• Title/Summary/Keyword: dynamic demand

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A Selection Model For Power Plant Project Delivery Method (화력발전소 발주방식 비교를 통한 적정 발주방식 선정 모형)

  • Kim, Sun-Kuk;Park, Jong-Kyoo;Park, Chan-Sik;Son, Ki-Young
    • Korean Journal of Construction Engineering and Management
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    • v.8 no.1 s.35
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    • pp.66-77
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    • 2007
  • With the electricity industry structure reformation of the government in April, 2001, Korea Power Electric Corporation was divided in to Korea water power nuclear power and 5 thermal power plant. After, various delivery method is introduced and applied for active profit creation according to the competition between each development companies for the public company privatization. However, the current situation does not satisfy the project participant by selecting the delivery method without reflecting the business goal and project characteristics of power plant construction business. The objective of this study is to research the influencing factors that should be considered to select the delivery method in thermal power construction business and develop a standard of selection of appropriate delivery method through questionnaire and interviews to establish a model to select the delivery method that fits the business goal of the subject of delivery. In the future, if the delivery method selection model suggested in this study is applied, it is expected to select the appropriate delivery method of power plant construction business by effectively reflecting the business goal, characteristics and demand of the delivery subject, and characteristics of the construction business apart from the existing customary practices that decided the delivery method dependent on the subjective and experience based judgement.

The Study on the Education System of Digital Film design in New Media Environment - Focusing on Graduate Courses in film and Digital Media - (뉴미디어 환경에서의 디지털 영상디자인 교육시스템 연구 - 영상ㆍ디지털미디어 대학원교육을 중심으로-)

  • 정봉금;김종덕
    • Archives of design research
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    • v.17 no.2
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    • pp.451-462
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    • 2004
  • The range of graphic design has expanded very widely as the digital era emerged, and many new areas of film design, including film, DVD, interactive TV, mobile and DMB, began to require the work of designers. This could be considered as an application as well as a case of digital film design as it has more developed new media environment as basis. The change in the expression techniques of film language is inevitable since major consumers of new media are the younger generation. The method of creating and distributing visual communication work is not standing still anymore. It has been diversified through dynamic movements and changes resulting from interaction. The major objective of this study is to find out and suggest the directions that film and digital media graduate school education of future by researching and analyzing how the nature of design, as an academic subject that keeps on changing and developing, is evolving in the new media environment. For this purpose, the methods of appropriate education system in higher design education, which are derived from case studies and previous studies on education system, are evaluated by examining the consumers. This study aims at finding the most effective training method in film and digital media design, and by integrating current design education with digital film design education establish a better fit education system that complies with the demands of today's society. It will suggest how an educational institute should see ahead of the time and provide what the society will demand in the future.

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A Study on Parallel Performance Optimization Method for Acceleration of High Resolution SAR Image Processing (고해상도 SAR 영상처리 고속화를 위한 병렬 성능 최적화 기법 연구)

  • Lee, Kyu Beom;Kim, Gyu Bin;An, Sol Bo Reum;Cho, Jin Yeon;Lim, Byoung-Gyun;Kim, Dong-Hyun;Kim, Jeong Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.6
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    • pp.503-512
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    • 2018
  • SAR(Synthetic Aperture Radar) is a technology to acquire images by processing signals obtained from radar, and there is an increasing demand for utilization of high-resolution SAR images. In this paper, for high-speed processing of high-resolution SAR image data, a study for SAR image processing algorithms to achieve optimal performance in multi-core based computer architecture is performed. The performance deterioration due to a large amount of input/output data for high resolution images is reduced by maximizing the memory utilization, and the parallelization ratio of the code is increased by using dynamic scheduling and nested parallelism of OpenMP. As a result, not only the total computation time is reduced, but also the upper bound of parallel performance is increased and the actual parallel performance on a multi-core system with 10 cores is improved by more than 8 times. The result of this study is expected to be used effectively in the development of high-resolution SAR image processing software for multi-core systems with large memory.

An Active Prefetch Filtering Schemes using Exclusive Prefetch Cache (선인출 전용 캐시를 이용한 적극적 선인출 필터링 기법)

  • Chon Young-Suk;Kim Suk-il;Jeon Joong-nam
    • The KIPS Transactions:PartA
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    • v.12A no.1 s.91
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    • pp.41-52
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    • 2005
  • Memory reference instruction caused by cache miss is the critical factor that limits the processing power of processor. Cache prefetching technique is an effective way to reduce the latency due to memory access. However, excessively aggressive prefetch leads to cache pollution and finally to cancel out the advantage of prefetch. In this study, an active prefetch filtering scheme is introduced which dynamically decides whether to commence prefetching after referring a filtering table to reduce the cache pollution due to unnecessary prefetches. For the precision filtering, an evicted address referencing scheme has been proposed where the filter directly compares the current prefetch address with previous unnecessary prefetch addresses stored in filtering table. Moreover, a small sized exclusive prefetch cache has been introduced to increase the amount of eviction of unnecessarily prefetched addresses to enhance the accuracy of dynamic filtering. The exclusive prefetch cache also prevents useful demand data from being pushed out by prefetched data, while the evicted address direct referencing scheme enables the prefetch cache to keep most of useful prefetch data within its small size. Experimental results from commonly used general and multimedia benchmarks show that the average cache miss ratio has been decreased by $13.3{\%}$ by virtue of enhanced filtering accuracy compared with conventional schemes.

Design and Evaluation of a Channel Reservation Patching Method for True VOD Systems (True VOD 시스템을 위한 채널 예약 패칭 방법의 설계 및 평가)

  • Lee, Joo-Yung;Ha, Sook-Jeong;Bae, Ihn-Han
    • The KIPS Transactions:PartB
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    • v.9B no.6
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    • pp.835-844
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    • 2002
  • The number of channels available to a video server is limited since the number of channels a video server can support is determined by its communication bandwidth. Several approaches such as batching, piggybacking and patching have been proposed to reduce I/O demand on the video server by sharing multicast data. Patching has been shown to be efficient in the matter of the cost for VOD systems. Unlike conventional multicast techniques, patching is a dynamic multicast scheme which enables a new request to join an ongoing multicast. In addition, true VOD can be achieved since a new request can be served immediately without having to wait for the next multicast. In this paper. we propose two types of channel reservation patching algorithm : a fixed channel reservation patching and a variable channel reservation patching. To immediately schedule the requests for popular videos, these algorithms reserve the channels of video server for the fixed number of popular videos or for the variable number of popular videos which is determined dynamically according to the load of video server. The performance of the proposed algorithms is evaluated through simulations, and compared with that of simple patching. Our performance measures are average defection rate, average latency, service fairness and the amount of buffered data according to video server loads. Simulation results show that the proposed channel reservation patching algorithms provide better performance compared to simple patching algorithm.

On-site Application of a Vehicle Tunnel Ventilation Simulator (도로터널 환기시뮬레이션 모델 현장적용 연구)

  • 이창우;김효규
    • Tunnel and Underground Space
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    • v.11 no.4
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    • pp.319-327
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    • 2001
  • Introduction of new design tools has been required to optimally design and operate the ventilation system of long vehicle tunnels.. The demand has led to wide spread use of the simulation technique throughout the would to analysis the dynamic relationship among the variables associated with vehicle tunnel ventilation. This paper aims at performing on-site study at local tunnels to test the applicability of NETVEN, a simulation model vehicle tunnel ventilation. The study was carried out at four urban as well as highway tunnels model of vehicle tunnel ventilation. The study was carried out at four urban as well as highway tunnels employing different ventilation systems as well as traffic methods. There were some discrepancies sound between the simulation output and measurements and the following four factors are considered to mainly cause those disagreement. (1) The real situation shows distinctive transient and retarding characteristics with respect to air flow and contaminant dispersion, while ventilation forces are not steady-state and in particular those traffic and climatic variables show significant instantaneous variation. (3) Near the exit portal, the CO levels show bigger differences. The general trend is that data with higher CO concentrations carry bigger discrepancies. Turbulent diffusion is though to be the main reason for it and also contribute to the fact hat the highest CO concentrations are found at the locations somewhat inward, not at the exit portals. (4) Higher traffic rate results in higher discrepancies of ventilation velocity. Along with the exhaust characteristics, the vehicle aerodynamic characteristics need to be studied continuously in order to reduce the velocity disagreement.

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An Estimation of Occupancy Population Using the Expanded Mobile Phone Data (이동통신 자료 전수화를 통한 존재인구 산정 방안)

  • KIM, Kyoung Tae;LEE, Inmook;KWAK, Ho-Chan;MIN, Jae Hong
    • Journal of Korean Society of Transportation
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    • v.34 no.3
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    • pp.222-233
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    • 2016
  • Recently, mobile phone data was applied in travel demand modeling as a new source of dynamic population movement. This study is also aimed to estimate "occupancy population" during a given period of time within a given spatial region using mobile phone data. An occupancy population was defined as the number of people residing or moving within a given time and space. In case of Seoul Metropolitan area, we divided the area into a number of administrative districts as zones for analysis and estimated the occupancy population of each zone by mobile phone data collected by SK telecom Co., a wireless telecommunication provider in Korea. For the expansion of mobile phone data, a new concept of "communication probability" was introduced and applied in the estimation of occupancy population of each zone by the hour. We compared the estimated number with the daytime population and the daytime population index referred by the Statistics Korea. The results showed that a positive correlation existed between the estimated number and the statistical number by nationwide survey. It was concluded that mobile phone data could be more cost-effective sources than a conventional survey method to estimate the pattern of population movement by the hour or by the day.

A Simulation Analysis on the Economic Impact of U.S. Tangerine Importing in the Korean Citrus Industry (미국 탄저린 수입이 감귤산업에 미치는 경제적 파급효과의 시뮬레이션 분석)

  • Kim, Bae-Sung;Kim, Hwa-Nyeon;Kim, Man-Keun;Ko, Seong-Bo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.303-311
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    • 2020
  • The acreage of tangerines in the U.S. sharply rose from 19,000 ha in 2009 to 27,000 ha in 2016, an increase of 42% in 7 years. Considering the recent surge in tangerine exports to Japan, the export volume of 6-7 thousand tons is highly likely to increase in the future. Therefore, the purpose of this study was to analyze the economic impact of U.S. tangerine imports on the Korean citrus industry under various scenarios. In order to examine the possibility of imports of U.S. tangerines, the unit price of U.S. exports to Japan was used since U.S. tangerines are not imported to South Korea. Citrus fruits are divided into field citrus, house citrus, and late-maturing citrus (including winter season citrus) based on the cultivation method and variety used to analyze. Considering both the field and house seasons, the import volume of U.S. tangerines can be expected to rise from roughly 4,700 tons in 2021 to 10,000 tons in 2027. Imports of U.S. tangerines may be pushed up or delayed depending not only on the harvest method and quality of domestic field and house citrus but also on the harvest of U.S. tangerines. However, it is necessary to note that tangerines could be imported after 2021, when the tariff rate on U.S. tangerines will fall below 50%.

Implementation of Parallel Local Alignment Method for DNA Sequence using Apache Spark (Apache Spark을 이용한 병렬 DNA 시퀀스 지역 정렬 기법 구현)

  • Kim, Bosung;Kim, Jinsu;Choi, Dojin;Kim, Sangsoo;Song, Seokil
    • The Journal of the Korea Contents Association
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    • v.16 no.10
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    • pp.608-616
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    • 2016
  • The Smith-Watrman (SW) algorithm is a local alignment algorithm which is one of important operations in DNA sequence analysis. The SW algorithm finds the optimal local alignment with respect to the scoring system being used, but it has a problem to demand long execution time. To solve the problem of SW, some methods to perform SW in distributed and parallel manner have been proposed. The ADAM which is a distributed and parallel processing framework for DNA sequence has parallel SW. However, the parallel SW of the ADAM does not consider that the SW is a dynamic programming method, so the parallel SW of the ADAM has the limit of its performance. In this paper, we propose a method to enhance the parallel SW of ADAM. The proposed parallel SW (PSW) is performed in two phases. In the first phase, the PSW splits a DNA sequence into the number of partitions and assigns them to multiple nodes. Then, the original Smith-Waterman algorithm is performed in parallel at each node. In the second phase, the PSW estimates the portion of data sequence that should be recalculated, and the recalculation is performed on the portions in parallel at each node. In the experiment, we compare the proposed PSW to the parallel SW of the ADAM to show the superiority of the PSW.

An Analysis on the Effect of Policy Using Macro-economic Forecasting Model of Jeju (제주지역 거시경제 전망모형을 이용한 정책효과 분석)

  • Ko, Bong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.458-465
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    • 2020
  • The purpose of this study is to analyze the effect of policy in Jeju, using a macro-economic forecasting model of Jeju. First, the model's reality explanatory power improved by updating its statistics to 2017 and expanding new policy variables and modules. Also, the industrial structure of the model was further subdivided and extended to be considered simultaneously in the demand side of Keynesian theory. Second, it was determined that the predictive power for the model of this study was better than that of the existing model. However, with some endogenous variables, it was possible to identify implications that should be developed and considered when the model is improved with additional data in the future. Third, when the second airport construction was considered, it was observed that its effect was an increase of 1.25 times for GRDP, 1.2 times for employment, 1.48 times for private consumption, and 2.06 times for investment. Also, the economic growth rate was estimated to be 1.6% point higher than when the second airport was not constructed. Finally, the results of this study are expected to be used for policy decision making of the Jeju Government.