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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

Intercomparison of Precipitation Simulated by Regional Climate Models over East Asia in 1997 and 1998

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Advances in Atmospheric Sciences 2007年第4期24卷 539-554页

作者： Dong-Kyou LEE William J.GUTOWSKI Hyun-suk kang Chun-Ji KIM School of Earth and Environmental Sciences Seoul National UniversitySeoulKorea Department of Geological and Atmospheric Sciences Iowa State UniversityAmesUSAJr Department of Atmospheric Sciences Yonsei UniversitySeoulKorea.School of Earth and Environmental SciencesSeoul National UniversitySeoulKorea

Regional climate simulations in Asia from May 1997 to August 1998 were performed using the seoul National University regional climate model （SNURCM） and Iowa State University regional climate model （***5/LSM）, which were developed by coupling the NCAR/Land Surface Model （LSM） and the Mesoscale Model （MM5）. However, for physical processes of precipitation, the SNURCM used the Grell scheme for the convective parameterization scheme （CPS） and the simple ice scheme for the explicit moisture scheme （EMS）, while the ***5/LSM used the Betts-Miller scheme for CPS and the mixed phase scheme for EMS.The simulated precipitation patterns and amounts over East Asia for the extreme climatic summer in 1997 （relative drought conditions） and 1998 （relative flood conditions） were especially focused upon. The ***5/LSM simulated more precipitation than was observed in 1997 due to more moisture and cloud water in the lower levels, despite weak upward motion. In the SNURCM, strong upward motion resulted in more precipitation than that was observed in 1998, with more moisture and cloud water in the middle levels. In the ***5/LSM, weak upward motion, unchanged moisture in the lower troposphere, and the decrease in latent heat flux at the surface increased convective precipitation only by 3% for the 1998 summer event. In the SNURCM, strong upward motion, the increase in moisture in the lower troposphere, and the increase in latent heat flux at the surface increased convective precipitation by 48% for the summer of 1998. The main differences between both simulations were moisture availability and horizontal momentum transport in the lower troposphere, which were also strongly influenced by large-scale forcing.

关键词： regional climate simulation summer precipitation variability extreme climatic event physical process

Interdecadal Variability of East Asian Summer Monsoon Precipitation over 220 Years (1777-1997)

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Advances in Atmospheric Sciences 2010年第2期27卷 253-264页

作者： Chun-Ji KIM 钱维宏 Hyun-suk kang Dong-Kyou LEE Atmospheric Sciences Program School of Earth and Environmental Sciences Seoul National University National Institute of Meteorological Research Korea Meteorological Administration Department of Geophysics Peking University

In this study, long-term （1777–1997） precipitation data for seoul, Korea, wetness indices from eastern China, and modern observations are used to identify the interdecadal variability in East Asian summer monsoon precipitation over the last 220 years. In the East Asian monsoon region, two long-term timescales of dry–wet transitions for the interdecadal variability and quasi-40-and quasi-60-year timescales are dominant in the 220-year precipitation data of seoul, as well as in the wetness indices over China. The wet and dry spells between seoul （southern China） and northern China are out-of-phase （out-of-phase） at the quasi-60-year timescale, and in-phase （out-of-phase by approximately 90 ？ before 1900 and in-phase after 1900） at the quasi-40-year timescale. In particular, during the last century, the dominant long-term timescales over East Asia tend to decrease from the quasi-60-year to the quasi-40-year with increasing time. The dominant quasi-40-year and quasi-60-year timescales of the seoul precipitation in Korea are strongly correlated with these timescales of the northern Pacific Ocean.

关键词： interdecadal variability East Asian summer monsoon precipitation timescales dry–wet transition

Priapism secondary to penile metastasis of rectal cancer

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World Journal of Gastroenterology 2009年第33期15卷 4209-4211页

作者： Ji Chan Park Wook Hyun Lee Min Kyu kang suk Young Park Division of Oncology Department of Internal MedicineThe Catholic University of KoreaDaejeon St. Mary's Hospital

Metastatic penile carcinoma is rare and usually originates from genitourinary tumors. The presenting symptoms or signs have been described as nonspecific except for priapism. Rectal adenocarcinoma is a very unusual source of metastatic penile carcinoma. We report a case of metastatic penile carcinoma that originated from the rectum. Symptomatic improvement occurred with palliative radiotherapy.

关键词：直肠癌阴茎异常发生症状非特异性转移性起源

Study on fracture behavior of SiCp/A356 composites

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Rare Metals 2006年第Z2期25卷 168-173页

作者： kang suk-Bong Department of Materials Engineering Korean Institute of Machinery & Materials Gyeongnam 641831 Korea

The fracture behavior of SiCp/A356 composite at room and high temperatures was studied. Under tensile stress condition at room temperature, the fracture is mostly a combination of the brittle fracture of SiC particles and ductile fracture of A356 matrix. As the tensile temperature increases, the composite changes the main fracture behavior to the separation fracture of the bonding surface between SiC particles and A356 matrix. When the tensile temperature reaches 573 K, the fracture behavior of the composites is almost the whole separation fracture of the bonding surface, which is the main strengthening mechanism at high temperature. Under the cycle stress condition at room and high temperatures, the main fracture behavior of the composites is always a combination of the brittle fracture of SiC particles and ductile fracture of A356 matrix. However, under the cycle stress at high temperature, cycle behavior of the composites changes from cycle hardening at room temperature to the cycle softening at high temperature.

关键词： SiCp/A356 composites brittle fracture ductile fracture separation fracture

SVC bitstream adaptation in MPEG-21 multimedia framework

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 764-772页

作者： THANG Truong Cong KIM Young suk RO Yong Man kang Jungwon KIM Jae-Gon Department of Engineering Information and Communications UniversityDaejeon 305-732 Korea Department of Engineering Information and Communications University Daejeon 305-732 Korea Electronics and Telecommunications Research Institute Daejeon 305-732 Korea

Scalable video coding (SVC) is the most promising video format for applications of collaborative communication. MPEG-21 standard has newly emerged to enable the interoperability of multimedia delivery in heterogeneous environments. In this paper we study adaptation of SVC bitstream in the context of MPEG-21 multimedia framework. For interfacing SVC bit- stream with MPEG-21 based adaptation system, we propose three SVC specific adaptation operators. Based on our previous work with multidimensional video adaptation, we present an effective approach, using MPEG-21 DIA AdaptationQoS description tool, to model QoS control for SVC adaptation. Then we show how the operator values could be computed from that representation. For the actual adaptation at bitstream level, we propose a procedure to remove the unnecessary NAL units from an SVC bitstream. The result of this study enables QoS management of SVC streaming in an efficient and standardized manner.

关键词： Multidimensional video adaptation, Scalable video coding (SVC), MPEG-21 DIA (Digital Item Adaptation), QoS

Effects of core/shell volumetric ratio on the dielectric-temperature behavior of BaTiO_(3)

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Journal of Advanced Ceramics 2014年第1期3卷 76-82页

作者： Sang-Chae JEON Byung-Kwon YOON Kwan-Hyeong KIM suk-Joong L.kang Materials Interface Laboratory Department of Materials Science and EngineeringKorea Advanced Institute of Science and Technology291 Daehak-roYuseong-gu Daejeon 305-701Korea LCR Division Samsung Electro-MechanicsSuwon 443-743Korea

Two sets of(Mg,Y)-doped BaTiO_(3)samples were prepared to investigate the effects of the core/shell volumetric ratio on the dielectric-temperature behavior of BaTiO3:one set with samples of the same grain size but different core sizes and the other with samples of the same core size but different shell *** microstructural variation of the samples was characterized and their dielectric properties were *** both sets of samples,the temperature stability of the dielectric properties was generally improved with a reduction of the volumetric shell ratio regardless of the grain and core *** existed,however,a limit of the reduction;for the studied range,shell thickness of one third of the core radius appeared to be an optimum thickness for the given amounts of *** was concluded that the volumetric shell ratio should be optimized so as not to exceed a specific limit,for our case two thirds of the grain volume,to secure temperature stability of the dielectric properties of BaTiO_(3).

关键词： barium titanate core/shell structure dielectric properties temperature stability

Hepatotoxicity Associated with a Short Course of Rosuvastatin

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Chinese Medical Journal 2015年第12期128卷 1693-1694页

作者： Na Kyoung Hwang Jin Sup Park Kwang Soo Cha Jin suk kang Division of Cardiology Department of Internal Medicine and Medical Research Institute Pusan National University Hospital Busan South Korea

Statins reduce cardiovascular morbidity and mortality with *** generally well-tolerated,dose-dependent adverse events develop in 10%-15% *** addition,up to 3% patients have mildly elevated serum aminotransferase level... 详细信息

关键词： Drug Hepatotoxicity Rosuvastatin

Do microRNA 96, 145 and 221 expressions really aid in Lhe prognosis of prostate carcinoma？

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Asian Journal of Andrology 2012年第5期14卷 752-757页

作者： Sung Gu kang Young Ran Ha seo Jin Kim seok Ho kang Hong seok Park Jeong Gu Lee Jun Cheon Department of Urology Korea University College of Medicine Seou1136-705 Republic of Korea and 2Department of Pathology Korea University College of Medicine Seoul 136 705 Republic of Korea Department of Pathology Korea University College of Medicine Seoul 136705 Republic of Korea

MicroRNAs （miRs） are small noncoding RNAs that have been reported to be premising diagnostic tools. We used quantitative real-time reverse transcription PCR （RT-qPCR） to analyze differentially expressed miRNAs in prostate tumor samples to determine its prognostic value. From 2007 to 2009, tumor tissues were obtained from 73 radical prostatectomy specimens. Differentially expressed miR-96, -145 and -221 were validated by TaqMan RT-qPCR using all 73 tissues. The prognostic value was assessed in terms of biochemical recurrence using Kaplan-Meier and Cox regression analyses. For our patient cohort, the mean age was 64.7 years （50-76 years） and the mean prostate-specific antigen （PSA） was 7.5 ng m1-1. During the follow-up period （mean, 19.4 months）, 14 of 73 （19.2%） patients developed biochemical recurrence. Expression of miR-96, -145 and -221 correlated strongly with each other, but there were no correlations between miRNA expression and clinicopathologic parameters. Kaplan-Meier survival curves using the log-rank test showed a decreased biochemical recurrence-free interval with pathologic stage （P〈O.O01）. In addition, patients with Gleason scores over 8, compared with those with a Gleason score of 6, showed a decreased biochemical recurrence-free interval in Kaplan-Meier analysis （P=O.O01）. However, expression of miR-96, -145 and -221 did not correlate with the biochemical recurrence interval in Kaplan-Meier survival curves or by multivariate analysis using the Cox proportional hazard regression model, either. In conclusion, we did not observe a significant correlation between the expression of miR-96, -145 and -221 and clinicopathologic parameters. To utilize miRNA as a diagnostic tool in clinical practice, more research is needed to understand miRNA mechanisms, identify miRNA targets, and further characterize miRNA function.

关键词： microRNA prognosis prostate cancer recurrence