MIMAC-He3: a new detector for non-baryonic dark matter search

The project of a micro-TPC matrix of cells of 3He for direct detection of non-baryonic dark matter is presented. The privileged properties of 3He for this detection are highlighted. The double detection: ionization-projection of tracks is explained and its rejection evaluated. The specific capabilities of this project with respect to other experiments are mentioned and its complementarities concerning the supersymmetric phenomenology explicitly showed.Comment: to appear in Proc. of 5th International Workshop on the Identification of Dark Matter (IDM2004), Sept. 2004, Edinburgh (Scotland

Creating Social Value within the Delivery of Construction Projects

The purpose of this paper is to present the current knowledge surrounding social value and show how lean approach supports social value realisation in the delivery of construction projects. A critical literature review was adopted, to gather the current knowledge surrounding social value from mainstream management sciences, construction management and lean literature. A total of 70 studies were critically reviewed. The study reveals that the separation theory propagated by Friedman, (1962), tends to separate social value from economic value, thus making organisations care less about delivering social value. The study found that there is still no clear or single criterion for measuring social value delivered and there is a dearth of scholarly publications on social value especially in construction management literature. The investigation shows that lean production approach has the potentials to enable construction organisations to conceptualise the community and the physical environment where they operate as customers, which contributes to the delivery of social value objectives in construction projects. This study conceptualises the community and the physical environment around where the construction project is executed as customers using lean production approach and shows that the Transformation, Flow & Value view support smooth workflow which enhances the achievement of social value objectives. This creates a new insight into how social value can be realised in construction project delivery. This study extends the on-going debate around the need for social value in construction project delivery and contributes to construction management and lean construction literature on social value. Future studies could build on this to obtain empirical data and develop an approach/method that would support the evidencing of social value delivery in construction projects

THE LAST PLANNER® SYSTEM PATH CLEARING APPROACH IN ACTION: A CASE STUDY

The “Last Planner® System” (LPS) is commonly viewed as the foundation of Lean Project Delivery. It is increasingly used in certain parts of the globe. However, LPS implementation often fades off due to issues reported at organisational, project and external levels. The LPS Path Clearing Approach (PCA) offers an antidote to these issues. The goal of this paper is to outline how the LPS-PCA helped restart a stalled implementation of the LPS through a “shallow and wide” organisational approach rather than a more traditional “narrow and deep” project approach. The LPS-PCA in action is documented within an on-going UK case study organisation. Action and covert research methods were used to introduce LPS principles, thinking and language without attributing them to LPS in response to resistance to the actual LPS. The 15 step actions within the LPS-PCA are expanded from a past, current and future state perspective. The study found that the LPS-PCA’s 15 step actions were useful as a benchmark to continuously remove constraints that blocked the implementation of the LPS. In summary, the use of the LPSPCA is recommended before, during and after organisations engage with LPS Consultants if organisations are serious about sustaining the implementation of the LPS

On the Complexity of Optimization Problems based on Compiled NNF Representations

Optimization is a key task in a number of applications. When the set of feasible solutions under consideration is of combinatorial nature and described in an implicit way as a set of constraints, optimization is typically NP-hard. Fortunately, in many problems, the set of feasible solutions does not often change and is independent from the user's request. In such cases, compiling the set of constraints describing the set of feasible solutions during an off-line phase makes sense, if this compilation step renders computationally easier the generation of a non-dominated, yet feasible solution matching the user's requirements and preferences (which are only known at the on-line step). In this article, we focus on propositional constraints. The subsets L of the NNF language analyzed in Darwiche and Marquis' knowledge compilation map are considered. A number of families F of representations of objective functions over propositional variables, including linear pseudo-Boolean functions and more sophisticated ones, are considered. For each language L and each family F, the complexity of generating an optimal solution when the constraints are compiled into L and optimality is to be considered w.r.t. a function from F is identified

EMPIRICAL STUDY ON THE INFLUENCE OF PROCUREMENT METHODS ON LAST PLANNER® SYSTEM IMPLEMENTATION

Previous studies have examined various factors that influence the implementation of the Last Planner System (LPS) in construction projects. However, there is limited documented evidence on the influence of procurement methods on the implementation of the LPS. The aim of this study, therefore; is to understand the influence of some selected procurement methods on the implementation of the LPS using case study approach. Three in-depth case studies were conducted on building and highways projects in the UK. The projects were managed with the LPS principles with dissimilar procurement methods. In addition to document analysis and physical observation, 28 in-depth-interviews were conducted. The investigation shows that the prevailing traditional mindset exhibited by the designers in the traditional design bid build (DBB) influences the quality of promises and commitments that could be made during the lookahead planning. From the study, it seems no single procurement method is a sure way to the full application of the LPS process on a project. The study observes that irrespective of the procurement route used, a mindset change towards collaboration among the different stakeholders on the project is fundamental to successful LPS implementation. For instance, on projects where DBB was used and the subcontractors were in framework agreement, the LPS implementation worked well among the subcontractors. The study recommends that the procurement approach to be used on LPS projects should not be too firm, but lithe enough to integrate collaborative working among the different stakeholders on the project for a smooth workflow