32636956
Viral System to Solve Optimization Problems: An Immune-Inspired Computational Intelligence Approach
This paper presents Viral System as a new immune-inspired computational intelligence approach to deal with optimization problems. The effectiveness of the approach is tested on the Steiner problem in networks a well known NP-Hard problem providing great quality solutions in the order of the best known approaches or even improving them.
16750894
A Genetic Algorithm for Solving a Production and Delivery Scheduling Problem with Time Windows
This paper deals with the problem of selecting and scheduling a set of orders to be processed by a manufacturing plant and immediately delivered to the customer site. Constraints to be considered are the limited production capacity, the available number of vehicles and the time windows within which orders must be served. We describe the problem relating it to similar problems studied in the literature. A genetic algorithm to solve the problem is developed and tested empirically with randomly generated problems. Comparisons with an exact procedure and a tabu search procedure show that the method finds very good-quality solutions.
32057483
An Evolutionary Algorithm for the Design of Hybrid Fiber Optic-Coaxial Cable Networks in Small Urban Areas
Telecommunication is one of the fastest growing business sectors. Future networks will need to integrate a wide variety of services demanding different qualities and capacities from the network. In this paper, network architecture based on hybrid fiber optic-coaxial cable (HFC) is proposed to develop cable integrated telematic services. An evolutionary algorithm is presented to solve the problem in suitable computation times when dealing with real times civil works problems. Finally we present the results over both problem library and real life scenarios.
206167311
Genetic algorithm for planning cable telecommunication networks
Abstract Optical fiber networks over synchronous digital hierarchy operating on ATM mode appear as one of the best alternatives for the new high-speed telecommunications networks. The network management requires planning studies so that the designed networks allow efficient operation in real time. A quantitative model evaluating the global topological design of an optical fiber network over synchronous digital hierarchy is described. The model includes the economic aspects involved in the project, the civil works, the capacity evaluation costs and the introduction of reliability conditions. A genetic approach based on the exploitation of the Kuhn–Tucker optimality conditions is proposed to solve the model.
7433683
Viral systems: A new bio-inspired optimisation approach
The paper presents a new approach to deal with combinatorial problems. It makes use of a biological analogy inspired by the performance of viruses. The replication mechanism, as well as the hosts' infection processes is used to generate a metaheuristic that allows the obtention of valuable results. The viral system (VS) theoretical context is described and it is applied to a library of medium-to-large-sized cases of the Steiner problem for which the optimal solution is known. The method is compared with the metaheuristics that have provided the best results for the Steiner problem. The VS provides better solutions than genetic algorithms and certain tabu search approaches. For the most sophisticated tabu search approaches (the best metaheuristic approximations to the Steiner problem solution) VS provides solutions of similar quality.
810767
A novel approach to improve the performance of interconnection networks with hot-spots
Congestion in interconnection networks due to the presence of hot spots is an important and difficult problem that occurs in parallel machines. This problem has been studied in depth and different solutions for the case of multiprocessors with shared memory have been proposed. Current trends point towards the implementation of systems with physically distributed memory, either based on, message passing (multicomputers) or on a single shared memory address space (multiprocessors). Our paper is developed in this context. Up to now, proposals to improve the throughput of networks with hot-spots have focused on using virtual channels or adaptive algorithms. We present a novel solution based on reconfigurable networks. A reconfigurable network is one in which nodes can change their position depending on the communication pattern in order to diminish the congestion produced in the network and, therefore, increase its throughput. We studied this problem in two-dimensional k-ary n-cube networks using a deterministic routing algorithm and wormhole routing. In this paper the main features of a reconfigurable network are presented and the results obtained by simulation are shown. These results confirm that this technique is a very interesting one for systems with distributed memory, with applications to a great variety of problems.
17271240
DualFS: a new journaling file system without meta-data duplication
In this paper we introduce DualFS, a new high performance journaling file system that puts data and meta-data on different devices (usually, two partitions on the same disk or on different disks), and manages them in very different ways. Unlike other journaling file systems, DualFS has only one copy of every meta-data block. This copy is in the meta-data device, a log which is used by DualFS both to read and to write meta-data blocks. By avoiding a time-expensive extra copy of meta-data blocks, DualFS can achieve a good performance as compared to other journaling file systems. Indeed, we have implemented a DualFS prototype, which has been evaluated with microbenchmarks and macrobenchmarks, and we have found that DualFS greatly reduces the total I/O time taken by the file system in most cases (up to 97%), whereas it slightly increases the total I/O time only in a few and limited cases.
18834648
Design and Implementation of a Grid-Enabled Component Container for CORBA Lightweight Components
Although Grid technology appears as a promising infrastructure for global computation and effective resource sharing, the development of Grid Applications is still based in traditional programming models such as Message Passing Interface (MPI), making it difficult to provide a good level of software reuse and productivity. Moreover, the Grid offers an environment where the component technology can be applied to a greater extent than ever, due to the intrinsic security enforced by the Grid, allowing the creation of a successful component market. Component technology accelerates software development enforcing software reuse and sharing. In this article we present CORBA-\(\mathcal{LC}\) and the design of its Container, that manage components and provides them with non-functional aspects such as security, concurrency, distribution, load balancing, fault tolerance, replication, data-parallelism, etc. Component implementors can thus focus only on the component functionality itself, independently of these aspects, provided by the Container. Furthermore, we identify these non-functional aspects in the Grid Computing domain and show the current status of the implementation.
11189945
Reconfigurable Wormhole Networks: A Realistic Approach
The major problem in an interconnection network is related with the contention due to message blocking. In order to avoid this problem, many alternatives have been proposed in the literature, mainly adaptive routing, random routing and dynamic network reconfiguration. Our paper deals with dynamic reconfigurable networks. Reconfigurable networks are an alternative to reduce the negative effect that congestion produces on the performance of the network. Network reconfiguration can be done in different ways. Our researches are focused on dynamic reconfiguration. This technique consists basically of placing the different processors in the network in those positions which, at each computational moment and according to the existing communication pattern among them, are more adequate for the development of such computation.
41430454
An Evaluation of Parallel Computing in PC Clusters with Fast Ethernet
Currently, clusters of Personal Computers (PCs) with sharing Fast Ethernet may offer a significant price/performance ratio in parallel processing. This paper presents a study of the promising possibilities of parallelism in this environment, using both a classical numerical method to solve a differential equation and an innovative algorithm to solve the statistical problem of density estimation. In addition, and to compare, some comparisons with an IBM SP2 are carried out.