MLS기반 유한요소와 그 응용에 관한 제언

조영삼,Cho, Young-Sam 한국전산구조공학회 2009 한국전산구조공학회논문집 Vol.22 No.4

본 논문에서는 MLS기반 유한요소에 대한 현재 개발상황에 대한 개관과 향후 예상할 수 있는 응용분야에 대한 제안을 하였다. 이동최소제곱근사를 이용하여 형상함수를 생성하는 MLS기반 유한요소는, 요소의 경계에서 기존 유한요소의 성질-크로네커 델타 조건-을 가지면서도 기존 요소가 갖지 못했던 임의의 절점 추가가 자유롭다는 장점이 있어 다양한 변절점 요소로의 개발이 이루어져 왔다. 선형 또는 이차형상함수를 갖는 2차원 변절점요소 뿐 아니라, 균열선단과 균열면을 포함하고 있는 2차원 균열요소와 3차원에서의 제한적인 변절점요소 등이 개발되어 다양한 불연속성 문제에 적용 가능함이 입증되었다. 이러한 MLS기반 유한요소는 향후 2차원 변절점 3각요소, 2차원 삼각균열요소, 변절점 쉘요소, 균열 쉘요소, 마칭큐브알고리즘에 적합한 3차원 다면체요소로의 개발이 가능할 것으로 예상되며, 본 논문에서는 그 일례로 3차원 다면체요소를 이용한 대퇴골의 요소망 생성을 보였다. In this paper, review of developed MLS-based finite elements and a proposal for their applications are described. The shape functions and their derivatives of MLS-based finite elements are constructed using Moving-Least Square approximation. In MLS-based finite element, using the adequate influence domain of weight function used in MLS approximation, kronecker delta condition could be satisfied at the element boundary. Moreover, because of the characteristics of MLS approximation, we could easily add extra nodes at an arbitrary position in MLS-based finite elements. For these reasons, until now, several variable-node elements(2D variable element for linear case and quadratic case and 3D variable-node elements) and finite crack elements are developed using MLS-based finite elements concept. MLS-based finite elements could be extended to 2D variable-node triangle element, 2D finite crack triangle element, variable-node shell element, finite crack shell element, and 3D polyhedron element. In this paper, we showed the feasibility of 3D polyhedron element at the case of femur meshing.

식량농업식물유전자원국제조약의 접근 및 이익공유에 관한 다자체제 개정의 핵심쟁점과 논의동향

박원석(Won Seog Park) 중앙대학교 법학연구원 2021 法學論文集 Vol.45 No.3

2001년 식량농업기구(Food and Agriculture Organization, 이하 FAO)의 당사국들은 지속 가능한 농업과 식량안보를 위해 식량농업용식물유전자원의 보전 및 지속 가능한 이용 그리고 그 이용으로부터 발생하는 이익의 공정하고 공평한 공유를 목적으로 식량농업식물유전자원국제조약을 체결하였다. ITPGRFA는 다자체제(Multilateral System, 이하 MLS)를 통해 나고야의정의서의 접근방식인 특정의 PGRFA에 대한 개별 접근허가방식이 아닌 포괄적 접근허가방식을 통해 사전접근허가 면제와 확정된 이익공유제도를 도입하고 있다. 그러나 MLS 대상 작물은 ITPGRFA 적용대상인 모든 PGRFA가 아니라 부속서 I에 있는 64개 작물(식량작물 35개, 사료작물 29개)에 한해서 육종, 연구, 교육의 목적인 경우에만 적용된다.그러나 2013년 제5차 ITPGRFA 운영기구(Governing Body, 이하 GB) 정기총회는 부속서 1 적용대상 작물을 64개 작물이 아닌 “모든” PGRFA까지 확대하기 위해 “MLS 기능 증진을 위한 개방형 특별작업반(AD-HOC OPEN-ENDED WORKING GROUP TO ENHANCE THE FUNCTIONING OF THE MULTILATERAL SYSTEM, 이하 MLS 작업반)”을 설립하였다. 2021년 11월까지 MLS 작업반은 총 9차례 개최되어 ITPGRFA 부속서 1의 개정 방안과 일명 성장계획(growth plan)이라고 불리는 표준물질이전계약(Standard Material Transfer Agreement) 개정 방안을 협상하여 왔다. ITPGRFA 당사국들은 ITPGRFA 본문은 개정하지 않고, 부속서 1의 개정과 ITPGRFA 제12조에 따라 PGRFA의 접근 및 이용시 강제하고 있는 표준물질이전계약(Standard Material Transfer Agreement, 이하 sMTA)의 수정을 통해 MLS 적용범위의 확대를 모색하고 있다. 그러나 이러한 접근방식은 ITPGRFA 조문 자체의 허용성, 운영기구의 권한, 해당 조문의 개정 필요성, sMTA 조문의 수정 및 내용 등에 대한 상당한 분석이 필요하다. 이 논문은 ITPGRFA 본문을 수정하지 않고 대신 그 부속서와 sMTA만을 수정하여 MLS의 적용대상 작물을 모든 PGRFA로 확대하기 위해 필요한 법적 쟁점을 다룬다. 제2장은 ITPGRFA 현행 다자체제의 규정과 내용을 검토한다. 제3장은 MLS 적용범위 확대를 위한 ITPGRFA 부속서 1 개정방안을, 제5장은 SMTA 관련 조문의 개정에 대한 잠정적 합의사항과 미해결 쟁점에 대해 분석한다. In 2001, the FAO concluded the International Treaty on Plant Genetic Resources for Food and Agriculutire for the conservation and sustainable use of plant genetic resources for food and agriculture and the fair and equitable sharing of the benefits arising out of their use, in harmony with the Convention on Biological Diversity, for sustainable agriculture and food security. ITPGRFA also established the Multilateral System to facilitate access to PGRFA and to share, in a fair and equitable way, the benefits arising from the utilization of 64 crops listed in Annex 1, and introduced a comprehensive authorization system instead of an individual prior informed consent system found in Nagoya Protocol. In the furtherance of this end, the Governing Body of ITPGRFA, in 2013, established Ad Hoc Open-ended Working Group to Enhance the Functioning of its Multilateral System (MLS) and reached tentative compromise to amend Annex I of the Treaty (list of crops in the MLS), to include all plant genetic resources for food and agriculture under the management and control of parties and in the public domain, in ex situ conditions, while allowing for reasoned national exemptions regarding a limited number of native species. The Working Group also agreed on a package of measures, also known as the growth plan, which simultaneously adopts the revised Standard Material Transfer Agreement (SMTA) and the amendment of Annex I. Negotiations continued on the draft revised SMTA. Consensus was reached on several provisions, with genetic sequence data (also addressed as digital sequence information) and rates for benefit-sharing payments remaining as the main outstanding issues. However, this tentative consensus failed to find its version due to the lack of common understanding of Digital Sequence Data. This paper analyses the Core Issues and Negotiation Trend for Amending the Multilateral System under International Treaty on Plant Genetic Resources for Food and Agriculture and its negotiation trend.

MLS차분법을 이용한 재료비선형 문제 해석

윤영철 한국전산구조공학회 2016 한국전산구조공학회논문집 Vol.29 No.3

본 연구는 재료비선형 문제를 다루기 위한 비선형 MLS 차분법의 정식화 과정을 제시한다. MLS 차분법은 절점모델을 기반으로 고속 미분근사식을 활용하여 지배 미분방정식을 직접 이산화 하는데, 변수를 변위로 일원화한 Navier 방정식을 사용하여 탄성재료 문제를 다룬 기존의 MLS 차분법은 재료의 구성방정식을 별도로 고려할 수 없다. 본 연구에서는 비선형 재료의 구성방정식을 반영할 수 있는 강정식화를 위해 1차 미분근사를 반복 사용하는 겹미분근사를 고안했다. 응력의 발산으로 표현되는 평형방정식을 그대로 이산화하고 Newton 방법을 적용하여 반복계산을 통해 수렴해를 찾는 비선형 알고리즘을 제시했다. 응력 계산과 내부변수의 갱신은 return mapping 알고리즘을 활용하였고, 알고리즘 접선계수(algorithmic tangent modulus)의 적용을 통해 빠르고 안정적인 반복계산이 가능하도록 하였다. 재생성 시험을 통해 겹미분근사의 정당성을 검증했고, 비선형재료에 대한 인장문제의 해석을 통해 개발된 비선형 MLS 차분 알고리즘의 정확성과 안정성을 확인하였다. This paper presents a nonlinear Moving Least Squares(MLS) difference method for material nonlinearity problem. The MLS difference method, which employs strong formulation involving the fast derivative approximation, discretizes governing partial differential equation based on a node model. However, the conventional MLS difference method cannot explicitly handle constitutive equation since it solves solid mechanics problems by using the Navier’s equation that unifies unknowns into one variable, displacement. In this study, a double derivative approximation is devised to treat the constitutive equation of inelastic material in the framework of strong formulation; in fact, it manipulates the first order derivative approximation two times. The equilibrium equation described by the divergence of stress tensor is directly discretized and is linearized by the Newton method; as a result, an iterative procedure is developed to find convergent solution. Stresses and internal variables are calculated and updated by the return mapping algorithm. Effectiveness and stability of the iterative procedure is improved by using algorithmic tangent modulus. The consistency of the double derivative approximation was shown by the reproducing property test. Also, accuracy and stability of the procedure were verified by analyzing inelastic beam under incremental tensile loading.

1차 미분 근사를 이용한 MLS차분법의 동적해석

김경환,윤영철,이상호 한국전산구조공학회 2018 한국전산구조공학회논문집 Vol.31 No.6

This paper presents dynamic algorithm of the MLS(moving least squares) difference method using first order differential Approximation. The governing equations are only discretized by the first order MLS derivative approximation. The system equation consists of an assembly of the approximate function, so the shape of system equation is similar to FEM(finite element method). The CDM(central difference method) is used for time integration of dynamic equilibrium equation. The natural frequency analyses of the MLS difference method and FEM are performed, and two analysis results are compared. Also, the accuracy of the proposed numerical method is verified by displaying the dynamic analysis results together with the results by the existing second order differential approximation. In the process of assembling the first order MLS derivative approximation, the oscillation error was suppressed and the stress distribution was interpreted as relatively uniform. 본 논문은 MLS(moving least squares) 차분법의 1차 미분 근사함수를 바탕으로 시간에 따른 수치해석이 가능한 해석기법을 제시한다. 오직 1차 미분 근사함수로만 지배방정식을 이산화했으며, 근사함수를 조립하는 형태로 전체 시스템 방정식을 구성하여 차분법으로 이산화된 운동방정식이 유한요소법(finite element method)과 유사한 모습을 갖게 되었다. 운동방정식을 시간적분하기 위해서 중앙차분법(central difference method)을 사용하였다. 유한요소 알고리즘을 통해서 MLS 차분법과 유한요소법의 고유진동 해석을 수행하였으며, 두 해석결과를 비교하였다. 또한, 동적해석 결과를 기존의 2차 미분 근사함수를 활용한 해석결과와 함께 도시함으로써 제안된 수치기법의 정확성을 검증하였다. 1차 미분 근사함수를 조립하는 과정에서 해석결과의 떨림현상이 억제되었으며 상대적으로 균일한 응력분포를 구할 수 있었다.

항행 및 항법 분야 : 고정위성업무와 마이크로파착륙장치 간의 주파수 공유 연구

이재욱 ( Jae Wook Lee ),오대섭 ( Dae Sub Oh ),임상석 ( Sang Seok Lim ),전병규 ( Byung Kyu Jun ),강지한 ( Ji Han Kang ),감혜미 ( Hye Mi Gam ) 한국항행학회 2011 韓國航行學會論文誌 Vol.15 No.1

본 논문에서는 C-대역에서 1차 업무로 할당되어 있는 마이크로파착륙장치 (MLS)와 고정위성업무 (FSS) 간 주파수 공유 가능성을 검토한다. ITU에서 국제표준으로 제시하고 있는 MLS와 FSS의 특성을 적용하고 국제민간항공기구 (ICAO)의 MLS 안전기준을 고려하여 간섭에 대한 3가지 시나리오를 구성하고 시뮬레이션을 통해 주파수 공유가능성을 분석한다. 시뮬레이션 결과로부터 공유를 위한 수신기 허용간섭기준 및 I/N (간섭대 잡음전력비) 보호기준을 사용하여 MLS 지상국과 고정위성업무 지구국의 이격거리를 산출한다. In this paper, we consider the frequency sharing feasibility of Fixed Satellite Service (FSS) with Microwave Landing System (MLS) allocated in the C-band. On the basis of characteristics of MLS and FSS suggested by ITU and safety standards of MLS by ICAO, three interference scenarios are built and numerical simulations are carried out for investigating the frequency sharing between the two systems. From the simulation results, we calculate the separation distance between MLS and FSS ground antennas, required for frequency sharing by employing standard protection limits regulating the interference to noise ratio (I/N) of the receiver.

MLS계 항생물질 유도 내성 유전자의 크로닝과 유전자의 조절기전 Streptococcus sp. TR-1에서 분리한 pMB4 Plasmid의 MLS계 항생물질 유도내성

정순학(Soon Hak Jeong),곽진환(Jin Hwan Kwak),김희선(Hee Sun Kim),심미자(Mi Ja Shim),최응칠(Eung Chil Choi),김병각(Byong Kak Kim) 대한약학회 1990 약학회지 Vol.34 No.2

Streptococcus sp. TR-1 which has inducible resistance to MLS antibiotics was isolated from soil samples in Korea. Streptococcus sp. TR-1 was cultured in Lysis broth, then a plasmid was isolated by modified Elliker method. Bacillus subtilis UOTO277 was transformed with that plasmid. This result showed that the plasmid has the gene relating with inducible resistance to MLS antibiotics. It was named pMB4 and its size was determined about 2.4 Kb by results of digestion with various restriction enzymes. Restriction endonuclease cleavage site map of pMB4 plasmid was made by double digestion of the plasmid. pMB4 plasmid has different restriction endonuclease site map from the other plasmids that have been discovered in Streptococcus sp. so far. And it could be identified that pMB4 plasmid does not have homology with erm K of Bacillus licheniformis EMR but has homology with erm C of Staphylococcus aureus from the results of Southern hybridization.

MLS$_B$계 항생물질 유도 내성 세균에서 In vitro로 선발된 지속성 내성형 erm(A)와 erm(C)의 분자적 특성 규명

윤은정,진성혜,최응칠,심미자,Yoon, Eun-Jeong,Jin, Sung-Hye,Choi, Eung-Chil,Shim, Mi-Ja 대한약학회 2007 약학회지 Vol.51 No.2

The predominant Macrolides-Lincosamide-Streptogramin B (MLS$_B$) antibiotics resistance genes in staphylococci are erm(A) and erm(C). There is the phenomenon that the ratio of constitutively MLS$_B$ antibiotics resistance (cMLS) in erm(A) is much higher than in erm(C). Thus, we confirmed that the difference of the mutation ratio between erm(A) and erm(C) makes the phenomenon. We examined 8 staphylococci carrying inducibly expressed (iMLS) erm(A) or erm(C) genes. After overnight incubation in the presence of the non-inducer MLS$_B$ antibiotics, spontaneous mutants constitutively expressed MLS$_B$ resistance were selected. Against our expectation, the mutation ratio of erm(A) was lower than erm(C). Therefore, possibilities of other factors determining the ratio of cMLS phenotype might be concerned. All the mutants showed sequence alterations in translational attenuator and all the alterations seemed to give rise to change the second structure of mRNA to express constitutively. For erm(A), 4 different types of sequence deletions ranging from 72 bp to 122 bp and 3 different types of duplications ranging 24 bp to 93 bp were detected. Also, there were 9 different types of duplications ranging 15bp to 154bp in erm(C).

요소망 구성이 편리한 3차원 MLS 기반 변절점요소 개발

조영삼(Young-Sam Cho),박종연(Jong-Youn Park) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

In this study, we developed 3D MLS-based variable-node elements for easy meshing. These elements should be derived from 2D MLS-based variable-node elements and would be utilized as key elements of easy meshing technique we proposed. Using developed 3D MLS-based variable-node elements, we demonstrated several examples having complex configuration compared with conventional meshing technique. Moreover, we compared with the stress results of our model and conventional one.

MLS계 항생물질 유도내성 유전자의 크로닝과 유전자의 발현조절 기전 Staphylococcus aureus TR-1균주의 프라스미드 pMB4에 존재하는 MLS 내성 유전자 ermC-4

김수환(Soo Hwan Kim),최응칠(Eung Chil Choi),김병각(Byong Kak Kim),심미자(Mi Ja Shim) 대한약학회 1991 약학회지 Vol.35 No.1

pMB4 is a 2.4-kilobase plasmid of Staphylococcus aureus TR-1 that confers inducible resistance to the macrolide-lincosamide-streptogramin B(MLS) antibiotics. By subcloning studies, it was found that the MLS resistance determinant was located at 1.0 Kb fragment between Sau3AI and TaqI sites. DNA sequence of the MLS resistant determinant, named ermC-4 was determined, and found to be highly homologous with that of ermC. Because the leader peptide sequence of ermC-4 was identical with that of ermC, the expression of the resistance gene is thought to be controlled by posttranscriptional attenuation in S. aureus TR-1.

MLS-based variable-node elements compatible with quadratic interpolation. Part I: formulation and application for non-matching meshes

Cho, Young-Sam,Im, Seyoung John Wiley Sons, Ltd. 2006 International journal for numerical methods in eng Vol.65 No.4

<P>Two-dimensional variable-node elements compatible with quadratic interpolation are developed using the moving least-square (MLS) approximation. The mapping from the parental domain to the physical element domain is implicitly obtained from MLS approximation, with the shape functions and their derivatives calculated and saved only at the numerical integration points. It is shown that the present MLS-based variable-node elements meet the patch test if a sufficiently large number of integration points are employed for numerical integration. The cantilever problem with non-matching meshes is chosen to check the feasibility of the present MLS-based variable-node elements, and the result is compared with that from the lower-order case compatible with linear interpolation. Copyright © 2005 John Wiley & Sons, Ltd.</P>