726 research outputs found
Commuting difference operators arising from the elliptic C_2^{(1)}-face model
We study a pair of commuting difference operators arising from the elliptic
C_2^{(1)}-face model. The operators, whose coefficients are expressed in terms
of the Jacobi's elliptic theta function, act on the space of meromorphic
functions on the weight space of the C_2 type simple Lie algebra. We show that
the space of functions spanned by the level one characters of the affine Lie
algebra sp(4,C) is invariant under the action of the difference operators.Comment: latex2e file, 19 pages, no figures; added reference
Implementation and evaluation of a simulation system based on particle swarm optimisation for node placement problem in wireless mesh networks
With the fast development of wireless technologies, wireless mesh networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless internet connectivity. This paper implements a simulation system based on particle swarm optimisation (PSO) in order to solve the problem of mesh router placement in WMNs. Four replacement methods of mesh routers are considered: constriction method (CM), random inertia weight method (RIWM), linearly decreasing Vmax method (LDVM) and linearly decreasing inertia weight method (LDIWM). Simulation results are provided, showing that the CM converges very fast, but has the worst performance among the methods. The considered performance metrics are the size of giant component (SGC) and the number of covered mesh clients (NCMC). The RIWM converges fast and the performance is good. The LDIWM is a combination of RIWM and LDVM. The LDVM converges after 170 number of phases but has a good performance.Peer ReviewedPostprint (author's final draft
The importance of C-terminal residues of vertebrate and invertebrate tachykinins for their contractile activities in gut tissues
AbstractThe C-terminal residues of mammalian tachykinins and urechistachykinins (Uru-TKs), tachykinin-related peptides of echiuroid worm origin, were substituted for each other. Their contractile effects were assayed on the cockroach hindgut and the guinea pig ileum. [Met10] substitution of Uru-TKs caused a 1000 times lower activity on the hindgut, but a 1000 times higher activity on the ileum. In contrast, [Arg11]substance P (SP) was 100 times more and 400 times less potent than SP on the hindgut and ileum, respectively. A SP antagonist blocked these Uru-TK activities on the hindgut. These results demonstrated that the C-terminal Met-NH2 is necessary for ileum contraction and the Arg-NH2 is required for hindgut contraction, which was caused by binding to the cockroach’s neurokinin-like receptor
Node placement in Wireless Mesh Networks: a comparison study of WMN-SA and WMN-PSO simulation systems
(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented a simulation system based on Simulated Annealing (SA) for solving node placement problem in wireless mesh networks, called WMN-SA. Also, we implemented a Particle Swarm Optimization (PSO) based simulation system, called WMN-PSO. In this paper, we compare two systems considering calculation time. From the simulation results, when the area size is 32 × 32 and 64 × 64, WMN-SA is better than WMN-PSO. When the area size is 128 × 128, WMN-SA performs better than WMN-PSO. However, WMN-SA needs more calculation time than WMN-PSO.Peer ReviewedPostprint (author's final draft
Investigation of fitness function weight-coefficients for optimization in WMN-PSO simulation system
(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented a simulation system based on Particle Swam Optimization for solving node placement problem in wireless mesh networks, called WMN-PSO. In this paper, we use Size of Giant Component (SGC) and Number of Covered Mesh Clients (NCMC) as metrics for optimization. Then, we analyze effects of weight-coefficients for SGC and NCMC. From the simulation results, we found that the best values of the weight-coefficients for SGC and NCMC are 0.7 and 0.3, respectively.Peer ReviewedPostprint (author's final draft
Performance evaluation of WMN-GA for different mutation and crossover rates considering number of covered users parameter
Node placement problems have been long investigated in the optimization field due to numerous applications in location science and classification. Facility location problems are showing their usefulness to communication networks, and more especially from Wireless Mesh Networks (WMNs) field. Recently, such problems are showing their usefulness to communication networks, where facilities could be servers or routers offering connectivity services to clients. In this paper, we deal with the effect of mutation and crossover operators in GA for node placement problem. We evaluate the performance of the proposed system using different selection operators and different distributions of router nodes considering number of covered users parameter. The simulation results show that for Linear and Exponential ranking methods, the system has a good performance for all rates of crossover and mutation.Peer ReviewedPostprint (published version
A GA-based simulation system for WMNs: performance analysis for different WMN architectures considering transmission rate and OLRS protocol
(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.In this paper, we evaluate the performance of two WMN architectures considering throughput, delay, jitter and fairness index metrics. For simulations, we used ns-3. We compare the performance for two architectures considering transmission rate and OLSR protocol. The simulation results show that for transmission rate 600 and 1200 [kbps], the throughput of Hybrid WMN is higher than I/B WMN. For transmission rate 600 and 1200 [kbps], the delay and jitter of Hybrid WMN is lower than I/B WMN. For transmission rate 600 and 1200 [kbps], the fairness index of I/B WMN is higher than Hybrid WMN.Peer ReviewedPostprint (author's final draft
<Summary of Doctorate>Comparative Aspects of Structure and Action of Bioactive Substances in the Ventral Nerve Cord of Urechis Unicinctus
Performance evaluation considering iterations per phase and SA temperature in WMN-SA system
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. In this work, we consider Simulated Annealing Algorithm (SA) temperature and Iteration per phase for 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 Normal distributed clients. From simulation results, we found how to optimize both the size of Giant Component and number of covered mesh clients. When the number of iterations per phase is big, the performance is better in WMN-SA System. From for SA temperature, when SA temperature is 0 and 1, the performance is almost same. When SA temperature is 2 and 3 or more, the performance decrease because there are many kick ups.Peer ReviewedPostprint (published version
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