• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.168-172
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• 2014

A new sustain driving method is proposed to improve luminous efficiency by the generation of the self-erasing discharge during a sustain period in AC plasma display panel. As one subfield time in the conventional AC PDP is divided into the reset, address, and sustain period. Among them, as the square sustain waveform is alternately applied to the X and Y electrodes on the front plate during the sustain period, the plasma discharge for displaying the image is continuously produced. Meanwhile, in the conventional driving method, the address waveform applied to the A electrode on the rear plate is only driving during an address period and grounded during a sustain period. In this experiment, the negative pulse is applied to the A electrode at the latter part of the sustain pulse for improving the luminous efficiency producing the self-erasing discharge during the sustain period. The negative pulse on the A electrode can change from the space to the wall charge and induce the additional discharge by the accumulated wall charge when the voltages of three electrodes are grounded. As a result, the luminous efficiency will be measured with changes in the voltage level of the A electrode and the new driving method can be improved to the luminous efficiency about 32 % compared with the conventional driving method.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.452-458
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• 1991

Psychrotrophs producing protease were isolated during ripening periods of Cheddar cheese and one of them containing the highest protease activity was identified as Pseudomonas fluorescens 65. The extracelluar proteolytic enzyme was partially purified from P. fluorescens 65 through the Sephadex G-100 gel filtration. The protease was eluted between 190 ml and 230 ml of elution volume of sodium phosphate buffer. The purified protease showed a single band in SDS-PAGE and its molecular weight was 47,000. The composition of amino acid for the protease was determined and the most abundant amino acids were glutamic acid (14.96%) and serine (13.86%). The optimum temperature and pH for the activity was $45{\sim}50^{\circ}C$ and 6.0, respectively.

• Korean Journal of Construction Engineering and Management
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• v.8 no.1 s.35
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• pp.87-95
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• 2007

If construction process operate composing work team by judgment manager's experience, possibility that progress of construction process becomes as inefficient is much. But, If produce optimal proposal of resources allocation, construction cost and duration through simulation at work plan step, work schedule because do quantification efficient operate do on. When plan construction process in this research, resources allocation by change of work team operation change, resources cost loss, total cost, optimal proposal of construction duration tentative plan of numerical formula model that can do simulation propose. Apply and revealed to apartment house framework which horizontal work area of process and vertical work area are composed as is each different construction process to verify proposed numerical formula model. Achieved efficiency than work team's operation results which apply numerical formula model that is presented in this research and enforce simulation is applied in actuality example construction.

• The Korean Journal of Applied Statistics
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• v.23 no.6
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• pp.1147-1156
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• 2010

This paper proposes a replacement policy following the expiration of a non-renewing free replacement-repair Warranty(NFFRW). The non-renewing free replacement-repair warranty is defined and then the maintenance model following the expiration of the NFRRW is studied from the user's point of view. As the criteria to determine the optimality of the maintenance policy, we consider the expected cost rate per unit time from the user's perspective. All maintenance costs of the system incurred after the expiration of the warranty are paid by the user. Given the cost structures during the life cycle of the system, we determine the optimal maintenance period following the expiration of a NFRRW. Finally, the numerical examples are presented for illustrative purposes.

• Journal of Intelligence and Information Systems
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• v.6 no.2
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• pp.1-14
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• 2000

The berth and crane scheduling problem in a container terminal encompasses the whole process of assigning berth to each ship, determining the duration of berthing, assigning container cranes to each ship, and determining the specific start and end time of each crane service, for all the ships scheduled to be arriving at the terminal during a certain scheduling horizon. This problem is basically a constraint satisfaction problem in which cranes and berths should be assigned in such a way that all the spatial and temporal constraints are satisfied without any interference. However, it is also an optimization problem because the requested arrival and departure time should be met for as many of the scheduled ships as possible, while the operation cost of the terminal should be minimized. In this paper, we present an effective and efficient approach to solving this type of problem, which combines constrain satisfaction search and heuristic repair. We first employ a constraint satisfaction search to find a feasib1e solution. Then, the feasible solution is modified to a more optimal one by iteratively applying our heuristic repair operations within the framework of constraint satisfaction search. Experimental results with a real data from Pusan East Container Terminal showed that our approach can derive a schedule of satisfactory quality in a very short time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.427-436
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• 2015

This study aims to select an optimal site for the development of small-scaled artificial ground water recharge system with the purpose of 50ton/day pumping in dry season. First of all, the topography shape satisfying the numerous factors of a hydraulic model experiment is defined and an appropriate pumping efficiency is calculated through the model experiment of injection and pumping scenario. In next step, GIS(Geographic Information System) database are constructed by processing several geospatial data to explore the optimal site. In detail, watershed images are generated from DEM(Digital Elevation Model) with 5m cell size, which is set for the minimum area of the optimal site selection. Slope maps are made from DEM to determine the optimal hydraulic gradient to procure the proper aquifer undercurrent period. Finally, the suitable site for artificial recharge system is selected using an integration of overall data, such as an alluvial map, DEM, orthoimages, slope map, and watershed images.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.40-50
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• 2009

Incorrect deployment of RFID readers occurs reader-to-reader interferences in many applications using RFID technologies. Reader-to-reader interference occurs when a reader transmits a signal that interferes with the operation of another reader, thus preventing the second reader from communicating with tags in its interrogation zone. Interference detected by one reader and caused by another reader is referred to as a reader collision. In RFID systems, the reader collision problem is considered to be the bottleneck for the system throughput and reading efficiency. In this paper, we propose a novel RFID reader anti-collision algorithm based on evolutionary algorithm(EA). First, we analyze characteristics of RFID antennas and build database. Also, we propose EA encoding algorithm, fitness algorithm and genetic operators to deploy antennas efficiently. To show superiority of our proposed algorithm, we simulated our proposed algorithm. In the result, our proposed algorithm obtains 95.45% coverage rate and 10.29% interference rate after about 100 generations.

• Journal of Radiation Protection and Research
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• v.23 no.4
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• pp.243-249
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• 1998

The methodology for justification and optimization of the countermeasures related with contamination management of milk was designed based on the cost and benefit analysis. The application results were discussed for the deposition on August 15, when pasture is fully developed in Korean agricultural conditions. A dynamic food chain model DYNACON was used to estimate the time-dependent radioactivity of milk after the deposition. The considered countermeasures are (1) the ban of milk consumption (2) the substitution of clean fodder, which are effective in reducing the ingestion dose as well as simple and easy to carry out in the first year after the deposition. The total costs of the countermeasures were quantitatively estimated in terms of cost equivalent of doses and monetary costs. It is obvious that a fast reaction after the deposition is an important factor in cost effectiveness of the countermeasures. In most cases, the substitution of clean fodder was more effective countermeasure than the ban of consumption. A fast reaction after the deposition made longer justifiable/optimal duration of the countermeasure.

• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.783-797
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• 2010

Based on the importance of asset allocation in the return of an investment portfolio, this article attempts to verify the appropriateness of mutual funds as means of investment to obtain optimal asset allocation. The return-based style analysis is applied to determine a mutual fund's allocation(or a style) among a set of specified asset classes. Assuming a particular investor who defines a range allowed a fund's style to differ from its original one, it is examined whether or not the fund style is continued over an investment time horizon. After verifying the fact that the original style of the investment fails to remain unchanged from the empirical analysis limited to domestic equity mutual funds, we further investigated the reasons for the style drift. Despite several limitations of the analysis, it yields the conclusion that domestic equity mutual funds do not seem to be an appropriate investment tool to achieve a target asset allocation.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1605-1609
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• 2010

CGCM3.1 SRES B1 시나리오의 2D 변수들을 입력값으로 인공신경망 모형을 이용한 스케일 상세화기법으로 강부식(2009)은 소양강댐 유역의 월 누적강수 경향분석을 실시하였다. 원시 GCM 시나리오를 스케일 상세화 시키기 위한 기법의 하나로 인공신경망 모형을 사용할 수 있는데, 이 경우 GCM에서 모의되는 강수플럭스, 해면기압, 지표면 근처에서의 일 평균온도, 지표면 근처에서의 일평균온도, 지표면으로부터 발생하는 잠열플럭스 등과 같은 22개의 변수를 잠재적인 예측인자로 사용하여 신경망을 구성하게 된다. 입력변수세트의 구성은 인공신경망의 계산 효율을 좌우하는 중요한 요소라 할 수 있다. 본 연구에서는 변수의 물리적 특성을 고려하여 순차적인 변수선택을 통한 신경망 입력변수 세트를 구성하고 입력세트 간의 학습성과 비교를 통하여, 최적 입력변수 선정 및 신경망의 학습효과를 높일 수 있는 방법에 대해 연구하였다. 물리적 상관성이 높다고 판단되는 GCM_Prec, huss, ps를 입력변수로 하여 순차적인 케이스를 학습해본 결과 huss와 ps를 입력변수로 하는 케이스에 대해서 적은 오차와 높은 상관성을 보였다, 또한, 신경망의 학습 효과를 높이기 위해 홍수기와 비홍수기로 구분하여 학습한 결과 홍수기와 비홍수기로 구분하여 신경망을 구성하였을 경우가 향상된 모의값을 나타내었다. 기후변화모의자료는 CCCma(Canadian Center for Climate Modeling and Analysis)에서 제공되는 CGCM3.1/T63 20C3M 시나리오를 사용하였으며, 관측값으로는 AWS에서 제공된 일 누적강수를 사용하였다. 인공신경망의 학습기간은 1997년부터 2000년이며, 검증기간은 2001년부터 2004년으로 구성하였다.