• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.384-388
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• 2016

Background: For a verification of newly-developed neutron absorbers, one of guidelines on the qualification and acceptance of neutron absorbers is the neutron attenuation test. However, this approach can cause a problem for the qualifications that it cannot distinguish how the neutron attenuates from materials. Materials and Methods: In this study, an estimation method of neutron absorption performances for materials is proposed to detect both direct penetration and back-scattering neutrons. For the verification of the proposed method, MCNP simulations with the experimental system designed in this study were pursued using the polyethylene, iron, normal glass and the vitrified form. Results and Discussion: The results show that it can easily test neutron absorption ability using single absorber model. Also, from simulation results of single absorber and double absorbers model, it is verified that the proposed method can evaluate not only the direct thermal neutrons passing through materials, but also the scattered neutrons reflected to the materials. Therefore, the neutron absorption performances can be accurately estimated using the proposed method comparing with the conventional neutron attenuation test. Conclusion: It is expected that the proposed method can contribute to increase the reliability of the performance of neutron absorbers.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제24권1호
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• pp.259-282
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• 2010

본 연구자들은 이 논문에서 다변수미적분학 수업에 적용한 변형 무어교수법(Modified Moore Method)을 소개하고, 이 교수법을 적용한 수업에서 학습에 대한 학생들의 인식변화와 학습 효과를 관찰하여 효과적인 교수 학습을 논의하였다. 본 연구는 3주 기간의 여름계절학기 강좌로 개설된 다변수미적분학 수업을 수강한 15명의 학생들을 대상으로 실시되었다. 학생들의 능동적 예습을 안내하기 위하여 주요 수학 개념에 관련된 단계별로 구조화된 발문 형식의 예습자료를 미리 제시하였다. 수업 중 학생들의 소그룹 협력학습 과정과 발표를 관찰하고, 매 수업 후반에 작성한 학생들의 강의일지와 학기말에 실시한 설문 조사를 분석한 결과에 의하면, 학생들은 스스로 탐구하여 발견하는 학습을 통하여 주제 개념에 대하여 보다 깊이 이해할 수 있음을 인식하게 되었고, 동료와의 토론 및 상호 가르침을 통하여 다양한 내용의 학습과 반성적 사고를 경험할 수 있었다.

• Wind and Structures
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• 제28권2호
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• pp.129-140
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• 2019

Accurately simulating the wind field of large-scale region, for instant urban areas, the locations of large span bridges, wind farms and so on, is very difficult, due to the complicated terrains or land surfaces. Currently, the regional wind field can be simulated through the combination of observation data and numerical model using observation-nudging in the Weather Research and Forecasting model (WRF). However, the main drawback of original observation-nudging method in WRF is the effects of observation on the surrounding field is fully mathematical express in terms of temporal and spatial, and it ignores the effects of terrain, wind direction and atmospheric circulation, while these are physically unreasonable for the turbulence. For these reasons, a spatial correlation-based observation-nudging method, which can take account the influence of complicated terrain, is proposed in the paper. The validation and comparation results show that proposed method can obtain more reasonable and accurate result than original observation-nudging method. Finally, the discussion of wind field along bridge span obtained from the simulation with spatial correlation-based observation-nudging method was carried out.

• 한국콘텐츠학회논문지
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• 제21권12호
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• pp.828-841
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• 2021

본 연구는 현대연기의 근간이 되는 스타니슬랍스키 시스템과 그 미국적 계승이라 할 수 있는 아메리칸 액팅 메소드가 전혀 다른 성격의 연기론이 될 수밖에 없었던 이유를 규명하고자 한다. 먼저, 시스템 계승의 주요 국가인 러시아와 미국, 그리고 우리나라를 대상으로 시스템 관련 스타니슬랍스키 저서의 출판과 번역 과정을 따라가며 각국에서 시스템이 전혀 다르게 이해되었음을 확인한다. 이를 바탕으로 시스템의 체계를 유지하는 '체험'과 배우의 '이중 의식'이 메소드에서 어떻게 받아들여진 것인지 논의하여 두 연기론의 차이와 그 원인을 밝히고자 한다. 시스템에서 메소드로의 변곡점이라 할 수 있는 스타니슬랍스키 저술 출판과 번역, 그리고 그로 인한 시스템에 관한 이해를 인식하고자 하는 것은 시스템과 메소드 모두를 온전히 이해하고자 하는 시도라 하겠다. 시스템과 메소드를 근본적으로 이해하고자 하는 본 연구가 앞으로의 시스템과 메소드에 대한 다양한 시각의 논의를 마련하는 밑거름이 될 수 있기를 기대한다.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.30-40
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• 2015

For a shunt power quality controller (SPQC) the DC side voltage value which is closely related to the compensation performance is a significant parameter. Buy so far, very little discussion has been conducted on this in a quantitative manner by previous publications. In this paper, a method to design the DC side voltage of SPQC is presented according to the compensation performance in the single-phase system and the three-phase system respectively. First, for the reactive current and the harmonic current compensation, a required minimal value of the DC side voltage with a zero total harmonic distortion (THD) of the source current and a unit power factor is obtained for a typical load, through the equivalent circuit analysis and the Fourier Transform analytical expressions. Second, when the DC side voltage of SPQC is lower than the above-obtained minimal value, the quantitative relationship between the DC side voltage and the THD after compensation is also elaborated using the curve diagram. Hardware experimental results verify the design method.

• 대한간호학회지
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• 제36권1호
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• pp.197-205
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• 2006

Purpose: The objective of the study is to analyze the review contents of reviewers for the submitted papers in the Journal of Korean Academy of Nursing in 2003. Method: The review contents of the 165 papers were selected 217 papers that were submitted in 2003. Among those 165 papers, the 21 papers belonged to the 'Do not publish' list and 17 papers, 'Revise manuscript and resubmit', list and the 94 papers, 'Publish if revisions are made' list. There are more than two level differences among the four levels of decision in acceptance of publication in 33 papers. Results: The analysis of the review contents for the papers were suggested according to review categories: introduction, method, results, discussion and conclusion. In addition, if papers had more than two levels of review they were rated poor accord or inconsistent. Conclusion: For the quality of the academic journal and development of the nursing science, it is important to disseminate and publish the research paper. Therefore, review of the submitted paper is also important. Implications for the profitable review were suggested in the study.

• Advances in nano research
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• 제9권3호
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• pp.133-145
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• 2020

In this study, nonlinear vibrations and dynamic instabilities of a smart embedded micro shell conveying varied fluid flow and subjected to the combined electro-thermo-mechanical loadings are investigated. With the aim of designing new hydraulic sensors and actuators, the piezoelectric materials are employed for the body and the effects of applying electric field on the stability of the system as well as the induced voltage due to the dynamic behavior of the system are studied. The nonlocal piezoelasticity theory and the nonlinear cylindrical shell model in conjunction with the energy approach are utilized to mathematically modeling of the structure. The fluid flow is assumed to be isentropic, incompressible and fully develop, and for more generality of the problem both steady and time dependent flow regimes are considered. The mathematical modeling of fluid flow is also carried out based on a scalar potential function, time mean Navier-Stokes equations and the theory of slip boundary condition. Employing the modified Lagrange equations for open systems, the nonlinear coupled governing equations of motion are achieved and solved via the state space problem; forth order numerical integration and Bolotin's method. In the numerical results, a comprehensive discussion is made on the dynamical instabilities of the system (such as divergence, flutter and parametric resonance). We found that applying positive electric potential field will improve the stability of the system as an actuator or vibration amplitude controller in the micro electro mechanical systems.

• 한국지진공학회논문집
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• 제19권2호
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• pp.45-53
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• 2015

This paper reviews the current seismic design code and research for dynamic earth pressure on retaining structures. Domestic design codes do not clearly define the estimation of dynamic earth pressure and give different comments for seismic coefficient, wall inertia and distribution of dynamic earth pressure using Mononobe-Okabe method. AASHTO has been revised reflecting current research and aims for effective seismic design. Various design codes are analyzed to compare their performance and economic efficiency. The results are used to make improvement of current domestic seismic design code. Further, it is concluded that the experimental investigation is also needed to verify and improve domestic seismic code for dynamic earth pressure.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.143.1-143.1
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• 2016

Ge is a promising candidate to replace Si in MOSFET because of its superior carrier mobility, particular that of the hole. However Ge oxide is thermodynamically unstable. At elevated temperature, GeO is formed at the interface of Ge and GeO2, and its formation increases the interface defect density, degrading its device performance. In search for a method to surmount the problem, we investigated Ge oxidation through an inert capped oxide layer. For this work, we prepared low doped n-type Ge(100) wafer by removing native oxide and depositing a capping layer, and show that GeO2 interface can be successfully grown through the capping layer by thermal oxidation in a furnace. The thickness and quality of thus grown GeO2 interface was examined by ellipsometry, XPS, and AFM, along with I-V and C-V measurements performed at 100K to 300K. We will present the result of our investigation, and provide the discussion on the oxide growth rate, interface state density and electrical characteristics in comparison with other studies using the direct oxidation method.

• International Journal of Fluid Machinery and Systems
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• 제3권2호
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• pp.122-128
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• 2010

The attachment of inducer in front of main impeller is a powerful method to improve cavitation performance; however, cavitation surge oscillation with low frequency occurs with blade cavity growing to each throat section of blade passage simultaneously. Then, one conceptual method of installing suction axi-asymmetrical plate has been proposed so as to keep every throat passage away from being unstable at once, and the effect on suppression of the oscillation were investigated. In the present study, cavitation behaviors in the inducer is observed with distributing multi-cameras circumferentially, recording simultaneously and reconstructing multi-photos on one plane field as moving a linear cascade. Observed results are utilized for discussion with other measuring results as casing wall pressure distribution. Then the suppression mechanism of oscillation by installing axi-asymmetrical inlet plate will be clarified in more details.