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This article introduces the realist survey, an extension of the realistic interview. In a realistic interview, the researcher adapts his or her own theory in response to comments by interviewees, explaining the extent to which the...
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This article introduces the realist survey, an extension of the realistic interview. In a realistic interview, the researcher adapts his or her own theory in response to comments by interviewees, explaining the extent to which the theory applies or does not apply to themselves. The realist survey expands the reach of the realistic interview by including application to generally accepted theories, and it enhances the generalizability of its outcomes through the use of quantitative survey data. As a result, this extended realist interview/survey is a tool that can be used by researchers in widely varying contexts. A realist survey on the effects of the often replicated technology acceptance model shows that the original model is not the best realist fit.
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Kanis provides an interesting but prescriptive view on reliability and validity in human
factors and ergonomics (HFE) research. For HFE recommendations to be implemented
the research must communicate with and convince the target...
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Kanis provides an interesting but prescriptive view on reliability and validity in human
factors and ergonomics (HFE) research. For HFE recommendations to be implemented
the research must communicate with and convince the target audience. To achieve
this, researchers will continue to use a selection of analytical tools across both disciplines
(and industrial sectors) and the methodological continuum. A major step forward
in improving the quality (including reliability and validity) of evaluation
research in HFE is the development and validation of mixed methods critical appraisal
tools. Sponsors, funders and editors should encourage researchers and reviewers to
take a more systematic approach to raise the quality of HFE research in practice and
publication.
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Abstract It is important to improve our understanding about what might be the specific characteristics of mental disorders to strengthen the scientific credibility of psychiatry and to clarify its position among other medical and ...
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Abstract It is important to improve our understanding about what might be the specific characteristics of mental disorders to strengthen the scientific credibility of psychiatry and to clarify its position among other medical and nonmedical sciences. On the other hand, this issue has diagnostic, research, therapeutic, legal, financial, and moral implications. Some authors defend a realistic and absolutist attitude towards validity and others an instrumental and relativistic stance. Regarding the organization of concepts, dimensional or categorical approaches have both advantages and disadvantages. Regarding the methodology by which validity is sought, it can be oriented externally or internally to the concept in question. On the other hand, the validity can be expert driven or data driven, the research can be based on disorders or in symptoms and quantitative or qualitative methods may be used. In this article, we review all these different kinds of perspectives that can be taken towards the definition of validity in psychiatry and the methodology to search for it.
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This article is a systematic collection of existing methods and techniques for evaluating rendering category in the field of computer graphics. The motive for doing this study was the difficulty of selecting appropriate methods fo...
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This article is a systematic collection of existing methods and techniques for evaluating rendering category in the field of computer graphics. The motive for doing this study was the difficulty of selecting appropriate methods for evaluating and validating specific results reported by many researchers. This difficulty lies in the availability of numerous methods and lack of robust discussion of them. To approach such problems, the features of well-known methods are critically reviewed to provide researchers with backgrounds on evaluating different styles in photo-realistic rendering part of computer graphics. There are many ways to evaluating a research. For this article, classification and systemization method is use. After reviewing the features of different methods, their future is also discussed. Finally, dome pointers are proposed as to the likely future issues in evaluating the research on realistic rendering. It is expected that this analysis helps researchers to overcome the difficulties of evaluation not only in research, but also in application.
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Study Design. This study shows the first phase of validation of a new model for realistic training on spine surgery, conducted from January 2014 to November 2015.
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The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These pos...
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The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building's radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology.
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This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The buildin...
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This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow-and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations from contaminant deposition on the roof and surrounding ground as well as for computing a weighted-average representative building shielding factor for single-and multi-story detached homes, both with and without basement as well for single-wide manufactured housing-unit.
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摘要 :AbstractWe present a pipeline that rapidly simulates X-ray transmission imaging for arbitrary system architectures using GPU-based ray-tracing techniques. The purpose of the pipeline is to enable statistical analysis of threat det...
展开AbstractWe present a pipeline that rapidly simulates X-ray transmission imaging for arbitrary system architectures using GPU-based ray-tracing techniques. The purpose of the pipeline is to enable statistical analysis of threat detection in the context of airline baggage inspection. As a faster alternative to Monte Carlo methods, we adopt a deterministic approach for simulating photoelectric absorption-based imaging. The highly-optimized NVIDIA OptiX API is used to implement ray-tracing, greatly speeding code execution. In addition, we implement the first hierarchical representation structure to determine the interaction path length of rays traversing heterogeneous media described by layered polygons. The accuracy of the pipeline has been validated by comparing simulated data with experimental data collected using a heterogenous phantom and a laboratory X-ray imaging system. On a single computer, our approach allows us to generate over 400 2D transmission projections (125×125 pixels per frame) per hour for a bag packed with hundreds of everyday objects. By implementing our approach on cloud-based GPU computing platforms, we find that the same 2D projections of approximately 3.9 million bags can be obtained in a single day using 400 GPU instances, at a cost of only $0.001 per bag.收起
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Background: Monte Carlo simulations of diffusion are commonly used as a model validation tool as they are especially suitable for generating the diffusion MRI signal in complicated tissue microgeometries. New method: Here we descr...
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Background: Monte Carlo simulations of diffusion are commonly used as a model validation tool as they are especially suitable for generating the diffusion MRI signal in complicated tissue microgeometries. New method: Here we describe the details of implementing Monte Carlo simulations in three-dimensional (3d) voxelized segmentations of cells in microscopy images. Using the concept of the corner reflector, we largely reduce the computational load of simulating diffusion within and exchange between multiple cells. Precision is further achieved by GPU-based parallel computations. Results: Our simulation of diffusion in white matter axons segmented from a mouse brain demonstrates its value in validating biophysical models. Furthermore, we provide the theoretical background for implementing a discretized diffusion process, and consider the finite-step effects of the particle-membrane reflection and permeation events, needed for efficient simulation of interactions with irregular boundaries, spatially variable diffusion coefficient, and exchange. Comparison with existing methods: To our knowledge, this is the first Monte Carlo pipeline for MR signal simulations in a substrate composed of numerous realistic cells, accounting for their permeable and irregularly-shaped membranes. Conclusions: The proposed RMS pipeline makes it possible to achieve fast and accurate simulations of diffusion in realistic tissue microgeometry, as well as the interplay with other MR contrasts. Presently, RMS focuses on simulations of diffusion, exchange, and T-1 and T-2 NMR relaxation in static tissues, with a possibility to straightforwardly account for susceptibility-induced T-2* effects and flow.
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This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding ...
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This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow-and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations as well as for computing a weighted-average representative building shielding factor for single-and multi-story detached homes, both with and without basement, as well for single-wide manufactured housing-units.
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