• Title/Summary/Keyword: Lee Sam

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Viscoplastic Solution of Thick Walled Cylinder Considering Axial Constraint (축방향 경계 조건을 고려한 두꺼운 실린더의 점소성 응력해)

  • Yoon, Sam-Son;Lee, Soon-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.9
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    • pp.1555-1561
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    • 2003
  • Finite element analysis using modern constitutive equation is one of the most general tools to simulate the deformation behavior and to predict the life of the structure. Constitutive equation becomes complicated so as to predict the material behavior more accurately than the classical models. Because of the complexity of constitutive model, numerical treatment becomes so difficult that the calculation should be verified carefully. One-element tests, simple tension or simple shear, are usually used to verify the accuracy of finite element analysis using complicated constitutive model. Since this test is mainly focused on the time integration scheme, it is also necessary to verify the equilibrium iteration using material stiffness matrix and to compare FE results with solution of structures. In this investigation, viscoplastic solution of thick walled cylinder was derived considering axial constraints and was compared with the finite element analysis. All the numerical solutions showed a good coincidence with FE results. This numerical solution can be used as a verification tool for newly developed FE code with complicated constitutive model.

A Study on Structural Analysis of Integrated Machining Center (집적화된 Machining Center의 구조해석에 관한 연구)

  • Park, Seong-Jin;Lee, Choon-Man;Kim, Woong;Byun, Sam-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.1
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    • pp.49-54
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    • 2010
  • An integrated machining center is developed for high precision and productivity manufacturing. The developed machine is composed of the high precision spindle using ball bearings, the high stiffness bed and the three axis CNC controller with the high resolution AC servo motor. In this paper, structural and modal analysis for the developed machine are carried out to check the design criteria of machine. The analysis is carried out by FEM simulation with using the commercial software, CATIA V5, ANSYS and ARMD. The simulation model of machine is made by shell and solid finite elements. This study also presents the measurement system on the modal analysis of an integrated machining center. The weak part of the machine is found by the analytical evaluation. The results provide with the structural modification data for good dynamic behaviors. And the safety of machine is confirmed by the modal analysis of modified machine design. As this study results can be trustworthy with the analysis of ANSYS and CATIA, integrated machining center can be successfully developed.

A Study on Direction of Industrial Utilization for Jellyfish in Korea (해파리 피해 실태 및 산업적 이용 방향)

  • Kim, Dae-Young;Lee, Jung-Sam;Kim, Do-Hoon
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.3
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    • pp.587-596
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    • 2014
  • The study aims at suggesting the direction of industrial utilization for harmful jellyfish which appears in large quantities in the Korean coastal areas. If the technology of industrial utilization for the jellyfish is developed, it will be possible to grow the industry to the export industry due to the mass appearance of jellyfish in Korean coastal areas. The industrial utilization of jellyfish should follow the direction of minimizing the damage by the jellyfish blooms and maximizing the resource recycling of the jellyfish. Therefore, Korea needs construction of infrastructure for the industrialization and promotion of R&D in order to activate the industrial utilization. Finally, the study suggested issues and tasks for promoting the industrial utilization of jellyfish as follows. First, Korea should stabilize the high quality raw material supply system. Second, mass processing technology should be developed for the industrial utilization of the jellyfish. Third, research and manual development should follow for the preparation of turning the jellyfish to the food. Fourth, extraction technology of useful non-food substance such as extracting collagen from jellyfish should be developed and accelerate the industrial utilization of non-food area.

Automatic Individual Tooth Region Separation using Accurate Tooth Curve Detection for Orthodontic Treatment Planning

  • Lee, Chan-woo;Chae, Ok-sam
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.4
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    • pp.57-64
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    • 2018
  • In this paper, we propose the automatic detection method for individual region separation using panorama image. Finding areas that contain individual teeth is one of the most important tasks in automating 3D models through individual tooth separation. In the conventional method, the maxillary and mandibular teeth regions are separated using a straight line or a specific CT slide, and the tooth regions are separated using a straight line in the vertical direction. In the conventional method, since the teeth are arranged in a curved shape, there is a problem that each tooth region is incorrectly detected in order to generate an accurate tooth region. This is a major obstacle to automating the creation of individual tooth models. In this study, we propose a method to find the correct tooth curve by using the jawbone curve which is very similar to the tooth curve in order to overcome the problem of finding the area containing the existing tooth. We have proposed a new method to accurately set individual tooth regions using the feature that individual teeth are arranged in a direction similar to the normal direction of the tooth alignment curve. In the proposed method, the maxillary and mandibular teeth can be more precisely separated than the conventional method, and the area including the individual teeth can be accurately set. Experiments using real dental CT images demonstrate the superiority of the proposed method.

A Study on the Location Improvement of the Pharmaceutical Logistics Center (의약품 물류센터 입지 개선 방안에 관한 연구)

  • Cho, Sam Hyun;Cho, Sang Lee
    • Journal of Korea Port Economic Association
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    • v.35 no.3
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    • pp.41-60
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    • 2019
  • This study aims to identify factors that pharmaceutical logistics companies must consider when selecting a logistics center; it also aims to analyze the importance-satisfaction-of these factors by using IPA. The main results are as follows. First, overall, the aforementioned factors are divided into logistics factor, economic factor, environmental factor, and policy factor, and most of the specific attributes of each main factor are less satisfied than the importance. Second, the users of pharmaceutical logistics are divided into producers, distributors, clinics, and pharmacies. The analysis of each user shows a need to improve logistics factors as well as an overinvestment in environmental factors. The results can provide drug distribution companies directions for selecting logistics centers as well as strategic implications.

Analysis of electric characteristics for extension power supply between different grounding railway distribution system (접지방식이 상이한 철도배전계통의 연장급전을 위한 전기적 특성분석)

  • Jung, Ho-Sung;Han, Moon-Seob;Lee, Chang-Mu;Kwon, Sam-Young;Park, Hyeun-Jun
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.736-741
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    • 2005
  • This paper presents electric characteristics analysis and safe configuration for extension power supply between existent 6.6kV ungrounded distribution system and establishment and improvement 22.9kV direct grounding distribution system. For this, we model 6.6kV ungrounded and 22.9kV direct grounding distribution system of urban underground, ground region. and rural electrical, unelectrical region using PSCAD/EMTDC and analyze voltage drop, charging current, ground and short fault through simulation. To analyze electric characteristics of extension power supply, we simulate extension power supply of overhead line of 6.6kV ungrounded system and underground line of 22.9kV direct grounding system of rural electrical region and propose operation condition for safe extension power supply through result of analysis. Characteristics of voltage drop, charging current, ground and short fault appear almost similarly with electrical characteristic of direct power supply. However, because unbalance of phases may cause relay's malfunction of ungrounded system and ground fault current of direct grounding system may demage facilities of ungrounded system, we propose safe system configuration such as impedance grounding system of neutral point.

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인삼사포닌의 모에 미치는 효과에 관한 연구

  • Kim, Chang-Gyu;Sim, Sam-Ju;Lee, Ok-Seop
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.7 no.1
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    • pp.1-18
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    • 1979
  • 인삼(人蔘)사포닌으로 처리(處理)한 모발(毛髮)의 인장강도(引張强度)와 신장도(伸張度)를 collagen 가수분해물(加水分解物)로 처리한 모발(毛髮)과 비교(比較)하였다. 모발(毛髮)에 인삼(人蔘)사포닌 흡수량(吸收量)은 high speed liquid chromatography로 측정(測定)하였으며 liquid scintillation counter로 확인(確認)하였다. 모발(毛髮)에 collagen 가수분해물(加水分解物)의 흡수량(吸收量)은 모발(毛髮)을 collagen 가수분해물(加水分解物) 용액(溶液)속에 침적(沈積)시켰을 때 처음 30분(分) 동안은 많은 량(量)의 흡착(吸着)이 일어났으나 1시간(時間) 경과후(經過後)부터는 더 이상(以上)의 증가(增加)는 보이지 않았다. 이와는 반대(反對)로 인삼(人蔘)사포닌의 경우(境遇)는 침적시간(沈積時間)의 증가(增加)에 비례(比例)하여 흡수량(吸收量)의 증가(增加)를 나타내었다. 실험결과(實驗結果)는 인삼(人蔘)사포닌이 collagen 가수분해물(加水分解物) 보다 모발(毛髮)에 더욱 효과적(效果的)임을 보여 주었고, 그리고 인삼(人蔘)사포닌의 모발(毛髮)에 대(對)한 흡수(吸收)와 인장강도(引張强度)의 증가(增加)는 모발(毛髮)의 strain-stress곡선(曲線)과 인삼(人蔘)사포닌의 계면활성(界面活性)에 의(依)해 설명(說明)하였다.

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Molecular Characterization of a PR4 Gene in Chinese Cabbage

  • Chung, Sam-Young;Lee, Kyung-Ah;Oh, Kyung-Jin;Cho, Tae-Ju
    • Animal cells and systems
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    • v.9 no.4
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    • pp.239-244
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    • 2005
  • A cDNA clone for a wound- and pathogen-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene, designated BrPR4, encodes a pathogenesis-related protein 4 (PR4) of 140 amino acids. The BrPR4 protein shows high similarity with wound-inducible antifungal proteins of tobacco, potato, barley, and wheat. The BrPR4 gene is locally induced by a nonhost pathogen, Pseudomonas syringae pv. tomato, that elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with benzothiadiazole (BTH), methyl jasmonate or ethephon showed that the BrPR4 gene expression is strongly induced by ethylene, but not by methyl jasmonate or BTH. The BrPR4 gene is also activated by wounding. Interestingly, however, the wound-inducible BrPR4 gene expression is repressed by salicylic acid or BTH, suggesting that there is cross-talk between salicylate-dependent and -independent signaling pathways.

A Development of Underground Water Management System Using an Analytic Model (지하수 해석 모델을 이용한 지하수 관리시스템의 개발)

  • Seo, Jeong-Min;Lee, Chang-Hoon;Kim, Sam-Keun
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.4 s.36
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    • pp.57-63
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    • 2005
  • An accurate system modeling in the underground water analysis requires many accurate parameters on the spot, which have a huge volume, because it may be generated more inaccurate products than to use mathematical analytical solution in a case that a degree of permeation, undercurrent coefficients, boundary conditions, and so on, are inadequately estimated. Recently, handling these parameters easily has been an active area of research. In this paper, we propose a new method which handles these parameters easily and accurately for a system model management using a well-known MODFLOW model. Also, we incorporate this method into ArcView functions. Results of the proposed system incorporated into ArcView are displayed visually.

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Suppressive Effects of Triterpenoids on CINC-1 Induction in Interleukin-1{\betha}-stimulated rat fibroblast NRK-49F cells

  • Ha, Joo-Young;Min, Kyung-Rak;Kang, She-Hoon;Kim, Ju-Sun;Lee, Gyeong-Im;Kang, Sam-Sik;Kim, Youngsoo
    • Archives of Pharmacal Research
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    • v.20 no.3
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    • pp.234-238
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    • 1997
  • CINC-1 is a member of chemokine family with chemotactic and activating properties to neutrophils. CINC-1 induction in IL-$1{\beta}$-stimulated rat fibroblast NRK-49F cells was quantitated by a sensitive ELISA. CINC-1 production was increased up to 135 ng/ml from basal 2-6 ng/ml by stimulation with IL-$1{\beta}$.Steroidal anti-inflammatory drugs including dexamethasone and prednisolone exhibited potent suppressive effects on IL-$1{\beta}$-induced CINC-1 production. Among 39 kinds of natural triterpenoids tested, acacigenin B exhibited the highest suppressive effects with about $10{\mu}M$ to be 50% of inhibition on the CINC-1 induction. The suppressive potency of acacigenin B on IL-$1{\beta}$induced CINC-1 production was about 10-fold less than that of the steroidal anti-inflammatory drugs.

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