Distributed Development

Coralline algae are one of the most important constructors of biogenic habitats. In the Mediterranean Sea, the dominant coralline algae species form crusts comprising formations known as coralligène, considered as very important fishing grounds by fishermen. Due to the destructive effect of fishing gear activities over coralligène, these formations were recently protected from the use of active benthic gears by the EU 1967/2006 Mediterranean fisheries management Regulation. However, the lack of maps and information on their distribution makes the effective application of these measures impossible. The present publication contributes to the mapping of coralligène in the southern Aegean Sea (eastern Mediterranean), and to the study of coralline algae formation morphology, distribution, development conditions and relation to fisheries using a combination of single-beam echo sounder, sidescan sonar, sub-bottom profiler recordings and biological and sedimentological ground-truthing techniques. The coralligène formations were recognized as two distinct acoustic signatures of localized backscatter facies distinguishable from other hard substrate reflectors at depths ranging from 55.9 to 114.0 m, but mainly between 70 and 90 m. Two types of formations were identified: minute reefs 0.5-2.5 m in height and superficial layer formations no more than 0.2 m thick over the substrate. The seismic profiles revealed a cavernous internal structure of the minute reefs and recorded their development on both hard and soft substrates. The distribution of formations was contagious, creating aggregations. The finding of superficial layer formations and coralline shreds around minute coralligène reefs indicated that the former could be an intermediate development type between isolated small coralline pebbles, rhodoliths, and minute reefs. Regarding the development conditions, sidescan sonar imagery indicated that the optimal conditions for the establishment and development of coralligène formations are medium intensity currents. Concerning human activity over coralligène, trawl traces were recorded near but not over minute reefs and both near and crossing superficial layer type aggregations, while a submarine cable was also recorded among minute reefs. The mapping of coralligène aggregation areas is essential for the application of the EU Regulation and the protection of this important marine habitat.

In order to find distributions other than infinitely divisible distributions which are suitable for disjunctive kriging, infinitesimal generators are used. In addition to distributions developed in Part I, this leads to development of suitable models for the beta (~), hypergeometric, and binomial distributions.

Previous research [1, 2] has indicated that pair programming is better than individual programming when the pairs are physically colocated. However, important questions arise: How effective is pair programming if the pairs are not physically next to each other? What if the programmers are geographically distributed? An experiment was conducted to compare the different working arrangements of student teams developing object-oriented software. The teams were both colocated and in distributed environments; ...

The development of most large and complex systems necessarily involves many people+ach with their own perspectives on the system defined by their knowledge, responsibilities, and commitments. To address this we have advocated distributed development of specifications from multiple perspectives. However, this leads to problems of identifying and handling inconsistencies between such perspectives. Maintaining absolute consistency is not always possible. Often this is not even desirable since this can unnecessarily constrain the development process, and can lead to the loss of important information. Indeed since the real-world forces us to work with inconsistencies, we should formalize some of the usually informal or extra-logical ways of responding to them. This is not necessarily done by eradicating inconsistencies but rather by supplying logical rules specifying how we should act on them. To achieve this, we combine two lines of existing research: the Viewpoints framework for perspective development, interaction and organization, and a logic-based approach to inconsistency handling. This paper presents our technique for inconsistency handling in the Viewpoints framework hy using simple examples.

The distributed development and maintenance paradigm for component delivery is fraught with problems. One wants a relationship between developers and clients that is autonomous and anonymous. Yet components written in languages such as C++ require the recompilation of all dependent subsystems when a new version of a component is released. The design of Java's binary format has side-stepped this constraint, removing the need for total recompilation with each change. But the potential is not fulfilled if programs have to be stopped to swap in each new component. This paper describes a framework that allows Java programs to be dynamically upgraded. Its key purpose is to allow libraries that are safe to replace existing libraries without adversely affecting running programs. The framework provides developers with a mechanism to release their libraries and provides clients with the surety of only upgrading when it is safe to do so.

Recently, the author has shown elsewhere a simplified model that allows quick evaluations of the annual overall energy collected by a surrounding heliostat field. This model is the combination of an analytical flux density function produced by a heliostat, developed by the own author, and an optimized mirror density distribution developed by University of Houston for the Solar One Project. As main conclusion of this previous work, it was recognized that such pseudo-continuous simplified model should not substitute much more accurate discrete evaluations, which manage thousands of individual heliostat coordinates. Here in this work, the difficulty of generating a preliminary discrete layout of a large number of heliostats is addressed. The main novelty is the direct definition of thousands of heliostat coordinates through basically two parameters i.e. a simplified blocking factor and an additional security distance. Such procedure, which was formerly theoretically suggested by the author, is put into practice here, showing examples and commenting their problems and advantages. Getting a previous set of thousands of heliostat coordinates would be a major first step in the complex process of designing solar power tower (SPT).

This chapter presents a case study from a global company developing a new generation of programmable controllers to replace several existing products. The system needs to incorporate support for a large number of I/O systems, network types, and communication protocols. To leverage its global development resources and the competency of different development centers, the company decided to adopt a component-based software architecture that allows I/O and communication functions to be realized by independently developed components. The architecture incorporates a subset of a standard component model. The process of redesigning the software architecture is presented, along with the experiences made during and after the project. An analysis of these experiences shows that the component-based architecture effectively supports distributed development and that the effort required for implementing certain functionality has been substantially reduced while, at the same time, the system's performance and other run-time quality attributes have been kept on a satisfactory level.

The failure rate function commonly has a bathtub shape in practice. In this paper we discuss a regression model considering new Weibull extended distribution developed by that can be used to model this type of failure rate function. Assuming censored data, we discuss parameter estimation: maximum likelihood method and a Bayesian approach where Gibbs algorithms along with Metropolis steps are used to obtain the posterior summaries of interest. We derive the appropriate matrices for assessing the local influence on the parameter estimates under different perturbation schemes, and we also present some ways to perform global influence. Also, some discussions on case deletion influence diagnostics are developed for the joint posterior distribution based on the Kullback-Leibler divergence. Besides, for different parameter settings, sample sizes and censoring percentages, are performed various simulations and display and compare the empirical distribution of the Martingale-type residual with the standard normal distribution. These studies suggest that the residual analysis usually performed in normal linear regression models can be straightforwardly extended to the martingale-type residual in log-Weibull extended models with censored data. Finally, we analyze a real data set under a log-Weibull extended regression model. We perform diagnostic analysis and model check based on the martingale-type residual to select an appropriate model.

Abstract. Due to the proliferation of the Internet and globalization, distributed information system development is becoming popular. In this paper we have reviewed some significant management issues like process management, project management, requirements management and ...

Finite element model a b s t r a c t Flash-butt welding is commonly used in the manufacture of continuously welded rails (CWR). The finished welds typically exhibit high levels of tensile residual stresses in the rail web. In addition, the surface condition of the web may contain shear drag or other defects resulting from the shearing process. When combined with torsional loading of the web under service loading (particularly at high axle loads), these conditions may contribute to fatigue failure of the weld in a horizontal split web mode. The risk of weld failure may be alleviated by reducing the magnitude of the tensile residual stresses. A sequentially coupled thermo-mechanical finite element (FE) model incorporating the phase transformation characteristics of the rail material has been used to predict the residual stress distribution developed during welding of AS60 and AS68 rails, by approximating the thermal distribution after upset from the heat-affected zone (HAZ) characteristics. The effect of localised, rapid post-weld heat treatment on residual stresses in the web region of the weld was also investigated. An experimental program covering measurement of post-weld cooling rates using infra-red thermography, and residual stresses by the strain-gauge and trepanning, was used to validate the finite element model. The results have shown that the FE model can satisfactorily predict the residual stress distribution. In addition, the (tensile) residual stress levels in both vertical and longitudinal directions of the web can be reduced by rapidly reheating the base of the foot directly after welding. Thereafter, both numerical and experimental approaches will be used to develop modifications to the flash-butt welding procedure that should result in improved weld performance under high axle load conditions.

Telecommunication technology is increasingly con- verging towards software-intensive solutions. As the role of software increases, it naturally follows that traditional software development procedures need to be reassessed. In South Africa, this need is especially urgent because of recent legislation that presages an increase in the number of competitors. This paper assesses two important contemporary software development ap- proaches - namely

Distributed agile development (DAD) has received increasing interest both in industry and academia as global software development (GSD) is becoming mainstream. However, agile methods and in particular agile practices have been designed for collocated software development, and are thus not directly applicable to DAD. In this paper, we present findings from a multiple case study on agile practices in two small and one midsized distributed Scrum project. Based on an interview study of 19 project team members, we describe how Scrum practices, such as daily scrums, backlogs, and sprints were successfully adopted to distributed development. We also describe supporting GSD practices employed, such as frequent visits and multiple communication modes that the projects used. Finally, we depict the challenges and benefits the case projects reported, as well as lessons learned from applying Scrum in distributed settings.

Software configuration management is an important support activity in the software development process. In global environments, the software configuration becomes critical due to the characteristics of the distributed development (physical distance, cultural differences, trust, communication and other factors). The objective of this paper is to analyze the software configuration management in a global software development environment, identifying the main challenges. The results are based on a case study carried on at a multinational organization that has offshore software development centers in Brazil, India and Russia, and was recently recognized in the CMM Model level 2 in the Brazilian unit. The results suggest the necessity to adapt and implement some activities in the software configuration management process addressing the main existing challenges. These activities were identified as lessons learned, collected at the end of each project. The problems and the solutions adopted are presented, aiming to relate these solutions to the organization distribution level, considering the project team, users and customers.

The Global Studio Project integrated the work of Software Engineering students spread across four countries into a single project and represented, for most of the students, their first major "real-world" development experience. Interviews indicated that the major areas of learning were informal skills that included learning to establish and work effectively within a team, learning how to react quickly to frequent changes in requirements, architecture and organization, and learning to manage and optimize communications. Since all these skills require rapid reaction to unpredictable factors, we view them as improvisation and discuss the role of experiential education in facilitating improvisation.

Global software development has gathered pace in recent years. Many software projects now involve asynchronous collaboration among geographically distributed teams several time zones apart. Software cost estimation for such projects becomes challenging due to factors such as effort expended in team building and knowledge transfer, creating an architecture of the software product that can be easily distributed and that minimizes crosssite communication, facilitating communication among remote teams collaborating on parts of the architecture that are interrelated and their day-to-day governance.

Company growth in a global setting causes challenges in the adaptation and maintenance of an organization's methods. In this paper, we will analyze incremental method evolution in software product management in a global environment. We validate a method increment approach, based on method engineering principles, by applying it to a retrospective case study conducted at a large ERP vendor. The results show that the method increment types cover all increments that were found in the case study. Also, we identified the following lessons learned for company growth in a global software product management context: method increment drivers, such as the change of business strategy, vary during evolution; a shared infrastructure is critical for rollout; small increments facilitate gradual process improvement; and global involvement is critical. We then claim that method increments enable software companies to accommodate evolutionary adaptations of development process in agreement with the overall company expansion.

In recent years, agile practices have become popular in the software development industry. Meanwhile, distributed development is becoming an alternative way to develop new systems. The most common mode of distributed development uses outsourcing primarily to reduce costs and ensure timely completion of projects. Agile methods are now being recommended for distributed development. However, the current agile practices break down when subjected to the realities of the outsourced development marked by geographical, language, temporal, social, and cultural barriers. The typical outsourced software project is also larger than the typical agile project. Thus, agile practices need to be modified so as to find application in today' s software development environment, which deems outsourcing as an important component. The paper comes up with a collaboration structure that can incorporate modified agile practices for outsourced projects.

Open source software is, software that users have the ability to run, copy, distribute, study, change, share and improve for any purpose. Open source library software's does not need the initial cost of commercial software and enables libraries to have greater control over their working environment. Library professionals should be aware of the advantages of open source software and should involve in their development. They should have basic knowledge about the selection, installation and maintenance. Open source software requires a greater degree of computing responsibility than commercial software. Library professionals do not think seriously about the advantages of open source software for automation and hence are reluctant to use it. They do not have the expertise to support open source software. Paper highlights major open source library software.

Telecommunication technology is increasingly converging towards software-intensive solutions. As the role of software increases, it naturally follows that traditional software development procedures need to be reassessed. In South Africa, this need is especially urgent because of recent legislation that presages an increase in the number of competitors. This paper assesses two important contemporary software development approaches-namely agile and open source-and their relationship to one another. A variant of open source software development that is highlighted, is Hewlett-Packard's so-called 'Progressive Open Source'. This is because it is specifically tailored to corporate use. The benefits and disadvantages of adopting the various development methods are assessed. Guidelines based on project characteristics are provided to indicate when each of the respective approaches should be considered.

Many project risks in distributed software development are very different from the ones in collocated development and therefore are often overlooked. At the same time, they depend to a large extent on project-specific characteristics. This article presents a model for identifying risks early in a project. This model systematically captures experiences from past projects and is based on a set of logical rules describing how project characteristics influence typical risks in distributed development. Thus, the model is able to assess risks individually for each project. It was developed by applying qualitative content analysis to 19 interviews with practitioners. An evaluation using expert interviews showed that the risks identified by the model matched the actual experiences in 81% of the cases; of these, 40% have not been regarded yet at project start. The article describes the concepts of the model, its instantiation and evaluation, followed by a conclusion and future work.

This case study discusses variation and formalization strategies for managing technology-use mediation of Web-based groupware technologies in an organizational context. Research and development projects of a multi-national pharmaceutical company entail a close collaboration between many geographically distributed actors. The use of a groupware technology in long term, cross-disciplinary and distributed development projects has been investigated in order to understand how Web-based technologies for collaboration become part of organizational work practices. In this paper, the work of project assistants in setting up and promoting the technology is described and analyzed as technology-use mediation. The ways in which the project assistants position themselves as system administrators by delegating access rights, providing content, and advocating use among development project members are identified as crucial to the integration of the groupware technology in work practices. Two configurations of the groupware technology and the cooperation within the development projects are compared under the metaphors of "the ultimate communication tool" and "a set of private and safe workspaces" respectively. The differences between them are brought forth to discuss the roles of the project assistants and the variety of ongoing meta-structuring activities. In conclusion, formalizing the technology-use mediations is discussed as beneficial if it renders the position of the project assistants more visible within the organization. This need not induce uniformity of configurations across the development projects, but might strengthen the mediating position of the project assistant and how well the groupware technology is suited to the local work practices.

The development and maintenance of UML models is an inherently distributed activity, where distribution may be geographical, temporal or both. It is therefore increasingly important to be able to interchange model information between tools - whether in a tool chain, for legacy reasons or because of the natural heterogeneity resulting from distributed development contexts. In this study we consider the

Coralline algae are one of the most important constructors of biogenic habitats. In the Mediterranean Sea, the dominant coralline algae species form crusts comprising formations known as coralligène, considered as very important fishing grounds by fishermen. Due to the destructive effect of fishing gear activities over coralligène, these formations were recently protected from the use of active benthic gears by the EU 1967/2006 Mediterranean fisheries management Regulation. However, the lack of maps and information on their distribution makes the effective application of these measures impossible. The present publication contributes to the mapping of coralligène in the southern Aegean Sea (eastern Mediterranean), and to the study of coralline algae formation morphology, distribution, development conditions and relation to fisheries using a combination of single-beam echo sounder, sidescan sonar, sub-bottom profiler recordings and biological and sedimentological ground-truthing techniques. The coralligène formations were recognized as two distinct acoustic signatures of localized backscatter facies distinguishable from other hard substrate reflectors at depths ranging from 55.9 to 114.0 m, but mainly between 70 and 90 m. Two types of formations were identified: minute reefs 0.5-2.5 m in height and superficial layer formations no more than 0.2 m thick over the substrate. The seismic profiles revealed a cavernous internal structure of the minute reefs and recorded their development on both hard and soft substrates. The distribution of formations was contagious, creating aggregations. The finding of superficial layer formations and coralline shreds around minute coralligène reefs indicated that the former could be an intermediate development type between isolated small coralline pebbles, rhodoliths, and minute reefs. Regarding the development conditions, sidescan sonar imagery indicated that the optimal conditions for the establishment and development of coralligène formations are medium intensity currents. Concerning human activity over coralligène, trawl traces were recorded near but not over minute reefs and both near and crossing superficial layer type aggregations, while a submarine cable was also recorded among minute reefs. The mapping of coralligène aggregation areas is essential for the application of the EU Regulation and the protection of this important marine habitat.

The architecture of a software system is both a success and a failure factor. Taking the wrong architectural decisions may break a project, since such errors are often systematic and affect cross-cutting aspects of the system to be built. Moreover, software projects get more and more challenging due to the rising complexity and dynamics of business processes, large team size and distributed development. As the software architecture is the common platform for many project activities, it constitutes a critical success factor. Thus, a comprehensive method for evaluating a software architecture and propagating important properties of it downstream to code is needed. At sd&m, we designed a comprehensive architecture evaluation and management framework in order to satisfy these needs. In this paper, we derive a list of requirements, such a framework should fulfill. We then present the components of our architecture evaluation method and demonstrate, how it fulfills these requirements.

Representing runoff process complexity in a simple model structure remains a challenge in hydrology. We present an integrated approach to investigate runoff processes using a hillslope tracer experiment and modeling exercise to explore model parameterization, process representation, and transit times. A spatially-explicit model constrained by soil hydrologic properties, runoff, and applied tracer data was used to identify the dominant processes necessary to explain both water and solute flux from a steep hillslope. The tracer data allowed for the rejection of model parameter sets based on the calibration to runoff data alone, thus reducing model uncertainty. The additional calibration to tracer data, improved parameter identifiability and provided further insight to process controls on hillslopescale water and solute flux. Transit time distributions developed using the model provided further insight to model structure such as subsurface volume, mixing assumptions, and the water table dynamics. Combining field experiments with the modeling exercise may lead to a more comprehensive assessment of runoff process representation in models.

Software configuration management is an important support activity in the software development process. In global environments, the software configuration becomes critical due to the characteristics of the distributed development (physical distance, cultural differences, trust, communication and other factors). The objective of this paper is to analyze the software configuration management in a global software development environment, identifying the main challenges. The results are based on a case study carried on at a multinational organization that has offshore software development centers in Brazil, India and Russia, and was recently recognized in the CMM Model level 2 in the Brazilian unit. The results suggest the necessity to adapt and implement some activities in the software configuration management process addressing the main existing challenges. These activities were identified as lessons learned, collected at the end of each project. The problems and the solutions adopted are presented, aiming to relate these solutions to the organization distribution level, considering the project team, users and customers.

In the software engineering area, has been observed a growing concern to perform experimental studies to evaluate the use of new technologies. However, conducting experimental research is a complex and challenging activity, once it suffers impacts related to human factors. The use of a well defined process for experimental study contributes to the control of the variables involved and their realization. It allows generalization of the results and also replication of the studies. This paper presents an experimental study to evaluate and improve an integrated approach to development and software testing. Such approach was proposed to be adopted when distributed development scenarios are considered.

Distributed software development has become the norm for the software industry today. As a result many organizations are leveraging the expertise of their existing staff by establishing virtual teams. Here we outline the results from three independent case studies undertaken over a period of eight years. The first study considered the operation of virtual teams whose members were situated in

In this paper, we report the findings of an empirical investigation into decision making processes (DMPes) in distributed teams. We conducted the study in a Fortune 500 organization with a total of sixteen respondents who participated in an hour-long interview. Our analysis of the DMP reported by our respondents suggests that there is a strong organizational culture that supersedes local and individual culture. We also found that while decisions are predominately made in consultation with team members, the leader is usually the decision maker regardless of team distribution or size. The role the leader plays in the DMP implies that greater consideration should be given to assigning a team leader and also the DMP in place. It is also significant that we did not find any evidence of support mechanisms to the DMP leading us to conclude that this possibility needs to be explored by the organization. Our data also suggests that the DMP is chosen ad-hoc and is not explicitly articulated in this organization, which may benefit from documentation.

WebCT is a tool which enables the distribution, development and control of distance learning courses via the Internet. It has a range of uses from the publication and management of education material to the monitoring of activities and student evaluation. In this article we concentrate our study on the Self Test WebCT tool: We describe how it works, we analyse its main problems, particularly those related to the design of the self-test exercises and we put forward solutions to improve its performance.

The grain-size fractions in the bedload transported over the five heterogeneous sediment beds of different values of bed roughness were computed from the flume experiments. The existence of an entrapment factor associated with the sorting observed from the bed to active layer was modeled based on the modified critical shear stress to estimate the grain-size fractions in the transport layer under given hydraulic conditions. The efficiency of these models was tested with the observed data. Subsequently, the patterns of observed grainsize distributions in the transport layer were tested to identify the distributions developed in the active layer due to sorting using three probability density functions (pdf), such as, log-normal, log-hyperbolic and logskew-Laplace. Tests indicated that a log-skew-Laplace distribution fitted best for 49%, a log-hyperbolic for 31%, and a log-normal for 20% out of forty-five bedload samples collected under unidirectional flow with changes in flow discharge and bed roughness. The results of this study would be useful to specify the grainsize distributions in the bedload formed under different hydrodynamic conditions in various sedimentary environments.

Software configuration management is an important support activity in the software development process. In global environments, the software configuration becomes critical due to the characteristics of the distributed development (physical distance, cultural differences, trust, communication and other factors). The objective of this paper is to analyze the software configuration management in a global software development environment, identifying the main challenges. The results are based on a case study carried on at a ...

1] Traditionally, the directional distribution of ocean waves has been regarded as unimodal, with energy concentrated mainly on the wind direction. However, numerical experiments and field measurements have already demonstrated that the energy of short waves tends to be accumulated along two off-wind directions, generating a bimodal directional distribution. Here, numerical simulations of the potential Euler equations are used to investigate the temporal evolution of initially unimodal directional wave spectra. Because this approach does not include external forcing such as wind and breaking dissipation, spectral changes are only driven by nonlinear interactions. The simulations show that the wave energy spreads outward from the spectral peak, following two characteristic directions. As a result, the directional distribution develops a bimodal form as the wavefield evolves. Although bimodal properties are more pronounced in the high wave number part of the spectrum, in agreement with previous field measurements, the simulations also show that directional bimodality characterizes the spectral peak.

We describe a hybrid computer simulation model of the software development process that is specifically architected to study alternative ways to configure global software development (GSD) projects, including phase-based, module-based, and follow-the-sun allocation strategies. The model is a hybrid system dynamics and discrete-event model. In this paper, test cases have been developed for each allocation strategy, and project duration is computed for each configuration under a range of plausible assumptions for key parameters. The primary finding is that although under ideal assumptions follow-the-sun is able to produce impressive reductions in time-to-market, under more realistic assumptions the reverse is true, thus corroborating findings by other researchers. We also conducted a factorial design to examine the impact of GSD factors including distance, culture, language, trust, and time zone on project duration under different task allocation strategies. The analysis reveals that different factors affected the performance of the selected allocation strategies in unique ways. These findings show how the unique ability of our GSD model to represent detailed development processes and work artifact transfer allows researchers to address challenging questions that are critical to GSD project success.

The popularity of agile software development methods, and agile software project management has been accompanied by significant successes in the delivery of software of business value and quality to client organizations, but has also given rise to more pressing difficulties especially in the support of remotely located teams, and distributed or multi-team development activities. The question of whether or not

Trust has long been a contentious issue in human endeavours. It is not readily given nor gained, more so when strangers are involved. It often becomes an issue during distributed development where individuals are expected to interact with strangers they may not "meet" during the project lifetime. Trust was spontaneously raised by respondents in an empirical study of practices within distributed development and is reported in this paper. A qualitative analysis of study data suggests that trust typically becomes an issue in large teams when developers are to deliver an innovative product. We also found that it is more likely to be an issue the greater the diversity (of culture, language, time zone…etc.) within the team. Finally the data also suggests that developers more readily trust an authoritative team member (e.g. team leader), even if remote. Data suggests these factors can act as positive and negative forces to influence trust within distributed teams. These forces are reported in this paper together with proposed approaches that can promote equilibrium of the net forces.

Extreme Programming (XP) is an Agile Methodology (AM) which doesn't require any specific supporting tool for being successfully applied. Despite this starting observation, there are many reasons leading a XP team to adopt Web based tools to support XP practices. For example, such tools could be useful for process and product data collection and analysis or for supporting distributed development. In this article we describe XPSuite, a tool composed of two parts: XPSwiki, a tool for managing XP projects and XP4IDE, a plug-in for integrating XPSwiki with an Integrated Development Environment (IDE). Moreover, we will show how the full Object Oriented implementation provides a powerful support for extracting all data represented in the model that the system implements.

... A problem is that prevailing software architecture models, such as UML component diagrams and architecture description languages (ADLs) are not designed to represent both softwarearchitecture structure and its associated organizational structure, that is, the communication ...

In this paper we analyze how concepts and symbolizations co-develop in the case of statistical data analysis. The focus is on the development of distribution, which ranges from a very concrete intuitive understanding to formal mathematical definitions. Examples from teaching experiments with 11 to 12 year-old students illustrate how their concept of distribution develops in relation to what the graphs they use and make mean for them. In particular we discuss an episode in which a student symbolizes data into a so-called 'bump' and we give examples of how other students reason with this 'bump' in connection to distribution.

In today's software industry, development teams are no longer co-located but distributed over locations, and problems associated with different time zones and cultures come into play. To reflect these industry scenarios, and to better prepare computer science students to capitalize upon the opportunities and address the challenges, five institutions distributed across four countries and two continents have been collaborating to investigate models of working in global software development settings. The model for the spring 2008 project emphasized friendly competition between distributed development teams and quality, via the support of coaches and the external feedback of auditors, to increase the likelihood that software suitable to deploy would be developed by the students. A virtual world environment was also used as a socialization tool with the expectation that it would provide support for the needed face-to-face interaction that lacks in distributed teams and so promote additional forms of communication. In this paper, we describe the goals behind investing in socialization and the emerging technologies that can support such activities in global software development projects. We also outline the setting and the results of our particular socialization study. We conclude the paper with reflections on the future use of virtual world environments in global projects of this nature and the resulting implications for practitioners.

This paper explores reasons for the high degree of variability in the sizes of ASes that have recently been observed, and the processes by which this variable distribution develops. AS size distribution is important for a number of reasons. First, when modeling network topologies, an AS size distribution assists in labeling routers with an associated AS. Second, AS size has been found to be positively correlated with the degree of the AS (number of peering links), so understanding the distribution of AS sizes has implications for AS ...

This paper presents an overview of the field of distributed development of software systems and applications (DD). Based on an analysis of the published literature, including its use in different industrial contexts, we provide a preliminary analysis that structures existing DD knowledge, indicating opportunities but identifying threats to communication, coordination, and control caused by temporal distance, geographical distance, and sociocultural distance. An analysis of the case and field study literature has been used to identify strategies considered effective for countering the identified threats. The paper synthesizes from these a set of 10 general strategies for successful DD which, if adopted, should lead to increased company resilience.

today, all the more so given the current trend towards globalisation. In this paper we present a reference model which can be used as a reference point for any company wishing to review their own DD scenario. This is particularised in two forms, one as an exemplar model for a global (GSD) development scenario and one as a particularisation of this for intra-national DD scenarios. By drawing from eight case-studies on DD, we present ten general strategies for successful DD together with our reference model which characterises an ideal DD situation.