867 resultados para Computer software selection and evaluation


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Changes of porosity, permeability, and tortuosity due to physical and geochemical processes are of vital importance for a variety of hydrogeological systems, including passive treatment facilities for contaminated groundwater, engineered barrier systems (EBS), and host rocks for high-level nuclear waste (HLW) repositories. Due to the nonlinear nature and chemical complexity of the problem, in most cases, it is impossible to verify reactive transport codes analytically, and code intercomparisons are the most suitable method to assess code capabilities and model performance. This paper summarizes model intercomparisons for six hypothetical scenarios with generally increasing geochemical or physical complexity using the reactive transport codes CrunchFlow, HP1, MIN3P, PFlotran, and TOUGHREACT. Benchmark problems include the enhancement of porosity and permeability through mineral dissolution, as well as near complete clogging due to localized mineral precipitation, leading to reduction of permeability and tortuosity. Processes considered in the benchmark simulations are advective-dispersive transport in saturated media, kinetically controlled mineral dissolution-precipitation, and aqueous complexation. Porosity changes are induced by mineral dissolution-precipitation reactions, and the Carman-Kozeny relationship is used to describe changes in permeability as a function of porosity. Archie’s law is used to update the tortuosity and the pore diffusion coefficient as a function of porosity. Results demonstrate that, generally, good agreement is reached amongst the computer models despite significant differences in model formulations. Some differences are observed, in particular for the more complex scenarios involving clogging; however, these differences do not affect the interpretation of system behavior and evolution.

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Early Employee Assistance Programs (EAPs) had their origin in humanitarian motives, and there was little concern for their cost/benefit ratios; however, as some programs began accumulating data and analyzing it over time, even with single variables such as absenteeism, it became apparent that the humanitarian reasons for a program could be reinforced by cost savings particularly when the existence of the program was subject to justification.^ Today there is general agreement that cost/benefit analyses of EAPs are desirable, but the specific models for such analyses, particularly those making use of sophisticated but simple computer based data management systems, are few.^ The purpose of this research and development project was to develop a method, a design, and a prototype for gathering managing and presenting information about EAPS. This scheme provides information retrieval and analyses relevant to such aspects of EAP operations as: (1) EAP personnel activities, (2) Supervisory training effectiveness, (3) Client population demographics, (4) Assessment and Referral Effectiveness, (5) Treatment network efficacy, (6) Economic worth of the EAP.^ This scheme has been implemented and made operational at The University of Texas Employee Assistance Programs for more than three years.^ Application of the scheme in the various programs has defined certain variables which remained necessary in all programs. Depending on the degree of aggressiveness for data acquisition maintained by program personnel, other program specific variables are also defined. ^

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The usage of intensity modulated radiotherapy (IMRT) treatments necessitates a significant amount of patient-specific quality assurance (QA). This research has investigated the precision and accuracy of Kodak EDR2 film measurements for IMRT verifications, the use of comparisons between 2D dose calculations and measurements to improve treatment plan beam models, and the dosimetric impact of delivery errors. New measurement techniques and software were developed and used clinically at M. D. Anderson Cancer Center. The software implemented two new dose comparison parameters, the 2D normalized agreement test (NAT) and the scalar NAT index. A single-film calibration technique using multileaf collimator (MLC) delivery was developed. EDR2 film's optical density response was found to be sensitive to several factors: radiation time, length of time between exposure and processing, and phantom material. Precision of EDR2 film measurements was found to be better than 1%. For IMRT verification, EDR2 film measurements agreed with ion chamber results to 2%/2mm accuracy for single-beam fluence map verifications and to 5%/2mm for transverse plane measurements of complete plan dose distributions. The same system was used to quantitatively optimize the radiation field offset and MLC transmission beam modeling parameters for Varian MLCs. While scalar dose comparison metrics can work well for optimization purposes, the influence of external parameters on the dose discrepancies must be minimized. The ability of 2D verifications to detect delivery errors was tested with simulated data. The dosimetric characteristics of delivery errors were compared to patient-specific clinical IMRT verifications. For the clinical verifications, the NAT index and percent of pixels failing the gamma index were exponentially distributed and dependent upon the measurement phantom but not the treatment site. Delivery errors affecting all beams in the treatment plan were flagged by the NAT index, although delivery errors impacting only one beam could not be differentiated from routine clinical verification discrepancies. Clinical use of this system will flag outliers, allow physicists to examine their causes, and perhaps improve the level of agreement between radiation dose distribution measurements and calculations. The principles used to design and evaluate this system are extensible to future multidimensional dose measurements and comparisons. ^

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The purpose of this study is to evaluate the theory-based Eat 5 nutrition badge. It is designed to increase fruit and vegetable (F&V) intake in 4th-6th grade junior Girl Scouts. Twenty-two troops were recruited and randomized by grade level (4th, 5th, 6th, or mixed) into either the intervention or control conditions. The leaders in the intervention condition received a brief training and the materials and conducted the program with their troops during four meetings. The Girl Scouts in the intervention condition completed 1-day Food Frequency Questionnaires and Nutrition Questionnaires both before and after completing the Eat 5 badge, and a third measurement of F&V intake three months after the posttest. Girl Scouts in the control condition were only evaluated at the three time periods.^ The primary hypotheses were that the Girl Scouts in the intervention condition would increase their daily intake of fruits and vegetables at both the posttest and three months later, compared to the Girl Scouts in the control condition. Other study questions investigated the impact of the Eat 5 program on intervening variables such as knowledge, self-efficacy, barriers, norms, F&V preference, and F&V selection and preparation skills.^ A nested ANOVA, with troop as the unit of analysis nested within condition, was used to assess the effects of the program. Pretest F&V intake and grade level were used as covariates. Pretest mean F&V intake for the total sample of 210 girls was 2.50 servings per day; 3.0 for the intervention group (n = 101). Significant increases in F&V intake (to 3.4 servings per day), knowledge, and fruit and vegetable preference were found for the intervention condition troops compared to the troops in the control condition. Three months later, the mean F&V intake had returned to pretest levels.^ This study indicates that social groups such as Girl Scouts can provide a channel for nutrition education. Long term effects were not sustained by the intervention; a possible cause was the lack of change in self-efficacy. Therefore, additional interventions are recommended such as booster lessons to maintain increased F&V intake by Girl Scouts. ^

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A descriptive study of the current educational programs of selected health personnel in Nigeria was made in 1986. Data on the content of educational programs was obtained from personal communication with the Heads of the various institutions and from their published materials (catalogs, course outlines and program descriptions). Adequacy of these programs was judged in the light of current health problems and needs of the population. Evaluation was based on the following criteria: (a) Selection of students to maximize their usefulness in the provision of health care. (b) Relevance of the curriculum to the tasks the trainee will be called upon to perform. (c) Types of courses that focus on community health needs. Using official reports, the health situation in the country was described to give a relative priority of health services.^ Findings indicate the following: (1) Health conditions in Nigeria are related to a high prevalence of illness and disease, unsanitary living conditions, a high ratio of infant mortality and a shortage of public health services. Priority needs for improvement call for attitudinal and environmental changes. (2) All health training programs have improved the relevance of education to community health needs by strengthening practical field experience, and teaching those courses which focus on disease prevention. (3) Prospective nurses and community health workers are selected on the basis of a number of personal and intellectual characteristics, but academic performance alone is the criterion for medical students. (4) The curriculum in the medical school needs to be restructured to cut back on time devoted to enriching the medical "background". Basic sciences need better integration with hospital work. (5) Managerial and organization courses have been well incorporated into the nursing and community health workers' curricula. (6) There is a marked overlap in the tasks the community health workers are expected to perform. This causes some redundancy in having four separate categories of these health personnel. ^

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When a firm decides to implement ERP softwares, the resulting consequences can pervade all levels, includ- ing organization, process, control and available information. Therefore, the first decision to be made is which ERP solution must be adopted from a wide range of offers and vendors. To this end, this paper describes a methodology based on multi-criteria factors that directly affects the process to help managers make this de- cision. This methodology has been applied to a medium-size company in the Spanish metal transformation sector which is interested in updating its IT capabilities in order to obtain greater control of and better infor- mation about business, thus achieving a competitive advantage. The paper proposes a decision matrix which takes into account all critical factors in ERP selection.

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This work introduces a web-based learning environment to facilitate learning in Project Management. The proposed web-based support system integrates methodological procedures and information systems, allowing to promote learning among geographically-dispersed students. Thus, students who are enrolled in different universities at different locations and attend their own project management courses, share a virtual experience in executing and managing projects. Specific support systems were used or developed to automatically collect information about student activities, making it possible to monitor the progress made on learning and assess learning performance as established in the defined rubric.

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Computers and multimedia equipment have improved a lot in the last years. They have reduced their cost and size while at the same time increased their capabilities. These improvements allowed us to design and implement a portable recording system that also integrates the teacher´s tablet PC to capture what he/she writes on the slides and all that happens in it. This paper explains this system in detail and the validation of the recordings that we did after using it to record all the lectures the “Communications Software” course in our university. The results show that pupils used the recordings for different purposes and consider them useful for a variety of things, especially after missing a lecture.

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The importance of vision-based systems for Sense-and-Avoid is increasing nowadays as remotely piloted and autonomous UAVs become part of the non-segregated airspace. The development and evaluation of these systems demand flight scenario images which are expensive and risky to obtain. Currently Augmented Reality techniques allow the compositing of real flight scenario images with 3D aircraft models to produce useful realistic images for system development and benchmarking purposes at a much lower cost and risk. With the techniques presented in this paper, 3D aircraft models are positioned firstly in a simulated 3D scene with controlled illumination and rendering parameters. Realistic simulated images are then obtained using an image processing algorithm which fuses the images obtained from the 3D scene with images from real UAV flights taking into account on board camera vibrations. Since the intruder and camera poses are user-defined, ground truth data is available. These ground truth annotations allow to develop and quantitatively evaluate aircraft detection and tracking algorithms. This paper presents the software developed to create a public dataset of 24 videos together with their annotations and some tracking application results.

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Federal Highway Administration, Washington, D.C.

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It is not surprising that students are unconvinced about the benefits of formal methods if we do not show them how these methods can be integrated with other activities in the software lifecycle. In this paper, we describe an approach to integrating formal specification with more traditional verification and validation techniques in a course that teaches formal specification and specification-based testing. This is accomplished through a series of assignments on a single software component that involves specifying the component in Object-Z, validating that specification using inspection and a specification animation tool, and then testing an implementation of the specification using test cases derived from the formal specification.