• 한국기계가공학회지
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• 제20권6호
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• pp.33-43
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• 2021

A60 class bulkhead penetration piece is a fire resistance system installed on a bulkhead compartment to protect lives and to prevent flame diffusion in a fire accident on a ship and offshore plant. This study focuses on the approximate optimization of the fire resistance design of the A60 class bulkhead penetration piece using a multi-island genetic algorithm. Transient heat transfer analysis was performed to evaluate the fire resistance design of the A60 class bulkhead penetration piece. For approximate optimization, the bulkhead penetration piece length, diameter, material type, and insulation density were considered discrete design variables; moreover, temperature, cost, and productivity were considered constraint functions. The approximate optimum design problem based on the meta-model was formulated by determining the discrete design variables by minimizing the weight of the A60 class bulkhead penetration piece subject to the constraint functions. The meta-models used for the approximate optimization were the Kriging model, response surface method, and radial basis function-based neural network. The results from the approximate optimization were compared to the actual results of the analysis to determine approximate accuracy. We conclude that the radial basis function-based neural network among the meta-models used in the approximate optimization generates the most accurate optimum design results for the fire resistance design of the A60 class bulkhead penetration piece.

• Industrial Engineering and Management Systems
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• 제11권4호
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• pp.331-338
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• 2012

This research proposes a Pareto-based multi-objective optimization approach to class-based storage warehouse design, considering a two-block warehouse that operates under the class-based storage policy in a low-level, picker-to-part and narrow aisle warehousing system. A mathematical model is formulated to determine the number of aisles, the length of aisle and the partial length of each pick aisle to allocate to each product class that minimizes the travel distance and maximizes the usable storage space. A solution approach based on multiple objective particle swarm optimization is proposed to find the Pareto front of the problems. Numerical examples are given to show how to apply the proposed algorithm. The results from the examples show that the proposed algorithm can provide design alternatives to conflicting warehouse design decisions.

• 공학교육연구
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• 제22권1호
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• pp.22-28
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• 2019

The purpose of this study is to develop instructional design model of flipped learning suitable for engineering education field and to draw out effects and improvements by applying it to actual lessons for engineering college students. Literature review and case studies were conducted to achieve the purpose of the study. For a case study, flipped learning was applied to 'creative problem solving methodology' which is a liberal arts course of engineering college at D university in Gyeonggi-do. As a result of the literature review, the PARTNER model was applied and weekly instructional guide was presented by each stage. In addition, the results of analysis on the reflection journal showed that the students were more able to achieve the deepening learning stage through active participation in class than the existing class, and found that they had a more challenging plan after the class.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.542-552
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• 2019

The strength assessment is the most important part at the design of ice-class propeller. Based on ice rules for ice-class propeller in IACS URI3 and FEM, the strength assessment method of ice-class propeller is established in this paper. To avoid the multifarious meshing process of propeller blade, an automatic meshing method has been developed by dividing the propeller geometry into a number of 8-node hexahedron elements along radial, chordwise and thickness directions, then the loaded areas in five cases can easily be calculated and identified. The static FEM is applied to calculate the stress and deformation of propeller blade. The fair agreements between the results of the present method and ANSYS/Workbench demonstrate its robust and the feasibility, and also the method is able to produce smooth gradient field. The blade stress and deformation distributions for five load cases are studied, and then the strength of the whole blade is checked.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.660-664
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• 2014

A diesel forklift truck under 3-ton class has disadvantages in the vibration transmission path. Because the weight ratio of body structure to powertrain which is source of excitation force is lower th an a mid-class forklift. In addition, the torsional and bending vibration mode frequencies of body structure are within the engine excitation frequency range, then high idle vibration generated by resonance. In this paper vehicle body structure design and optimization technique considering idle vibration reduction are presented. Design sensitivity analysis is applied to search the sensitive of design parameters in body structure. The design parameters such as thickness and pillar cross section were optimized to increase the torsional and bending vibration mode frequencies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1605-1607
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• 2000

In this paper, the design of class AB BiCMOS log-domain filter for low-voltage and low-power was proposed. This filter is consist of a log-domain integrator using folded junctions with capacitor connected to emitter and it's class AB structure. A comparison between the proposed class AB BiCMOS log-domain filter and classical class A BiCMOS log-domain filter is drawn on the basis of SNR, THD and the frequency response. This comparison shows proposed filter are more than good SNR, THD and frequency characteristics than more class A log-domain filter for low voltage and low power.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.525-530
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• 2013

The importance of engineering design increases due to the expansion of engineering education certification. But there are not much teaching methods and examples of engineering design to be referred to the college classes. This paper introduces a new teaching and learning method of Action Learning adopted to a engineering design class in the Department of Architectural Engineering, J University in Korea. The class included a team project to find problems of facilities or safety management factors in a building construction site, and to provide the alternatives to solve the problems. The Action Learning helped to improve the learning effect of students and to increase the quality of the project deliverables.

• 공학교육연구
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• 제9권4호
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• pp.5-9
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• 2006

본 논문에서는 한남대학교 토목환경공학과 4학년 전공선택 과목인 상하수도공학에서 진행한 협동학습을 소개하였다. 도시 비점원 처리시설을 설계하는 문제중심 학습을 실시하면서 토목구조물의 설계-시공-감리를 통합하여 수주하는 턴키(turn-key) 제도를 모사하여 수업을 진행하였다. 수강생 25명을 4개 조로 나누었으며 각 조를 각각 하나의 회사로 가정하여 사장-임원-사원에 이르는 직급을 정하게 하였다. 발주공사에 대한 설계개념 정립에서부터 공사비용의 산정, 공정 계획, 설계, 응찰에 이르는 전 과정을 수업 중 설명하였으며 비점원오염물질 처리시설물 수주를 위하여 각 조간 경쟁하도록 하였다. 설계가 가장 우수하면서 입찰금액을 낮게 쓴 조가 공사를 수주하되 1인당 예상 이익으로 과목의 성적을 평가하였다. 강의 진행과 효과분석을 위하여 각 팀별로 1명씩을 초점그룹으로 선택하였으며 중점적으로 학기 중 면담을 실시하여 수업에 반영하였다. 학생들은 턴키 제도의 운용, 인사고과에 대한 인식이 향상되었으며 수업의 긴장감을 효과적으로 높일 수 있었으며, 복잡한 설계과제를 수행할 수 있었다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.85-89
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• 2004

The paper presents a summary of the multidisciplinary/optimization method for the preliminary design of container feeder vessel. The current scenario in the ship building industry highly focuses on container ship design and construction proving the inherent demand in maritime industry. The design accomplishes the outer circle of the design spiral giving stress in areas of Hull Form Design, Resistance & Propulsion. Empirical relations, model test results, data from built ships, class rules and latest market demands stood as the criteria for the design. Optimization of the design as per the owners requirement. class rules, and the trade route selected are the major challenges met with. Strength. reliability, structural safety and stability have been incorporated in compromising standards.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2099-2101
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• 2005

The problem of observer design for a class of Lipschitz nonlinear systems is considered. We propose a new observer design method which takes into account the structure of perturbed nonlinear terms with a scaling factor ${\epsilon}$. An example is provided to demonstrate the usefulness of our result over the existing method.