Francis Hunt

Release Management in Free Software Projects: Practices and Problems

Release management plays an important role in every software project since it is concerned with the delivery of a high quality product to end-users. This paper explores release practices employed by volunteer free software projects and shows problems that occur. A challenge that has been identified is the difficulty of coordinating a distributed team of volunteers in order to align their work for a release.

Valuation of technology: exploring a practical hybrid model

How much is this technology worth? This is a question of great interest and importance in a wide variety of circumstances. These vary from companies considering investing in R&D projects, to venture capitalists funding start-up companies. However, such valuation is notoriously difficult to get right, and the cost of failure can be very high. Many techniques have been proposed to assist managers facing this issue, from traditional discounted cash flow analysis to more recent methods based on real options thinking. This paper discusses the practicality of the various methods available, and explores the application of a hybrid model, which aims to make these rather abstract ideas more accessible to practicing managers.

Customizing the Technology Roadmapping Technique for Software Companies

Software importance keeps growing fast and consistently for many organizations. The growth of software functionality in manufactured products and the emergence of digital media, convergent spaces including digital content, software, and multi-channels to the market, are recent examples of organizational changes where software assumed a central position for the corporate strategy. This paper analyzes the alignment between strategic objectives and software development processes at software companies and proposes a methodology to ensure that development processes are aligned with the corporate capabilities required to exploit future market opportunities. The methodology includes the categorization of different software companies according to their core capabilities and the customization of the technology roadmapping technique for software companies. The research process included the realization of case studies and a survey

Modeling rainfall drop size distribution in southern England using a Gaussian Mixture Model

Understanding and modeling the rainfall drop size distribution is important in a number of applications, in particular predicting and mitigating attenuation of satellite signals in the millimeter band. Various standard statistical distributions have been proposed as suitable models, the first widely accepted being the exponential distribution. Subsequently, gamma and lognormal distributions have been shown to provide better rainfall rate computations. Some empirical studies have revealed bimodal distributions under some circumstances. A natural question to ask therefore is how often gamma and lognormal distributions fit the empirical data. In this paper we fit lognormal and gamma distributions to 1 min slices of rainfall drop size distributions taken from 7 year data from the Chilbolton Observatory in southern England. The chi-square goodness of fit of the models against the data is calculated, and it is found that failure to fit is greater than would normally be expected. This failure to fit is broken down and examined against seasonal variations, different rain rates, atmospheric temperature, and wind speed. Possible reasons for the lack of fit are explored, and alternative fits using models based on Gaussian Mixture Models are developed and found to be an improvement.

Exploiting Spatial Separations in CDMA Systems With Correlation Constrained Sets of Hadamard Matrices

Spreading codes for code-division multiple-access (CDMA) systems are constructed based on Hadamard matrices and almost-bent functions. These codes can be assigned to a tessellation of hexagonal cells in such a way that codewords assigned to the same cell or to adjacent cells have zero cross-correlation. The nonzero cross-correlations in the code only apply to pairs of codewords assigned to nonadjacent cells. The codes have four times as many codewords as codes constructed from a single Hadamard matrix, which leads to significantly increased codeword re-use distances in comparison with the conventional use of a single Hadamard matrix with the same number of codewords per cell.

The Construction of Orthogonal Variable Spreading Factor Codes from Semi-Bent Functions

In a recent paper spreading codes for CDMA systems were constructed based on Hadamard matrices and semi-bent functions. These codes were applicable to synchronous CDMA systems and to quasi-synchronous CDMA systems when a loosely-synchronized code is used. The codes consist of the union of rows of four Hadamard matrices. The codes can be assigned to a regular tessellation of hexagonal cells in such a way that the correlation between codewords assigned to adjacent cells is zero, while the correlation between codewords assigned to non-adjacent cells is small. The use of codewords from four Hadamard matrices allows greater codeword re-use distances than the use of codewords from a single Hadamard matrix. This has advantages for both satellite and terrestrial systems. These codes only support a single data rate. The current paper shows how orthogonal variable spreading factor codes can be created from them by a careful selection of the semi-bent functions used.

The Assignment of CDMA Spreading Codes Constructed from Hadamard Matrices and Almost Bent Functions

Almost bent functions and Hadamard matrices can be used to construct spreading codes for code-division multiple-access (CDMA) systems. Four specific Hadamard matrices can be constructed and each one can be divided into eight octants in such a way that spreading codewords from certain pairs of octants have zero correlation. It is possible to assign these octants to a regular tessellation of hexagonal cells in such a way that there is zero correlation between adjacent cells, small correlation between non-adjacent cells and a large codeword re-use distance. If synchronous CDMA is used in a satellite system, interference is reduced in comparison with the use of a single Hadamard matrix. In this case the regular hexagonal tessellation is usually a good model of the areas covered by satellite spot beams. The same approach can be advantageous when the Hadamard matrices are used to construct loosely synchronized codes for a terrestrial system. The tessellation of cells is unlikely to be a regular hexagonal tessellation and the question arises of whether an assignment to an irregular tessellation with these properties can be found. In this paper a positive answer is given to this question, confirming that the approach is applicable to a terrestrial system.

Internal technology valuation: real world issues

Although well-known, methods for valuing projects in the face of uncertainty, such as decision trees, do not seem to have been widely adopted by industry. This is despite widespread academic confidence that they should produce more realistic financial valuation of projects than naive use of discounted cash flow (DCF) techniques. An obvious question is why these tools have not been more widely adopted. In this paper we propose one reason for this. We argue that the ambiguity (i.e., the uncertainty about the uncertainties) in most technology valuations prevents significant increases in confidence in the financial valuations produced by techniques more sophisticated than DCF, although there may well be better understanding of the underlying issues. We illustrate this argument by considering the uncertainties in a technology development at an SME. We then reflect on the role of financial valuations at the early stage in technology projects, suggesting that they are to help create a credible story rather than provide definitive figures. We then suggest some avenues of further research. First of all, however, we review the literature on uncertainty and ambiguity, and on valuation of technology projects in the face of these challenges.

Multiple Perspectives On Appraisal Techniques For New Technologies: Examples From The Aerospace Industry

Appraising the benefits of new technologies is a commonly accepted challenge for any organization and is a prime area for technology management research. A wide variety of methods are available that intend to service this need, such as discounted cash-flow, real options, portfolio methods, roadmapping, etc. However, little evidence exists on who applies these techniques and how they are used in practice. This paper will evaluate the techniques from literature and compare the results with cases from the Aerospace industry. The paper will show that there are two distinct perspectives that can be taken when looking at the valuation process and these perspectives change in the course of the technologys life cycle.

An interdisciplinary perspective on business appraisals for technology potentials

Appraising the benefits of new technologies is a commonly accepted challenge for any organisation and is a prime area for technology management research. As the future potential of any technology is always associated with some level of uncertainty it is thus important to either reduce or better understand this uncertainty in order to make appropriate business decisions. A wide variety of methods are available that intend to service this need, such as net present value calculations, real options, portfolio methods, road-mapping, expert systems, etc. Technology companies often use a selection of or hybrid models. The problem is thus inherently interdisciplinary. The techniques used to appraise new technologies range from “hard” mathematics, often taken from the finance sector, to more “softer” techniques that enable people to systematically structure the potential outcomes and their underlying uncertainty. Furthermore, the use or purpose of the techniques can vary as well. Methods can be applied to justify decisions and judgements made, but also to support the process of shaping this judgement, or to provide boundary conditions and hence enable the decision making process. This paper aims to provide an overview of prevailing methods and tools and evaluate their relative value in the process of business appraisals. We will elaborate on the overlaps and gaps and conclude with recommendations for future research.