Parallel efficiency of a boundary integral equation method for nonlinear water waves

We describe the application of domain decomposition on a boundary integral method for the study of nonlinear surface waves on water in a test case for which the domain decomposition approach is an important tool to reduce the computational effort. An important aspect is the determination of the optimum number of domains for a given parallel architecture. Previous work on hetero- geneous clusters of workstations is extended to (dedicated) parallel platforms. For these systems a better indication of the parallel performance of the domain decomposition method is obtained because of the absence of varying speed of the processing elements

Understanding Construction Supply Chains: An Alternative Interpretation

Much research work has assessed that construction is ineffective and many problems can be observed. Analysis of these problems has shown that a major part of them are supply chain problems, originating at the interfaces of different parties or functions. There have been several kinds of initiatives aiming at improvement and renewal of construction supply chains, but only few have a track record of consequent and significant successes. Here construction supply chains are approached from an alternative theoretical viewpoint, namely that of the language/action perspective. In this approach, organizations are seen as networks of commitments. Two avenues have been pinpointed for practical application of this approach. First, the process of requesting, creating and monitoring commitments can be facilitated by heuristic models and computer systems, when suitably designed. Secondly, people can learn to communicate for action by developing new sensibility towards the ways their language acts participate in networks of human commitments, and improving their skills in understanding requests, and making commitments. By closer study, existing empirical observations support the idea that a large share of construction supply chain problems are caused by poor articulation and activation of commitments. But would this new approach also facilitate the implementation of a new supply chain management that has proved to be so difficult in practice? In this regard, two initiatives are reviewed. The Dutch initiative to create a framework for communication in large civil engineering projects is first presented and initial experiences from its implementation are discussed. Then, Last Planner implementations are analyzed. By drawing on the concept of small wins, it is concluded that these implementations act as a stimulus for wider changes towards an environment of firm commitments and high trust. The paper ends with a review on research tasks ahead

Project resources leveling using software agents

Different approaches to project planning and scheduling have been developed. The Operational Research (OR) approach provides two major planning techniques: CPM and PERT. Artificial Intelligence (AI) initially promoted the automatic planner concept. In order to plan a project, the automatic application of predefined operators is required. However, most domains are not so easily formalized in the form of predefined planning operators. The paper focus is on the agent-based approach to project planning and scheduling, especially in Resource Leveling issues. The authors have developed and implemented the ResourceLeveler system, an agent-based model for leveling project resources. The objective of Resource Leveler is to find a scheduling of resources similar to the optimal theoretical solution which takes into consideration all constraints stemming from the relationships between projects, activity calendars, resource calendars, resource allotment to the activities and resource availability. ResourceLeveler was developed in C# as a plug-in for Microsoft Project.project management, agent-based models, artificial intelligence, project resource leveling

Turbulent Premixed Flames in Microgravity

The experimental cold-flow facility is now full operational and is currently being used to obtain baseline turbulence data in a Couette flow. The baseline turbulence data is necessary to confirm the capability of the chosen device to generate and maintain the required turbulence intensity. Subsequent reacting flow studies will assume that a similar turbulent flow field exists ahead of the premixed flame. Some modifications and refinements had to be made to enable accurate measurements. It consists of two rollers, one (driven by a motor) which drives a continuous belt and four smaller rollers used to set the belt spacing and tension to minimize belt flutter. The entire assemble is enclosed in a structure that has the dimensions to enable future drop tower experiments of the hot facility. All critical dimensions are the same as the original plans except for the pulley ratio which has been changed to enable a wider operating regime in terms of the Reynolds number. With the current setup, Reynolds numbers as low as 100 and as high as 14,000 can be achieved. This is because the in-between belt spacing can be varied from 1 cm to 7.6 cm, and the belt speed can be accurately varied from .15 m/sec to 3.1 m/sec

Business engineering building blocks

In order to utilize the contemporary advanced technology, business processes need sound software support. With respect to this, one frequent cause of software project failure is the mismatch between the business requirements and the actual functionality of the delivered software application. To solve this problem, it is necessary to build software stemming out from a business process model. Aiming at aligning business process modeling and software design in a component-based way, the proposed research investigates the identification of generic business engineering building blocks and their use for building ICT applications which effectively support business processes