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Characteristics of damaged layer in micro-machining of copper material

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中国有色金属学会会刊：英文版 2009年第B9期19卷 295-300页

作者： Dong-Hee kwon Jeong-Suk KIM Myung-Chang KANG Se-Hun kwon Jong-Hwan LEE School of Mechanical Engineering Pusan National University National Core Research Center for Hybrid Materials Solution Pusan National University Department of Mechatronics Busan College of Korea Polytechnic Ⅶ

The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-machining characteristics, such as cutting speed, feed rate and cutting depth, of a micro-damaged layer produced by an ultra-high speed air turbine spindle. The micro cutting force, surface roughness and plastic deformation layer were investigated according to the machining conditions. The damaged layer was measured using optical microscope on samples prepared through metallographic techniques. The scale of the damaged layer depends on the cutting process parameters, particularly, the feed per tooth and axial depth of the cut. According to the experimental results, the depth of the damaged layer is increased by increasing the feed per tooth and cutting depth, also the damaged layer occurs less in down-milling compared with up-milling during the micro-machining operation.

关键词：机械加工性微观特征损伤层铜材样品制备技术微型机器切削速度切削深度

Nanomechanical Characterization of Bone Quality Depending on Tissue Age via Bimodal Atomic Force Microscopy

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Nanomanufacturing and Metrology 2023年第4期6卷 24-34页

作者： Jinha kwon Hanna Cho Department of Mechanical and Aerospace Engineering The Ohio State UniversityColumbusOH 43210USA

Characterization of bone quality during the healing process is crucial for successful implantation procedures and patient *** this study,a bone implant specimen that underwent a 4-week healing period was *** atomic force microscopy(AFM)was employed to simultaneously obtain the morphology and elastic modulus maps of the newly formed and pre-existing bone regions within the *** indicate that the new bone matrix possessed lower miner-alization levels and presented larger,uneven mineral grains,exhibiting the attributes of a woven *** the other hand,the old bone matrix exhibited a more uniform and mineralized structure,which is characteristic of lamellar *** new bone had a lower overall elastic modulus than the old *** AFM further confrmed that the new bone displayed three regions comprising unmineralized,partially mineralized,and fully matured sections,which indicate a turbulent change in its ***,the old bone exhibited two sections comprising partially mineralized and matured bone parts,which denote the fnal phase of *** study provides valuable insights into the morphological and nanome-chanical diferences between the old and new bone matrixes and presents a novel approach to investigate bone quality at diferent phases of the bone-healing process.

关键词： Bone quality Atomic force microscopy Bimodal AFM Nanomechanical characterization Bone tissue age Woven bone Lamellar bone

Effect of Yanggyuksanhwa-Tang on Non-Insulin-Dependent Diabetes Mellitus Unresponsive to Oral Hypoglycemic Agents:A Case Report

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Chinese Journal of Integrative Medicine 2015年第2期21卷 157-160页

作者： Jiman Kim Seungwon kwon Kyunghee-saeng Haniwon(Korean Medicine Clinic) Department of Cardiovascular and Neurologic Diseases College of Korean MedicineKyungHee University

Diabetes mellitus is the fourth leading cause of death worldwide, following cancer, cerebrovascular disease, and heart disease. It is triggered by hyperglycemia and other metabolic disorders. Diabetes is a complex endocrine disease that causes chronic vascular complications such as diabetic nephropathy, retinopathy, and polyneuropathy.

关键词： oral Effect of Yanggyuksanhwa-Tang on Non-Insulin-Dependent Diabetes Mellitus Unresponsive to Oral Hypoglycemic Agents DCCT

Use of Total Precipitable Water Classification of A Priori Error and Quality Control in Atmospheric Temperature and Water Vapor Sounding Retrieval

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Advances in Atmospheric Sciences 2012年第2期29卷 263-273页

作者： Eun-Han kwon Elisabeth WEISZ School of Earth and Environmental Sciences Seoul National University Seoul 151-747 Korea Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-Madison1225 West Dayton Street Madison WI 53706 USA

This study investigates the use of dynamic a priori error information according to atmospheric moistness and the use of quality controls in temperature and water vapor profile retrievals from hyperspectral infrared （IR） sounders. Temperature and water vapor profiles are retrieved from Atmospheric InfraRed Sounder （AIRS） radiance measurements by applying a physical iterative method using regression retrieval as the first guess. Based on the dependency of first-guess errors on the degree of atmospheric moistness, the a priori first-guess errors classified by total precipitable water （TPW） are applied in the AIRS physical retrieval procedure. Compared to the retrieval results from a fixed a priori error, boundary layer moisture retrievals appear to be improved via TPW classification of a priori first-guess errors. Six quality control （QC） tests, which check non-converged or bad retrievals, large residuals, high terrain and desert areas, and large temperature and moisture deviations from the first guess regression retrieval, are also applied in the AIRS physical retrievals. Significantly large errors are found for the retrievals rejected by these six QCs, and the retrieval errors are substantially reduced via QC over land, which suggest the usefulness and high impact of the QCs, especially over land. In conclusion, the use of dynamic a priori error information according to atmospheric moistness, and the use of appropriate QCs dealing with the geographical information and the deviation from the first-guess as well as the conventional inverse performance are suggested to improve temperature and moisture retrievals and their applications.

关键词： atmospheric sounding AIRS total precipitable water a priori error quality control

Key-Value Store Coupled with an Operating System for Storing Large-Scale Values

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Computers, Materials & Continua 2022年第11期73卷 3333-3350页

作者： Jeonghwan Im Hyuk-Yoon kwon Graduate School of Data Science Seoul National University of Science and TechnologySeoulKorea Department of Industrial Engineering Graduate School of Data ScienceResearch Center for Electrical and Information ScienceSeoul National University of Science and TechnologySeoulKorea

The key-value store can provide flexibility of data types because it does not need to specify the data types to be stored in advance and can store any types of data as the value of the key-value *** types of studies have been conducted to improve the performance of the key-value store while maintaining its ***,the research efforts storing the large-scale values such as multimedia data files(e.g.,images or videos)in the key-value store were *** this study,we propose a new key-value store,WR-Store++aiming to store the large-scale values ***,it provides a new design of separating data and index by working with the built-in data structure of the Windows operating system and the file *** utilization of the built-in data structure of the Windows operating system achieves the efficiency of the key-value store and that of the file system extends the limited space of the storage *** also present chunk-based memory management and parallel processing of WR-Store++to further improve its performance in the GET *** the experiments,we show that WR-Store++can store at least 32.74 times larger datasets than the existing baseline key-value store,WR-Store,which has the limitation in storing large-scale data ***,in terms of processing efficiency,we show that WR-Store++outperforms not only WR-Store but also the other state-ofthe-art key-value stores,LevelDB,RocksDB,and BerkeleyDB,for individual key-value operations and mixed workloads.

关键词： Key-value stores large-scale values chunk-based memory management parallel processing

Dielectrophoretic assembly of semiconducting single-walled carbon nanotube transistor

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 126-129页

作者： Se-Hun kwon Young-Keun JEONG Soongeun kwon Myung-Chang KANG Hyung-Woo LEE National Core Research Center for Hybrid Materials Solution Pusan National University Department of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 305-701 Korea

A novel burning technique for making a semiconducting single-walled carbon nanotubes （SWNTs） transistor assembled by the dielectrophoretic force was suggested. The fabrication process consisted of two steps. First, to align and attach a bundle of SWNTs between the source and drain, the alternating （AC） voltage was applied to the electrodes. When a bundle of SWNTs was connected between two electrodes, some of metallic nanotubes and semi-conducing nanotubes existed together. The second step is to burn the metallic SWNTS by applying the voltage between two electrodes. With increasing the voltage, more current flowed through the metallic SWNTs, thus, the metallic SWNTs burnt earlier than the semiconducting one. This technique enables to obtain only semi-conducting SWNTs connection in the transistor. Through the 1--V characteristic graph, the moment of metallic SWNTs burning and the characteristic of semi-conducing nanotubes were verified.

关键词： single-walled carbon nanotube (SWNT) semi-conducting carbon nanotube burning technique dielectrophoresis

Effect of Squeeze Cast Process Parameters on Fluidity of Hypereutectic Al-Si Alloy

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Journal of Materials Science & Technology 2008年第1期24卷 7-11页

作者： Jong-Kyu Baek Hae-Wook kwon School of Materials Science and Engineering Yeungnam University Gyeongsan 712-749 Korea

The effects of processing variables on the fluidity of hypereutectic Al-Si alloy melt during squeeze casting were *** maximum fluidity of Al-16.0%Si alloy during squeeze casting was obtained under the applied pressure of 30 *** fluidity increased with *** fluidity increased with silicon content in the range from 12.0% to 20.0%.That was decreased respectively by eutectic modification and primary silicon refinement.

关键词： Squeeze casting Al-alloy Fluidity Melt treatment

Decomposing Composite Changes for Code Review and Regression Test Selection in Evolving Software

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Journal of Computer Science & Technology 2019年第2期34卷 416-436页

作者： Bo Guo Young-Woo kwon Myoungkyu Song Department of Global Operations PayPal Omaha Nebraska 68128 U.S.A. School of Computer Science and Engineering Kyungpook National University Daegu 702-701 South Korea Department of Computer Science University of Nebraska at Omaha Omaha 68128 U.S.A.

Inspecting and testing code changes typically require a significant amount of developer *** a system evolves,developers often create composite changes by mixing multiple development issues,as opposed to addressing one independent issue—an atomic *** composite changes often becomes time-consuming and *** test unrelated edits on composite changes,rerunning all regression tests may require excessive *** address the problem,we present an interactive technique for change decomposition to support code reviews and regression test selection,called *** a developer specifies code change within a diff patch,ChgCutter partitions composite changes into a set of related atomic changes,which is more cohesive and self-contained regarding the issue being *** composite change inspection,it generates an intermediate program version that only includes a related change subset using program dependence *** cost reduction during regression testing,it safely selects only affected tests responsible for changes to an intermediate *** the evaluation,we apply ChgCutter to 28 composite changes in four open source *** partitions these changes with 95.7% accuracy,while selecting affected tests with 89.0% *** conduct a user study with professional software engineers at PayPal and find that ChgCutter is helpful in understanding and validating composite changes,scaling to industry projects.

关键词： software maintenance and evolution code review test selection program slicing

An XPath-based OWL storage model for effective ontology management in Semantic Web environment

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第6期10卷 843-857页

作者： Jinhyung KIM Dongwon JEONG Doo-kwon BAIK Department of Computer Science and Engineering Korea University Department of Informatics and Statistics Kunsan National University

With the rapid growth of the Web, the volume of information on the Web is increasing exponentially. However, information on the current Web is only understandable to humans, and this makes precise information retrieval difficult. To solve this problem, the Semantic Web was proposed. We must use ontology languages that can assign data the semantics for realizing the Semantic Web. One of the representative ontology languages is the Web ontology language OWL, adopted as a recommen-dation by the World-Wide Web Consortium (W3C). OWL includes hierarchical structural information between classes or prop-erties. Therefore, an efficient OWL storage model that considers a hierarchical structure for effective information retrieval on the Semantic Web is required. In this paper we suggest an XPath-based OWL storage (XPOS) model, which includes hierarchical information between classes or properties in XPath form, and enables intuitive and effective information retrieval. Also, we show the comparative evaluation results for the performance of the XPOS model, Sesame, and the XML file system-based storage (XFSS) model, in terms of query processing and ontology updating.

关键词： XPath Web ontology language Hierarchical structure Ontology storage Semantic Web