number of uploads (NU) and the output is peer reliability (PR). System 2 has two FLCs. In FLC1 use three input parameters: number of jobs (NJ), number of connections (NC) and connection lifetime (CL) and the output is actual behavioural criterion (ABC). We use ABC and reputation (R) as input linguistic parameters for FLC2 and the output is peer reliability (PR). We evaluate the proposed systems by computer simulations. The simulation results show that the proposed systems have a good behaviour and can be used successfully to evaluate the reliability of the new peer connected in JXTA-overlay.Fri, 27 Mar 2015 15:44:52 GMThttp://hdl.handle.net/2117/271022015-03-27T15:44:52ZSpaho, Evjola; Sakamoto, Shinji; Barolli, Leonard; Xhafa Xhafa, Fatos; Ikeda, MakotonoP2P systems, Fuzzy system, Peer reliability, ControllerPeer-to-peer (P2P) networks, will be very important for future distributed systems and applications. In such networks, peers are heterogeneous in providing the services and they do not have the same competence of reliability. Therefore, it is necessary to estimate whether a peer is trustworthy or not for file sharing and other services. In this paper, we propose two fuzzy-based trustworthiness system for P2P communication in JXTA-overlay. System 1 has only one fuzzy logic controller (FLC) and uses four input parameters: mutually agreed behaviour (MAB), actual behaviour criterion (ABC), peer disconnections (PD) and number of uploads (NU) and the output is peer reliability (PR). System 2 has two FLCs. In FLC1 use three input parameters: number of jobs (NJ), number of connections (NC) and connection lifetime (CL) and the output is actual behavioural criterion (ABC). We use ABC and reputation (R) as input linguistic parameters for FLC2 and the output is peer reliability (PR). We evaluate the proposed systems by computer simulations. The simulation results show that the proposed systems have a good behaviour and can be used successfully to evaluate the reliability of the new peer connected in JXTA-overlay.Decomposing utility functions in Bounded Max-Sum for distributed constraint optimization
http://hdl.handle.net/2117/27089
Title: Decomposing utility functions in Bounded Max-Sum for distributed constraint optimization
Authors: Rollón Rico, Emma; Larrosa Bondia, Francisco Javier
Abstract: Bounded Max-Sum is a message-passing algorithm for solving distributed Constraint Optimization Problems (DCOP) able to compute solutions with a guaranteed approximation ratio. In this paper we show that the introduction of an intermediate step that decomposes functions may significantly improve its accuracy. This is especially relevant in critical applications (e.g. automatic surveillance, disaster response scenarios) where the accuracy of solutions is of vital importance.Fri, 27 Mar 2015 11:43:28 GMThttp://hdl.handle.net/2117/270892015-03-27T11:43:28ZRollón Rico, Emma; Larrosa Bondia, Francisco JaviernoGraphical model, Approximate inference, Guaranteed approximation ratioBounded Max-Sum is a message-passing algorithm for solving distributed Constraint Optimization Problems (DCOP) able to compute solutions with a guaranteed approximation ratio. In this paper we show that the introduction of an intermediate step that decomposes functions may significantly improve its accuracy. This is especially relevant in critical applications (e.g. automatic surveillance, disaster response scenarios) where the accuracy of solutions is of vital importance.Word's vector representations meet machine translation
http://hdl.handle.net/2117/26978
Title: Word's vector representations meet machine translation
Authors: Martínez Garcia, Eva; España Bonet, Cristina; Tiedemann, Jörg; Márquez Villodre, Luís
Abstract: Distributed vector representations of words are useful in various NLP tasks. We briefly review the CBOW approach and propose a bilingual application of this architecture with the aim to improve consistency and coherence of Machine Translation. The primary goal of the bilingual extension is to handle ambiguous words for which the different senses are conflated in the monolingual setup.Tue, 24 Mar 2015 13:14:52 GMThttp://hdl.handle.net/2117/269782015-03-24T13:14:52ZMartínez Garcia, Eva; España Bonet, Cristina; Tiedemann, Jörg; Márquez Villodre, LuísnoDistributed vector representations of words are useful in various NLP tasks. We briefly review the CBOW approach and propose a bilingual application of this architecture with the aim to improve consistency and coherence of Machine Translation. The primary goal of the bilingual extension is to handle ambiguous words for which the different senses are conflated in the monolingual setup.Wikicardi : hacia la extracción de oraciones paralelas de Wikipedia
http://hdl.handle.net/2117/26966
Title: Wikicardi : hacia la extracción de oraciones paralelas de Wikipedia
Authors: Boldoba Trapote, Josu; Barrón Cedeño, Luis Alberto; España Bonet, Cristina
Abstract: Uno de los objetivos del proyecto Tacardi (TIN2012-38523-C02-00) consiste en extraer oraciones paralelas de corpus comparables para enriquecer y adaptar traductores automáticos. En esta investigación usamos un subconjunto de Wikipedia como corpus comparable. En este reporte se describen nuestros avances con respecto a la extracción de fragmentos paralelos de Wikipedia. Primero, discutimos cómo hemos definido los tres dominios de interés -ciencia, informática y deporte-, en el marco de la enciclopedia y cómo hemos extraído los textos y demás datos necesarios para la caracterización de los artículos en las distintas lenguas. Después discutimos brevemente los modelos que usaremos para identificar oraciones paralelas y damos sólo una muestra de algunos resultados preliminares. Los datos obtenidos hasta ahora permiten vislumbran que será posible extraer oraciones paralelas de los dominios de interés a corto plazo, si bien aún no contamos con una estimación del volumen de éstos.Tue, 24 Mar 2015 09:37:02 GMThttp://hdl.handle.net/2117/269662015-03-24T09:37:02ZBoldoba Trapote, Josu; Barrón Cedeño, Luis Alberto; España Bonet, CristinanoUno de los objetivos del proyecto Tacardi (TIN2012-38523-C02-00) consiste en extraer oraciones paralelas de corpus comparables para enriquecer y adaptar traductores automáticos. En esta investigación usamos un subconjunto de Wikipedia como corpus comparable. En este reporte se describen nuestros avances con respecto a la extracción de fragmentos paralelos de Wikipedia. Primero, discutimos cómo hemos definido los tres dominios de interés -ciencia, informática y deporte-, en el marco de la enciclopedia y cómo hemos extraído los textos y demás datos necesarios para la caracterización de los artículos en las distintas lenguas. Después discutimos brevemente los modelos que usaremos para identificar oraciones paralelas y damos sólo una muestra de algunos resultados preliminares. Los datos obtenidos hasta ahora permiten vislumbran que será posible extraer oraciones paralelas de los dominios de interés a corto plazo, si bien aún no contamos con una estimación del volumen de éstos.Experiments on document level machine translation
http://hdl.handle.net/2117/26965
Title: Experiments on document level machine translation
Authors: Martínez Garcia, Eva; España Bonet, Cristina; Márquez Villodre, Luís
Abstract: Most of the current SMT systems work at sentence level. They translate a text assuming that sentences are independent, but, when one looks at a well formed document, it is clear that there exist many inter sentence relations. There is much contextual information that, unfortunately, is lost when translating sentences in an independent way.
We want to improve translation coherence and cohesion using document level information. So, we are interested in develop new strategies to take advantage of context information to achieve our goal. For example, we want to approach this challenge developing postprocesses in order to try to fix a first translation obtained by an SMT system. Also we are interested in taking advantage of the document level translation framework given by the Docent decoder to implement and test some of our ideas.
The analogous problem can be found regarding to automatic MT evaluation metrics because most of them are designed at sentence level so, they do not capture improvements in lexical cohesion and coherence or discourse structure. However, we will left this topic for future workTue, 24 Mar 2015 09:30:12 GMThttp://hdl.handle.net/2117/269652015-03-24T09:30:12ZMartínez Garcia, Eva; España Bonet, Cristina; Márquez Villodre, LuísnoMost of the current SMT systems work at sentence level. They translate a text assuming that sentences are independent, but, when one looks at a well formed document, it is clear that there exist many inter sentence relations. There is much contextual information that, unfortunately, is lost when translating sentences in an independent way.
We want to improve translation coherence and cohesion using document level information. So, we are interested in develop new strategies to take advantage of context information to achieve our goal. For example, we want to approach this challenge developing postprocesses in order to try to fix a first translation obtained by an SMT system. Also we are interested in taking advantage of the document level translation framework given by the Docent decoder to implement and test some of our ideas.
The analogous problem can be found regarding to automatic MT evaluation metrics because most of them are designed at sentence level so, they do not capture improvements in lexical cohesion and coherence or discourse structure. However, we will left this topic for future workWMN-SA system for node placement in WMNs: evaluation for different realistic distributions of mesh clients
http://hdl.handle.net/2117/26860
Title: WMN-SA system for node placement in WMNs: evaluation for different realistic distributions of mesh clients
Authors: Sakamoto, Shinji; Oda, Tetsuya; Bravo, Albert; Barolli, Leonard; Ikeda, Makoto; Xhafa Xhafa, Fatos
Abstract: One of the key advantages of Wireless Mesh Networks (WMNs) is their importance for providing cost-efficient broadband connectivity. There are issues for achieving the network connectivity and user coverage, which are related with the node placement problem. We implemented a simulation system where we consider the router node placement problem in WMNs. We want to find the optimal distribution of router nodes in order to provide the best network connectivity and provide the best coverage in a set of randomly distributed clients. We modeled 3 different realistic distribution of mesh clients (Subway, Boulevard and Stadium models). From simulation results, we found that, in the case of Subway model distribution of mesh clients, connectivity and coverage reach maximum performance. For all 3 models, when the instance size increases, the performance decreases.Thu, 19 Mar 2015 14:21:51 GMThttp://hdl.handle.net/2117/268602015-03-19T14:21:51ZSakamoto, Shinji; Oda, Tetsuya; Bravo, Albert; Barolli, Leonard; Ikeda, Makoto; Xhafa Xhafa, FatosnoConnectivity, Coverage, Number of Mesh Clients, Number of Phases, Simulated Annealing, WMN-SA, WMNsOne of the key advantages of Wireless Mesh Networks (WMNs) is their importance for providing cost-efficient broadband connectivity. There are issues for achieving the network connectivity and user coverage, which are related with the node placement problem. We implemented a simulation system where we consider the router node placement problem in WMNs. We want to find the optimal distribution of router nodes in order to provide the best network connectivity and provide the best coverage in a set of randomly distributed clients. We modeled 3 different realistic distribution of mesh clients (Subway, Boulevard and Stadium models). From simulation results, we found that, in the case of Subway model distribution of mesh clients, connectivity and coverage reach maximum performance. For all 3 models, when the instance size increases, the performance decreases.