Decision aid for allocation of transportation funds to guardrails

We address the need for allocation of resources to run-off-road and fixed-object hazards on immense secondary road systems. In Virginia, there are 95,000km of roadway with uncharacterized hazards in need of guardrail upgrade, installation, or related warning signs or other protection. A decision aid is developed to assist the planner in guardrail resource allocation by accounting for the potential crash severities, traffic exposures, costs of treatment, and other factors. A premise is that no single benefit-cost ratio or selection criterion applies across all localities. The decision aid enables the planner to interpret the variety of benefits and costs in their own units, emphasizing the needs and preferences of individual localities. The paper describes: (1) archiving and comparison of protected and unprotected hazards; (2) regional screening of hazardous corridors and (3) multicriteria benefit-cost analyses of guardrail sites. A case study of guardrail selection is presented.     

A literature review of portable fluorescence-based oil-in-water monitors

The results of a literature search on fluorescence-based portable detectors to measure the real-time concentration of oil are reported. For more than two decades, fluorometers have been commonly employed to monitor dispersed oil levels at oil spills on water. The focus of this paper has been to extract specific information from references about how the instruments were used, including set up and calibration procedures, the oil and dispersant measured, the approximate concentration range of the oil in the water column, and how the real-time data compared to traditional laboratory techniques.     

Solvent vapour monitoring in work space by solid phase micro extraction

Solid phase micro extraction (SPME) is a fast, solvent-less alternative to conventional charcoal tube sampling/carbon disulfide extraction for volatile organic compounds (VOC). In this work, SPME was compared to the active sampling technique in a typical lab atmosphere. Two different types of fibre coatings were evaluated for solvent vapour at ambient concentration. A general purpose 100 microm film polydimethylsiloxane (PDMS) fibre was found to be unsuitable for VOC work, despite the thick coating. The mixed-phase carboxen/PDMS fibre was found to be suitable. Sensitivity of the SPME was far greater than charcoal sorbent tube method. Calibration studies using typical solvent such as dichloromethane (DCM), benzene (B) and toluene (T) showed an optimal exposure time of 5 min, with a repeatability of less than 20% for a broad spectrum of organic vapour. Minimum detectable amount for DCM is in the range of 0.01 microg/l (0.003 ppmv). Variation among different fibres was generally within 30% at a vapour concentration of 1 microg DCM/l, which was more than adequate for field monitoring purpose. Adsorption characteristics and calibration procedures were studied. An actual application of SPME was carried out to measure background level of solvent vapour at a bench where DCM was used extensively. Agreement between the SPME and the charcoal sampling method was generally within a factor of two. No DCM concentration was found to be above the regulatory limit of 50 ppmv.     

A shadow fraction method for mapping biomass of northern boreal black spruce forests using QuickBird imagery

We have developed and tested a method for mapping above-ground forest biomass of black spruce (Picea mariana (Mill.) B.S.P.) stands in northern boreal forests of eastern Canada. The method uses QuickBird images and applies image processing algorithms to extract tree shadow fraction (SF) as a predictive variable for estimating biomass. Three QuickBird images acquired over three test sites and 108 ground sample plots (GSP) were used to develop and test the method. SF was calculated from the fraction of tree shadow area over the area of a reference square overlaid on the images. Linear regressions between biomass of GSP and SF from the images for each test site resulted in R² in the range from 0.85 to 0.87 (except one case at 0.41), RMSE of 11 to 18 t/ha and bias of 2 to 5 t/ha. Statistical tests demonstrated that local regressions for the three test sites were not statistically significantly different. Consequently, a global regression was calculated with all GSP and produced R², RMSE, and bias of 0.84, 14.2 t/ha and 4.2 t/ha, respectively. While generalization of these results to extended areas of the boreal forest would require further assessment, the SF method provided an efficient means for mapping biomass of black spruce stands for three test areas that are characteristic of the northern boreal forest of eastern Canada (boreal and taiga shield ecozones).     

A Semantic Web-Based Approach to Knowledge Management for Grid Applications

Knowledge has become increasingly important to support intelligent process automation and collaborative problem solving in large-scale science over the Internet. This paper addresses distributed knowledge management, its approach and methodology, in the context of grid application. We start by analyzing the nature of grid computing and its requirements for knowledge support; then, we discuss knowledge characteristics and the challenges for knowledge management on the grid. A semantic Web-based approach is proposed to tackle the six challenges of the knowledge lifecycle - namely, those of acquiring, modeling, retrieving, reusing, publishing, and maintaining knowledge. To facilitate the application of the approach, a systematic methodology is conceived and designed to provide a general implementation guideline. We use a real-world Grid application, the GEODISE project, as a case study in which the core semantic Web technologies such as ontologies, semantic enrichment, and semantic reasoning are used for knowledge engineering and management. The case study has been fully implemented and deployed through which the evaluation and validation for the approach and methodology have been performed     

Optimizing disassembly processes subjected to sequence-dependent cost

Detection of the optimum disassembly sequence for a given product can proceed via mathematical programming, which is based on the AND/OR graph representation of its disassembly process. This is called the exact method for it reveals the global optimum. This paper describes an extension of the exact method in case sequence-dependent costs are considered. Previously presented methods confined themselves either to sequential disassembly, or were based on heuristics. The only exact method for the full problem known so far, needs an elaborate transformation of the AND/OR graph, and is based on integer linear programming. This paper discusses an alternate approach that uses a binary integer linear programming approach and that lacks the need of transforming the AND/OR graph. The proposed method is applied to arbitrary instances of some product structures that have been taken from the literature. Apart from this, the method is applied to an expandable AND/OR graph, that enables gradual increase of product complexity. It is demonstrated that the convergence of the iteration process is satisfactory, and the required CPU time appears comparatively small and only moderately increases with the number of constraints. It appears that the method applies to products with a complexity that cannot be managed with the integer linear programming model. The iterative method is promising for dealing with modularized products and as a benchmark for heuristic algorithms, which are used if products exhibit still higher complexity.     

The impact of Web3D technologies on medical education and training

This paper provides a survey of medical applications that make use of Web3D technologies, covering the period from 1995 to 2005. We assess the impact that Web3D has made on medical education and training during this time and highlight current and future trends. The applications identified are categorized into: general education tools; tools for diagnosis; procedures training; and collaborative training. A summary of work that has been carried out to validate these tools is also included in the survey.     

A rural perspective on health care for the whole person.

The authors summarize the health care problems facing rural and frontier America by addressing five key issues within the framework of health care for the whole person: how to (a) provide health care access, (b) ensure health care quality, (c) provide a range of health care or meet the scope of practice demands, (d) address regional, rural-specific characteristics that may exist, and (e) address health professionals' quality of life. When working in rural and frontier areas it is crucial for providers to collaborate across all types of health care to provide better care and better utilize a region's tautly stretched resources. Rural health care resources are provided. The authors attempt to demonstrate characteristics of rural culture and rural and frontier populations' health care disparities, highlighting the need for collaborative care. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Equity Metrics With Risk, Performance, and Cost Objectives for the Prioritization of Transportation Projects

Prioritizing and selecting a few critical transportation projects from several competing projects is a multiobjective combinatorial optimization problem (MOCO). Transportation planners and managers are always interested in analyzing and visualizing the tradeoffs involved, but equity issues in distribution of resources are given much less attention. This paper develops a methodology for integrating equity metrics with traditional metrics for planning and prioritizing a large and diverse portfolio of transportation investment projects. The methodology serves to help planners, managers, and engineers to visualize and compare measures of the distributed equity of the allocation along with cost-benefit tradeoffs. It is based on incorporating network-level equity metrics along with traditional metrics in formulating a generic multiobjective combinatorial optimization (MOCO) problem and visualizing multiobjective tradeoffs on the spatial network. A case study of a region demonstrates the use of the methodology in tradeoff analysis for prioritizing and selecting transportation projects. The approach is adaptable to other manufacturing and service industries where consideration of the distributed equity of allocation is an important issue.     

Compiler optimizations for processors with SIMD instructions

To achieve maximum efficiency, modern embedded processors for media applications exploit single instruction multiple data (SIMD) instructions. SIMD instructions provide a form of vectorization where a large machine word is viewed as a vector of subwords and the same operation is performed on all subwords in parallel. Systematic usage of SIMD instructions can significantly improve program performance. With C becoming the dominant language for programming embedded devices, there is a clear need for C compilers that use SIMD instructions whenever appropriate. However, SIMD instructions typically require each memory access to be aligned with the instruction's data access size. Therefore an important problem in designing the compiler is to determine whether a C pointer is aligned, i.e. whether it refers to the beginning of a machine word. In this paper, we describe our SIMD generation algorithm and present an analysis method which determines the alignment of pointers at compile time. The alignment information is used to reduce the number of dynamic alignment checks and the overhead incurred by them. Our method uses an interprocedural analysis which propagates pointer alignment information in function bodies and through function calls. The effectiveness of our method is supported by experimental results which show that in typical programs the alignments of about 50% of the pointers can be statically determined. Copyright © 2006 John Wiley & Sons, Ltd.