• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1717-1726
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• 2017

In the nuclear industry, mechanical engineers spend a significant portion of their time designing equipment such as manipulators, bogies, mechanical grippers, and so on. Some customized designs can be considered as standard mechanical equipment in this area, although it is not unusual to find that an existing design cannot simply be copied from one project to another. Varied performance requirements can dictate that redesign, often quite extensive redesign, is required. However, if something similar has been done before, engineers could use that as a starting point for the new project. In this regard, this study presents several guidelines inspired by previous design knowledge for similar development cases. Moreover, this study presents more detailed suggestions such as design guidelines for an argon-based hot cell atmosphere and design experience for a large-scale practical hot cell facility. Design considerations and case studies dealt with in this study are dedicated to teleoperation manipulators that are used at a large-scale argon cell facility for pyroprocess integrated inactive demonstration (PRIDE), at the Korea Atomic Energy Research Institute. In particular, for case studies to support the suggested recommendations, a fabricated telemanipulator system for PRIDE is introduced, and several kinds of experimental results associated with it are presented.

• 전기학회논문지
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• 제62권1호
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• pp.49-56
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• 2013

In this paper, for constrained optimization problem, one multi-objective optimization algorithm that ensures both performance robustness and constraint feasibility is proposed when uncertainties are involved in design variables. In the proposed algorithm, the gradient index of objective function assisted by design sensitivity with the help of finite element method is applied to evaluate robustness; the reliability calculated by the sensitivity-assisted Monte Carlo simulation method is used to assess the feasibility of constraint function. As a demonstration, the performance and numerical efficiency of the proposed method is investigated through application to the optimal design of TEAM problem 22--a superconducting magnetic energy storage system.

• 한국초등과학교육학회지:초등과학교육
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• 제41권4호
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• pp.754-770
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• 2022

노티싱은 교사가 교수학습 맥락에서 무엇에 주의를 기울이는지, 그것을 어떻게 해석하고 반응해야 하는지 결정하는 것을 의미한다. 노티싱을 분석하여 교육 설계 및 실행의 주체인 교사의 수업설계, 실행, 반성의 전반적 특성을 이해할 수 있으며 이는 교사 역량 강화를 위한 교사교육 설계의 기초자료로 활용할 수 있다. 이에 이 연구에서는 수업설계와 시연 후의 성찰 과정에서 나타나는 초등 예비교사의 노티싱 특성을 분석하였다. 이를 위하여 강원도 소재 교육대학에 재학 중인 초등 예비교사 106명이 온도에 따른 기체의 부피 변화 개념을 다루는 과학수업의 시연 후에 작성한 수업 성찰지를 분석하였다. '주체', '수업 단계', '주제', '초점', '견지'의 다섯 가지 차원으로 이루어진 노티싱 분석틀을 설계한 후 이를 활용하여 각 차원의 구성요소별 빈도와 비율을 도출하였다. 또한 '수업 단계'와 '주제'에 따른 '초점'의 빈도와 비율을 분석하였다. 연구 결과 '주체' 차원에서는 '교사와 학생'을 동시에 주목한 빈도가 가장 높았으며, '수업 단계' 차원에서는 '탐구 활동'의 빈도가 가장 높았다. '주제' 차원에서는 '수업전략에 따른 수업설계'가 가장 빈번하게 나타났으며 '초점' 차원에서는 수업의 목표이자 학생이 달성해야 할 역량을 특정하지 않은 경우가 가장 많았다. '견지' 차원에서는 '기술'이 가장 높은 빈도로 나타났다. '수업 단계'와 '주제'에 따라 '초점'이 어떻게 달라지는지 분석한 결과 차원의 구성요소별로 특징적인 초점이 나타난 것을 알 수 있었다. 연구 결과를 토대로 예비교사의 노티싱 특성이 교사교육의 설계 및 운영에 갖는 시사점을 논의하였다.

• 지질공학
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• 제28권2호
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• pp.133-160
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• 2018

신기후체제 출범 이후 온실가스 감축목표 달성을 위한 대규모 $CO_2$ 직접 감축의 거의 유일한 방안으로 알려져 있는 대용량 $CO_2$ 지중저장의 중요성이 강조되고 있다. 포항 분지 해상 중소규모 $CO_2$ 지중저장 실증사업은 대규모 $CO_2$ 저장 사업에 필요한 핵심 기술을 우선적으로 확보하기 위해 추진하고 있는 연구개발 사업이다. 국내 저장 실증을 위한 $CO_2$ 저장소 확보를 위해 2010년부터 3년간 육상-연안 $CO_2$ 저장소 탐사 연구 과제를 수행하여, 한반도 동남부 육상 및 연안에 걸쳐 발달하고 있는 포항분지를 중소규모 $CO_2$ 지중저장 실증 후보지역으로 선정한 바 있다. 2013년부터는 포항분지 해상 지층을 대상으로 저장소 탐사, 탐사시추, 저장소 특성화, 저장 설계, 플랫폼 설계 및 설치, 주입공 시추 및 완결, 주입설비 설치, 주입 및 모니터링 등의 개별 기술 개발을 수행하였으며, 2017년 초 국내 기술력을 기반으로 해저 실증 저장소에 국내 최초로 $CO_2$ 시험주입 실증에 성공하였다. 향후에는 $CO_2$ 저장소 연속 운전 실증을 위한 수송체계 구축과 저장소 운영체계 확립 연구를 진행할 계획이다. 안전하고 효율적인 저장소 운영을 위해 상시 주입 모니터링 및 정기적인 거동 누출 환경 모니터링을 수행할 계획이며, 이를 위한 주입 전 모니터링을 완수하고 모니터링 체계를 구축하였다. 포항분지 해상 중소규모 $CO_2$ 지중저장 실증 연구를 통해 국내 대규모 CCS 통합실증 및 상용화 사업에 필요한 핵심적 $CO_2$ 저장 기술을 자립화 하였고, 성공적인 시험 주입으로 대규모 $CO_2$ 지중저장 사업의 기술적 경험적 기초를 확보하였다. 또한 본 연구 사업은 국제적으로 점차 확대되고 있는 $CO_2$ 지중저장 기술 시장에서 우리나라의 기술 경쟁력을 확보하는데 기여할 것으로 기대된다.

• 상하수도학회지
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• 제20권1호
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• pp.138-146
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• 2006

The characteristics of backwash and concentrate discharges depend upon the quality of the water being treated and the net recovery of the membrane system. This paper is to indicate a design methods on the capacities of residuals treatment facilities in membrane processes for drinking water. We operated a demonstration membrane plant with a recovery rate of 90% for designing G-water treatment plant. We investigated on design parameter (optimum coagulant dosage and surface loading rate etc.) to design efficiently the residuals treatment facilities. The settling test was conducted with 1m columns dosing PACl to kaolin and membrane residuals under the experimental condition that discharge permit was under a 60mg/L. When the quantity of membrane residuals was $1,575m^3/day$, the estimated results for 1st thickener demonstrated the surface loading rate of 14.4m/day, detention time of 5.83hr, available depth of 3.5m.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.927-937
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• 2020

Global warming awareness through energy conservation is growing due to the regulatory policies issued by governments and voluntary organization that established carbon emission limits. Transportation is one of the major contributors to carbon emissions. Bike will be simultaneously saving money, getting fit and helping to reduce global warming. Web design has been identified as a key factor for the acceptance and success of the websites and electronic commerce. The purpose of this research is to investigate the effective implementation of the proposed Analytic Hierarchy Process (AHP) technique on a bike case study whose company (Bike Company) is involved in web design for a critical component in the demonstration. Survey research used a variety of data collection methods, with the most common being questionnaires and interviews of some exporters. The research results reveal that the top five key success factors are Good reputation, Transaction security, Ease of use, Promotion, and Diversified choices, which provide the guidelines and directions for decision-makers to design effective websites in the current competitive business scenario. The major findings of this study are suggesting that Internet marketing channels are securing the company's relevance, together with paving the way for methods to increase web traffic.

• Structural Engineering and Mechanics
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• 제76권3호
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• pp.367-378
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• 2020

This paper presents a new design concept for ocean nuclear power plants (ONPPs) using a tension leg platform (TLP). The system-integrated modular advanced reactor, which is one of the successful small modular reactors, is mounted for demonstration. The authors define the design requirements and parameters, modularize and rearrange the nuclear and other facilities, and propose a new total general arrangement. The most fundamental level of design results for the platform and tendon system are provided, and the construction procedure and safety features are discussed. The integrated passive safety system developed for the gravity based structure-type ONPP is also available in the TLP-type ONPP with minor modifications. The safety system fully utilizes the benefits of the ocean environment, and enhances the safety features of the proposed concept. For the verification of the design concept, hydrodynamic analyses are performed using the commercial software ANSYS AQWA with the Pierson-Moskowitz and JONSWAP wave spectra that represent various ocean environments and the results are discussed.

• Earthquakes and Structures
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• 제17권3호
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• pp.307-315
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• 2019

Building prediction and control theory have been drawing the attention of many scientists over the past few years because design and control efficiency consumes the most financial and energy. In the literature, many methods have been proposed to achieve this goal by trying different control theorems, but all of these methods face some problems in correctly solving the problem. The Evolutionary Bat (EB) Algorithm is one of the recently introduced optimization methods and providing researchers to solve different types of optimization problems. This paper applies EB to the optimization of building control design. The optimized parameter is the input to the fuzzy controller, which gives the status response as an output, which in turn changes the state of the associated actuator. The novel control criterion for guarantee of the stability of the system is also derived for the demonstration in the analysis. This systematic and simplified controller design approach is the contribution for solving complex dynamic engineering system subjected to external disturbances. The experimental results show that the method achieves effective results in the design of closed-loop system. Therefore, by establishing the stability of the closed-loop system, the behavior of the closed-loop building system can be precisely predicted and stabilized.

• Smart Structures and Systems
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• 제32권6호
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• pp.383-391
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• 2023

Energy harvesting in trams may become a prevalent source of passive energy generation due to the high density of vibrational energy, and this may help power structural health monitoring systems for the trams. This paper presents a broadband vibrational energy harvesting device design that utilizes a varied frequency from a tram vehicle using a 2 DOF vibrational system combined with electromagnetic energy conversion. This paper will demonstrate stepwise optimization processes to determine mechanical parameters for frequency tuning to adjust to the trams' operational conditions, and electromagnetic parameters for the whole system design to maximize power output. The initial optimization will determine 5 important design parameters in a 2 DOF vibrational system, namely the masses (m₁, m₂ (and spring constants (k₁, k₂, k₃). The second step will use these parameters as initial guesses for the second optimization which will maintain the ratios of these parameters and present electrical parameters to maximize the power output from this system. The obtained values indicated a successful demonstration of design optimization as the average power generated increased from 1.475 mW to 17.44 mW (around 12 times).

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제31회 춘계학술대회
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• pp.211-218
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• 2000

Hot spot behaviors on the disk-pad contact surface during a braking operation have been analyzed for a ventilated disk brake using the finite element method. Hot spots which were studied using a coupled thermal-mechanical analysis technique are influenced by all of the mechanical, thermal, elastic and plastic processes that are involved in braking cycles, but their temperature gradients are most affected by rubbing speeds, braking forces, and design parameters between the disk and the pad. Undesirable hot spots that are generated by local thermoelastic instabilities are intended to be removed by optimized design parameters and material properties. In this study, a three-dimensional numerical method for the demonstration of hot spot behaviors has been applied to the rubbing surfaces between the disk and the pad.