• 가정과삶의질연구
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• 제16권1호
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• pp.125-139
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• 1998

This study investigates work loads and coping strategies of the married female production workers(MFPW). The data of 370 MFPW in manufacturing sector in Taegu are collected by using a questionare in August 1995 The findings of this study are as follow: 1) The results of objective work loads assessed time dairy show that the average working hours is 14.25 hours during weekdays. The respondents spend 11.5 hours and 2.75 hours on doing paid and household work respectively,. The shortage of phisiological and leisure time due to spending excessively long time on work. 2) MFPW perceive the severe subjective work loads in the areas of personal family and social life. The perceived burden from paid work itself is relatively low due to the nature of their job. 3) The coping strategies MFPW actually adopted are limited mostly to those from an individual domain such as shortening the time for sleep leisure or household labor.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.411-416
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• 2003

On the tunnel design, 3D model substituted for 2D model because of economic reason and time shortage. It is applied Load Distribution Factor, which is compared of displacement of tunnel crown, generally 50-25-25, 40-30-30 are used for tunnel design. Logicality about used Load Distribution Factor will investigated

• 한국수자원학회논문집
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• 제49권12호
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• pp.1027-1034
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• 2016

다목적댐을 건설하는 중요한 기능 중 하나는 대량의 수자원을 저수하여 건기에 적절하게 활용하는 것이다. 그러나 건설 당시 제한된 수문정보를 이용하여 건설된 다목적댐은 기후변화로 인한 유입량 감소와 같은 문제에 직면할 수 있어 물 부족이 발생할 경우 대처하는데 어려움이 있다. 국토교통부에서는 이러한 문제를 해결하기 위해 2015년 댐 용수부족 대비 용수공급 조정기준을 제시하였으나 아직 충분한 검토가 진행되지 않아 이에 대한 결과를 논하기엔 어려움이 있다. 또한 국내의 다목적댐은 비상용량을 확보하고 있으나 이를 활용할 수 있는 기준이 없다. 하지만 이를 효과적으로 사용한다면 가뭄에 대비할 수 있는 방안이 될 수 있을 것으로 판단된다. 따라서 본 연구에서는 댐 용수부족 대비 용수공급 조정기준과 다목적댐의 비상용량을 활용하는 방안을 검토하였다. 이수안전도 지표를 이용하여 대안들을 평가한 결과 대안별 용수공급능력이 다소 증가하지만 한계가 나타났다. 그러나 두 가지 대안을 복합적으로 활용할 경우 기존에 나타나던 문제를 보완하여 더욱 효과적인 용수공급을 할 수 있는 것으로 나타났다.

• 대한전기학회논문지
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• 제40권1호
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• pp.58-66
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• 1991

In inverters, time delays are inserted in the switching signals to prevent the dc lind shortage. This causes detrimental effects on the performance of the inverters, that is, the fundamental voltage drop and the generation of low order harmonics. This paper derives simple formula to describe the time delay effects in PWM inverters, where the effects may become significant because of relatively high switching frequencies. To compensate the tice delay effects, this paper presents two methods which are suitable for sinusoidal PWM and memory-based PWM respectively. Both are simple, easy to implement, and are shown to be effective, through the experiments, in improving the output waveform of PWM inverters.

• 한국공간정보시스템학회 논문지
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• 제11권2호
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• pp.162-169
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• 2009

The real-time traffic data is generated continuous and unbounded stream data type while intelligent transport system (ITS) needs to provide various and high quality services by combining with spatial information. Traditional database techniques in ITS has shortage for processing dynamic real-time stream data and static spatial data simultaneously. In this paper, we design and implement an advanced traffic monitoring system (ATMS) with the integration of existed data stream management system (DSMS) and spatial DBMS using IntraMap. Besides, the developed ATMS can deal with the stream data of DSMS, the trajectory data of relational DBMS, and the spatial data of SDBMS concurrently. The implemented ATMS supports historical and one time query, continuous query and combined query. Application programmer can develop various intelligent services such as moving trajectory tracking, k-nearest neighbor (KNN) query and dynamic intelligent navigation by using components of the ATMS.

• 한국경영과학회지
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• 제11권1호
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• pp.44-50
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• 1986

In this paper, we find optimal policy for the (Q, r) inventory model under the lead time uncertainty. The (Q, r) inventory model is such that the fixed order quantity Q is placed whenever the level of on hand stock reaches the reorder point r. We first develop the single level inventory model as the basis for the analysis multi-level distribution systems. The functional problem is to determine when and how much to order in order to minimize the expected total cost per unit time, which includes the set up, inventory holding and inventory shortage cost. The model, then, is extended to the multi-level distribution system consisting of the factory, warehouses and retailers. In this case, we also find an optimal policy which minimizes the total cost of the contralized multi-level distribution system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1312-1315
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• 1996

Polishing work for a curved surface die demands simple and repetitive operations and requires much time while it also demands high precision. Therefore it is operated by skilled worker in handiwork. But workers avoid polishing work gradually because of the poor environments such as dust and noise. In order to reduce the polishing time and to alleviate the problem of shortage of skilled workers, researches for automation of polishing have been pursued in the developed countries such as Japan. In this research we develop a polishing robot with 2 degrees of freedom motion and pneumatic system, and attach it to machining center with 3 degrees of freedom to form an automatic polishing system which keeps the polishing tool vertically on the surface of die and maintains constant pneumatic pressure. The developed polishing robot is controlled by real time sliding mode control using DSP(digital signal processor). A synchronization between machining center and polishing robot is accomplished by using M code of machining center. A performance experiment for polishing work is executed by the developed polishing robot.

• Journal of Construction Engineering and Project Management
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• 제4권3호
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• pp.53-59
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• 2014

Project managers are responsible to conduct project on time with least amount of costs and the most possible quality with respect to shortage of resources and environmental certainties. They have to make the best decision to reach such conflicting objects. In this study the project scheduling with multi goals-multi modes was planned in fuzzy conditions under resource constraints and expanded by fuzzy goal programing (FGP). The project cost was calculated by the price of renewable resources and the quality criteria were evaluated by the quality function deployment method (QFD). Finally the model was verified by a construction case study with 22 activities along with solving by GAMS. The results showed that this model could provide a systematic framework to facilitate the decision making process and made the project managers to be able to schedule the project closer to reality.

• Journal of Advanced Marine Engineering and Technology
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• 제36권7호
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• pp.927-934
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• 2012

This paper suggests a new fuzzy PID controller with variable parameters which improves the shortage of the fuzzy PID controller with fixed parameters suggested in [9]. The derivation procedure follows the general design procedure of the fuzzy logic controller, while the resultant control law is the form of the conventional PID controller. Therefore, the suggested controller has two advantages. One is that it has only four fuzzy linguistic rules and analytical form of control laws so that the real-time control system can be implemented based on low-price microprocessors. The other is that the PID control action can always be achieved with time-varying PID controller gains only by adjusting the input and output scalers at each sampling time.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.122-122
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• 2000

Polishing work of a free-curved surface die demands simple and repetitive operations but requires a considerable amount of time for high precision. In out previous study, to reduce the polishing time and solve the problem of the shortage of skilled workers, the automatic polishing system was developed. However, in the polishing process of die, workers have to stay still in factory to monitor the polishing process for a long time in the poor environment. Therefore, this study proposes the remote operation and monitoring system of the automatic polishing robot. The developing system offer worker monitoring functions and teleoperating functions, as following: system state check, manual manipulation mode, automatic mode, manual teaching mode, automatic teaching mode, simulation by virtual manufacturing device. And automatic teaching system is developed to easily obtain a teaching data.