Stephen P. Bradley

Fractional Programming with Homogeneous Functions

This paper extends the well known results for linear fractional programming to the class of programming problems involving the ratio of nonlinear functionals subject to nonlinear constraints, where the constraints are homogeneous of degree one and the functionals are homogeneous of degree one to within a constant. Two rather general auxiliary problems are developed, and the relations between the solutions of the auxiliary problems and the solutions of the original problem are codified. Applications of the results for specific problems are also presented.

Toward an evolution strategy for the digital goods business

Purpose – The purpose of this conceptual paper is to provide a typology for classification of the digital goods business (DGB), analyzing its characteristics with selected cases, to suggest an evolution strategy appropriate for todays digital business economy, and to address the research implications.Design/methodology/approach – Based on a focus group interview, the study identified and classified the DGB models into four types in terms of sales channels and service methods, and further proposed five evolution strategies for the DGM.Findings – The paper proposes five evolution strategies for the DGB: from streaming direct to streaming intermediary; from download direct to download intermediary; from download intermediary to streaming intermediary; from download direct to streaming direct; and from download direct to streaming intermediary. These evaluation strategies will be suitably applicable to the type of digital goods for which a business strives.Research limitations/implications – As the study is ...

Equivalent Mathematical Programming Models of Pure Capital Rationing

In the applications of mathematical programming to the “pure capital rationing” problem, much of the attention has been focused on the search for an appropriate discount rate to account for the time value of money. The essential difficulty was first observed by Hirshleifer [10] in the classical economics context: “The discount rate to be used for calculating present values…cannot be discovered until the solution is attained, and so is of no assistance in reaching the solution.” Baumol and Quandt [1] showed that this problem persists in the Lorie and Savage [11] and Weingartner [15, Chap. 3] mathematical programming formulation and concluded that: “If there is capital rationing and external rates of interest are irrelevant, we cannot simultaneously insist on a present value formulation of the objective function and have the relevant discount rates determined internally by our program.” They then went on to propose an alternative utility formulation of the objective function.

U-business: a taxonomy and growth strategies

U-business uses ubiquitous computing technologies to support uninterrupted communications in business transactions to gain competitive advantage. This study seeks to identify patterns underlying successful U-business growth. It follows four stages: 1 dimensions important for the study of U-business growth strategies were identified through examining past cases. Two dimensions were identified: nature of change Improvement vs. Innovation and implementation environment Physical vs. Virtual Value Chain. 2 These dimensions were then used to build a taxonomy of U-business types and a growth strategy type was defined as a transition from one of these types to another. 3 A focus group consisting of U-business and UbiComp experts was then used to validate these dimensions and generate hypotheses about successful strategies. 4 These strategies were then tested by using the transition strategies that Apple has used in its product offerings. These findings are used to provide guidelines about growth strategies for U-business companies.

A DYNAMIC MODEL FOR BOND PORTFOLIO MANAGEMENT

The bond portfolio problem is viewed as a multistage decision problem in which buy, sell, and hold decisions are made at successive (discrete) points in time. Normative models of this decision problem tend to become very large, particularly when its dynamic structure and the uncertainty of future interest rates and cash flows are incorporated in the model. In this paper we present a multiple period bond portfolio model and suggest a new approach for efficiently solving problems which are large enough to make use of as much information as portfolio managers can reasonably provide. The procedure utilizes the decomposition algorithm of mathematical programming and an efficient technique developed for solving subproblems of the overall portfolio model. The key to the procedure is the definition of subproblems which are easily solved via a simple recursive relationship.