Gauge Backgrounds and Zero-Mode Counting in F-Theory

Computing the exact spectrum of charged massless matter is a crucial step towards understanding the effective field theory describing F-theory vacua in four dimensions. In this work we further develop a coherent framework to determine the charged massless matter in F-theory compactified on elliptic fourfolds, and demonstrate its application in a concrete example. The gauge background is represented, via duality with M-theory, by algebraic cycles modulo rational equivalence. Intersection theory within the Chow ring allows us to extract coherent sheaves on the base of the elliptic fibration whose cohomology groups encode the charged zero-mode spectrum. The dimensions of these cohomology groups are computed with the help of modern techniques from algebraic geometry, which we implement in the software gap. We exemplify this approach in models with an Abelian and non-Abelian gauge group and observe jumps in the exact massless spectrum as the complex structure moduli are varied. An extended mathematical appendix gives a self-contained introduction to the algebro-geometric concepts underlying our framework.Comment: 41 pages + extended appendice

Firm Assets and Investments in Open Source Software Products

Open source software (OSS) has recently emerged as a new way to organize innovation and product development in the software industry. This paper investigates the factors that explain the investment of profit-oriented firms in OSS products. Drawing on the resource-based theory of the firm, we focus on the role played by pre-OSS firm assets both upstream and downstream, in the software and the hardware dimensions, to explain the rate of product introduction in OSS. Using a self-assembled database of firms that have announced releases of OSS products during the period 1995-2003, we find that the intensity of product introduction can be explained by a strong position in software technology and downstream market presence in hardware. Firms with consolidated market presence in proprietary software and strong technological competences in hardware are more reluctant to shift to the new paradigm. The evidence is stronger for operating systems than for applications. The fear of cannibalization, the crucial role of absorptive capacity, and complementarities between hardware and software are plausible explanations behind our findings.Product Introduction, Open Source Software, Absorptive Capacity

Describing Agile Requirements Development and Communication using Complex Adaptive Systems Theory

Agile software development methods help software development teams respond to changing requirements. Fundamental to this ability to respond to change is the manner in which requirements are communicated and developed. The question of agile requirements development is considered through the lens of Complex Adaptive Systems theory, a theory used to explain agility in software development teams. A case study of the communication and development of requirements in a software development team is reported, where the three dimensions of CAS Theory described by Vidgen and Colleagues (Vidgen and Wang 2009) are adapted to describe requirements communication and development practices in greater detail. We find that this focus on requirements practices can further explain increases in a software team’s agility

A MATLAB Package for Markov Chain Monte Carlo with a Multi-Unidimensional IRT Model

Unidimensional item response theory (IRT) models are useful when each item is designed to measure some facet of a unified latent trait. In practical applications, items are not necessarily measuring the same underlying trait, and hence the more general multi-unidimensional model should be considered. This paper provides the requisite information and description of software that implements the Gibbs sampler for such models with two item parameters and a normal ogive form. The software developed is written in the MATLAB package IRTmu2no. The package is flexible enough to allow a user the choice to simulate binary response data with multiple dimensions, set the number of total or burn-in iterations, specify starting values or prior distributions for model parameters, check convergence of the Markov chain, as well as obtain Bayesian fit statistics. Illustrative examples are provided to demonstrate and validate the use of the software package.

Collaboration in Agile Software Development: Concept and Dimensions

One of the four values listed in the Agile Manifesto emphasizes customer collaboration over contract negotiation, yet the literature has not explained what constitutes customer collaboration and how to assess it. Little research has examined the nature and dimensions of collaboration in the context of agile software development. Based on a grounded theory methodology and using interview data collected from five software development outsourcing vendors in China, we explore the nature and key underlying dimensions of collaboration in agile software development. Five major dimensions of collaboration emerged from our analysis: mutual benefits, engagement, coordination, communication, and knowledge sharing. In turn, each dimension comprises key subdimensions that provide a comprehensive view of collaboration. By revealing the underlying nature and key dimensions, we provide a conceptual basis for operationalizing collaboration that one can employ in future quantitative studies on agility and other project outcomes. Our study results suggest that collaboration in agile software development is multifaceted and mutually occurring in both directions between the customer and the vendor rather than single dimensional as the term “customer collaboration” in the Agile Manifesto indicates

The dimensions of software engineering success

Software engineering research and practice are hampered by the lack of a well-understood, top-level dependent variable. Recent initiatives on General Theory of Software Engineering suggest a multifaceted variable – Software Engineering Success. However, its exact dimensions are unknown. This paper investigates the dimensions (not causes) of software engineering success. An interdisciplinary sample of 191 design professionals (68 in the software industry) were interviewed concerning their perceptions of success. Non-software designers (e.g. architects) were included to increase the breadth of ideas and facilitate comparative analysis. Transcripts were subjected to supervised, semi-automated semantic content analysis, including a software developer vs. other professionals comparison. Findings suggest that participants view their work as time-constrained projects with explicit clients and other stakeholders. Success depends on stakeholder impacts – financial, social, physical and emotional – and is understood through feedback. Concern with meeting explicit requirements is peculiar to software engineering and design is not equated with aesthetics in many other fields. Software engineering success is a complex multifaceted variable, which cannot sufficiently be explained by traditional dimensions including user satisfaction, profitability or meeting requirements, budgets and schedules. A proto-theory of success is proposed, which models success as the net impact on a particular stakeholder at a particular time. Stakeholder impacts are driven by project efficiency, artifact quality and market performance. Success is not additive, e.g., ‘low’ success for clients does not average with ‘high’ success for developers to make ‘moderate’ success overall; rather, a project may be simultaneously successful and unsuccessful from different perspectives

A RELIABLE METHOD TO ANALYSE SOCIAL NETWORK SITES WITH INTERVIEWS

The paper determine the dimensions of social capital which has been described from Sander / Teh (Sander & Teh, 2014a). The dimensions can be used to measure and identify social capital in social network sites. The dimensions are formulated on a theoretical basis. The aim of the paper is to explore the use of social network sites by students and to identify parts of the social capital theory in social network sites under consideration of the framework. This paper use the results of 59 structured interviews with students analysed with a software to explore the behaviour of students in social network sites under consideration of the social capital theory. The second purpose for this paper is to use a method to analyse expert interviews as a qualitative method with a software. The software provides an objective perspective on the data as good as objective a method can be. This method can give critical feedback about an individual interpretation from a human researcher and new insights in the collected data. Further provides the method a reliable result for interviews as any replication provide the same result

A RELIABLE METHOD TO ANALYSE SOCIAL NETWORK SITES WITH INTERVIEWS

The paper determine the dimensions of social capital which has been described from Sander / Teh (Sander & Teh, 2014a). The dimensions can be used to measure and identify social capital in social network sites. The dimensions are formulated on a theoretical basis. The aim of the paper is to explore the use of social network sites by students and to identify parts of the social capital theory in social network sites under consideration of the framework. This paper use the results of 59 structured interviews with students analysed with a software to explore the behaviour of students in social network sites under consideration of the social capital theory. The second purpose for this paper is to use a method to analyse expert interviews as a qualitative method with a software. The software provides an objective perspective on the data as good as objective a method can be. This method can give critical feedback about an individual interpretation from a human researcher and new insights in the collected data. Further provides the method a reliable result for interviews as any replication provide the same result