Strategies for Dynamic Network Management

We study management of transport networks based on virtual paths, i.e. rearrangable end-to-end transport network \highways". Among its main advantages are found cost savings, network op- eration simplification and enhanced network management capabilities. Virtual paths networks are readily implemented in any network using the synchronous digital hierarchy and/or the asyn- chronous transfer mode. Algorithms for virtual path designs are reviewed and found to have a few shortcomings. A new algorithm is therefore proposed and it is found to compare favourably with the algorithm providing the most similar features. Applying the proposed algorithm to a large number of networks, we discuss operational con- siderations associated with reconfigurable networks and investigate simple traffic estimation pro- cedures and their performance in this context. Finally, the choice of reconfiguration parameters such as updating frequency, and the impact of network design time are examined

Strategies for Dynamic Capacity Management

We study networks based on virtual paths, i.e. rearrangable end-to-end transport network. Virtual paths networks are readily implemented in any network using the synchronous digital hierarchy and/or the asynchronous transfer mode. The concept and its advantages, for example cost savings, network operation simplification and enhanced network management capabilities, are discussed. Algorithms for virtual path designs are reviewed and a new algorithm is presented which is found to compare favourably with the algorithm providing the most similar features. Applying it to a real network, we turn to operational aspects of reconfigurable networks such as methods and parameters for traffic estimation and network updating. The validity of the results is demonstrated by means of simulations of a number of networks subject to variable traffics

On Dynamic Capacity Management in Voice/Frame Relaying Networks

We consider call admission and capacity management in a dynamically reconfigurable network that carries a multitude of traffics. Our approach is a heuristic capacity as- signment algorithm designed to maximise an arbitrary profit function. The algorithm is based on the concept of equivalent circuits, i.e. a given relationship between transmis- sion capacities and call handling capabilities expressed as effective numbers of circuits. Such relationships are examined for the two traffics of our application, voice and frame relaying. Methods and results are independent of the transfer mode used

An Optimal Execution Time Estimate of Static versus Dynamic Allocation in Multiprocessor Systems

Consider a multiprocessor with $k$ identical processors, executing parallel programs consisting of $n$ processes. Let $T_s(P)$ and $T_d(P)$ denote the execution times for the program $P$ with optimal static and dynamic allocations respectively, i. e. allocations giving minimal execution time. We derive a general and explicit formula for the maximal execution time ratio $g(n,k)=\max T_s(P)/T_d(P)$, where the maximum is taken over all programs $P$ consisting of $n$ processes. Any interprocess dependency structure for the programs $P$ is allowed, only avoiding deadlock. Overhead for synchronization and reallocation is neglected. Basic properties of the function $g(n,k)$ are established, from which we obtain a global description of the function. Plots of $g(n,k)$ are included. The results are obtained by investigating a mathematical formulation. The mathematical tools involved are essentially tools of elementary combinatorics. The formula is a combinatorial function applied on certain extremal matrices corresponding to extremal programs. It is mathematically complicated but rapidly computed for reasonable $n$ and $k$, in contrast to the np-completeness of the problems of finding optimal allocations

Performance Comparison of Bursty Traffic Models

Models of bursty arrival processes are reviewed and compared with re- spect to their in uence on the performance of a single server system. Considerable variations are found between different models fitted to the same traffic, though some models exhibit similar behaviour. Comparing the ability of the models to reproduce the performance of an explicitly given parcel they all tend to fail

Evaluating Business Intelligence Software - Testing the SSAV Model

Choosing the right Business Intelligence (BI) software is critical to increasing productivity and effectiveness in organizations today. At the same time it is a very elaborating and complex process to choose the right software due to the fact that a large number of BI products exist on the market, which are quite different and updated frequently. The objective of this study is to develop and test a model for the evaluation of BI Software. The findings of the study revealed that it is difficult to declare what is the most competitive BI software as what is good for one user might not be good for another depending on their different business needs. Having said that the study initiated a new classification of BI Software vendors depending on the degree to which they comply with the functions in the Competitive Intelligence (CI) cycle. The software tested was divided into five categories: Fully complete, Complete, Semi Complete, Incomplete and Insubstantial. We conclude that the SSAV (Solberg Søilen, Amara, Vriens) Model Together with some proposed non technological variables and a classification developed can be used as a user's selection tool for deciding which BI Software to purchase

Enhancing supply chain collaboration in automotive industry by value driven simulation

This paper presents a computer-based approach for conceptual design that aims to enhance collaborative supply chain development in the automotive sector when dealing with product-service development or radical innovations. The focus of the research has been to design a simulation approach that will enable designers and managers to simulate and evaluate the value of different design options for the different stakeholders involved in the development process and to have insights about the implications between business model innovation and the engineered aspects of the solutions early in the conceptual phase. The approach is presented using a case study within the current project, after following a team responsible for the car cockpit. Four possible scenario have been simulated and evaluated using a commercial simulation software. The main advantage of the proposed approach is to enhance the awareness among designers and managers of the value of different design options, and allow them to explore further how business and design aspects profoundly affect each other, in order to support early decision-making in the design process