James K. Ho

Evaluating the World Wide Web: A Global Study of Commercial Sites

While commercial applications of the Internet proliferate, particularly in the form of business sites on the World Wide Web, on-line business is still relatively insignificant. One reason is that truly compelling applications have yet to be devised to penetrate the mass market. To help identify approaches that may eventually be successful, one must address the question of what value is being created on the Web. As a first step, this paper proposes a framework to evaluate Web sites from a customers perspective of value-added. A global study covering 1,800 sites, with representative samples from diverse industries and localities worldwide, is conducted to give a profile of commercial use of the World Wide Web in 1996.

Load balancing in the parallel optimization of block-angular linear programs

Decomposition algorithms for block-angular linear programs give rise to a natural, coarse-grained parallelism that can be exploited by processing the subproblems concurrently within a distributed-memory environment. The parallel efficiency of the distributed approach, however, is critically dependent on the duration of the inherently serial master phase relative to that of the bottleneck subproblem. This paper investigates strategies for improving efficiency in distributed Dantzig—Wolfe decomposition by better balancing the load between the master and subproblem processors. We report computational experience on an Intel iPSC/2 hypercube multiprocessor with test problems having dimensions up to about 30 000 rows, 87 000 columns, and 200 coupling constraints.

Topological Analysis of Online Auction Markets

Online auctions have demonstrated how e-commerce can transform business, and not merely transplant conventional processes to a new medium. The resulting emergence and growth of diverse markets pose the intriguing question of what ‘shape’ a given market is in at a particular moment of development. This work aims to construct a topological model based only on operational data, without any expert knowledge of the specific auction market, or economic details from the transactions. Using extensive analysis of data available on eBay.com, the foremost online auction platform to date, the dimensions for a topology are identified. A graphical model is then proposed to visualize this topology, for the purpose of comparing markets at different points of a life cycle, and whether they are efficient, or tend to favour either buyers or sellers. Preliminary results of such applications are presented. Potential extension and refinement of this topological model, and its use in analysing emerging markets are discussed.

Computing True Shadow Prices in Linear Programming.

Abstract : It is well known that in linear programming, the optimal values of the dual variables can be interpreted as shadow prices (marginal values) of the right-hand-side coefficients. However, this is true only under nondegeneracy assumptions. Since real problems are often degenerate, the output from conventional LP software regarding such marginal information can be misleading. This paper surveys and generalizes known results in this topic and demonstrates how true shadow prices can be computed with or without modification to existing software. Keywords: Optimization software.

On the efficacy of distributed simplex algorithms for linear programming

We consider the use of distributed computation to solve general unstructured linear programs by the inherently serial approach of the simplex method. Timing models for the distributed algorithms are presented to predict results which are then verified empirically. Our results contribute to the identification of all viable exploitations of distributed computing which is likely to become a prevalent environment.

Hyperlink Obsolescence in Scholarly Online Journals

Hyperlinks to resources available on the Web are commonly used in footnotes or citation of references in scholarly online journals. A review of three well-established online journals revealed that nearly half of such links are broken, raising questions regarding the archival integrity of the published material. Some practical recommendations are advanced for online journal editors and authors based on a consideration of the role of hyperlinked references.

Maximum Resolution Topology for Online Auction Markets

A topological model of an online auction market is a simultaneous graphical display of all the dimensions of its relevant database, providing a geometrical shape as a visually descriptive statistics of the market at any particular instance of its development. In particular, various dimensions were identified for constructing a multi-attribute dichotomy that can help discern relative advantages to buyers and sellers, using only available, operational data, and without expert knowledge of the items involved or the prices attained. With a reference subset of prejudged cases, the configuration of the dimensions and the angles among them can be optimized for a topology that maximizes the resolution of such dichotomies. The approach is illustrated in a global comparative study of four markets in five countries. It can be a useful tool for data mining and visualization in the design, study, and analysis of online auction markets.

Stock selection heuristics for interdependent items

Abstract In a distribution environment, the problem of choosing the best mix of items to stock frequently involves considerations of interdependencies between the items. We address the problem of selecting a subset of items to stock from among a large set of potential items, when the objective is to maximize net revenue subject to a budget constraint, and when the items may be options, complements, or substitutes for one another. We develop a nonlinear integer programming model for this stock selection problem, and propose heuristic methods for its solution. Computational testing with randomly generated problem instances indicate the practical viability of this approach for rationalizing stock choice.

Bridging the Academic Research and Business Practice with the New Media

Much academic research on information technology IT, systems IS, and management IM has been branded by practitioners in business as unusable, irrelevant, and unreadable. Consequently, it is highly unlikely that conventional outlets for such work, e.g. scholarly journals and conference proceedings can receive significant real-world exposure. By reversing the push-pull dynamics of information dissemination and retrieval in the New Media, alternative approaches are emerging. This article presents the history of a case in point with data recorded over a period of 15 months. It is shown that the Internet in general, and the World Wide Web in particular, will be a significant resource in bridging the gap between practice and relevant research.

Distributed nested decomposition of staircase linear programs

This article considers the application of a primal nested-decomposition method to solve staircase linear programs (SLPs) on distributed-memory, multiple-instruction-multiple-data computers. Due to the coupling that exists among the stages of an SLP, a standard parallel-decompositon algorithm for these problems would allow only a subset of the subproblem processes to overlap with one another at any give time. We propose algorithms that seek to increase the amount of overlap among the processes as well as utilize idle time beneficially. Computational results testing the effectiveness of our algoritms are reported, using a standard set of test problems.