자유표면 근처에서의 구형 셸과 충격파의 비정상 유체-구조물 상호작용 해석

이민형,이범헌,이승엽,Lee, Min-Hyung,Lee, Beom-Heon,Lee, Seung-Yop 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.6

This paper analyses the transient response of a spherical elastic shell located near fee surface and impinged by spherical step-exponential acoustic shock waves. The problem is solved through extension of a method (Huang, 1969) previously formulated for the excitation in an infinite domain, which employs the classical separation of variables, series solutions, and Laplace transform technique The effect of the free surface reflection is taken into account using the image source method. The reflection of the incident wave has been treated by the same image formulation. If the reflection of the pressure field scattered and radiated by the shell is considered, the problem becomes that of multiple scattering by two spheres. However, this is in general negligible considering errors inherent from other sources and that the scattered and radiated pressure waves emanating from the shell are small. Thus, the problem is reduced to that of a structure immersed in an infinite fluid and impinged upon the origin and the image incident.

황기의 재배년차(栽培年差)에 따른 천식(喘息)의 면역학적 치료효과에 대한 비교연구

이민형,노성수,서영배,Lee, Min-Hyung,Roh, Seong-Soo,Seo, Young-Bae 대한본초학회 2008 大韓本草學會誌 Vol.23 No.2

Objectives : The present study was carried out to investigate the effects of Astragali radix on the asthma treatment. EAR-I is an extract of astragali radix cultured for one year and EAR-III is an extract of astragali radix cultured for three years. Methods : Two asthma-induced groups mice group was treated respectively with EAR- I and EAR- III. The other group was not. Each group was analyzed in vivo and in vitro experiments. Results : In asthma-induced mice by OVA treatment, the weight of lung, total cell number of leukocyte and eosinophil in BALF, both EAR- I and EAR- III treated groups were significantly decreased compared to control group. IL-4, IL-5, IL-13, histamine, IgE in BLAF of group treated with both EAR-I and EM-III were significantly decreased compared to control group. In FACS analyzing, granulocytes, $CD3e^-$/$CCR3^+$, $CD3^+$/$CD19^$, $CD3e^+$/$CD69^+$, $CD4^+$, $CD8^+$ and $GR-1^+$/$CD11b^+$ were significantly increased in asthma induced mice group by OVA treatment compared to control group, and decreased in group treated with both EAR- I and EAR-III. Conclusions : The present data proves that extract of astragali radix has an effect on the inhibiting asthma. Moreover, astragali radix cultured for three years was proved to be superior to the one cultured for one year.

3차원 FEM 다중물질 하이드로코드 개발 현황

이민형,Lee, Min-Hyung 한국군사과학기술학회 2008 한국군사과학기술학회지 Vol.11 No.5

Hydrocodes are large computer programs that can be used to solve a wide variety of highly transient problems such as high-speed impact and explosion events. This paper describes the recent activity to develop a Multi-material hydrocode in Korea. The code consists of two stages; Lagrangian, and remap stages. Although a sophisticated contact algorithm has been developed for Lagrangian calculations, a relatively simple mechanics at the interfaces of materials are used in the multi-material Eulerian code. Volume of fluid interface reconstruction methods are used to resolve the interfaces between different materials. For the advection stage of the cell centered properties, one-dimensional hyperbolic equation is used. Test problems demonstrated here are the high-speed impact/penetration and explosion problems.

청열약류(淸熱藥類)의 면역약리학적(免疫藥理學的) 고찰(考察)(I)

이민형,서영배,Lee, Min-hyung,Seo, Young Bae 대전대학교 한의학연구소 2001 혜화의학회지 Vol.9 No.2

In the result of investigating traditional chinese medical literatures to understand definite immunopharmacologic effects of drugs for clearing away heat and detoxicating such as Sophorae tonkinensis Radix, Houttuyniae Herba, Smilacis glabrae Rhizoma, Belamcandae Rhizoma, Lasiosphaera seu Calvatia, Paridis Rhizoma, Lobeliae chinensis Herba, we could reach conclusions as follows: 1. Sophorae tonkinensis Radix, Houttuyniae Herba can increase voracity of leukocytes and activities of T cells. 2. Sophorae tonkinensis Radix, Smilacis glabrae Rhizoma can inhibit DTH. 3. Sophorae tonkinensis Radix, Houttuyniae Herba increase activities of B cells in low density but decrease activities of B cells in high density. 4. Sophorae tonkinensis Radix, Houttuyniae Herba, Smilacis glabrae Rhizoma, Belamcandae Rhizoma have anti-inflammatory effects. Studies about drugs for clearing away heat and detoxicating is on. but their range is wide and their effects are numerous. Therefore. we think that more deep and wide researches about them shoud be accomplished.

극대변형 해석을 위한 SPH 수치기법 개발 및 ExLO 코드 연계

이민형,조영준,Lee, Min-Hyung,Cho, Young-Jun 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.3

This paper describes the development of SPH(Smooth Particle Hydrodynamics) scheme and integration into the multi-material shock physics code(ExLO) for the purpose of the application to the extreme large deformation problems. SPH numerical scheme has been extended into the fluid dynamics and the high-speed impact events, such as space structure protection against space debris and meteorite catering. Like other hydrocodes, SPH scheme also solves the conservation equations with the constitutive equation including equation of state. The benchmark problem, Taylor-Impact test, was simulated and the predictions show good agreements with both the published numerical data and experimental data. Currently, the contact treatment between materials is under development.

신경 신장 적용 시간에 따른 신경흥분성 변화

이동률,이민형,엄주리,김종순,Lee, Dong-Rour,Rhee, Min-Hyung,Eom, Ju-Ri,Kim, Jong-Soon 대한고유수용성신경근촉진법학회 2018 PNF and Movement Vol.16 No.2

Purpose: The neurodynamic test used to implicate symptoms arising from the nerve is proposed to selectively increase the strain of the nerve without increasing the strain of adjacent tissue, although this has not yet been established in the time of nerve tension application. This study aimed to investigate the acute effects of nerve stretching time on nerve excitability using compound nerve action potential (CNAP) analysis. Methods: Thirty healthy young adults (mean age=23.10 years) with no medical history of neurological or musculoskeletal disorder voluntarily participated in this study. Nerve excitability was assessed using the median nerve conduction velocity test. The amplitude of the CNAP was measured under three conditions: resting phase (supra-maximal stimulus, without nerve stretching), baseline phase (two-thirds of the supra-maximal stimulus, without nerve stretching), and stretch phase (two-thirds of the supra-maximal stimulus, with 1-5 minutes nerve stretching). One-way repeated measures ANOVA was conducted to compare the latency and amplitude of CNAP. A post-hoc test was analyzed using the contrast test. Results: The latency was significantly delayed after 1 min. of nerve stretching in comparison with the baseline test. However, no significant difference was found during the nerve stretching (1-5 min.). The amplitude was significantly increased by nerve stretching. Conclusion: Nerve stretching can induce nerve excitability without any nerve injury. Based on the results, more than 1 min. of nerve stretching as a neurodynamic test can be a useful method in the clinical setting.

생분해성 고분자를 이용한 발수 에멀션의 제조 (I)

이민형(Min-Hyung Lee),김강재(Kang-Jae Kim),엄태진(Tae-Jin Eom) 한국펄프·종이공학회 2012 펄프.종이기술 Vol.44 No.6

실내 기류 분석을 위한 전산유체역학 모델의 격자 독립성 검정 제안

이민형(Lee, Min-Hyung),김창민(Kim, Chang-Min),박관용(Park, Gwan-Yong),최창호(Choi, Chang-Ho),박창영(Park, Chang-Young) 한국건축친환경설비학회 2020 한국건축친환경설비학회 논문집 Vol.14 No.2

Computational Fluid Dynamics (CFD) is a simulation tool that predicts fluid flow through numerical analysis and is used in various research fields. CFD performs a numerical analysis based on finite grids obtained by dividing the target space. Therefore, an optimal grid design for the CFD model is required for the accurate results of CFD simulation. Therefore, a grid independence test is performed to establish an optimal grid. However, there are no clear guidelines for the grid independence test in Korea and the subjective judgment of the researchers may be affected in the test. For this reason, different grid condition may be selected under the same analysis conditions and targets. As buildings vary in size, an objective grid candidate selection is required to obtain accurate CFD results. Therefore, an improved grid independence test was suggested in this study, and the pilot test was conducted to confirm its suitability. For improvement, characteristic length and grid resolution were applied to the existing grid independence test. Pilot test results showed that the proposed grid independence test derived an appropriate grid resolution considering the change in airflow distribution.

반려동물 생체신호 측정 시스템에 관한 연구

이민형(Min-Hyung Lee),유래현(Rae-Hyun Yu),김수연(Soo-Yeon Kim),김경호(Kyung-Ho Kim) 대한전기학회 2021 정보 및 제어 심포지엄 논문집 Vol.2021 No.10

출연연구기관 기관평가의 책임성 요소 변화 분석

이민형(Min Hyung Lee) 한국기술혁신학회 2007 기술혁신학회지 Vol.10 No.3

본 연구는 출연연구기관의 기관평가요소 분석을 통해 최근까지 출연연구기관에 대한 책임성(accountability)이 어떻게 변화 및 발전되어 왔는가를 분석하고자 한다. 구체적으로 1991년부터 2005까지 기관평가요소를 연구회 설립 이전과 연구회 설립 이후 기간으로 구분하여 분석하였다. 출연연구기관에 요구되는 책임성을 법규준수 책임성, 관리적 책임성, 재무적 책임성, 사업성과 책임성, 사회적 책임성 등 다섯 가지 책임성으로 구분하여 분석한 결과, 연구회 설립이전에는 법규 준수 책임성, 관리적 책임성 등이 강조 되었으며, 연구회 설립 이후에는 사업성과 책임성, 관리적 책임성이 강조되었다. 법규준수 책임성과 관리적 책임성은 시간이 흐름에 따라 요구하는 구체적인 책임내용이 상당히 변화되었다. 최근에는 사업성과 책임성이 가장 중요한 책임성으로 강조되고 있으며 재무적 책임성도 연구회 설립 이후 새롭게 등장하였다. This paper examines accountability trend for government supported research institutes through the analysis of what aspects of accountability have been emphasized in the institute evaluation from 191 to 2005. We divided research period into pre-research council period0991-1998) and post-research council period0999-2005). In pre-research council period, we find four kinds of accountability for government supported research institutes, that is, compliance accountability for regulation, managerial accountability, performance accountability and social accountability and great emphasis has been put on compliance accountability for regulation and managerial accountability. In post-research council period, financial accountability for soundness has been added to the above four kinds of accountability and great emphasis has been put on performance accountability and managerial accountability, especially performance accountability. The concrete contents of an accountability has been also changed between pre-research council period0991-1998) and post-research council period(1999-2005L Regulation accountability in the pre-research council period are related to conforming to government rules for institute operation and regulation defining institute function for reformulation, but in post-research council period, it has been focused on rules for the rationalization of management. Managerial accountability has been changed from emphasizing on management efficiency approximately to focusing on more specific management efficiency like the appropriateness of personnel management, the efficiency of budget management and project management, reasonableness of evaluation and compensation. Performance accountability has been changed in methods for measuring performance, in the pre-research council period, it has been taken quantitative method for measuring productivity, but, in post-research council period, qualitative approach like objective management has been complemented. Finally, accountability for government supported research institutes has been changed towards being concrete in many sided accountabilities and focusing on performance accountability.