Cloud computing advocates a promising paradigm that facilitates the access within heterogeneous services, platforms, and end users. However, platforms (or host servers) have confined to devices which require a conside...
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Cloud computing advocates a promising paradigm that facilitates the access within heterogeneous services, platforms, and end users. However, platforms (or host servers) have confined to devices which require a considerable computing resources. In this case, solutions concerning the efficient use of pervasive devices with constrained resources become an open issue. This study investigates the seamless connection between embedded devices and cloud resources to enhance the capability of computing and furthermore provide context-aware services. A method for wireless program dissemination and boot loading is proposed to transfer necessary information and resources between service and target device(s). The experiment results on time delay and energy cost demonstrate the feasibility and performance. (C) 2013 Elsevier B.V. All rights reserved.
Piecewise-Linear programming (PLP) is an important area of Mathematical programming and concerns the minimisation of a convex separable piecewise-linear objective function, subject to linear constraints. In this paper...
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Piecewise-Linear programming (PLP) is an important area of Mathematical programming and concerns the minimisation of a convex separable piecewise-linear objective function, subject to linear constraints. In this paper a subarea of PLP called network Piecewise-Linear programming (NPLP) is explored. The paper presents four specialised algorithms for NPLP: (Strongly Feasible) Primal Simplex, Dual Method, Out-of-Kilter and (Strongly Polynomial) Cost-Scaling and their relative efficiency is studied. A statistically designed experiment is used to perform a computational comparison of the algorithms. The response variable observed in the experiment is the CPU time to solve randomly generated network piecewise-linear problems classified according to problem class (Transportation, Transshipment and Circulation), problem size, extent of capacitation, and number of breakpoints per are. Results and conclusions on performance of the algorithms are reported.
In this paper, we present a branch and bound algorithm for solving the constrained entropy mathematical programming problem. Unlike other methods for solving this problem, our method solves more general problems with ...
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In this paper, we present a branch and bound algorithm for solving the constrained entropy mathematical programming problem. Unlike other methods for solving this problem, our method solves more general problems with inequality constraints. The advantage of the proposed technique is that the relaxed problem solved at each node is a singly constrained network problem. The;disadvantage is that the relaxed problem has twice as many variables as the original problem. An application to regional planning is given, and an example problem is solved.
Skid-trail locations directly influence the economics and environmental impacts of harvesting operations. Typically, field managers design skid-trail networks manually based on field observations of vegetation and ter...
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Skid-trail locations directly influence the economics and environmental impacts of harvesting operations. Typically, field managers design skid-trail networks manually based on field observations of vegetation and terrain conditions. We designed a model to automatically design skid-trail networks to reduce skidding costs and soil disturbances. The model simulates tree-bunch locations, creates a feasible skid-trail network across the harvest unit, estimates skidding cost and soil recovery cost for each feasible skid-trail segment, and finds the network design that connects each tree bunch to landings while reducing skidding and soil recovery costs. The model was applied to a 24-ha hypothetical harvest unit to test its ability to design optimal networks under different scenarios representing conditions commonly found in timber harvesting operations (e.g., skidding pattern, uneven volume distribution, skidding obstacles, and different weights given to skidding and soil recovery costs). It was also applied to an actual 124-ha harvest unit to evaluate its ability to design skid-trail networks considering more realistic conditions with multiple design factors. The model successfully created optimized skid-trail networks for all scenarios considered, and results suggest that it provides a useful tool to help forest engineers and field managers design economically efficient and environmentally sound ground-based timber harvesting operations.
The explosive growth of the Web, the increasing popularity of PCs and the advances in high-speed network access have brought distributed computing into the mainstream. To simplify network programming and to realize co...
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The explosive growth of the Web, the increasing popularity of PCs and the advances in high-speed network access have brought distributed computing into the mainstream. To simplify network programming and to realize component-based software architecture, distributed object models have emerged as standards. One of those models is distributed component object model (DCOM) which is a protocol that enables software components to communicate directly over a network in a reliable, and efficient manner. In this paper, we investigate an aspect of DCOM concerning software architecture and security mechanism. Also, we describe the concept of role-based access control (RBAC) which began with multi-user and multi-application on-line systems pioneered in the 1970s. And we investigate how we can enforce the role-based access control as a security provider within DCOM, specially in access security policy. (C) 2000 Elsevier Science B.V. All rights reserved.
Today, firms have to compete on international openness markets. The resulting production organisation is a multi-site production system. Several production units called sites have to supply irregular demands at the lo...
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Today, firms have to compete on international openness markets. The resulting production organisation is a multi-site production system. Several production units called sites have to supply irregular demands at the lower costs. We propose a two-level production management approach to control such systems. It results in a global multi-site production planning and in local multi-workshop scheduling. This paper focuses on the multi-site production planning problem. A primal-dual approach is proposed to solve this problem. It allows us to minimise variable and fixed costs. This heuristic has been experimented on a wide range of problem test data. (C) 2001 Elsevier Science B.V. All rights reserved.
In this paper, a shortest route formulation of simple U-type assembly line balancing (SULB) problem is presented and illustrated on a numerical example. This model is based on the shortest route model developed in [Ma...
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In this paper, a shortest route formulation of simple U-type assembly line balancing (SULB) problem is presented and illustrated on a numerical example. This model is based on the shortest route model developed in [Manage. Sci. 11 (2) (1964) 308.] for the traditional single model assembly line balancing problem. (C) 2004 Elsevier Inc. All rights reserved.
Many algorithms and applications call for the use of a network subprogram which must be optimized numerous times with slight changes to the problem data. Bound anal right-hand-side changes to an existing basis tree ma...
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Many algorithms and applications call for the use of a network subprogram which must be optimized numerous times with slight changes to the problem data. Bound anal right-hand-side changes to an existing basis tree may yield an infeasible basic solution. This report gives a sequence of steps that modify an existing basic solution to reflect such changes and streamline the reoptimization process. [ABSTRACT FROM AUTHOR]
The paper presents a computerized model for finding the single most economical landing location for ground-based timber harvesting and finding the least cost road path from the selected landing point to the existing o...
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The paper presents a computerized model for finding the single most economical landing location for ground-based timber harvesting and finding the least cost road path from the selected landing point to the existing off-road. The model uses raster-based GIS data and considers multiple design factors influencing the optimal landing location. Terrain conditions, the volume of stock distribution, downhill and uphill skidding directions, and distance to the existing road were the influencing design factors in the model. Three approaches were adopted for finding a landing location within three harvest units. In the first approach, a preliminary process evaluated all cells of a 20m x 20m network within the harvest units and determined the candidate landing cells with the largest gentle slope (<10%) area. In the second and third approaches, the points on a 50m x 50m mesh grid and the harvest units' centroids were assumed as candidate landings, respectively. The sum of skidding, road construction, and hauling costs was as total harvesting costs. Results indicated that the distance to the existing roads and the access direction from the existing road to the candidate landings could effectively limit the choice options for landing location. Results of feeding a penalized cost estimation model as an objective function to the modified Dijkstra's shortest path algorithm led to planning the road alignments with the least expected excavation and soil disturbance. Results also showed that the optimal landings could ensure the least total harvesting cost within the harvest unit.
In this paper, we study the single commodity flow problem, optimizing two objectives simultaneously. We propose a method that finds all the efficient extreme points in the objective space. This method is based on the ...
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In this paper, we study the single commodity flow problem, optimizing two objectives simultaneously. We propose a method that finds all the efficient extreme points in the objective space. This method is based on the well known method of Lee and Pulat, which also computes some efficient points of the objective space that are not extreme points. Our alternative method corrects this particularity by using the idea of adjacency among efficient extreme points in the objective space and introduces computational improvements that are shown in an experimental study. (C) 2000 Elsevier Science B.V. All rights reserved.
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