• Nuclear Engineering and Technology
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• 제14권1호
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• pp.10-16
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• 1982

액체특성구조이론을 액체 갈륨의 구조와 성질연구에 적용하였다. 이 연구에서 액체 Ga 속에는 $\beta$-Ga와 비슷한 구조와 $\alpha$-Ga와 비슷한 구조의 두가지가 있다는 가정을 하여 액체분배함수를 구하였다. 이를 사용하여 넓은 온도 범위에서 액체 Ga의 열역학적 및 수송학적 성질을 구하였다. 계산결과는 실험치와 잘 일치함을 보여주고 있다.

• 대한교통학회지
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• 제7권2호
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• pp.17-27
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• 1989

A nonlinear programming model for evaluating public transit fare system is proposed. The model finds transit fare level and the structure that maximizes gross fare-box revenue subject to constraints on minimum ridership and the form of the fare equations. It is assumed that the demand for transit is a function of fare and its own-fare elasticity. It is assumed that the demand for transit is a function of fare and its own-fare elasticity. It is also assumed that the conditions including fare of the other modes are unchanged ; i.e., partial equilibrium. Empirical study has been performed for the case of Seoul subway system. This study includes an analysis of fare structure ; flat system and distance-based fare system. Sensitivity and comperative static analysis for elasticity has been also demonstrated.

• Journal of Magnetics
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• 제18권1호
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• pp.1-4
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• 2013

Structural and magnetic properties of $Fe_{50}Mn_{50}$ nanocrystalline alloys prepared by the mechanical alloying technique (using commercial Fe and Mn powders as the precursors) are studied as a function of milling time, 1 hr to 48 hrs. The nano-crystallite size and shape are examined by using scanning electron microscopy (SEM). The effect of milling time on structural characterization was investigated using X-ray diffractometer (XRD) and extended X-ray absorption fine structure spectroscopy (EXAFS). Both XRD and EXAFS studies showed that the alloying process should be completed after 36 hrs milling. Concerning the magnetic behavior, the data obtained from superconducting quantum interference devices (SQUID) exhibited both magnetic saturation ($M_s$) and coercivity ($H_c$) depend strongly on the milling time, which are related to the changes in the crystallite size and magnetic dilution.

• Steel and Composite Structures
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• 제46권1호
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• pp.107-114
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• 2023

A new intelligent adaptive control scheme was proposed that combines observer disturbance-based adaptive control and fuzzy adaptive control for a composite structure with a mass-adjustable damper. The most important advantage is that the control structures do not need to know the uncertainty limits and the interference effect is eliminated. Three adjustable parameters in LMI are used to control the gain of the 2D fuzzy control. Binary performance indices with weighted matrices are constructed to separately evaluate validation and training performance using the revalidation learning function. Determining the appropriate weight matrix balances control and learning efficiency and prevents large gains in control. It is proved that the stability of the control system can be ensured by a linear matrix theory of equality based on Lyapunov's theory. Simulation results show that the multilevel simulation approach combines accuracy with high computational efficiency. The M-TMD system, by slightly reducing critical joint load amplitudes, can significantly improve the overall response of an uncontrolled structure.

• 한국시뮬레이션학회논문지
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• 제25권4호
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• pp.77-84
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• 2016

본 논문은 시스템에 대한 기능 중심의 신뢰도 예측을 수행하기 위한 모델링 방법론을 제안한다. 신뢰도 예측에 대한 다양한 기존 연구들이 있지만, 이 연구들의 공통점은 하드웨어 중심으로 신뢰도 예측을 수행하였다는 점이다. 신뢰성이 제품이 주어진 사용 조건 아래서 의도하는 기간 동안 정해진 기능을 성공적으로 수행하는 능력이라고 정의되는 점에서 보았을 때, 하드웨어 중심의 신뢰도는 논리적 모순을 가진다. 본 논문에서는 기능 중심의 신뢰도 예측을 위해 4-단계 모델링 절차(four-phase modeling procedure)를 제안하였다. 제안되는 모델링 방법론은 네 개의 모델로 구성된다; 1) 구조적 블록 모델(structure block model), 2) 기능 블록 모델 (function block model), 3) 장치 모델 (device model), 그리고 4) 신뢰성 예측 모델 (reliability prediction model). 본 논문에서는 제안하는 모델링 방법론을 이용하여 전자식 안정기에 대한 기능 중심의 신뢰도 예측을 수행하였으며, 하드웨어의 신뢰도를 결정하기 위해 신뢰도 예측 규격 중 하나인 MIL-HDBK-217F를 이용하였다.

• Earthquakes and Structures
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• 제1권3호
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• pp.289-306
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• 2010

A gradient-based evolutionary optimization methodology is presented for finding the optimal design of viscous dampers to minimize an objective function defined for a linear multi-storey structure. The maximum value along height of the transfer function amplitudes for the interstorey drifts is taken as the objective function. Since the ground motion includes various uncertainties, the optimal damper placement may be different depending on the ground motion used for design. Furthermore, the transfer function treated as the objective function depends on the properties of structural parameters and added dampers. This implies that a more robust damper design is desired. A reliable and robust damping design system against any unpredictable ground motions can be provided by minimizing the maximum transfer function. Such design system is proposed in this paper.

• Journal of information and communication convergence engineering
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• 제9권2호
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• pp.150-154
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• 2011

In this paper a four-pole elliptic function bandpass filter is designed with two ground slots. A research of microstrip bandpass filters (BPF) using defected ground structures (DGS) is presented. DGS technique allows designs of tight couplings without the necessity of using very narrow coupling gaps. The simulator Sonnet is used to design the resonator and to calculate the coupling coefficient of the basic coupling structure. Compared to similar microstrip filters without defected ground structure, the simulated performances of these novel structures indicate some technological advantages.

• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.993-1001
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• 2010

In this paper, we introduce the concept of fuzzy weakly r-M continuous function on r-minimal structures and investigate characterizations and properties for such functions.

• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1553-1560
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• 2010

We introduce the concept of fuzzy almost r-M continuous function on fuzzy r-minimal structures, and investigate characterizations and properties for such a function.

• Journal of Korean Biological Nursing Science
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• 제15권1호
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• pp.33-42
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• 2013

Purpose: The purpose of this study was to develop standard syllabuses of 4 subjects (Structure and Function of Human Body, Pathogenic Microbiology, Pathophysiology, Mechanisms and Effects of Drug) of bionursing. Methods: We developed standard syllabuses of 4 subjects through 3 step discussions and analysis. At first each committee for 4 subjects made the syllabus, after then all researchers discussed together. Finally each committee concluded final one. Committee members consisted of professors who teach that subject at nursing college. Results: Standard syllabus for Biological Nursing I-1 or Structure & Function of Human Body I consisted of 3 parts and 9 themes and for Biological Nursing I-2 or Structure & Function of Human Body II was 3 parts and 9 themes. Standard syllabus for Biological Nursing II or Pathogenic Microbiology consisted of 8 themes and Biological Nursing III or Pathophysiology consisted of 2 parts and 19 themes. Standard syllabus for Biological Nursing IV or Mechanisms & Effects of Drug consisted of 2 parts and 13 themes. Conclusion: The standard syllabuses and titles of 4 subjects of bionursing need to be disseminated to all the nursing college by Academy of Korean Biological Nursing Science. Further researches to investigate curriculum for bionursing and to identify the effects of 4 standard syllabuses were recommended.