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Microsystems & Nanoengineering 2022年第4期8卷 233-249页

作者： Yongkui Tang Eun sok kim Department of Electrical and Computer Engineering University of Southern CaliforniaLos AngelesCA90089-0271USA

Focused ultrasound(FUs)is a powerful tool widely used in biomedical therapy and imaging as well as in sensors and *** focusing techniques based on curved surfaces,metamaterial structures,and multielement phased arrays either present diffculties in massively parallel manufacturing with high precision or require complex drive electronics to *** difficulties have been addressed by microfabricated self-focusing acoustic transducers(SFATs)with Parylene air-cavity Fresnel acoustic lenses(ACFALs),which require a time-demanding step in removing the sacrificial *** paper presents three new and improved types of ACFALs based on polydimethylsiloxane(PDMS),an SU-8/PDMS bilayer,and SU-8,which are manufactured through simple sacrificiallayer-free microfabrication processes that are two to four times faster than that for the Parylene ***,by studying the effect of the lens thickness on the acoustic transmittance through the lens,the performance of the transducers has been optimized with improved thickness control techniques developed for PDMS and *** a result,the measured power transfer effciency(PTE)and peak output acoustic pressure are up to 2.0 and 1.8 times higher than those of the Parylene ACFALs,*** simple microfabrication techniques described in this paper are useful for manufacturing not only high-performance ACFALs but also other miniaturized devices with hollow or suspended structures formicrofluidicand optical applications.

关键词： Parylene Fresnel cavity

A modeling method for vibration analysis of cracked beam with arbitrary boundary condition

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Journal of Ocean Engineering and Science 2018年第4期3卷 367-381页

作者： Kwanghun kim sok kim Kyongjin sok Chanil Pak Kwangbok Han Department of Engineering Machine Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea Department of Information Engineering Chongjin Mine&Metal UniversityChongjin 999091Democratic People’s Republic of Korea Institute of Information Technology University of SciencesPyongyang 999093Democratic People’s Republic of Korea Information Center Kim Chaek University of TechnologyPyongyang 950003Democratic People’s Republic of Korea Department of Resource Development Machinery Engineering Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea

This paper establishes a cracked Timoshenko beams model to investigate the vibration behavior based on the ultraspherical *** beam theory is applied to model the free vibration analysis of the cracked beam and the numerical results are obtained by using ultraspherical orthogonal *** boundary conditions of both ends of the cracked beam are modeled as the elastic spring and the beam is divided into two parts by the crack section,and continuous conditions at the connecting face are modeled by the inverse of the flexibility coefficients of fracture mechanics *** the influence of boundary conditions,displacements admissible functions of cracked Timoshenko beam can be set up as ultraspherical orthogonal *** accuracy and robustness of the present method are evidenced through comparison with previous literature and the results achieved by the finite element method(FEM).In addition,the effects of flexibility coefficient on the natural frequencies are also investigated by using the proposed *** examples are given for free vibration analysis of cracked beams with various boundary conditions,which may be provided as reference data for future study.

关键词： Cracked beam Free vibration Ultraspherical polynomials Arbitrary boundary conditions

A semi-analytical method for forced vibration analysis of cracked laminated composite beam with general boundary condition

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Journal of Ocean Engineering and Science 2021年第1期6卷 40-53页

作者： sok kim Kwanghun kim Myongchol Ri Yongsong Paek Choljun kim Department of Information Engineering Chongjin Mine&Metal UniversityChongjin 999091Democratic People’s Republic of Korea Department of Engineering Machine Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea Institute of Science Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea Department of Resources Development Mechanical Engineering Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea

In this paper,a semi-analytical method for the forced vibration analysis of cracked laminated composite beam(CLCB)is *** computational model is formulated by Timoshenko beam theory and its dynamic solution is solved using the Jacobi-Ritz *** boundary conditions(BCs)at both ends of the CLCB are generalized by the application of artificial elastic springs,the CLCB is separated into two elements along the crack,the flexibility coefficient of fracture theory is used to model the essential continuous condition of the connective *** the allowable displacement functions used to analyze dynamic characteristics of CLCB are expressed by classical Jacobi orthogonal polynomials in a more general *** accuracy of the proposed method is verified through the compare with results of the finite element method(software ABAQUS is used in this paper).On this basis,the parametric study for dynamic analysis characteristics of CLCB is performed to provide reference datum for engineers.

关键词： Semi-analytical method Cracked laminated composite beam(CLCB) Dynamic analysis General boundary condition Numerical analysis

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柬埔寨Artisans公司经营策略研究

柬埔寨Artisans公司经营策略研究

作者：金松（kim sok）北京交通大学

学位级别：硕士

Over the last few years, international tourist arrival in the Kingdom of Cambodia has increased unprecedentedly, being projected to reach 5 million international tourists by the end of 2015. The minister of tourism, in his speech to Chinese tourists in 2013, explained about the increase, having cited two main reasons, the nation-wide full piece and the prosperity of Khmer culture. Simultaneously, the needs of tourism services also increase while the souvenir industry, one of the tourism services, remarkably *** study aims to develop a business strategy for Artisans Cambodia (AC) to improve its current standing in the souvenir art industry in Cambodia. The study attempts to answer the following questions:(1) How can the operation of AC be sustained?(2) What are strategic options available for AC to sustain its operations?(3) What marketing strategies must be adopted to take advantage of the growing business opportunities in Cambodia tourism industry?The study information was gathered both from primary and secondary *** data are generated from the interviews of sellers and international tourists. Using convenience sampling technique in interviewing respondents numbering to approximate 100 foreign tourists and 20 sellers of souvenir art shops, a fact to face interview was undertaken in the capital of Phnom Penh and the town of Siem Reap, the two most wanted places to visit for both international and local tourists. An actual visit was conducted by the researchers at the manufacturing plant of AC in Phnom Penh and Siem Reap, where a case study was held. This result validates main findings of the *** result of the survey showed about the number (in percentage) of tourists from the other foreign countries who like buying the souvenirs, the kinds of souvenir products and their average costs per piece the international customers preferred, the places of the potential tourism markets all over Cambodia where the tourists preferred to visit and buy souv

关键词： Figure 经营策略 weighing ancient tourist Artisans heritage Temple tourism silver

Nanotribological properties and scratch resistance of MoS_(2)bilayerona SiO_(2)/Si substrate

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Friction 2023年第1期11卷 154-164页

作者： Si-hwan kim Hyo-sok AHN Department of Transdisciplinary Studies Seoul National UniversitySeoul 08826Republic of Korea Department of Manufacturing Systems and Design Engineering Seoul National University of Science and TechnologySeoul 08826 Republic of Korea

The tribological properties and scratch resistance of MoS_(2)bilayer deposited on SiO_(2)/Si substrates prepared via chemical vapor deposition are *** force microscopy(FFM)is employed to investigate the friction and wear properties of the MoS_(2)bilayer at the nanoscale by applying a normal load ranging from 200 to 1,000 *** resistance is measured using the scratch mode in FFM based on a linearly increasing load from 100 to 1,000 *** probe force microscopy(KPFM)is performed to locally measure the surface potential in the tested surface to qualitatively measure the wear/removal of Mos,layers and identify critical loads associated with the individual failures of the top and bottom *** analysis of the contact potential difference values as well as that of KPFM,friction,and height images show that the wear/removal of the top and bottom layers in the MoS_(2)bilayer system occurred *** FFM and KPFM results show that the top MoS_(2)layer begins to degrade at the end of the low friction stage,followed by the bottom layer,thereby resulting in a transitional friction stage owing to the direct contact between the diamond tip and SiO_(2)*** the stable third stage,the transfer of lubricious MoS_(2)debris to the tip apex results in contact between the MoS_(2)-transferred tip and SiO_(2).Nanoscratch test results show two ranges of critical loads,which correspond to the sequential removal of the top and bottom layers.

关键词： chemical vapor deposition(CVD)-grown MoS,bilayer friction force microscopy(FFM) nanoscratch test Kelvin probe force microscopy(KPFM) scratch resistance

Evaluation of early-age strains and stresses in roller-compacted concrete pavement

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第1期9卷 93-105页

作者： Tetsya sok Young Kyu kim Jun Young Park Seung Woo Lee Public Infrastructure Department Ministry of Public Works and TransportPhnom Penh 12100Cambodia Institute for Disaster Prevention Gangneung-Wonju National UniversityGangneung-si 25457South Korea Korea Expressway Research Institute Korea Expressway CorporationHwaseong-si 18489South Korea Civil Engineering Department Gangneung-Wonju National UniversityGangneung-si 25457South Korea

In the structural design of a roller-compacted concrete pavement(RCCP), it is crucial to estimate strain and stress developments in the RCCP slab realistically. Since the RCCP mix uses less cement and lower amount of water, shrinkage strain and concrete temperature during the hardening stage are expected to be reduced as compared to those of conventional concrete mixture, resulting in a reduction of the concrete early-age deformation and stress developments in the RCCP slab. In this paper, early-age concrete strain and stress developments in RCCP slab subjected to environmental loads were evaluated. A full-scale test section of RCCP under real climatic conditions was monitored. The early-age total strains,stress-independent strains, shrinkage strains, and coefficient of thermal expansion(CTE) of the RCCP were measured and analyzed. Using the results of measured strains, in-situ CTE and shrinkage strain, and temperature, the early-age concrete stress development is computed by incorporating a viscoelastic property of the early-age concrete. The results revealed that the shrinkage strain of the RCCP is quite low as compared to that of conventional concrete. The early-age stress developments in the RCCP slab are strongly governed by the thermal-induced stresses. Shrinkage-induced stresses were quite small and might be negligible in a preliminary estimation of early-age stress developments in the RCCP slab.

关键词： Road engineering Roller-compacted concrete pavement Concrete strain Concrete stress Shrinkage strain Environmental loads

利用CF_4等离子体制作高开口率TFT-LCD(英文)

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液晶与显示 2006年第5期21卷 409-413页

作者：金奉柱崔瑩石劉聖烈張炳鉉柳在一李禹奉李貞烈京东方科技集团股份有限公司中央研究院北京100016

为了获得高的开口率,有必要优化设计参数和工艺容差。通常的过孔刻蚀工艺采用SF6基气体进行刻蚀,但是这种方法在金属和钝化层之间的选择性太小,因此,必须增加过孔的尺寸才行。为了克服上述问题,在本研究中用CF4气体代替SF6气体进行刻蚀... 详细信息

为了获得高的开口率,有必要优化设计参数和工艺容差。通常的过孔刻蚀工艺采用SF6基气体进行刻蚀,但是这种方法在金属和钝化层之间的选择性太小,因此,必须增加过孔的尺寸才行。为了克服上述问题,在本研究中用CF4气体代替SF6气体进行刻蚀,结果在FFS 5 .16(2 .03 in)像素结构中,开口率提高了60 %。

关键词： TFT—LCD 开口率刻蚀 CF4等离子体

Single omental metastasis of renal cell carcinoma after radical nephrectomy:A case report

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世界临床病例杂志 2023年第25期11卷 5994-5999页

作者： Jae-Wook Chung Jun-Koo Kang Eun Hye Lee So Young Chun Yun-sok Ha Jun Nyung Lee Tae-Hwan kim Tae Gyun Kwon Ghil Suk Yoon Department of Urology Kyungpook National University HospitalDaegu 41404South Korea Department of Urology School of MedicineKyungpook National UniversityDaegu 41404South Korea Biomedical Research Institute Kyungpook National UniversityDaegu 41404South Korea Joint Institute for Regenerative Medicine Kyungpook National UniversityDaegu 41404South Korea Department of Pathology Kyungpook National University HospitalDaegu 41404South Korea Department of Pathology School of MedicineKyungpook National UniversityDaegu 41404South Korea

BACKGROUND Renal cell carcinoma(RCC)is the third most common malignancy in the genitourinary *** lungs,bone,lymph nodes,liver,and brain are common metastatic sites of ***,there is limited literature on single omental metastasis of *** SUMMARY We present the case of a 44-year-old man with single omental metastasis of RCC after laparoscopic radical *** diagnosis of the resected left kidney revealed pT3a clear cell RCC(Fuhrman grade III).At 6 mo postoperatively,abdominal computed tomography revealed a 12-mm enhancing nodule in the left lower *** 7 mo after initial operation,laparoscopic removal of the left omental nodule was *** pathological results indicated metastatic clear cell ***,the patient is being treated with adjuvant *** Omental metastasis of RCC owing to laparoscopic radical nephrectomy is *** should be aware of the diverse nature of RCC.

关键词： Metastasis Omentum Renal cell carcinoma Radical nephrectomy Case report

Newly developed autoimmune cholangitis without relapse of autoimmune pancreatitis after discontinuing prednisolone

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World Journal of Gastroenterology 2012年第41期18卷 5990-5993页

作者： Ji Hun kim Jae Hyuck Chang Sung Min Nam Mi Jeong Lee Il Ho Maeng Jin Young Park Yun Sun Im Tae Ho kim Chang Whan kim sok Won Han Department of Internal Medicine College of MedicineThe Catholic University of KoreaSeoul 137-701South Korea

A 57-year-old man presented with a 2-wk history of painless jaundice and weight *** had a large illdefined enhancing mass-like lesion in the uncinate process of the pancreas with stricture of the distal common bile *** cytology of the pancreatic mass demonstrated inflammatory cells without evidence of *** serum immunoglobulin G level was slightly elevated,but IgG4 level was *** the 2-wk 40 mg prednisolone trial,the patient's symptoms and bilirubin level improved significantly.A follow-up computed tomography(CT) scan showed a dramatic resolution of the pancreatic lesion.A low dose steroid was *** six months he self-discontinued prednisolone for 3 wk,and was presented with jaundice again.A CT scan showed newly developed intrahepatic biliary dilatation and marked concentric wall thickening of the common hepatic duct and the proximal common bile duct without pancreatic *** patient' s IgG4 level was elevated to 2.51 g/*** was started again,after which his serum bilirubin level became normal and the thickening of the bile duct was *** case suggests that autoimmune pancreatitis can progress to other organs that are not involved at the initial diagnosis,even with sustained pancreatic remission.

关键词：自身免疫性泼尼松龙胰腺炎胆管开发计算机断层扫描复发免疫球蛋白G

Genetic variation of the PSCA gene(rs2294008) is not associated with the risk of prostate cancer

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The Journal of Biomedical Research 2017年第3期31卷 226-231页

作者： II-Seok Lee Sung Pil Seo Yun sok Ha Pildu Jeong Ho Won Kang Won Tae kim Yong-June kim Seok Joong Yun Sang Cheol Lee Wun-Jae kim Department of Urology Chungbuk National University College of Medicine Department of Urology School of MedicineKyungpook National University

Prostate stem cell antigen（PSCA） is a cell-membrane glycoprotein consisting of 123 amino acids and highly expressed in the prostate,but there have been few reports on the relationship between rs2294008 of PSCA and prostate cancer in the ***,we evaluated the association between rs2294008 and the risk of prostate cancer.A total of 240 prostate cancer patients and 306 controls（patients with benign prostatic hyperplasia） were *** analysis of rs2294008 of PSCA was performed using *** regression analysis was performed according to the genotype of PSCA *** found that CT and TT genotypes were associated with an insignificant risk of prostate cancer compared with the CC genotype（P= 0.627 and 0.397,respectively）.In addition,there was no significant difference in rs2294008 according to clinicopathological parameters,such as age,Gleason score,prostate-specific antigen（PSA）,stage,and metastasis in prostate cancer（P 〉 0.05 for each）.Age,Gleason score,PSA,pathologic stage,and metastasis did not modify the association between PSCA and the risk of prostate cancer（each P 〉 0.05 for each）.Taken together,the genetic polymorphism of PSCA rs2294008 was not associated with the risk of prostate *** results suggest that rs2294008 may not play a role in prostate carcinogenesis.

关键词： prostatic neoplasms polymorphism genetic risk prostate polymorphism single nucleotide