• Title/Summary/Keyword: Change-point model

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Prediction of Continuous Discharge and Water Quality Change for Gate Operation in Seonakdong River Experimental Catchment Using SWAT (서낙동강 시험유역에서의 SWAT 모형을 이용한 수문 운영에 따른 연속유출 및 수질변화 예측)

  • Kang, Deok-Ho;Kim, Jung-Min;Kim, Tae-Won;Kim, Young-Do
    • Journal of Wetlands Research
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    • v.14 no.1
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    • pp.21-33
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    • 2012
  • The dominant land use at the Seonakdong river watershed is paddy and forest areas and the Seonakdong river stands still. Thus, the water pollution in the Seonakdong river is becoming more serious for the non-point source. In this study, SWAT(Soil and Water Assessment Tool) model was evaluated for simulation of flow and water quality behaviors in Seonakdong river. To perform the calibration and verification of the SWAT model, the measurements of discharge and water quality were performed for the period from 2006 to 2007 at 5 gauging stations in Seonakdong river. The $R^2$ value for discharge and water quality were 0.86 and 0.70 respectively for calibration after the sensitive analysis. The $R^2$ value for discharge and water quality were 0.81 and 0.51 respectively for verification. The simulation results show that BOD value in the river tends to decrease after the opening of gates and the patterns of TN and TP concentrations are similar as that of BOD. The gate operators need to determine how to supply water in drought season for effective water quality improvement. This study shows that the SWAT model, which is capable of simulating hydrologic and water quality behaviors temporarily and spatially at watershed scale, could be used to get the gate operation rule for the water quality management in Seonakdong river.

A Study on Visual Comfort for Light Control Method of Applied Daylighting (자연채광방식의 응용에 따른 시각적 쾌적성에 관한 연구)

  • Han, Sang-Pil;Han, Sang-Cheol
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.140-145
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    • 2012
  • The purpose of this study is to understand the change of impression by comparing the uniformity lighting with the compound lighting. In previous study, we proposed a light controlling method to harmonize daylight from a window and artificial lights from a ceiling and obtained the results to support our method. We referred this method as the Adjusted Compound-Lighting Model (AC Model). The model claims that lighting in a room with a side-window are perceived as harmonious when the overall light distribution in the room is well approximated by a compound of lights from the window and the entire ceiling. The experiment is carried out with the scaled-models and mock-up spaces that were supposed to be an office space. One is lit by the uniform lighting and the other by the compound lighting in each experimental space. In order to present varying illuminance distributions, thetwo variables were used in this study. One was the ratio of thelight from the window and ceiling in the standard and evaluation box. The standard box was provided by the ratio of 20% to 40% from the window and 80% to 60% from the ceiling as two lighting ratio patterns [Wu20(=Cu80) and Wu40(=Cu60)]. And the evaluation box was provided by the light ratio of 0% to 40 from the window and 100% to 60% from the ceiling [Wcp0(=Ccp100), Wcp20(=Ccp80) and Wcp40(=Ccp60)]. The other variable was themean illuminance level in both boxes. Two level of mean illuminance (700lx and 300lx) were used in this experiment. Each lighting condition was established at equal horizontal mean illuminance level, held constant near 700lx or 300lx in both boxes. Both of them were similar in the shape of distribution when there were same ratios of lights from the window and the ceiling. Subjects were asked to evaluate the point of difference by semantic differential rating on their overall impression after comparing with two rooms. The results showed that the impressions of compound lighting were more positive score than that of uniformity lighting on the items of 'dim-bright', 'dislike-like', 'artificial-natural' and 'closed-open', and that there was no significant difference in impressions between two spaces on other items.

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Electricity Consumption as an Indicator of Real Economic Status (전력소비를 이용한 실물경기지수 개발에 관한 연구)

  • Oh, Seung-Hwan;Kim, Tea-Joong;Kwak, Dong-Chul
    • Journal of Distribution Science
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    • v.14 no.3
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    • pp.63-71
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    • 2016
  • Purpose - A variety of indicators are used for the diagnosis of economic situation. However, most indicators explain the past economic situation because of the time difference between the measurement and announcement. This study aims to argue for the resurrection of an idea: electricity demand can be used as an indicator of economic activity. In addition, this study made an endeavor to develop a new Real Business Index(RBI) which could quickly represent the real economic condition based on the sales statistics of industrial and public electricity. Research design, data, and methodology - In this study monthly sales of industrial and public electricity from 2000 to 2015 was investigated to analyze the relationship between the economic condition and the amount of electricity consumption and to develop a new Real Business Index. To formulate the Index, this study followed next three steps. First, we decided the explanatory variables, period, and collected data. Second, after calculating the monthly changes for each variable, standardization and estimating the weighted value were conducted. Third, the computation of RBI finalized the development of empirical model. The principal component analysis was used to evaluate the weighted contribution ratio among 3 sectors and 17 data. Hodrick-Prescott filter analysis was used to verify the robustness of out model. Results - The empirical results are as follows. First, compatibility of the predictability between the new RBI and the existing monthly cycle of coincident composite index was extremely high. Second, two indexes had a high correlation of 0.7156. In addition, Hodrick-Prescott filter analysis demonstrated that two indexed also had accompany relationship. Third, when the changes of two indexes were compared, they were found that the times when the highest and the lowest point happened were similar, which suggested that it is possible to use the new RBI index as a complementing indicator in a sense that the RBI can explain the economic condition almost in real time. Conclusion - A new economic index which can explain the economic condition needs to be developed well and rapidly in a sense that it is useful to determine accurately the current economic condition to establish economic policy and corporate strategy. The salse of electricity has a close relationship with economic conditions because electricity is utilized as a main resource of industrial production. Furthermore, the result of the sales of electricity can be gathered almost in real time. This study applied the econometrics model to the statistics of the sales of industrial and public electricity. In conclusion, the new RBI index was highly related with the existing monthly economic indexes. In addition, the comparison between the RBI index and other indexes demonstrated that the direction of the economic change and the times when the highest and lowest points had happened were almost the same. Therefore, this RBI index can become the supplementary indicator of the official indicators published by Korean Bank or the statistics Korea.

Remodeling Process Model Applying Service Life and Functionality Evaluation for Military Facilities (내용연수와 기능성 평가를 활용한 군 시설물 리모델링 대상 선정 프로세스 모델)

  • Cho, Jongwoo;Lee, Hyun-Soo;Park, Moonseo;Kim, Jaegon;Moon, Hyo-Soo
    • Korean Journal of Construction Engineering and Management
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    • v.16 no.6
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    • pp.41-52
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    • 2015
  • The number of military facilities has been rapidly increased due to growing requirement of modernization and military welfare. However, adequate maintenance has not implemented to these facilities. As a result, they are deteriorated quickly and require performance enhancement treatments. There are two ways of performance enhancement, reconstruction and remodeling. Despite the research result that remodeling within the standard remodeling range is more economical, remodeling of military facilities is not considered equivalent to reconstruction as an option of performance improvement. Therefore, derived from the relationship between performance change during life cycle of building and range of remodeling needs, this study tries to propose Remodeling Process Model(RPM) which uses a method to choose remodeling in a Specific Point of Time(SPT) when remodeling is considered more economical than reconstruction. In addition, this study suggests practical service life and functionality evaluation standard together which require to realize the RPM. This RPM make it possible to avoid the cases that facilities which do not have any problem on structural reliability but have low level of functionality miss appropriate remodeling timing and inevitably choose reconstruction as a performance improvement option. It also present the possibility of simple reconstruction / remodeling decision-making for facility managers who administrate building having various type, compilation and elapsed time. Consequently, this process model focusing on remodeling more may contribute to reduce resource waste caused by reconstruction.

A Study on Scale Effects of the MAUP According to the Degree of Spatial Autocorrelation - Focused on LBSNS Data - (공간적 자기상관성의 정도에 따른 MAUP에서의 스케일 효과 연구 - LBSNS 데이터를 중심으로 -)

  • Lee, Young Min;Kwon, Pil;Yu, Ki Yun;Huh, Yong
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.1
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    • pp.25-33
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    • 2016
  • In order to visualize point based Location-Based Social Network Services(LBSNS) data on multi-scaled tile map effectively, it is necessary to apply tile-based clustering method. Then determinating reasonable numbers and size of tiles is required. However, there is no such criteria and the numbers and size of tiles are modified based on data type and the purpose of analysis. In other words, researchers' subjectivity is always involved in this type of study. This is when Modifiable Areal Unit Problem(MAUP) occurs, that affects the results of analysis. Among LBSNS, geotagged Twitter data were chosen to find the influence of MAUP in scale effects perspective. For this purpose, the degree of spatial autocorrelation using spatial error model was altered, and change of distributions was analyzed using Morna's I. As a result, positive spatial autocorrelation showed in the original data and the spatial autocorrelation was decreased as the value of spatial autoregressive coefficient was increasing. Therefore, the intensity of the spatial autocorrelation of Twitter data was adjusted to five levels, and for each level, nine different size of grid was created. For each level and different grid sizes, Moran's I was calculated. It was found that the spatial autocorrelation was increased when the aggregation level was being increased and decreased in a certainpoint. Another tendency was found that the scale effect of MAUP was decreased when the spatial autocorrelation was high.

Development of Village Health Worker Training Program in Tuguegarao, Phillipines (필리핀 뚜게가라오 지역에서의 마을보건원 훈련 프로그램 개발 사례)

  • Kim, Jung-Min;Lee, Hye-Yeon;Pakr, Dae-Jin;Oak, Chul-Ho;Jeon, Man-Joong;Yu, Byeng-Chul;Koh, Kwang-Wook;Lee, Yong-Hwan
    • Journal of agricultural medicine and community health
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    • v.33 no.3
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    • pp.324-334
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    • 2008
  • Objectives: The purpose of this study was to develop and execute the village heath worker(VHW) training program which based on short term overseas medical volunteer and medical mission. Methods: Through case studies of previous VHW program and review articles about the state of medical volunteer and medical mission, we developed the VHW training program. Pilot test of the program was carried out in Tugeugarao city, Phillipines on July, 2008. The subject were 32 persons from 15 villages around Tuguegarao city. After training we surveyed regarding the satisfaction of training and the degree of getting knowledge and skills. Results: Through article review, we got the common subjects of previous VHW training program and the limitations of overseas medical volunteer and medical mission. We developed VHW training program aiming to community health promotion through community participation and community change. The main text was "Where There Is No Doctor" of Hesperian Foundation. The program executed through 1 day intensive lecture and practice. The satisfaction of the program was 8.95±1.70 on 10 point rating scale. Conclusions: We strongly expect VHW training program can be available as new model of short overseas medical volunteer as well as medical mission if we could systemize it with the confirming subject before training , management after training and continuous support through connection with the field.

Thermodynamics of Hydrogen-Induced Phase Separation on Pd-Co Alloys (수소유기에 따른 Pd-Co합금들의 상 분리 현상에 대한 열역학적 고찰)

  • Song, D.M.;Park, C.N.;Choi, J.
    • Transactions of the Korean hydrogen and new energy society
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    • v.16 no.3
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    • pp.244-252
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    • 2005
  • It is very interesting and important in the academic point of view and in practical use the hydrogen-induced phase separation(HIPS) which appears during hydrogen heat treatment. Since hydrogen can be removed very fast by pumping it out the hydrogen-induced new lattice phase which can not be obtained without hydrogen can be preserved as meta-stable state. In this study it has been investigated whether the HIPS appear in Pd-Al, Pd-Co, Pd-Cr, Pd-Ti, Pd-V and Pd-Zr alloys and discussed thermodynamic representation of the HIPS. The Pd alloys were arc-melted under argon atmosphere and remelted 4 or 5 times for homogenization. The alloys were annealed at 600$^{\circ}C$ under vacuum for 24 hrs and then subjected to pressure-composition isotherm measurements at 100$^{\circ}C$. The hydrogen heat treatment(HHT) of samples was carried out at 600$^{\circ}C$ under hydrogen pressure of 70 bar for 6 days and PC isotherms at 100$^{\circ}C$ were measured. By comparing the PC isotherms measured before and after HHT, occurrence of phase separation was determined. The experimental results showed that the HIPS appeared only in Pd-0.05Co alloy. For Pd-Co alloys with various composition the PC isotherms were measured. By adopting Park-Flanagan model for ternary thermodynamics the Gibbs free energy change for Pd-Co-H solid solution was calculated and subsequently with this the HIPS in Pd-Co alloy was explained fairly.

Analysis of Erosion and Deposition by Debris-flow with LiDAR (지상 LiDAR를 이용한 토석류 발생에 의한 침식, 퇴적량 측정)

  • Jun, Byong-Hee;Jang, Chang-Deok;Kim, Nam-Gyun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.13 no.2
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    • pp.54-63
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    • 2010
  • The intensive rainfall over 455 mm occurred between on 9 to 14 July 2009 triggered debris flows around the mountain area in Jecheon County. We mapped the debris flow area and estimated the debris flow volume using a high resolution digital elevation model (DEM) generated respectively from terrestrial LiDAR (Light Detection And Ranging) and topographic maps. For the LiDAR measurement, the terrestrial laser scanning system RIEGL LMS-Z390i which is equipped with GPS system and high-resolution digital camera were used. After the clipping and filtering, the point data generated by LiDAR scanning were overlapped with digital map and produced DEM after debris flow. The comparison between digital map and LiDAR scanning result showed the erosion and deposition volumes of about $17,586m^3$ and $7,520m^3$, respectively. The LiDAR data allowed comprehensive investigation of the morphological features present along the sliding surface and in the deposit areas.

A Study on Ship's Maneuverability Evaluation by Real Ship Test (선박조종성능 평가를 위한 실선 실험연구)

  • Im, Nam-Kyun;Han, Song-Hee;Nguyen, Thanh Nhat Lai
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.4
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    • pp.383-389
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    • 2011
  • At the design stage, it is very important to know the ship maneuvering characteristics from the view point of ship performance and for the safety of navigation. IMO only gives some criteria for ships in full load even keel condition. However, the ship generally is operated not only in full load condition but also in half load condition or ballast condition. Therefore we must estimate the ship maneuvering in different loading condition to ensure that the ship will satisfy with IMO rules and navigate safely in every condition. In this paper, we have investigated the maneuvering characteristics of a ship by simulation and experiments with real ship. By comparing with the results of simulation, the real ship tests conform with simulation test and previous researches. Therefore, the method base on real data is well done to estimate the ship maneuvering in different loading conditions. The change of ship's manoeuverability accoriding to ship's operation conditions was estimated.

A study for Promoting Digital Healthcare in Korea through an Improved Regulatory System (디지털 헬스케어 발전을 위한 규제 개선 방안에 관한 연구)

  • Park, Jung-Won;Shim, Woo-Hyun;Lee, Jun-Seok
    • Informatization Policy
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    • v.25 no.1
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    • pp.60-81
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    • 2018
  • Healthcare is on the verge of a paradigm shift towards an emphasis on wellbeing, integrative health, and prevention of disease, while the traditional medical model focuses solely on end-point treatment. The development of digital technologies has played a major role in this change as digital technology and health have converged. Therefore, many developed countries promote the digital healthcare industry as a new economic growth engine, and Korea is no exception. To promote the digital healthcare industry, the Korean government provides institutional support by improving the legal and regulatory system for medical devices and health data. However, Korea still has an underdeveloped legal and regulatory framework for digital healthcare compared with other countries. In this study, we review the relevant regulatory systems in the United States, United Kingdom, Germany, and Japan. We then explore newspaper articles and conduct expert interviews to analyze the regulatory situation in Korea and the problems the digital healthcare industry faces. In conclusion, we discuss a regulatory reform plan for development of the digital healthcare industry in Korea.