• 제어로봇시스템학회논문지
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• 제7권10호
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• pp.812-818
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• 2001

This paper proposes an optimum design method of structural and control systems, taking a 2-D truss structure as an example. The structure is supposed to be subjected to initial static loads and disturbances. For the structure, a FEM model is formed, and using modal transformation, the equation of motion is transformed into that of modal coordinates in order to reduce the D.O.F. of the FEM model. The structure is controlled by an output feedback $H^$\infty$$ controller to suppress the effect of the disturbances. The design variables of the simultaneous optimal design of control-structure systems are the cross sectional areas of truss members. The structural objective function is the structural weight. The control objective function is the $H^$\infty$$ norm, that is, the performance index of control. The second structural objective function is the energy of the response related to the initial state, which is derived from the time integration of the quadratic form of the state in the closed-loop system. In a numerical example, simulations have been carried out. Through the consideration of structural weight and $H^$\infty$$ norm, an advantage of the simultaneous optimum design of structural and control systems is shown. Moreover, while the optimized performance index of control is almost kept, we can acquire better design of structural strength.

• Structural Engineering and Mechanics
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• 제57권6호
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• pp.1015-1038
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• 2016

In the current research an advanced criterion with non-associated flow rule (non-AFR) for depicting the behavior of anisotropic sheet metals is presented to consider the strength differential effects (SDEs) for these materials. Owing to the fact that Lou et al. (2013) yield function is dependent on structure of an anisotropic material (BCC, FCC and HCP), an advanced yield function with inspiring of Yoon et al. (2014) yield function is proposed which is dependent upon anisotropic structures. Furthermore, to compute Lankford coefficients, a new pressure sensitive plastic potential function which would be dependent to anisotropic structure is presented and coupled with the proposed yield function with employing a non-AFR in a novel criterion which is called here 'dvanced criterion'. Totally eighteen experimental data are required to calibrate the criterion contained of directional tensile and compressive yield stresses for the yield function and directional Lankford coefficients for the plastic potential function. To verify the criterion, three anisotropic sheet metals with different structures are taken as case studies such as Al 2008-T4 (a BCC material), Al 2090-T3 (a FCC material) and AZ31 (a HCP material).

• 전자공학회논문지B
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• 제29B권8호
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• pp.24-34
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• 1992

A process control language is developed using function block configuration, to simplify software development for large scale process control systems, and to implement advanced control algorithms with ease. A function block parser and controller is implemented to be suitable for multi-loop control systems having hierachical structure. On-line change of controller parameter is possible, and inclusion of user defined function block is also possible. By adding plant model block, control performance can be checked in advance. Function blocks of the Smith Predicotor, auto-tuners are implemented to demonstrate usefulness of function block configuration.

• 전자공학회논문지CI
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• 제39권6호
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• pp.47-52
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• 2002

웨이블릿 함수의 경우 스케일링 함수에서 비롯되었으며, 스케일과 중심을 결정함으로써 신경회로망의 노드로 구성된다. 본 논문에서는 웨이블릿 함수를 이용하여 망을 구성하는 과정에 스케일링 함수를 은닉층의 노드로 복합 구성한 구조를 제안하고자 한다. 제안한 구조의 특징은 스케일링 함수를 이용하여 대강 근사(rough approximation)를 행한 다음, 웨이블릿 함수를 이용하여 미세 근사(fine approximation)를 행하도록 신경회로망의 은닉층을 복합 구성하는 데 있다. 또한, 복합 신경회로망을 구성하는 과정에서 미세 근사에 필요한 웨이블릿 함수의 개수를 유전 알고리즘을 이용하여 결정하는 초기 구조의 최적화를 도모하고자 한다.

• 대한기계학회논문집A
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• 제21권11호
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• pp.1950-1956
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• 1997

An engineering goal in vibration and noise professionals is to develope quiet machines at the preliminary design stage, and various numerical techniques such as FEM, SEA or BEM are one of the schemes toward the goal. In this paper, the research has been focused on the sensitivity effect of mesh sizes for FEM application so that the optimum size of the mesh that leads to engineering solution within acceptable computing time could be generated. In order to evaluate the mesh size effect, three important parameters have been examined : natural frequencies, number of modes and driving point mobility. First, several lower modes including the fundamental frequency of a 2-D plate structure have been calculated as mesh size changes. Since theoretical values of natural frequencies for a simple structure are known, the deviation between the numerical and theoretical values is obtained as a function of mesh size. The result shows that the error is no longer decreased if the mesh size becomes a quarter wavelength or smaller than that. Second, the mesh size effect is also investigated for the number of modes. For the frequency band up to 1.4 kHz, the structure should have 38 modes in total. As the mesh size reaches to the quarter wavelength, the total count in modes approaches to the same values. Third, a mobility function at the driving point is compared between SEA and FEM result. In SEA application, the mobility function is determined by the modal density and the mass of the structure. It is independent of excitation frequencies. When the mobility function is calculated from a wavelength to one-tenth of it, the mobility becomes constant if the mesh becomes a quarter wavelength or smaller. We can conclude that dynamic parameters, such as eigenvalues, mode count, and mobility function, can be correctly estimated, while saving the computing burden, if a quarter wavelength (.lambda./4) mesh is used. Therefore, (.lambda./4) mesh is recommended in structural vibration analysis.

• Journal of Korean Biological Nursing Science
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• 제16권1호
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• pp.17-25
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• 2014

Purpose: The purpose of this study was to review the curriculum on biological nursing: structure and function of the human body, clinical microbiology, pathophysiology, and function and effect of drugs. Methods: Data was collected by searching and reviewing internet websites of 102 nursing schools or universities which provide 4 years nursing education in the Republic of Korea. The 74 curriculum on biological nursing science were available and analyzed by title, credits, hours, types of major (core or selective), offering semester, and laboratory practice. Results: The titles of 4 courses were diverse and were offered as core major (core requisites) or selective major. Structure and function of human body was offered in priority with more credits. Laboratory practice was poorly established in most courses. Biological nursing science courses were mostly taught in the second semester of the first year and the first or second semester of second year nursing education courses. Conclusion: There is a need to standardize the curriculum on biological nursing science and to expand the use of titles proposed by academic society. Also further research is necessary to identify curriculum details and to reflect the needs of professors.

• 한국통신학회논문지
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• 제28권5C호
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• pp.452-460
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• 2003

본 논문에서는 optimal Bayesian equalization solution인 RBF(radial basis function)를 이용한 등화기 (RE)의 구조를 보다 단순화하고, 비선형 왜곡 등의 심각한 정보 신호의 손상에 대한 보상 능력을 향상시키기 위하여 비선형 다층 결합을 갖는 RBF측 이용한 등화기(RNE)를 새로이 제안한다. 기존의 RE는 RBF로 구성된 은닉층의 출력 값을 선형 결합하여 등화기 출력을 얻는다. 이와 달리 새로이 제안하는 RNE는 기존의 RE에서 RBF로 구성된 은닉층의 출력 값에 대한 결합 기법으로 perceptron을 이용한 비선형 다층 결합을 사용한다. 제안한 equalizer를 결정궤환 방식이 있는 경우와 없는 경우의 등화기로 각각 구현한다. 실험 결과 제안한 등화기는 선형 간섭이 존재하는 디지털 통신 시스템과 비선형 왜곡이 존재하는 자기기록 시스템에서보다 간단한 구조로 기존의 optimal Bayesian 등화기와 거의 같거나 우수한 비트 오류 화률 성능 및 MSE(men squared error) 수렴 특성을 나타내었다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2000년도 International Symposium on Bioinformatics
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• pp.17-20
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• 2000

Structural genomics aims to provide a good experimental structure or computational model of every tractable protein in a complete genome. Underlying this goal is the immense value of protein structure, especially in permitting recognition of distant evolutionary relationships for proteins whose sequence analysis has failed to find any significant homolog. A considerable fraction of the genes in all sequenced genomes have no known function, and structure determination provides a direct means of revealing homology that may be used to infer their putative molecular function. The solved structures will be similarly useful for elucidating the biochemical or biophysical role of proteins that have been previously ascribed only phenotypic functions. More generally, knowledge of an increasingly complete repertoire of protein structures will aid structure prediction methods, improve understanding of protein structure, and ultimately lend insight into molecular interactions and pathways. We use computational methods to select families whose structures cannot be predicted and which are likely to be amenable to experimental characterization. Methods to be employed included modern sequence analysis and clustering algorithms. A critical component is consultation of the presage database for structural genomics, which records the community's experimental work underway and computational predictions. The protein families are ranked according to several criteria including taxonomic diversity and known functional information. Individual proteins, often homologs from hyperthermophiles, are selected from these families as targets for structure determination. The solved structures are examined for structural similarity to other proteins of known structure. Homologous proteins in sequence databases are computationally modeled, to provide a resource of protein structure models complementing the experimentally solved protein structures.

• 한국공간구조학회논문집
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• 제23권4호
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• pp.97-105
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• 2023

The membrane structure should maintain the membrane materials in tension for structural stability guaranty. The anchoring part in the membrane structure is an important part. It has the function to introduce tension into membrane materials and function to transmit stress which membrane materials receives to boundary structure such as steel frames. In this paper, it grasps anchoring system of the anchoring part in the membrane structure concerning the fracturing characteristic condition of membrane structure, and the influence which is caused to yield it designates the stress state when breaking the membrane structure which includes the anchoring part and that stress transition mechanism is elucidated as purpose. This paper follows to previous paper, does 1 axial tensile test concerning the bolting part specimen, grasp of fracturing progress of the bolting part and the edge rope and hardness of the rubber, does the appraisal in addition with the difference of bolt tightening torque. As a result, the influence which the bolt anchoring exerts on the fracturing characteristics of the membrane material in the membrane structure anchoring part is examined.

• 융합신호처리학회논문지
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• 제11권1호
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• pp.80-87
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• 2010

함수합성법은 주어진 입출력 데이터 쌍으로부터 입출력관계를 충족하는 함수를 예측하는 것으로, 특성을 알 수 없는 시스템을 제어할 때에 필수적이다. 일반적으로 시스템은 비선형인 성질을 갖는 경우가 많고, 함수 합성에 취급하는 변수, 정수, 제약 등으로 조합된 문제가 발생하기가 쉽다. 그 함수를 합성하는 방법 중 한 가지로 유전적 프로그래밍이 제안되고 있다. 이것은 함수를 트리구조로 표시한 함수 트리에 유전적 조작을 적용하여, 입출력 관계를 충족하는 함수 트리를 탐색하는 방법이다. 본 논문에서는 기존의 유전적 프로그래밍에 의한 함수 합성법의 문제점을 지적하고, 새로운 4종류의 개선법을 제안한다. 즉, 함수 트리를 탐색할 때에 함수가 복잡하게 되는 것을 방지하기 위하여 함수 트리의 성장 억제, 조기 수렴을 목표로 하는 국소 탐색법의 채택, 함수 트리 내의 필요 없이 길어지는 요소의 효과적인 삭제, 대상으로 하는 문제의 특성을 이용하는 방법이다. 이러한 개선법을 이용할 경우, 기존의 유전적 프로그래밍에 의한 함수 합성법보다도 짧은 시간에 우수한 구조의 함수 트리가 구해지는 것을 2-spirals 문제에 대하여 컴퓨터 시뮬레이션을 통하여 확인하였다.