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When developing a complex, multi‐authored code, daily testing on multiple platforms and under a variety of conditions is essential. It is therefore necessary to have a regression test suite that is easily administered and configured, as well as a way to easily view and interpret the test suite results. We describe the methodology for verification of FLASH, a highly capable multiphysics scientific application code with a wide user base. The methodology uses a combination of unit and regression tests and an in‐house testing software that is optimized for operation under limited resources. Although our practical implementations do not always comply with theoretical regression‐testing research, our methodology provides a comprehensive verification of a large scientific code under resource constraints.Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
63.
This paper examines the social meaning behind the adoption of mobile telephones by teenagers in Norway. Through this adoption process one can see the way in which youths are developing their adult identity as well as their gendered identity. The primary database used in this analysis is from two telephone questionnaires of Norwegian youth aged 13–20 carried out in October and December 1998. A total of 2007 interviews are included. The survey instrument covered teenagers’ ownership of mobile telephones, payment forms and the use of mobile telephones to send and receive Short Message System (SMS) text messages. In addition, the analysis draws on a survey of 1001 Norwegian parents and ethnographic interviews of 12 families.  相似文献   
64.
1. Part of the DNA extruded by cultured rat spleen cells occurs in the form of a low density lipid complex. 2. The present work indicates that this complex is also associated with protein but not with RNA and its elementary properties have been studied. 3. For example, it is destroyed by freezing and thawing or by deoxycholate treatment and small quantities of copper salts added to the medium may either inhibit or stimulate its release depending on the conditions.  相似文献   
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Speech text entry can be problematic during ideal dictation conditions, but difficulties are magnified when external conditions deteriorate. Motion during speech is an extraordinary condition that might have detrimental effects on automatic speech recognition. This research examined speech text entry while mobile. Speech enrollment profiles were created by participants in both a seated and walking environment. Dictation tasks were also completed in both the seated and walking conditions. Although results from an earlier study suggested that completing the enrollment process under more challenging conditions may lead to improved recognition accuracy under both challenging and less challenging conditions, the current study provided contradictory results. A detailed review of error rates confirmed that some participants minimized errors by enrolling under more challenging conditions while others benefited by enrolling under less challenging conditions. Still others minimized errors when different enrollment models were used under the opposing condition. Leveraging these insights, we developed a decision model to minimize recognition error rates regardless of the conditions experienced while completing dictation tasks. When applying the model to existing data, error rates were reduced significantly but additional research is necessary to effectively validate the proposed solution.  相似文献   
67.
A real-time photo-realistic visual flythrough   总被引:1,自引:0,他引:1  
In this paper we present a comprehensive flythrough system which generates photo-realistic images in true real-time. The high performance is due to an innovative rendering algorithm based on a discrete ray casting approach, accelerated by ray coherence and multiresolution traversal. The terrain as well as the 3D objects are represented by a textured mapped voxel-based model. The system is based on a pure software algorithm and is thus portable. It was first implemented on a workstation and then ported to a general-purpose parallel architecture to achieve real-time performance  相似文献   
68.
Dataflow programs are widely used. Each program is a directed graph where nodes are computations and edges indicate the flow of data. In prior work, we reverse-engineered legacy dataflow programs by deriving their optimized implementations from a simple specification graph using graph transformations called refinements and optimizations. In MDE speak, our derivations were PIM-to-PSM mappings. In this paper, we show how extensions complement refinements, optimizations, and PIM-to-PSM derivations to make the process of reverse engineering complex legacy dataflow programs tractable. We explain how optional functionality in transformations can be encoded, thereby enabling us to encode product lines of transformations as well as product lines of dataflow programs. We describe the implementation of extensions in the \(\mathtt{ReFlO}\) tool and present two non-trivial case studies as evidence of our work’s generality.  相似文献   
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The Cambrian explosion is named for the geologically sudden appearance of numerous metazoan body plans (many of living phyla) between about 530 and 520 million years ago, only 1.7% of the duration of the fossil record of animals. Earlier indications of metazoans are found in the Neoproterozic; minute trails suggesting bilaterian activity date from about 600 million years ago. Larger and more elaborate fossil burrows appear near 543 million years ago, the beginning of the Cambrian Period. Evidence of metazoan activity in both trace and body fossils then increased during the 13 million years leading to the explosion. All living phyla may have originated by the end of the explosion. Molecular divergences among lineages leading to phyla record speciation events that have been earlier than the origins of the new body plans, which can arise many tens of millions of years after an initial branching. Various attempts to date those branchings by using molecular clocks have disagreed widely. While the timing of the evolution of the developmental systems of living metazoan body plans is still uncertain, the distribution of Hox and other developmental control genes among metazoans indicates that an extensive patterning system was in place prior to the Cambrian. However, it is likely that much genomic repatterning occurred during the Early Cambrian, involving both key control genes and regulators within their downstream cascades, as novel body plans evolved.  相似文献   
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