As an integrated application of modern information technologies and artificial intelligence,Prognostic and Health Management(PHM)is important for machine health monitoring.Prediction of tool wear is one of the symboli...As an integrated application of modern information technologies and artificial intelligence,Prognostic and Health Management(PHM)is important for machine health monitoring.Prediction of tool wear is one of the symbolic applications of PHM technology in modern manufacturing systems and industry.In this paper,a multi-scale Convolutional Gated Recurrent Unit network(MCGRU)is proposed to address raw sensory data for tool wear prediction.At the bottom of MCGRU,six parallel and independent branches with different kernel sizes are designed to form a multi-scale convolutional neural network,which augments the adaptability to features of different time scales.These features of different scales extracted from raw data are then fed into a Deep Gated Recurrent Unit network to capture long-term dependencies and learn significant representations.At the top of the MCGRU,a fully connected layer and a regression layer are built for cutting tool wear prediction.Two case studies are performed to verify the capability and effectiveness of the proposed MCGRU network and results show that MCGRU outperforms several state-of-the-art baseline models.展开更多
Given the fact that cultures are a distinct way of identifying the mores and customs of a people, culture-specific units such as proverbs could serve as veritable teaching tools to pass on otherwise difficult language...Given the fact that cultures are a distinct way of identifying the mores and customs of a people, culture-specific units such as proverbs could serve as veritable teaching tools to pass on otherwise difficult language concepts to students, especially in the context of acquiring a foreign language. Proverbs can actually be viewed as succinct sayings that convey semantically-laden units expressing a people＇s worldview. In this paper, an attempt is made to illustrate the effectiveness of using culture-specific units like French proverbs to teach challenging grammatical features to English-speaking students in a French class. For example, grammatical aspects like verb conjugation French syntax, etc., can be effectively tackled. Translational techniques could then serve as pedagogical tools to bring about a better grasp of the foreign language being acquired, and in the process, exposure to a larger world culture would be achieved展开更多
AIM To assess the performance of a newly designed,culturally adapted screening tool for autism spectrum disorder(ASD).METHODS Items for the screening tool were modeled from already documented checklists and diagnostic...AIM To assess the performance of a newly designed,culturally adapted screening tool for autism spectrum disorder(ASD).METHODS Items for the screening tool were modeled from already documented checklists and diagnostic criteria for ASD.Each item in text was paired with a photograph that illustrated the written content,which was in the 2 main local languages.The final product had 21 items and was named the pictorial autism assessment schedule(PAAS).Performance of PAAS was tested on a clinical sample of 18-48 mo old children,diagnosis na?ve,presenting with developmental deficits.Mothers completed PAAS checklist.Based on clinical diagnosis,which was taken as the gold standard,children were later grouped into ASD(Group 1) and non-ASD developmental disorders(Group 2).Mothers of a control sample of typically developing children also completed PAAS(Group 3).RESULTS A total of 105 children(Group 1-45,Group 2-30,Group 3-30) participated in the study.Mean age of Group 1 and Group 2 were 36 and 40 mo respectively.Majority were male in all 3 groups.Performance of PAAS in discriminating between ASD and non-ASD developmental disorders was sensitivity 88.8%,specificity 60.7%,positive predictive value(PPV) 78.4%,negative predictive value(NPV) 77.2%,likelihood ratio(LR+) 2.26,and LR-0.18.Performance of PAAS in discriminating between ASD and typical development was sensitivity 88.0%,specificity 93.3%,PPV 95.2%,NPV 84.0%,LR+ 13.3 and LR- 0.12.The results indicated that that a positive result from PAAS was 2.26 times more likely to be found in a child with ASD than in a child with non-ASD developmental disorder.A positive result from PAAS was 13.3 times more likely to be found in a child with ASD than in a child with typical development.CONCLUSION PAAS is an effective tool in screening for ASD.Further study is indicated to evaluate the feasibility of using this instrument for community screening for ASD.展开更多
This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a ...This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a contaminant migration pathway based on the groundwater gradient interpreted from groundwater elevation data, which is based on the underlying assumption that the subsurface conditions are homogeneous. However, the buried channel deposits render the underlying geology highly heterogeneous, and this heterogeneity plays a significant role in the subsurface migration of contaminants. Chemical fingerprinting evidence suggested that contamination at the downgradient property boundary was related to an off-site contaminant source. But, this alone was not a compelling argument. However, Environmental Sequence Stratigraphy (ESS), a geology-based environmental forensic technique, was applied to define the permeability architecture or the “plumbing” that controls subsurface fluid flow and contaminant migration. First, the geologic and depositional setting was synthesized based on regional geologic data, and representative facies models were identified for the site. Second, the existing CSM and site lithology data were reviewed and existing lithology data were graphically presented to display vertical grain-size patterns. This analysis focused on the nexus between the depositional environment and the site-specific subsurface data resulting in correlations/interpretations between and beyond data points that are based on established stratigraphic principles. The depositional environment results in buried river channels as the primary control on subsurface fluid flow, which defines hydrostratigraphic units (or HSUs). Finally, a hydrostratigraphic CSM that includes maps and cross sections was constructed to depict the HSUs present as a framework to integrate hydro-geology and chemistry data. This study demonstrates that: 1) Highly per-meable buried river channel deposits control subsurface fluid flow and contaminant transport, and have distinct chemical constituents and concentrations (i.e., they represent distinct HSUs), 2) Mapping of such HSUs is feasible with existing boring log data, 3) In settings such as the Santa Clara Valley where groundwater flow is governed by subsurface channel deposits, a hydrostratigraphic mapping approach is superior to a depth-based aquifer zonation approach, and 4) For heterogeneous subsurface, a detailed geology-based definition of the subsurface is an integral component of an environmental forensic analyses to determine contaminant source(s) and pathways.展开更多
There exist many automated unit test-generator tools for Java with the primary task of generating test cases, comprised of inputs and a corresponding oracle, each of which is explicitly paired with a specific supporti...There exist many automated unit test-generator tools for Java with the primary task of generating test cases, comprised of inputs and a corresponding oracle, each of which is explicitly paired with a specific supporting test implementation. The authors posit that this explicit pairing, or conflating, of test implementation with test case is unnecessary and counter-productive. The authors address this problem by separating the conflated concerns into two distinct tasks: 1) instantiating test implementations and 2) instantiating test cases. This paper focuses on automating the first task in support of the second with the goal of freeing the test engineer to concentrate on test case instantiation. The authors present a new open-source test-preparation tool Obsidian that produces robust, comprehensive, and maintainable unit test implementations. Obsidian, built on the JUnit framework, uses a set of context patterns and associated algorithms combined with information from the Java Reflection API to generate these unit test implementations from Java byte code. These context patterns guide Obsidian to prepare test implementations that guarantee compilation, support exception handling, enable multiple test cases when required, and provide a suitable location for assertions about the test case outcome(s). Obsidian supports regression testing and test-driven development through its novel audits of the testing process.展开更多
基金Supported in part by Natural Science Foundation of China(Grant Nos.51835009,51705398)Shaanxi Province 2020 Natural Science Basic Research Plan(Grant No.2020JQ-042)Aeronautical Science Foundation(Grant No.2019ZB070001).
文摘As an integrated application of modern information technologies and artificial intelligence,Prognostic and Health Management(PHM)is important for machine health monitoring.Prediction of tool wear is one of the symbolic applications of PHM technology in modern manufacturing systems and industry.In this paper,a multi-scale Convolutional Gated Recurrent Unit network(MCGRU)is proposed to address raw sensory data for tool wear prediction.At the bottom of MCGRU,six parallel and independent branches with different kernel sizes are designed to form a multi-scale convolutional neural network,which augments the adaptability to features of different time scales.These features of different scales extracted from raw data are then fed into a Deep Gated Recurrent Unit network to capture long-term dependencies and learn significant representations.At the top of the MCGRU,a fully connected layer and a regression layer are built for cutting tool wear prediction.Two case studies are performed to verify the capability and effectiveness of the proposed MCGRU network and results show that MCGRU outperforms several state-of-the-art baseline models.
文摘Given the fact that cultures are a distinct way of identifying the mores and customs of a people, culture-specific units such as proverbs could serve as veritable teaching tools to pass on otherwise difficult language concepts to students, especially in the context of acquiring a foreign language. Proverbs can actually be viewed as succinct sayings that convey semantically-laden units expressing a people＇s worldview. In this paper, an attempt is made to illustrate the effectiveness of using culture-specific units like French proverbs to teach challenging grammatical features to English-speaking students in a French class. For example, grammatical aspects like verb conjugation French syntax, etc., can be effectively tackled. Translational techniques could then serve as pedagogical tools to bring about a better grasp of the foreign language being acquired, and in the process, exposure to a larger world culture would be achieved
文摘AIM To assess the performance of a newly designed,culturally adapted screening tool for autism spectrum disorder(ASD).METHODS Items for the screening tool were modeled from already documented checklists and diagnostic criteria for ASD.Each item in text was paired with a photograph that illustrated the written content,which was in the 2 main local languages.The final product had 21 items and was named the pictorial autism assessment schedule(PAAS).Performance of PAAS was tested on a clinical sample of 18-48 mo old children,diagnosis na?ve,presenting with developmental deficits.Mothers completed PAAS checklist.Based on clinical diagnosis,which was taken as the gold standard,children were later grouped into ASD(Group 1) and non-ASD developmental disorders(Group 2).Mothers of a control sample of typically developing children also completed PAAS(Group 3).RESULTS A total of 105 children(Group 1-45,Group 2-30,Group 3-30) participated in the study.Mean age of Group 1 and Group 2 were 36 and 40 mo respectively.Majority were male in all 3 groups.Performance of PAAS in discriminating between ASD and non-ASD developmental disorders was sensitivity 88.8%,specificity 60.7%,positive predictive value(PPV) 78.4%,negative predictive value(NPV) 77.2%,likelihood ratio(LR+) 2.26,and LR-0.18.Performance of PAAS in discriminating between ASD and typical development was sensitivity 88.0%,specificity 93.3%,PPV 95.2%,NPV 84.0%,LR+ 13.3 and LR- 0.12.The results indicated that that a positive result from PAAS was 2.26 times more likely to be found in a child with ASD than in a child with non-ASD developmental disorder.A positive result from PAAS was 13.3 times more likely to be found in a child with ASD than in a child with typical development.CONCLUSION PAAS is an effective tool in screening for ASD.Further study is indicated to evaluate the feasibility of using this instrument for community screening for ASD.
文摘This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a contaminant migration pathway based on the groundwater gradient interpreted from groundwater elevation data, which is based on the underlying assumption that the subsurface conditions are homogeneous. However, the buried channel deposits render the underlying geology highly heterogeneous, and this heterogeneity plays a significant role in the subsurface migration of contaminants. Chemical fingerprinting evidence suggested that contamination at the downgradient property boundary was related to an off-site contaminant source. But, this alone was not a compelling argument. However, Environmental Sequence Stratigraphy (ESS), a geology-based environmental forensic technique, was applied to define the permeability architecture or the “plumbing” that controls subsurface fluid flow and contaminant migration. First, the geologic and depositional setting was synthesized based on regional geologic data, and representative facies models were identified for the site. Second, the existing CSM and site lithology data were reviewed and existing lithology data were graphically presented to display vertical grain-size patterns. This analysis focused on the nexus between the depositional environment and the site-specific subsurface data resulting in correlations/interpretations between and beyond data points that are based on established stratigraphic principles. The depositional environment results in buried river channels as the primary control on subsurface fluid flow, which defines hydrostratigraphic units (or HSUs). Finally, a hydrostratigraphic CSM that includes maps and cross sections was constructed to depict the HSUs present as a framework to integrate hydro-geology and chemistry data. This study demonstrates that: 1) Highly per-meable buried river channel deposits control subsurface fluid flow and contaminant transport, and have distinct chemical constituents and concentrations (i.e., they represent distinct HSUs), 2) Mapping of such HSUs is feasible with existing boring log data, 3) In settings such as the Santa Clara Valley where groundwater flow is governed by subsurface channel deposits, a hydrostratigraphic mapping approach is superior to a depth-based aquifer zonation approach, and 4) For heterogeneous subsurface, a detailed geology-based definition of the subsurface is an integral component of an environmental forensic analyses to determine contaminant source(s) and pathways.
文摘There exist many automated unit test-generator tools for Java with the primary task of generating test cases, comprised of inputs and a corresponding oracle, each of which is explicitly paired with a specific supporting test implementation. The authors posit that this explicit pairing, or conflating, of test implementation with test case is unnecessary and counter-productive. The authors address this problem by separating the conflated concerns into two distinct tasks: 1) instantiating test implementations and 2) instantiating test cases. This paper focuses on automating the first task in support of the second with the goal of freeing the test engineer to concentrate on test case instantiation. The authors present a new open-source test-preparation tool Obsidian that produces robust, comprehensive, and maintainable unit test implementations. Obsidian, built on the JUnit framework, uses a set of context patterns and associated algorithms combined with information from the Java Reflection API to generate these unit test implementations from Java byte code. These context patterns guide Obsidian to prepare test implementations that guarantee compilation, support exception handling, enable multiple test cases when required, and provide a suitable location for assertions about the test case outcome(s). Obsidian supports regression testing and test-driven development through its novel audits of the testing process.
