• Title/Summary/Keyword: demand pattern

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A Multimedia Data Compression Scheme for Disaster Prevention in Wireless Multimedia Sensor Networks

  • Park, Jun-Ho;Lim, Jong-Tae;Yoo, Jae-Soo;Oh, Yong-Sun;Oh, Sang-Hoon;Min, Byung-Won;Park, Sun-Gyu;Noh, Hwang-Woo;Hayashida, Yukuo
    • International Journal of Contents
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    • v.11 no.2
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    • pp.31-36
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    • 2015
  • Recent years have seen a significant increase in demand for multimedia data over wireless sensor networks for monitoring applications that utilize sensor nodes to collect multimedia data, including sound and video. However, the multimedia streams generate a very large amount of data. When data transmission schemes for traditional wireless sensor networks are applied in wireless multimedia sensor networks, the network lifetime significantly decreases due to the excessive energy consumption of specific nodes. In this paper, we propose a data compression scheme that implements the Chinese remainder theorem to a wireless multimedia sensor network. The proposed scheme uses the Chinese Remainder Theorem (CRT) to compress and split multimedia data, and it then transmits the bit-pattern packets of the remainder to the base station. As a result, the amount of multimedia data that is transmitted is reduced. The superiority of our proposed scheme is demonstrated by comparing its performance to that of an existing scheme. The results of our experiment indicate that our proposed scheme significantly increased the compression ratio and reduced the compression operation in comparison to those of existing compression schemes.

International Comparison of Fare Policy in Urban Metro (도시철도 운임정책 국제비교)

  • Chung, Sung Bong;Choi, Ji Ho;Kim, Ji Yeon;Kim, Dong Sun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.5
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    • pp.703-711
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    • 2018
  • Recently, as various metro lines have been constructed and connected to other lines the rate of utilization has also been increased. However, the existing fare policy which the government does still stick to causes not only inappropriate action to the demand pattern but aggravation of the profit of the operation company. This study reviewed rail fare policy of major countries such as Japan and U.K etc. to improve the rationality of fare policy in Korea. In order to systematical analysis of fare policy, such viewpoints as of fare decision method, the card fare discounting system, the structure of fare, and the government subsidy policy were reviewed. Based on the results from the review, various problems and improvement plans were drawn. Through this study, appropriate fare systems to urban railway users could be given to improve the chronic deficit problem of urban railway operators.

Shear Performance of Full-scale Reinforced Concrete Beams with Recycled Fine Aggregates (순환잔골재의 치환율에 따른 철근콘크리트 보의 전단성능)

  • Ji, Sang-Kyu;Song, Seon-Hwa;Yun, Hyun-Do;Choi, Ki-Sun;You, Young-Chan;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.205-208
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    • 2008
  • Using the recycled aggregate can reduces the landfill space, the demand for natural raw material for new construction. Some investigations have been carried out to study the shear behaviors of RC beams with recycled aggregates. But these have some limitation due to the use of low quality recycled aggregates and small-scale specimens in the laboratory. In this study, four full-scaled RC beams were tested to evaluate the effects of replacement level (0,30, 60, and 100%) of recycled fine aggregate on shear behavior of RC beams. The results showed that the beams with recycled fine aggregates show similar crack pattern and failure mode compared with the beam with natural aggregate. Also, the beams with recycled fine aggregates present the similar shear strength except the one with the replacement level of 100% recycled fine aggregates. Shear strength were compared with the provisions in current code (KCI2007) and the equation proposed by Zsutty. The KCI equations were conservative and subsequently can be used for the shear design of recycled aggregate concrete beam.

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Social Geography of Poverty and Social Welfare Services (빈곤계층과 사회복지서비스의 공간적 연계성)

  • Bae, Mi-Ae
    • Journal of the Korean Geographical Society
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    • v.42 no.2 s.119
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    • pp.177-195
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    • 2007
  • The central aim of this paper is to identify the distributional pattern of poverty and to investigate the spatial relationship between poverty and welfare service providers in Busan, Korea. It is intended to explain how the relationship of service-dependency between impoverished people and social welfare services leads to uneven social geography. Welfare services controlled by public or private agencies may support the impoverished people in different ways, generating social outcomes. By exploiting the spatial variations in the incidence of poverty and the provisions of social welfare services, this paper is to understand the dynamics of the geography of poverty from a local scale so that it can help us understand how various governmental and nongovernmental area-based service providers are spatially uneven when they are compared to the distribution of service dependency group such as impoverished people. From this research, it is finally argued that the implications of locational interdependence between such needed groups and social welfare services for their support demand a paradigm for urban social geography that centers on the changing welfare provision structure and the linkages between population and service-provision.

Effects of Hydrogen in SNG on Gas Turbine Combustion Characteristics (합성천연가스의 수소함량 변화에 따른 가스터빈 연소특성 평가)

  • Park, Se-Ik;Kim, Ui-Sik;Chung, Jae-Hwa;Hong, Jin-Pyo;Kim, Sung-Chul;Cha, Dong-Jin
    • Journal of Hydrogen and New Energy
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    • v.23 no.4
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    • pp.412-419
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    • 2012
  • Increasing demand for natural gas and higher natural gas prices in the recent decades have led many people to pursue unconventional methods of natural gas production. POSCO-Gwangyang synthetic natural gas (SNG) project was launched in 2010. As the market price of natural gas goes up, the increase of its price gets more sensitive due to the high cost of transportation and liquefaction. This project can make the SNG economically viable. In parallel with this project, KEPCO (Korea Electric Power Corporation) joined in launching the SNG Quality Standard Bureau along with KOGAS (Korea Gas Corporation), POSCO and so on. KEPCO Research Institute is in charge of SNG fueled gas turbine combustion test. In this research, several combustion tests were conducted to find out the effect of hydrogen contents in SNG on gas turbine combustion. The hydrogen in synthetic natural gas did not affect on gas turbine combustion characteristics which are turbine inlet temperature including pattern factor and emission performance. However, flame stable region in ${\Phi}$-Air flow rate map was shifted to the lean condition due to autocatalytic effect of hydrogen.

Development of the Power Consumption Simulator and Classification of the Types of Household by Using Data Mining Over Smart Grid (스마트 그리드 환경에서 가정의 소비전력 생성 시뮬레이터 개발 및 데이터 마이닝 기법을 이용한 가족 유형 분류)

  • Kim, Ji-Hyun;Lee, Yun-Jin;Kim, Ho-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.1
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    • pp.72-81
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    • 2014
  • Recently, because of irregular power demand, we have suffered from an electric power shortage. The necessity of the adoption of smart grid which makes effective supply of power by using the two-way communication across the grid between the customers and electric energy providers is growing more and more. If smart grid set up in our country, the third-parties which provide services to customer using the information acquired from smart grid, might be revved up. In this paper, we suggest a methodology how classify the types of family by analysing an power consumption pattern using data mining technique. To make a classifier for categorizing the household types, we need power consumption data and their family type. However, it is hard to get both of them. Therefore we develop the simulator that generates power consumption patterns of the household and classify the types of family. Also, we present a potential for application services such as customized services for a specific family or goods marketing.

Daily influent variation for dynamic modeling of wastewater treatment plants

  • Dzubur, Alma;Serdarevic, Amra
    • Coupled systems mechanics
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    • v.9 no.2
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    • pp.111-123
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    • 2020
  • Wastewater treatment plants (WWTPs) with activated sludge system are widely used throughout the most common technologies in the world. Most treatment plants require optimization of certain treatment processes using dynamic modeling. A lot of examples of dynamic simulations require reliable data base of diurnal variation of the inflow and typical concentrations of parameters such as Chemical Oxygen Demand (COD), Total Kjeldahl Nitrogen (TKN), etc. Such detailed data are not available, which leads to problemsin the application of dynamic simulations. In many examples of plants, continuous flow measurements are only performed after the primary clarifier, whereas measurements from influent to the plant are missing, as is the case with the examples in this paper. In some cases, a simpler, faster and cheaper way can be applied to determine influent variations, such as the "HSG-Sim" method ("Hochschulgruppe Simulation"). "Hochschulgruppe Simulation" is a group of researchers from Germany, Austria, Switzerland, Luxembourg, Netherlands and Poland (see http://www.hsgsim.org). This paper presents a model for generating daily variations of inflow and concentration of municipal wastewater quality parameters, applied to several existing WWTPs in Bosnia and Herzegovina (B&H). The main goal of the applied method is to generate realistic influent data of the existing plants in B&H, in terms of flow and quality, without any prior comprehensive survey and measurements at the site. The examples of plants show the influence of overflow facilities on the dynamics of input flow and quality of wastewater, and a strong influence of the problems of the sewerage systems.

Study on the Stress and Coping Patterns of Mothers with Cerebral Palsy Children (뇌성마비아 어머니의 스트레스와 대처양상에 관한 연구)

  • Lee Hwa Za;Lee Ji Won
    • Child Health Nursing Research
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    • v.3 no.2
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    • pp.190-202
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    • 1997
  • Mothers with cerebral palsy children have much stress that is related to the care of children with cerebral palsy and to other household duties, and this state of the mother has an effect on the cerebral palsy child and on other household member. Mothers in such stressful situations use various coping patterns. The purpose of this study was as follows : to develop instruments that can be used for measuring the stress and coping patterns of mothers with cerebral palsy children, and to test a hypothetical model on the relationship between the mother's stress, her coping patterns and the variable affecting the stress and coping patterns. The results of this study can be summarized as follows : 1. The stress scale was composed of 44 items and Cronbach's α was .94, and the coping pattern scale was composed of 19 items and Cronbach's α was. 80. The mean score of stress scale was 136.12 out of a total of 220, and the mean score of the coping scale was 72.87 in a total of 95. 2. In test of the hypothetical model, it was found that extra-care demand, the support of the husband, the degree of handicap, health status and self-esteem had statistically significant influence on the mother's stress(r=.285,-.262,-.133, -.126). And the support of the husband, formal support, informal support, and economic status were found to have statitically significant influence on the mother's coping patterns (r=.412, .178, 178, .138).

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Curriculum and Standardization of Preventive Medicine Education in Traditional Korean Medicine (한의과대학의 예방(사회)의학 관련 교과목의 교육과정 및 표준화방안)

  • Ko, Seong-Gyu;Shin, Yong-Cheol
    • Journal of Society of Preventive Korean Medicine
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    • v.12 no.2
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    • pp.73-83
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    • 2008
  • The rapid change of the health and medical environment and the globalization of medicine has driven doctors to converge and analyse of new and up-to-date medical information and decide to what to make decision for diagnosis and treatments in clinical practice. Medical environment goes with the changes with social environment such as rapid increase of aging population, changes of disease pattern, formation of new area of experts except doctors, government intervention for the medical system, medical insurance of the charges of medical treatment, a increased desire for human rights. These trends should be adopted rapidly to the education system for the students of medical school. The learning objectives of the preventive medicine was developed in 1995 and underwent necessary revision of the contents to create the first revision in 2006. However, the required educational contents of health promotion and disease prevention have been changed by the new trends of medical education such as PBL and integrated curriculum and the 2006 revision does not satisfy these needs. We formed a task force which surveyed all the Western and Traditional Korean medical colleges to describe the state of preventive medicine education in Korea, analyzed the changing education demand according to the change of health environment and quantitatively measured the validity and usefulness of each learning objective in the previous curriculum. With these results, for the good education for preventive medicine, each Traditional Korean medicine schools need more preventive medicine faculties and teaching assistants and opening of some required subjects such as Yangsaeng and Qigong. And future studies of the learning process and ongoing development of teaching materials according to the new learning objectives should be undertaken with persistence in order to ensure the progress of preventive medicine education.

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Developing the travel cost function based on Microscopic Simulator(VISSIM) Data (미시적 교통류 시뮬레이터기반 통행비용함수의 개발 및 적용)

  • Cho, Hyun-Woo;Lee, Yong-Taeck
    • International Journal of Highway Engineering
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    • v.9 no.4
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    • pp.129-134
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    • 2007
  • In general, based on traffic data in a ideal traffic condition, BPR cost function is used to a variety of transportation policies. However, Some researchers have reported that BRP cost function is not appropriate for analyzing traffic pattern as well as forecasting future demand.(Spiess, 1989 ; Singh, 1999) Therefore, in this paper to solve this problem, a methodology based on data through Micro traffic Simulator Based(MSB) is developed. As a result following outputs are obtained ; (1) presenting a methodology to develop a travel cost function through VISSIM in order to assess transportation policies and (2) developing BRP cost function and MSB cost function from data analysis through VISSIM and verifying availability of MSB function by comparative analysis.

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