In the process of developing computer based applications the use of descriptive models to depict the architecture and design of the application is practical and brings many advantages. The most commonly used standard today is the Unified Modeling Language. There are many tools that implemented support for this standard for modeling, and they vary in functionality. A comparative study, including a selection of these tools, will show advantages and disadvantages for each tool. The purpose of this study is to test a selection of these modeling tools for a typical three-tier layered web service application. The tools tested in this study are Microsoft Visual Studio 2005 .NET Beta, PowerDesigner and Visual Paradigm. Rational Rose would have been included if it would have supported C#. In this study tests are performed in regard to modeling a class diagram, forward engineering to source code from the class diagram and reverse engineering from source code to class diagram. Despite the shortage of diagram types MS Visual Studio proved to be the most reliable tool for this particular type of applications.

In this paper, we present the creation process andthe purpose behind the Midnight cluster. It isdisguised as a computer laboratory during the day,but turns into a high performance compute clusterduring the night.The main focus of this paper is on the basic issueswith creating a part time compute cluster. TheMidnight cluster was constructed to serve both as aCPU harvester and as a platform for further studies.The main goal of our upcoming research is toev aluate different methods for handling shapechangeand process management on the cluster, andhow these factors affect running processes, stabilityand performance.

This paper is based on an extensive study performed on a large software suite for over a decade. From the experiences derived from this study we created a first draft of a method combining an extended robustness analysis (RA) method with the future oriented method of technology forecasting (TF). In this method TF provides information about the systems future evolution to the RA which then generates the software design. The RA and TF methods then form a feedback loop, which results in an improved reusable and robust software design. The purpose of the RATF method is to predict the evolutional path of the software system, thus making preparations for (example) functionality that will be needed in future generations, i.e. utilizing the power-of-prediction to implement the base of tomorrow's functions today

Seven software engineering methods and one general purpose system engineering method TRIZ was evaluated concerning their abilities to combine software technology forecasting, that is prediction of potential software evolution with robustness analysis, which is a method to model a system tolerant to changes. None of the investigated software engineering method or process concepts combines software technology forecasting with robustness analysis to any great extent. Several of the methods evaluated do contribute with techniques and principles, that potentially could be combined and give systematically technology forecasting with comprehensively robustness analysis though. This defines a new frontier for research into a combined "super class" method for software development.

The relative importance of economics and environment in debate may soon be reversed due to the influence of three factors. Firstly, in the global economy it is hard to hide the unwanted products of economic processes. Secondly, huge advances in science will reduce the imperfect knowledge of markets, making some monitoring and analyzing tools show the design of sensible and equitable livelihood in communities, which is more important than the motivation of maximising profits for some individuals or firms. Thirdly, China, as the last major player on the planet to take on economic growth, comes from traditions fundamentally different from those economies that have experienced the Industrial Revolution previously. Its challenges with sustainability and environmental conservation predate Western economics by millennia, and it is implementing policies domestically and starting to work on the world stage that acknowledges that the surroundings are the host for any economic and socio-political system.

The study presented in this paper highlights an important issue that was subject for discussionsand research about a decade ago and now have gained new interest with the current advances ofgrid computing and desktop grids. New techniques are being invented on how to utilize desktopcomputers for computational tasks but no other study, to our knowledge, has explored theavailability of the said resources. The general assumption has been that there are resources andthat they are available. The study is based on a survey on the availability of resources in anordinary o±ce environment. The aim of the study was to determine if there are truly usableunder-utilized networked desktop computers available for non-desktop tasks during the off-hours. We found that in more than 96% of the cases the computers in the current investigationwas available for the formation of part-time (night and weekend) computer clusters. Finally wecompare the performance of a full time and a metamorphosic cluster, based on one hypotheticallinear scalable application and a real world welding simulation.

The disproportion between processor and memory bus capacities has increased constantly during the last decades. With the introduction of multi-core processors the memory bus capacity is divided between the simultaneously executing processes (cores). The memory bus capacity directly affects the number of applications that can be executed simultaneously at its full potential. Thus, against this backdrop it becomes important to estimate how the limitation of the memory bus effects the applications performance. Towards this end we introduce a method and a tool for experimental estimation of an applications memory requirement as well as the impact of sharing the memory bus has on the execution times. The tool enables black-box approximate profiling of an applications memory bus usage during execution. It executes entirely in user-space and does not require access to the application code, only the binary. 

When most commercial clusters had one processor core each, decreasing the runtime meant executing the application over more nodes – the associated cost (in $) would scale linearly with the number of nodes. However with the recent advances of multi-core processors the execution time can be increased by utilizing more nodes or by utilizing more cores in the same nodes. In the industrial cluster environments a key question is how to run the applications, to minimize the total cost while maximizing the throughput and solution times of the individual jobs. The number of core used and their contribution to the total runtime reduction is especially interesting since companies often use commercial software that is licensed per year and process. The annual license cost of one single process is often far greater than that of a complete cluster node including maintenance and power. In this paper we present a metric for the calculation of the optimal way to run an application on a cluster consisting of multi-core nodes in order to minimize the cost of executing the said job. 

Multicore processors have come to stay, fulfill Moore’s law and might very well revolutionize the computer industry. However, we are now in a transitional period before the new programming models, numerical algorithms and general computer architecture have been developed and the software has been rewritten. This paper focuses on the effects multicore based systems have on industrial computational fluid dynamics (CFD) simulations. The most significant finding was that five of the models ran faster when only one process was executed on each multicore node instead of two. In these cases the execution time was increased by between 6.5% and 64% with a median increase of 10% when utilizing both cores.

In large organizations there are usually rather large groups of heterogeneous users with different tasks and different needs. Their requirements would most likely vary a lot when the system is designed to grant them access to different parts of the functions and applications In our earlier work we have tested the interface concept of Multi-Layered Design (MLD) on an operating system where each layer had a set of applications and tools. The users working with the system could get access to different applications depending on their level of experience or their different needs. The current paper presents how the MLD concept is taken one step further; implementing a layered design in a multi-user portal on a Citrix server. When a network solution is used, new available possibilities are given. The MLD approach can be combined with a role based access technique can the layered structure can be used in different ways for many different groups of users. In the study a MLD mushroom structure is employed where the user category decides the set of layers the different user groups can choose from while the individual user’s tasks and experience guide the choice of the specific layer. Thin clients are used to access the layer structure and five personas are made to represent the potential user groups. The results show that MLD can be used within a Citrix environment and that it is a viable alternative or complement for multi-user portals

The stability and evolution of the structure of consecutive versions of a series of software architecture graphs are analysed using the theory of complex networks. Brief comparisons are drawn between the scale-free behaviour and second order phase transitions. On this basis a software design metric Icc is proposed. This software metric is used to quantify the evolution of the stability vs. maintainability of the software through various releases. It is demonstrated that the classes in the software graph are acquiring more out-going calls than incoming calls as the software ages. Three examples of software applications where maintainability and continuous refactoring are an inherent part of their development process are presented, in addition to a Sun Java2 framework where growth and backward compatibility are the more important factors for the development. Further to this a projected future evolution of the software structure and maintainability is calculated. Suggestions for future applications to software engineering and the natural sciences are briefly presented.

We explore the use of complex networks for understanding of the interaction of computer software applications written in the Java object-oriented language with the "library classes" that they use (those provided by the Java Runtime Environment) as, essentially, a merged network of classes. The dependence of the software on the library is quantified using a recently introduced model that identifies phases close to a second-order phase transition existing in scale-free networks. An example is given of a piece of software whose class network collapses without the presence of the library classes, providing validation of a novel structural coupling measure; Rcoupling. The structural properties of the merged software-Java class networks were found to correlate with the proportion of Java classes contained within the subset delimited by Rcoupling. A mechanism for the preservation of the software class network is also provided for the cases studied where the removal of the library classes does not cause collapse.

The focus of this paper is to evaluate the use of two different network topologies for Ethernet networks in small Common

Off The Shelf (COTS) clusters. The fully meshed network topology was evaluated and its impact on latency and

bandwidth was measured and compared to the more traditional switched network topology. This was done at MPI level

by measuring the point-to-point round trip latency (ping-pong) and all-to-alla bandwidth for different sized messages.

The results from the experiments are presented and the overall the benefits and drawbacks of the both approaches are

discussed.

In this paper we have implemented and verified Cpugen, a tool for characterization of processor resource utilization of HPC applications .Toward this end we implemented Cpugen, an application with good accuracy for processor load generation. Cpugen was verified through three different phases of passive, active and real world application measurements. The measurement results show that our implemented method is a viable option for non-intrusive, stable and robust load generation. The error range for all generated target loads are between 0.00% minimum and 1.04% maximum, with a median deviation of 0.11%. We can conclude that the method utilized in this investigation provides the ability to generate stable and robust processor load.

In this paper we present a first attempt to an analytical method to discover and understand how the available resources influence the execution time. Our method is based on a piecewise linear model for dominating execution limitations and black-box observations. We verify this analysis method by a set of real-world experiments. Finally, we conclude that the different effects follow a linear superposition within a certain range.

When creating software, people from many different areas are involved. To make them work efficiently together they need to communicate but communication requires a common language and common understanding. The Unified Modeling Language (UML) is often used as a common ground for understanding when modeling and designing software products. However, after practically working with many large projects we have found UML to have shortcomings in the area of modeling Graphical User Interface (GUI). There are many other ways to model GUIs but it could be beneficial to use a modeling method that the more technical developers are familiar with and also beneficial to be able to put in the interface into the framework of UML when it comes to drawing applications and code generation. In this study we first of all have investigated the possibility of adding GUI design to UML and then we have explored different solutions for what a GUI UML-diagram could look like and what problems there are with diagrams when it comes to visualizing objects. We have then put forward an idea for a GUI diagram or an UML extension; a graphical element diagram, and discussed its benefits and drawbacks. © 2009 IADIS.

In this paper we evaluate the potential in combining different testing methodologies. The evaluation indicates an increase in effectiveness when adding random testing to partition testing. At the same time, the increase in efficiency inevitably fades because of the added number of random test cases being executed. Nevertheless, the potential in an automation scheme for creating and executing test cases is visible, thus indicating that a future implementation combining the best of two worlds, i.e. partition and random testing could be pursued.