• Journal of Construction Engineering and Project Management
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• 제3권3호
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• pp.35-41
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• 2013

All infrastructure projects are said to be inter-dependent, uncertain and labour-intensive in nature. There is no exception for building services sub sector. For a real time project such as 'The construction, extension and refurbishment of Employees' State Insurance Corporation (ESIC) Hospital at Tirupathy, India with total area of 45,000 square feet at an estimated cost of 1100 million rupees, a generic process model is developed to simulate the effect of set of identified variables on construction project. The 'Stocks and Flows' of dynamic model affords relevant insights to project managers, who apply this knowledge when designing better performance through more appropriate project planning. It is concluded from the model-based approach that building services works can be improved through specific better focussed managerial efforts, such as an increasing coordination effectiveness at the planning stage, clarifying prerequisite conditions prior to installations. Otherwise, pending works arising from work clashes can lead to knock-on effects resulting in productivity constraints and pressures, as well as more rework and demolition. Current study reveals that the model enables deep insight into various interdependent processes, their by improving construction performance levels, by addressing the dynamics of design errors and defective works, and recovering delayed schedule.

• 대한조선학회논문집
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• 제53권4호
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• pp.275-281
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• 2016

One of the most important things for quality to meet ship-production schedule is an accuracy control. A ship is assembled by welding through whole production process, so it is important that loss by correction will not happen as much as possible by using some engineering skills like reverse design, reverse setting and margin for thermal shrinkage. These efforts are a quite effective in fabrication stages, but not in erection stages. If a ship block which consists of common steel is exposed to directional solar radiation, its dimensional accuracy will change high as time by its thermal expansion coefficient. Therefore, the measuring work would be often done at dawn or evening even with having a very accurate device. In this study, an FE analysis method is developed to solve this problem. It can change measured data affected by solar thermal distortion to ones not, even though ship-block is measured at an arbitrary time. It will use the time when measuring, the direction of block and the weather record by satellites. It is confirmed by a comparison between measured data of a ship-block and the result by suggested analysis method. Furthermore, a pre-processing system is also developed for fast application of the suggested analysis method.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.825-830
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• 2005

Traffic control is the center of the railway traffic control system. The main objective of railway traffic control system is to minimize delays, providing the customers with on-time train operating service according to the given train schedule. Particularly, within the station control area, the departure & arrival of train. the decision on the train priority and the shunting of train are decided by the authority of the local traffic controller. Therefore, it is necessary to have a lot of information and communications between each departments. And for such decision making of the local traffic controller, not only the communication between each stations are needed, but also the communication between other stations are needed too. In this paper, we have analyzed the main work of the local traffic controller in large scale stations and have designed the station traffic control system needed to be built within the station considering the local traffic. And we have proposed not only the communication with other system within station, but also the communication methods for communications with the neighboring stations.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.163-171
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• 1999

The abnormal grain coarsening in wire rolling induces detrimental defects, such as jagged size tolorance, severe bending after heat treatments and drawing troubles, in the following secondary processes. Neishi et al observed that there is a band type region where grain coarsenting occurs in the plastic strain vs. deformation temperature plot. Based on the finding, we have investigate whether grain sizes and ferrite volume fractions are correlation to deformation strain with three kinds of wire rod diameters as for the different average deformation conditions. The samples were chosen from the No.2 Wire Rod Mill of POSCO where 3-roll type of finishing mill stand are used. It was found in the present work that the grain size and ferrite volume fraction of the rolled and cooled microstructure were changed with rolling reduction and rolling temperature. Abnormally grown grains at various observed points were also found. To have homogeneously fine grains of microstructure from the No. 2 Wire Rod Mill, it will be easier to control finish rolling temperature at around 750$^{\circ}C$ rather than to find another rolling schedule.

• 한국중재학회지:중재연구
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• 제15권3호
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• pp.303-324
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• 2005

Turnkey project in construction which accounts for about $10\%$ of the total annual construction orders in the nation is expected to grow in size as an effort to strengthen international competitiveness and improve quality of construction work. However, problems of turnkey project in construction raise concern for many possible cases of possible claims. Based on the understanding that bidding guidelines which plays a critical role in turnkey project in construction actually contain some unequal clauses and causes for problems which undermine development of turnkey construction and further create possible cases of claims, the paper aims to identify and analyze the unequal clauses and problems contained in the guidelines in order to make suggestions for improvement. Among all the turnkey construction orders that has been placed since 2000 when domestic turnkey project in construction became relatively formulated, 13 constructions costing more than 50 billion won were selected for this study since their construction scale were large enough that the bidding guidelines for them were regarded as containing little difference among one another. In order to enhance construction technology and to prevent claims while trying to achieve the original purpose of Turnkey system, the parties involved in or schedule to take part in Turnkey project including ordering institution, Construction Company and Design Company should make an effort to have more reasonable bidding guidelines drawn up.

• 한국직업건강간호학회지
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• 제25권4호
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• pp.373-383
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• 2016

Purpose: The purpose of this study was to identify the factors affecting shiftwork tolerance among nurses and provide basic data, ultimately, in formulating a plan for improving their shiftwork tolerance. Methods: The participants were 317 nurses who were working at three general hospitals in Daejeon and Seoul. Data analyzed t-test, ANOVA, correlation analysis, and regression analysis using SPSS 20.0 program. Results: As for the sub-areas of shiftwork tolerance for the respondents, more than a half of nurses working at shifts suffered from insomnia, felt drowsy, complained of chronic fatigue, and were at the anxious and depressed state. Shiftwork tolerance differed by the daily intake of coffee and exercise. Shiftwork tolerance was significantly positively correlated with sleep-wake habits, hardiness, and flexibility and negatively correlated with a languidity. Regression analysis revealed that shiftwork tolerance was affected by age, sleep-wake habits, languidity, flexibility, and hardiness. Conclusion: To put the results, nurses had shiftwork tolerance affected by sleep-wake habits, languidity, and hardiness. It is therefore necessary to make a scheme for allowing nurses to improve hardiness and flexibility and decrease the languidity with the objective of improving their shiftwork tolerance.

• 대한산업공학회지
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• 제33권2호
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• pp.254-264
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• 2007

This paper considers a scheduling problem to minimize the total weighted completion time in the two-stage assembly-type flowshop. The system is composed of multiple fabrication machines in the first stage and a final-assembly machine in the second stage. Each job consists of multiple components, each component is machined on the fabrication machine specified in advance. The manufactured components of each job are subsequently assembled into a final product on the final-assembly machine. The objective of this paper is to find the optimal schedule minimizing the total weighted completion time of jobs. Three lower bounds are derived and tested in a branch-and-bound (B&B) Procedure. Also, three heuristic algorithms are developed based on the greedy strategies. Computational results show that the proposed B&B procedure is more efficient than the previous work which has considered the same problem as this paper.

• 한국멀티미디어학회논문지
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• 제23권2호
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• pp.155-165
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• 2020

In this paper, we propose a smart thermostat temperature set-point control method based on machine learning and rule engine, which controls thermostat's temperature set-point so that it can achieve energy savings as much as possible without sacrifice of occupants' comfort while users' preference usage pattern is respected. First, the proposed method periodically mines data about how user likes for heating (winter)/cooling (summer) his or her home by learning his or her usage pattern of setting temperature set-point of the thermostat during the past several weeks. Then, from this learning, the proposed method establishes a weekly schedule about temperature setting. Next, by referring to thermal comfort chart by ASHRAE, it makes rules about how to adjust temperature set-points as much as low (winter) or high (summer) while the newly adjusted temperature set-point satisfies thermal comfort zone for predicted humidity. In order to make rules work on time or events, we adopt rule engine so that it can achieve energy savings properly without sacrifice of occupants' comfort. Through experiments, it is shown that the proposed smart thermostat temperature set-point control method can achieve better energy savings while keeping human comfort compared to other conventional thermostat.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.119-120
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• 2012

The management for materials and inventory is one of the factors which are considered the most for profits of a business in almost all industrial fields. Resource procurement which occupies more than 40% of an overall construction cost has a strong relationship with profits of a business but it is regarded as a work for a manager rather than for a technician. It makes the importance of resource procurement relatively low and slows down the development of workings. As the construction project becomes more larger and complicated, effective management for materials are directly affecting the profits of a business. Therefore, this research works on finding an economical managing method for materials according to a characteristic of construction project based on accurately forecasted BIM data. Finding a reorder point by using BIM data which contains an accurate data for schedule and material enables a better management for materials and provides more accurate data on matters which were used to be determined by an intuition of a manager.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.515-518
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• 2006

건설공사는 매우 다양한 요인들에 의해 영향을 받으며 생산 주체도 공정별로 다양해서 생산과정상에 많은 변이를 내재하고 있다. 그러나 현재의 공정관리는 결과위주의 관리 방식으로 작업의 상호연관성과 변이 발생을 충분히 고려하지 못하고 있어 많은 문제가 발생하고 있다. 린 건설은 현재의 공정관리방식의 한계를 인식하고 있으며 공정계획의 신뢰성 향상, 공정의 안정성 확보 건축 생산의 효용성 증진을 위한 새로운 관리기술로써 평가 되고 있다. 본 연구에서는 린 건설 이론을 기반으로 한 기법들을 실무적용가능성 측면에서 분석하여 VSM 및 TACT를 이용한 공정관리 기법의 현장적용성을 검토하였다.