A power filter for the detection of burst sources of gravitational radiation in interferometric detectors

We present a filter for detecting gravitational wave signals from burst sources. This filter requires only minimal advance knowledge of the expected signal: i.e. the signal's frequency band and time duration. It consists of a threshold on the total power in the data stream in the specified signal band during the specified time. This filter is optimal (in the Neyman-Pearson sense) for signal searches where only this minimal information is available.Comment: 3 pages, RevTeX, GWDAW '99 proceedings contribution, submitted to Int. J. Modern Phys.

Simple sufficient conditions for the generalized covariant entropy bound

The generalized covariant entropy bound is the conjecture that the entropy of the matter present on any non-expanding null hypersurface L will not exceed the difference between the areas, in Planck units, of the initial and final spatial 2-surfaces bounding L. The generalized Bekenstein bound is a special case which states that the entropy of a weakly gravitating isolated matter system will not exceed the product of its mass and its width. Here we show that both bounds can be derived directly from the following phenomenological assumptions: that entropy can be computed by integrating an entropy current which vanishes on the initial boundary and whose gradient is bounded by the energy density. Though we note that any local description of entropy has intrinsic limitations, we argue that our assumptions apply in a wide regime. We closely follow the framework of an earlier derivation, but our assumptions take a simpler form, making their validity more transparent in some examples.Comment: 7 pages, revte

Understanding the competitiveness factors of Korean contractors in the international construction market

The international construction markets (ICM) are constantly changing with new pressures creating opportunities and threats., Enterprises from advanced major advanced economies have been successful in venturing overseas and winning projects by exploiting their design, engineering, technological, and managerial competencies. Construction markets have changed with Chinese, Japanese, Korean, and Turkish construction enterprises securing more projects overseas. Understanding and exploiting the competitive advantage possessed by enterprises from major advanced economies is being challenged by enterprises from newly industrialised economies. This study investigates the competitiveness factors of the Korean construction (KOC) enterprises to understand how they have been successful in exploiting their competitive advantages. The competitiveness evaluation model (CEM) is developed using system dynamics which compares the project performances between the models generated by general and Korea-featured competitiveness factors in winning work in the ICM. The findings reveal that ownership of the enterprise, government strategy and support for the construction industry enterprises, strong leadership, technology-intensive, and special characteristics of large Korean enterprises (Chaebol system) could be critical factors for creating competitive advantage

Minimisation of risk exposure at the pre-production stage through the use of contractor-led design management

Many large-scale construction projects (LSPs) are designed in a collaboration between famous international architects and local design firms. Design management usually evolves as a tool at the design stage for designers and design solution. One of the special characteristics of the Korean construction environment places a duty and responsibility on the contractor to coordinate and check design information. Hence the contractor must manage and integrate diverse design information into the production process. This research considers how the design management diagram (DMD) can help as a part of the system at the pre-production stage of LSPs in Korea. The pre-production stage receives insufficient attention from the research community from the perspective of design management; it is a complex process involving interdependence, risk, and uncertainty. Through the application of a DMD from the pre-production stage, the contractor can predict and manage the design-related uncertainty during production stages. The design management factors (DMFs) were analysed by the analytic hierarchy process (AHP), and then used complexity system theory to understand the interrelationship between the causal factors. DMFs are presented as a causal loop diagram which can help the contractor to cope with design related uncertainties at the early production phase

Gravitational Interactions in a General Multibrane Model

The gravitational interactions of the four-dimensional effective theory describing a general $N$-brane model in five dimensions without radion stabilization are analyzed. Both uncompactified and orbifolded models are considered. The parameter space is constrained by requiring that there be no ghost modes in the theory, and that the Eddington parameterized post-Newtonian parameter $\gamma$ be consistent with observations. We show that we must reside on the brane on which the warp factor is maximized. The resultant theory contains $N-1$ radion modes in a nonlinear sigma model, with the target space being a subset of hyperbolic space. Imposing observational constraints on the relative strengths of gravitational interactions of dark and visible matter shows that at least 99.8% of the dark matter must live on our brane in this model.Comment: 18 pages, 4 figures. Version 2 (submitted to PRD) adds analysis on orbifold