• 한국컴퓨터정보학회논문지
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• 제22권10호
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• pp.63-71
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• 2017

In this paper, we develop the system for audio volume equalization of video on demand(VoD) content and propose the solution for it. In recent years, there has been a steady increase in the number of VoD users in addition to linear channels. However, viewers ought to sit in an uncomfortable way, adjusting the volume intermittently while they are broadcasted. Sudden changes of volume occur between the broadcasting channels, the programs from the co-channel, or the linear channels and the VoDs. Especially, upsurged dissatisfaction from the televiewers has been found due to the unequalized volume when shifting between the linear channel and the VoD. In order to solve this problem, multilateral efforts were put forth, such as a system for keeping the volume at a certain level in digital broadcasting program has been legislated domestically. It leads success in equalizing linear channel volume. On contrary, too little notice has been taken for distorted volume problem of video on demand(VoD) content. In this paper, we developed and applied the volume equalization system into VoD content to achieve uniformization, a similar condition with linear channel(-24LKFS). This suggestion helped uneven current of volume which was in the stage -16 ~ -20LKFS to stable condition by lowering into the stage of -24LKFS. It also brought 20% increase in perspective of volume quality satisfaction level.

• 산업기술연구
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• 제21권B호
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• pp.37-44
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• 2001

Distribution System is considered as the most important part of SCM when the satisfaction of customer demand is considered. This paper focus on the backorder policies for stockout which is occurred in each regional distribution center of two-echelon distribution system facing stochastic demand process. Four concepts for the efficient system operation are suggested. First, at least 30% reduction of stockout is achieved by introduction of 50/25 allocation policy to distribution system. Second, transportation cost and lead-time of backorder are decreased by allowance of internal supply between regional distribution centers. Third, the frequency of emergency supply is minimized by application of Ship-up-to- expected-demand backorder policies. Finally we suggest several effective rules to select multi-internal suppliers. Simulation tests show the efficiency of our backorder policies and enhancement of customer service level.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.1056-1061
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• 2009

This paper proposes a short-term water demand forecasting algorithm based on kalman filtering with data mining for sustainable water supply and effective energy saving. The proposed algorithm utilizes a mining method of water supply data and a decision tree method with special days like Chuseok. And the parameters of MLAR (Multi Linear Auto Regression) model are estimated by Kalman filtering algorithm. Thus, we can achieve the practicality of the proposed forecasting algorithm through the good results applied to actual operation data.

• 한국태양에너지학회 논문집
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• 제29권5호
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• pp.1-7
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• 2009

Energy demands for offices in Korea are surveyed and analyzed to generate communicational models for simulations. Daily energy loads of 13 office buildings scattered in the 6 largest cities in the country are surveyed and analyzed based on energy consumption log sheets. Detailed hourly loads that are frequently required when a detailed operation simulation is performed are measured using remote data acquisition processes for 3 offices. The complete load demand models of electricity, cooling, heating and hot water are established by combining the daily and hourly patterns based on the statistical behavior of the hourly patterns.

• 한국철도학회논문집
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• 제10권6호
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• pp.742-750
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• 2007

본 논문은 장래 도입되는 KTX2 고속차량을 이용한 중련편성 운영계획 최적화를 위한 방법론 제시를 목적으로 한다. 중련편성 운영계획 최적화를 위한 수리적 모형을 제시하고, 제안된 수리적 모형의 적용방안을 제시한다. 특히 확률적 수요를 고려한 모형을 수립하여, 계획수립 단계에서 수요의 확률적 요소를 보다 현실적으로 반영하고, 모형내에서 좌석 서비스 수준을 직접 조정할 수 있다.

• 한국도로학회논문집
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• 제10권3호
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• pp.139-147
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• 2008

1996년 천호대로 중앙버스전용차로가 시행된 이후 2008년 까지 8개 구간이 운영되고 있다. 그러나 중앙버스전용차로의 시행에 따른 직 간접적 영향권 내의 도로교통량 변화는 보고되지 않고 있다. 따라서 본 연구에서는 2004년 7월에 동시 개통된 3개 구간에 대한 사전 사후 도로교통량 변화를 분석하였다. 분석결과, 중앙버스전용차로 구간의 교통량은 중앙버스전용차로 개통 후(2004년 11월) 24.7%로 급격히 감소한 후, 개통 후 1년(2005년 11월) 1.4%로 안정화 된 것으로 분석되었다. 인접 우회도로 교통량은 개통 후(2004년 11월) 2.9% 감소한 후, 개통 후 1년(2005년 11월) 0.3%로 미비하게 증가하였다. 측정오차(${\pm}5%$)를 고려하면 중앙버스전용차로 교통수요는 안정화 단계에 들어섰으며, 자동차 수요가 인접지역으로 우회하기 보다는 타 수단으로 전환된 것으로 판단된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.1047-1053
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• 2005

This study explored pattern of train operation between Seoul Cheonan after the introduction of KTX in 2004. Both number of trains and seat capacity per day have increased but maximum number of trains per specific hour hasn't changed much. Demand for train shows that it concentrated in a specific time, so number of trains during the peak hour should be increased. But, it is difficult due to line capacity, so increasing seat capacity per train might be an option. An increase in seat capacity should be considered the characteristics of each train lines.

• 전기학회논문지
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• 제60권8호
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• pp.1467-1472
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• 2011

This paper presents an optimal operation of microgrid systems and considering a tie-lines capacities that concerned each grid. The microgrid system consists of a wind turbine, a diesel generator, and a fuel cell. An one day load profile and wind resource for wind turbine generator were used for the study. For the grid interconnection, tie-line capacities were applied as constraints. The capacity constraints of tie-lines in production cost analysis are very important issues in the operation and planning of microgrid. In optimization, the Harmony Search (HS) algorithm is used for solving the problem of microgrid system operation which a various generation resources are available to meet the customer load demand with minimum operating cost. The application of HS algorithm to optimal operation of microgrid proves its effectiveness to determine optimally the generating resources without any differences of load mismatch.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2821-2829
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• 2011

Since the KTX was in operation in 2004, a number of researches on increasing the train speed have been conducted. Currently, the Honam High-speed train system is designed for the operation velocity of 350km/h. The societal demand expects higher operation speed, whereas the existing construction method and design specification are questioned in the KTX operation in the velocity over 350 km/h. In this study, a full-scale model test was conducted to obtain the preliminary data that is necessary to understand deformation characteristics of the reinforced road bed and the subgrade layers. In the full-scale model test, direct arrival seismic tests, crosshole seimic test, in-situ bender element test and sensing bar test were employed to measure the stiffness and deformation of the trackbed. The systematic analysis on the different set of measurements enhances the understanding of the behavior of the trackbed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.715-718
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• 2005

Mobile devices is getting to include more functions according to the demand of digital convergence. Applications based on 3D graphic calculation such as 3D games and navigation are one of the functions. 3D graphic calculation requires heavy calculation. Therefore, we need dedicated 3D graphic hardware unit with high performance. 3D graphic calculation needs a lot of complicated floating-point arithmetic operation. However, most of current mobile 3D graphics processors do not have efficient architecture for mobile devices because they are based on those for conventional computer systems. In this paper, we propose arithmetic units for special functions of lighting operation of 3D graphics. Transcendental arithmetic units are designed using approximation of logarithm function. Special function units for lighting operation such as reciprocal, square root, reciprocal of square root, and power can be obtained. The proposed arithmetic unit has lower error rate and smaller silicon area than conventional arithmetic architecture.