Managing the supply chain has become vital to business success in the contemporary Electronic Commerce environment. There is broad agreement among practitioners and academics that integration, on a variety of dimensions, is the key to supply chain performance. Information integration is one important dimension, and the Internet is rapidly improving our ability to do so across global supply chains. Significant investments in information technology (IT) generally, and Internet technologies in particular, are being targeted specifically at supply chain management. The business impact of these IT investments depends not just on the information flows supported by these systems, but also on other physical characteristics of the supply chain. It is the complex interplay among information and non-information characteristics that results in business performance or the lack thereof.

An integer programming model and Lagrangian relaxation-based heuristic solution method is developed, to determine transmission capacity in private backbone networks using DCS's, such that multibusy-hour point-to-point circuit requirements can be met at low cost. It simultaneously determines capacity, routing and topology. Numerical results for T1 networks are shown.>

A method is developed for integrating heuristic design knowledge with optimization models to create a tool for the topological design of computer communication networks. Design choices are based on suggestions from optimization models, as well as heuristic knowledge, which interact through a blackboard. A truth maintenance system (TMS) records justification for current design choices, as well as promising alternatives. A dependency-directed backtracking mechanism works with the TMS to choose other alternatives as warranted. This hybrid tool can consider a wider range of design requirements than is possible using one type of knowledge alone, is flexible in handling variations in these requirements, and has a modular structure which facilitates incremental refinement. Computational results on separate networks show it is effective in identifying good low-cost solutions.>

A mathematical planning model is developed to help make cost effective decisions on key physical and operational parameters, for a satellite intended to provide customer premises services. The major characteristics of the model are: (1) interactions and tradeoffs among technical variables are formally captured; (2) values for capacity and operational parameters are obtained through optimization; (3) effects of physical and regulatory constraints are included; and (4) the effects of market prices for transmission capacity on planning variables are explicitly captured. The model is solved optimally using geometric programming methods. Sensitivity analysis yields coefficients, analogous to shadow prices, that quantitatively indicate the change in objective function value resulting from variations in input parameter values. This helps in determining the robustness of planning decisions and in coping with some of the uncertainty that exists at the planning stage. The model can therefore be useful in making economically viable planning decisions for communications satellites.>

Decisionmakers often have to deal with knowledge that is both unstructured and imprecise in nature. Lack of structure forces the use of heuristic programming and artificial intelligence methods in automated decision support systems for such problems. At the same time, the knowledge representation and manipulation methods used should be able to include imprecise knowledge, where imprecision may be caused by uncertainty and/or fuzziness. The authors use their previously developed methodology (see Decision Support Syst. vol.2, no.3, 1986 and vol.2, no.4, 1986) for using imprecise reasoning in decision support systems to describe a prototype system based on this methodology. The system's behavior is examined using a set of sample problems. The knowledge representation mechanisms used are shown to have significant expressive power and facilitate the knowledge of engineering process through greater flexibility in the representation and use of imprecise knowledge. The system is able to provide additional information to the user that cannot readily be provided in systems limited to precise reasoning.>

Abstract One of the major purposes of a high‐level language is to provide a large measure of machine‐Independence in the specification of algorithms. Definitions of languages such as FORTRAN IV and ALGOL 60 encourage compatibility between various implementations. Language specifications are inadequate in that they normally underdefine a language. In particular, the specifications do not normally demand a response to a language violation. The freedom normally given to an implementor to decide the degree and nature of error detection and response hinders portability and may lead to‐unexpected results when moving code from one machine to another or even when changing implementations on the same machine. To support the contention that languages should specify a response to violations, an analysis of four FORTRAN IV implementations and a FORTRAN IV verifier was conducted. The study showed that different implementations often lead to different results for the same illegal program. A study of programmers also revealed that they cannot be relied upon to avoid language violations without compiler aids.