• BMB Reports
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• 제33권1호
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• pp.1-36
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• 2000

Acetohydroxyacid synthase (EC 4.1.3.18) catalyses the first reaction in the pathway for synthesis of the branched-chain amino acids. The enzyme is inhibited by several commercial herbicides and has been subjected to detailed study over the last 20 to 30 years. Here we review the progress that has been made in understanding its structure, regulation, mechanism, and inhibition.

• 한국콘텐츠학회논문지
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• 제13권7호
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• pp.24-37
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• 2013

본 연구는, 픽사의 와 에 나타난 부모와 자녀 캐릭터 사이의 갈등구도를, MBTI의 유형역동이라는 관점에서 비교 분석하고자 했다. 이에, 캐릭터의 성격유형과 심리기능의 위계를 추론하고, 유형역동에 의한 갈등과 화해의 구조를 분석하였다. 작품 분석을 통해 도출된 결론은: (1) 부모의 사고기능이 자녀의 직관기능을 구속하는 구조로, '현실과 가능성의 충돌'로 은유됨. (2) 보완 역할 캐릭터의 외향적 심리기능이, 결핍 캐릭터의 미발달된 3차기능을 보완하면서, 유형발달에 기여함. (3) 에서는, 갈등주체에 의한 직접적 단방향의 보완을 이루며, (4) 에서는, 갈등주체가 아닌 거울캐릭터에 의한 간접적 쌍방향의 상호보완을 이루는 방법론의 차이를 보인다.

• 대한조선학회 특별논문집
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• 대한조선학회 2006년도 특별논문집
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• pp.53-58
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• 2006

When the vibration troubles occur on the ship structure during the sea trial, the rectification work is very restricted because of in-situ limitation. Usually the finite element method is used to improve vibration characteristics of the structure, but it takes lots of time and effort in modeling the structure and adjusting the finite element model in order to consider appropriate boundary conditions of a complex ship structure. Therefore, experimental methods have been in general suggested to obtain proper countermeasures without time-consuming in modeling. In this paper, FRF(frequency response function) synthesis method is applied to estimate natural frequency of the modified ship structure, which is obtained from experimental and numerical methods.

• 천문학회지
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• 제38권2호
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• pp.161-164
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• 2005

We present a theoretical formalism by which the global and the local mass functions of dark matter substructures (dark subhalos) can be analytically estimated. The global subhalo mass function is defined to give the total number density of dark subhalos in the universe as a function of mass, while the local subhalo mass function counts only those sub halos included in one individual host halo. We develop our formalism by modifying the Press-Schechter theory to incorporate the followings: (i) the internal structure of dark halos; (ii) the correlations between the halos and the subhalos; (iii) the subhalo mass-loss effect driven by the tidal forces. We find that the resulting (cumulative) subhalo mass function is close to a power law with the slope of ${\~}$ -1, that the subhalos contribute approximately $10\%$ of the total mass, and that the tidal stripping effect changes the subhalo mass function self-similarly, all consistent with recent numerical detections.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.24-29
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• 1993

In this paper, the estimation of the structure of a logic circuit under test is made from the observation of the input-output correlation function by use of M-sequence, from which we can estimate whether or not any fault exist in the logic circuit. Especially, investigation was made in case of the 2_stage logic circuit. We checked theoretically the sequence of correlation function, and we have shown that the correlation function is a function of period of M-sequence only, land the appearing number of correlation function in a period is a constant value depending on the logic circuit only. And by computer simulations we have shown that the structure of the circuit under test can be estimated from the observation of sequence of correlation function.

• 디자인학연구
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• 제19권2호
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• pp.251-260
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• 2006

산업의 발달은 제품 성능의 대형화와 다기능화를 가능케 하였지만 복잡성을 가중시켜 제품의 사용편의성 문제가 항상 이슈로 등장한다. 따라서 효과적인 사용자-제품 상호작용을 개선시키는 중요한 설계요소 중의 하나가 사용자의 인지적 특성을 인터페이스 설계에 반영하는 것이다. 본 연구는 대표적 생활 가전제품의 하나인 세탁기의 인터페이스를 사용자의 상호작용방식을 기준으로 평가하고자 한다. 세탁기는 수많은 기능들이 메뉴 구동방식으로 제공되므로 먼저, 설문조사단계에서 경로발견알고리즘을 사용하여 사용자가 선호하는 새로운 메뉴구조를 제시하였다. 두 번째 단계에서는 이와 같은 사용자와 설계자의 메뉴구조 차이를 비교하기 위하여 세 제품을 선택한 후 작업 수행도를 평가하였고 실험작업 동안 각 제품이 제공하는 기능들의 구동방식 및 경로를 응용 상태전이도로 표현하였다. 그리고 사용자가 세 제품에서 공통적으로 선호하는 구동방식 및 작업경로를 상태전이도로 작성하였다. 그 결과, 실험작업에서 사용자가 갖는 구동방식과 작업경로는 설계자의 요구사항과 달랐지만 설문조사단계에서 확인된 인지적 메뉴구조의 구동방식과 일치함을 입증할 수 있었다. 연구의 결과는 설계자가 예상치 못한 메뉴구동방식을 제공함으로써 제품 기능의 활용도를 높이고 사용자를 위한 세탁기 인터페이스의 디자인 개선 방안으로 활용될 수 있을 것이다.

• BMB Reports
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• 제38권3호
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• pp.266-274
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• 2005

High temperature requirement A (HtrA) and its homologues constitute the HtrA familiy proteins, a group of heat shock-induced serine proteases. Bacterial HtrA proteins perform crucial functions with regard to protein quality control in the periplasmic space, functioning as both molecular chaperones and proteases. In contrast to other bacterial quality control proteins, including ClpXP, ClpAP, and HslUV, HtrA proteins contain no regulatory components or ATP binding domains. Thus, they are commonly referred to as ATP-independent chaperone proteases. Whereas the function of ATP-dependent chaperone-proteases is regulated by ATP hydrolysis, HtrA exhibits a PDZ domain and a temperature-dependent switch mechanism, which effects the change in its function from molecular chaperone to protease. This mechanism is also related to substrate recognition and the fine control of its function. Structural and biochemical analyses of the three HtrA proteins, DegP, DegQ, and DegS, have provided us with clues as to the functional regulation of HtrA proteins, as well as their roles in protein quality control at atomic scales. The objective of this brief review is to discuss some of the recent studies which have been conducted regarding the structure and function of these HtrA proteins, and to compare their roles in the context of protein quality control.

• ETRI Journal
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• 제21권1호
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• pp.1-27
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• 1999

We present a new description of envelope-function equation of the superlattice (SL). The SL wave function and corresponding effective-mass equation are formulated in terms of a linear combination of Bloch states of the constituent material with smaller band gap. In this envelope-function formalism, we review the fundamental concept on the motion of a wave packet in the SL structure subjected to steady and uniform electric fields F. The review confirms that the average of SL crystal momentums K = ($k_x,k_y,q$), where ($K_x,k_y$) are bulk inplane wave vectors and q SL wave vector, included in a wave packet satisfies the equation of motion = $_0+Ft/h$; and that the velocity and acceleration theorems provide the same type of group velocity and definition of the effective mass tensor, respectively, as in the Bulk. Finally, Schlosser and Marcus's method for the band theory of metals has been by Altarelli to include the interface-matching condition in the variational calculation for the SL structure in the multi-band envelope-function approximation. We re-examine this procedure more thoroughly and present variational equations in both general and reduced forms for SLs, which agrees in form with the proposed envelope-function formalism. As an illustration of the application of the present work and also for a brief investigation of effects of band-parameter difference on the subband energy structure, we calculate by the proposed variational method energies of non-strained $GaAs/Al_{0.32}Ga_{0.68}As$ and strained $In_{0.63}Ga_{0.37}As/In_{0.73}Ga_{0.27}As_{0.58}P_{0.42}SLs$ with well/barrier widths of $60{\AA}/500{\AA}$ and 30${\AA}/30{\AA}$, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.54-60
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• 2001

A study was conducted to assess the nutritive value of two diets based on a low-energy variety of wheat, RAC C1 and their effects on intestinal mucosal structure and function in broiler chickens. The diets were fed with or without microbial enzyme supplement to male and female broiler chickens. The digesta viscosity was reduced (p<0.001) through supplementation with a microbial enzyme in male and female chicks. Enzyme supplementation also improved the dietary apparent metabolizable energy content (p<0.001) and had slight but non-significant positive effects on chick growth and feed conversion ratio. Intestinal mucosal structure and enzyme function were not affected by microbial enzyme supplement. Male chicks consumed more feeds (p<0.001), attained higher final body weight (p<0.001) and were more efficient at feed utilization (p<0.01) than the female chicks. Except for duodenal villus surface area and ileal protein content, intestinal mucosal structure and enzyme activities were similar between the two sexes and dietary treatment groups. The study showed an improvement in the nutritive value of the diets in the presence of the microbial enzyme supplement.

• 소음진동
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• 제10권4호
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• pp.648-654
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• 2000

A procedure to determine the realizable optimal positions of rigid supports is suggested to get a maximum fundamental natural frequency. a measured frequency response function based substructure-coupling technique is used to model the supported structure. The optimization procedure carries out the eigenvalue sensitivity analysis with respect to the stiffness of supports. As a result of such stiffness optimization, the optimal rigid-support positions are shown to be determined by choosing the position of the largest stiffness. The optimally determined support conditions are verified to satisfy the eigenvalue limit theorem. To demonstrate the effectiveness of the proposed method, the optimal support positions of a plate model are investigated. Experimental results indicate that the proposed method can effectively find out the optimal support conditions of the structure just based on the measured frequency response functions without any use of numerical model of the structure.