• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.1029-1034
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• 2003

The basic Physical properties, Slump, Slump Flow, Air content, Bleeding, and Settlement of concrete was investigateed to test Characteristic of Setting and to evaluate the relation between Model Specimen and Heat of hydration for construction Over the High Temperature (CFT). The objective of this study is to take the partial core after the cementation of Model Specimen, test the compression intensity and analyze the relation to Test Piece.

• 대한산업공학회지
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• 제11권2호
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• pp.141-154
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• 1985

The capacity expansion problem has been defined. Existing literatures on capacity expansion problems have been reviewed and unified under a structure of problem domain. The problem domain has been defined by three relavent coordinates; function or objective of the project, consideration of resource allocation, and consideration of project sequencing. Long range planning is of vital importance in setting up ultimately efficient capital investment plans to meet immediate demand increase. Simplified expansion sequencing example problems have been introduced and solved to help understanding of a solution scheme.

• Journal of information and communication convergence engineering
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• 제15권3호
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• pp.182-186
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• 2017

Maintaining a proper lookout activity routine is integral to preventing ship collision accidents caused by human errors. Various subjective measures such as interviewing, self-report diaries, and questionnaires have been widely used to monitor the lookout activity patterns of navigators. An objective measurement of a lookout activity pattern classification system is required to improve lookout performance evaluation in a real navigation setting. The purpose of this study was to develop an objective navigator lookout activity classification system using wearable accelerometers. In the training session, 90.4% accuracy was achieved in classifying five fundamental lookout activities. The developed model was then applied to predict real-lookout activity in the second session during an actual ship voyage. 86.9% agreement was attained between the directly observed activity and predicted activity. Based on these promising results, the proposed unobstructed wearable system is expected to objectively evaluate navigator lookout patterns to provide a better understanding of lookout performance.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 춘계학술대회논문집
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• pp.10-16
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• 1997

The ride comfort is one of the most important indices which decide the quality of automotive seats. A subjective evaluation is the general method for comfort evaluation of automotive seats. But the subjective evaluation assess the individual sensibility using questionnaire. Therefore, a need to develop methodologies to obtain objective measurements of the fatigue evaluation is evident. In an effort to monitor muscle activity during driving electromyography (EMG) was employed. In an experimental setting the subjective evaluation was conducted using questionnaire under the static conditions (8 subjects) and the fatigue was induced in muscles using EMG under the dynamic conditions (2 drivers). The resultant EMG signals were then sampled for three different muscles. In test involving 2 subjects of similar size and build, utilizing four different automotive seats, test results support the use of EMG to quantify muscular fatigue as a viable means of objective evaluation for the different automotive seats.

• 대한감각통합치료학회지
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• 제17권2호
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• pp.41-55
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• 2019

목적 : 본 연구는 9-19세의 학생과 학교 환경과의 적합성을 평가하는 학교 환경 인터뷰(School Setting Interview; SSI)를 한국어로 번안하고 내용타당도를 검증하기 위해 실시하였다. 연구방법 : 번역-역번역의 과정을 거쳐 완성된 한국판 SSI를 전문가 집단 35명에게 항목 적합성에 대한 설문을 총 2회 실시하여 내용타당도를 검증하였다. 연구결과 : K-SSI(Korean-School Setting Interview) 도구 전체의 내용타당도 지수(Content Validity Index; CVI)는 1차 검증에서 .90으로 나타났고, 1차 검증에서 .75 이하로 나온 항목들인 읽기 항목의 '지도와 도표', 스포츠 활동하기 항목의 '샤워하기'에 대해서 수정을 거쳐 2차 검증을 하였다. 그 결과 2차 검증은 .93로 더 상승된 결과를 보였다. 결론 : K-SSI는 국내문화에 부적합한 항목이 없음을 확인하였으며 높은 내용타당도를 가진 평가도구임이 증명되었다. 앞으로의 연구에서는 타당도와 신뢰도 연구가 진행되어야 하며, 실질적으로 학교 환경에서 어려움을 겪는 학생들에게 적용하는 연구와 같이 임상에서의 지속적인 활용이 이루어져야한다.

• International Journal of Control, Automation, and Systems
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• 제5권4호
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• pp.436-443
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• 2007

In this paper, an intelligent method called BELBIC (Brain Emotional Learning Based Intelligent Controller) is used to control of Locally Linear Neuro-Fuzzy Model (LOLIMOT) of Washing Machine. The Locally Linear Neuro-Fuzzy Model of Washing Machine is obtained based on previously extracted data. One of the important issues in using BELBIC is its parameters setting. On the other hand, the controller design for Washing Machine is a multi objective problem. Indeed, the two objectives, energy consumption and effectiveness of washing process, are main issues in this problem, and these two objectives are in contrast. Due to these challenges, a Multi Objective Genetic Algorithm is used for tuning the BELBIC parameters. The algorithm provides a set of non-dominated set points rather than a single point, so the designer has the advantage of selecting the desired set point. With considering the proper parameters after using additional assumptions, the simulation results show that this controller with optimal parameters has very good performance and considerable saving in energy consumption.

• Industrial Engineering and Management Systems
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• 제10권2호
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• pp.134-139
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• 2011

The problem of scheduling in permutation flowshops has been extensively investigated by many researchers. Recently, attempts are being made to consider more than one objective simultaneously and develop algorithms to obtain a set of Pareto-optimal solutions. Varadharajan et al. (2005) presented a multi-objective simulated-annealing algorithm (MOSA) for the problem of permutation-flowshop scheduling with the objectives of minimizing the makespan and the total flowtime of jobs. The MOSA uses two initial sequences obtained using heuristics, and seeks to obtain non-dominated solutions through the implementation of a probability function, which probabilistically selects the objective of minimizing either the makespan or the total flowtime of jobs. In this paper, the same problem of heuristically developing non-dominated sequences is considered. We propose an effective heuristics based on simulated annealing (SA), in which the weighted sum of the makespan and the total flowtime is used. The essences of the heuristics are in selecting the initial sequence, setting the weight and generating a solution in the search process. Using a benchmark problem provided by Taillard (1993), which was used in the MOSA, these conditions are extracted in a large-scale experiment. The non-dominated sets obtained from the existing algorithms and the proposed heuristics are compared. It was found that the proposed heuristics drastically improved the performance of finding the non-dominated frontier.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.89-96
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• 2018

When a fault occurs in a power system, the existing analytic models for the power system fault diagnosis could generate multiple solutions under the condition of one or more protective relays (PRs) and/or circuit breakers (CBs) malfunctioning, and/or an alarm or alarms of these PRs and/or CBs failing. Therefore, this paper presents an improved analytic model addressing the above problem. It takes into account the interaction between the uncertainty involved with PR operation and CB tripping and the uncertainty of the alarm reception, which makes the analytic model more reasonable. In addition, the existing analytic models apply the penalty function method to deal with constraints, which is influenced by the artificial setting of the penalty factor. In order to avoid the penalty factor's effects, this paper transforms constraints into an objective function, and then puts forward an improved immune clonal multi-objective optimization algorithm to solve the optimal solution. Finally, the cases of the power system fault diagnosis are served for demonstrating the feasibility and efficiency of the proposed model and method.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.644-654
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• 2024

After the Tohoku earthquake and tsunami (Japan, 2011), regulatory efforts to mitigate external hazards have increased both the safety requirements and the total capital cost of nuclear power plants (NPPs). In these circumstances, identifying not only disaster robustness but also cost-effective capacity setting of NPPs has become one of the most important tasks for the nuclear power industry. A few studies have been performed to relocate the seismic capacity of NPPs, yet the effects of multiple hazards have not been accounted for in NPP capacity optimization. The major challenges in extending this problem to the multihazard dimension are (1) the high computational costs for both multihazard risk quantification and system-level optimization and (2) the lack of capital cost databases of NPPs. To resolve these issues, this paper proposes an effective method that identifies the optimal multihazard capacity of NPPs using a multi-objective genetic algorithm and the two-stage direct quantification of fault trees using Monte Carlo simulation method, called the two-stage DQFM. Also, a capacity-based indirect capital cost measure is proposed. Such a proposed method enables NPP to achieve safety and cost-effectiveness against multi-hazard simultaneously within the computationally efficient platform. The proposed multihazard capacity optimization framework is demonstrated and tested with an earthquake-tsunami example.

• 한국도로학회논문집
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• 제19권1호
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• pp.1-9
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• 2017

PURPOSES : The objective of this study is to develop an optimized method of mix design for rapid-set lightweight-formed mortar mix. To achieve this objective, the workability, setting time, and compressive strength of mixes under various conditions of mix design were evaluated. METHODS : The water-bonder ratio, fly-ash substitution ratio, and forming agent injection amount were selected as design variables in the study. The fluidity, setting time, density, and strength of the mortar mix were considered as major evaluation criteria of the mixture, and were subsequently utilized to evaluate the characteristics of the mortar mix under various conditions. RESULTS : The observations made from the mix design process are as follows: 1) the air content and fluidity increase as the forming agent ratio and forming agent ratio increase, respectively; 2) the maximum air content is approximately 20%; 3) the accelerating agent decreases the fluidity of the mortar mix by 15% on average; 4) the forming agent injection ratio and fly-ash substitution ratio yield significant effects on the initial and final set times of the mortar mix; 5) as the forming agent injection ratio and fly-ash substitution ratio increase, the compressive strength of the mortar mix decreases; and 6) the 28-day compressive strengths of the forming agent injection ratio and fly-ash substitution ratio yield the most significant effects. CONCLUSIONS : It is concluded that the governing design variables for the rapid-set lightweight-formed mortar mix are the forming agent injection ratio and fly-ash substitution ratio.