Showing papers on "Network planning and design published in 1977"

Network Design: An Algorithm for the Access Facility Location Problem

Abstract: In any network where a large number of widely dispersed "users" share a limited number of "resources," the strategy for access will play a large part in determining the cost and performance of the network. In this paper we consider a topological design aspect of the access problem. In particular, we consider the problem of locating "access facilities," or concentration points, to obtain an economic connection of users to resources. The problem is formulated as the locating of generic access facilities (GAF's) to obtain an economic connection of nodes (users) to a resource connection point (RESCOP). The nodes may be connected through multipoint lines, but with a constraint on the number of nodes which may share a single line. The GAF's are constrained in capacity, expressed as the number of nodes they can support, and have a cost associated with them. The basic solution technique presented is a heuristic algorithm characterized by the following four steps. 1) Simplify the problem to a point-to-point problem by replacing clusters of nodes by single "center-of-mass" (COM) nodes. 2) Partition the reduced set of COM nodes by applying an Add algorithm, resulting in one of the COM nodes selected as a GAF site. 3) Select one of the original nodes as a real GAF site in each partition by examining the original nodes closest to the COM node selected in the Add algorithm, and selecting the best. 4) Apply a line-layout algorithm to each partition, with its selected GAF site serving as the central node.

A Discrete-Convex Programming Approach to the Simultaneous Optimization of Land Use and Transportation

Abstract: Three design problems are discussed in this article. First, it is shown that the network design problem with congestion reduces to an all-or nothing traffic assignment problem under some assumptions on the congestion function and the investment cost function. Second, the land use design problem is formulated as an extension of the Koopmans-Beckmann problem and a heuristic is proposed to solve this problem. Third, it is shown that the seemingly more complex problem of designing jointly a land-use plan and a transportation network reduces to a pure land-use design problem. All that is needed to solve the joint optimization problem is a shortest path algorithm and a heuristic to solve the land use design problem. Computational experience is reported for each algorithm.

Planning considerations for alternative transit route structures

Abstract: Transit route structures historically have focused on the central business district (CBD), and this orientation is often reinforced by planners wishing to improve transit. Unfortunately, their efforts have not halted the historic decline in transit usage. This result is not surprising. Travel to the CBD generally constitutes a small and declining percentage of the total. It would appear that planners wishing to achieve higher overall transit ridership should instead develop transit route structures oriented to larger and increasing segments of the spectrum of travel within the region. Network design configurations oriented to this objective exist. They include the grid and timed transfer system concepts. These designs are multi-destination systems, allowing travelers the ability to conveniently get from many points of origin to many points of destination throughout the metropolitan area. With a significantly smaller deficit per passenger trip, they can theoretically attract many more passengers t...

A generalized upper bounding approach to a communications network planning problem

Abstract: An important network optimization problem is to determine the routing of circuits and construction of additional are capacity in a communications network so as to satisfy forecasted circuit requirements at minimum cost. This paper considers the single-time-period version of the problem formulated as a linear program in the arc-chain form. The special structure of this linear program is exploited to develop an efficient solution procedure. In particular, the generalized upper bounding technique devised by Dantzig and Van Slyke is applied. The computer implementation of the procedure is discussed and computational experience is reported. Brief mention is also made of certain extensions that are being pursued.

Mathematical programming in sewer network design

Abstract: This paper addresses itself to the question of obtaining the minimum cost design for a wastewater collection network. It first presents an empirical cost function for a single sewer line. The concept of optimization is then explored with respect lo sewer networks. The design problems of selecting an optimal mix of pipe diameters and slopes, given a set of economic and technological inputs as well as a network layout is then presented in three alternative mathematical programming formulations: separable convex, dynamic and geometric programming. These formulations guarantee the generation of global optimal solutions. Numerical solutions can be obtained using presently available computer capabilities. The paper concludes with an evaluation of the proposed formulations and their implications for both design practice and overall cost reduction in the area of wastewater collection.

Topological Design of Distributed Data Communication Networks Using Linear Regression Clustering

Abstract: A new network decomposition-optimization algorithm is presented and evaluated via computer simulation. The network is first partitioned into subnetworks on the basis of lines fitted via linear regression to the node locations weighted by their traffic loads. Each node is then connected via a data line of appropriate capacity to a concentrator-multiplexer. The concentrators are then regarded as nodes, and the process is repeated as often as required. The resulting singly connected network consists of a hierarchy of concentrators whose number, capacity, location, and interconnection are selected as an inherent part of the design procedure to minimize network cost. The linear regression clustering (LRC) design procedure is evaluated via computer simulation by comparing the costs and performance of the resulting networks with that which results from use of an algorithm based on the generally applicable network design approach of iterative local optimizations or "search" procedures. The data supplied to the LRC and search algorithms include randomly generated node locations and traffic matrices, and specific (realistic) cost vs. capacity schedules for data lines and concentrators. Comparisons of network costs, queuing and transmission delays, network reliability and network design costs show the LRC algorithm to be markedly superior to the search algorithm. The paper includes a brief discussion of our results, and their implications.

The Economic Basis of Resource Information Systems: The Case of Streamflow Data Network Design

Abstract: A general method for the economic design of natural resource information systems is presented for a certain class of natural phenomena. The system design is determined by the interaction of the technical input-output relationship, i.e., the production function, the set of resource constraints, and an economic loss function defined in terms of parameter uncertainty. An application of the proposed method to streamflow network design is presented. Results of this analysis indicate that the method is fairly robust with respect to the assumptions. Observations are made which suggest extensions to flood measurement networks, long-term precipitation networks, and seismic observation network design.

Decomposition approach to bus network design

Abstract: This paper presents a decomposition approach to bus network design in which the task of network design is accomplished through the optimization of a series of subproblems. Bus routes are classified into several types, each having a different development priority. The basis design unit in the proposed approach is a development stage. Only one type of bus route is to be considered in each stage. After the number of bus routes to be included in each stage is determined, the origins and destinations of potential routes are identified. Optimal alignment connecting each pair or origin and destination is subsequently located.

An IEEE meeting on subjective testing of voiceband codecs

Abstract: Subjective testing of existing and proposed communication systems is an important element of network planning and equipment design. With the evolution over the years of world telecommunications, the nature and levels of impairments experienced by system users have changed,and as a consequence, a variety of subjective testing procedures have come into existence. Discusses the technologies, communications services, and applications that support effective network strategic planning.

Computer code for transportation network design and analysis

Abstract: This document describes the results of research into the application of the mathematical programming technique of decomposition to practical transportation network problems. A computer code called Catnap (for Control Analysis Transportation Network Analysis Program) has been developed in the course of this study; this code has the capability to solve the following problems: (1) The traffic assignment problem with fixed demands; (2) The transportation network design problem with or without a budget constraint; (3) The optimal staging problem for transportation network investments over a fixed time horizon. In this report the authors describe the basic structure and algorithms employed in Catnap and give actual numerical results obtained in some representative sample problems. These results indicated that Catnap is an improvement over existing transportation network codes, particularly for solving the network design problem.

Management of large scale computer program production

Abstract: This paper describes a management/computer interactive system for the planning and control of the development of computer software programs on a large scale.Linked planning (PERT type) networks are used to represent the basic information model. This composite network is formed within the computer from individual networks using computerized library techniques. The model then represents the overall definition of the projected work load.This information model is then manipulated by varying both the planning data (resources available, etc.) and scheduling parameters. Multi-project scheduling methods, using advanced resource allocation procedures, are then employed to rapidly obtain basic planning information (manpower loading, completion dates, costs, etc.).These basic concepts are established within a framework of a flexible system which responds to changes in product requirements, resource availability levels and project priorities. The interaction between management and the computer based network planning system enables the work to be effectively planned and provides a sound basis for subsequent control.

Design and implementation of a local computer network

Abstract: An intralaboratory computer communications network was designed and is being implemented at Argonne National Laboratory. Parameters which were considered to be important in the network design are discussed; and the network, including its hardware and software components, is described. A discussion of the relationship between computer networks and distributed processing systems is also presented. The problems which the network is designed to solve and the consequent network structure represent considerations which are of general interest. 5 figures.

Logistics Network Design: A Simulation Study of a Nursery Stock Channel

Abstract: This study describes a simulation approach to the design of a logistics network involving the processes of growing and distributing a classifica‐tion of forest products. Since this activity represents a new venture for the particular firm involved, the advantage exists of being able to approach the problem in a perspective with few restrictions or limitations from a network design viewpoint. Although the logistics considerations involved in this study relate to a particular industry or product line, i.e., nursery stock, it is felt that the approach to the network design is generalisable, with minor modifications, to other manufactured or agricultural products. For American applications, the adaptation of the PICADAD System as the basis for an automated coding system is emphasised. The scope and objectives of the simulation model include examining the following components of the logistics network: (1) the number and location of facilities, i.e., production or growing points; (2) the product allocations, i.e., which product lines should be grown at which locations; and, (3) the transportation modes within the continental United States. As indicated, the emphasis focuses on the network concerns of nodes and linkages; secondary issues regarding logistics, namely packaging, materials handling, and communication or order processing, are beyond the scope of the study.