• Title/Summary/Keyword: Data period

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Climate Change Assessment on Air Temperature over Han River and Imjin River Watersheds in Korea

  • Jang, S.;Hwang, M.
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.740-741
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    • 2015
  • the downscaled air temperature data over study region for the projected 2001 - 2099 period were then ensemble averaged, and the ensemble averages of 6 realizations were compared against the corresponding historical downscaled data for the 1961 - 2000 period in order to assess the impact of climate change on air temperature over study region by graphical, spatial and statistical methods. In order to evaluate the seasonal trends under future climate change conditions, the simulated annual, annual DJF (December-January-February), and annual JJA (June-July-August) mean air temperature for 5 watersheds during historical and future periods were evaluated. From the results, it is clear that there is a rising trend in the projected air temperature and future air temperature would be warmer by about 3 degrees Celsius toward the end of 21st century if the ensemble projections of air temperature become true. Spatial comparison of 30-year average annual mean air temperature between historical period (1970 - 1999) and ensemble average of 6-realization shows that air temperature is warmer toward end of 21st century compared to historical period.

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A Study on the Comparison of Electricity Forecasting Models: Korea and China

  • Zheng, Xueyan;Kim, Sahm
    • Communications for Statistical Applications and Methods
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    • v.22 no.6
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    • pp.675-683
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    • 2015
  • In the 21st century, we now face the serious problems of the enormous consumption of the energy resources. Depending on the power consumption increases, both China and South Korea face a reduction in available resources. This paper considers the regression models and time-series models to compare the performance of the forecasting accuracy based on Mean Absolute Percentage Error (MAPE) in order to forecast the electricity demand accurately on the short-term period (68 months) data in Northeast China and find the relationship with Korea. Among the models the support vector regression (SVR) model shows superior performance than time-series models for the short-term period data and the time-series models show similar results with the SVR model when we use long-term period data.

A Study of Business Cycle Index Using Dynamic Factor Model (동태적 요인모형을 이용한 경기동행지수 개발에 관한 연구)

  • Na, In-Gang;Sonn, Yang-Hoon
    • Environmental and Resource Economics Review
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    • v.9 no.5
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    • pp.903-924
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    • 2000
  • This paper examines the alternative method to measure the state of overall economic activity. The macroeconomic variables, used for business cycle, take more than a month after a period for collection and aggregation. The electricity generation data is compiled in mechanical ways just after the period. Based on this fact, we develop the two stage estimation method for coincident economic indicators in order to detect the business cycle in an earlier period, using Stock-Watson's Dynamic Factor Model. Using monthly data from 1970 to 1999, it is found that the experimental coincidence economic indicators are well-fitted to data and also that the estimates of two stage estimation method have good explanatory power, equivalent to the experimental coincidence economic indicators. While the RMSE of coincidence economic indicators is found to be 1.27%, that of the experimental coincidence economic indicators is found to be 1.31% and that of the two stage estimation method is around 1.44%. If we take consideration into the fact that it measures the business cycle in one month earlier, we come to the conclusion that the two stage estimation is of great use.

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2D ECG Compression Method Using Sorting and Mean Normalization (정렬과 평균 정규화를 이용한 2D ECG 신호 압축 방법)

  • Lee, Gyu-Bong;Joo, Young-Bok;Han, Chan-Ho;Huh, Kyung-Moo;Park, Kil-Houm
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.193-195
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    • 2009
  • In this paper, we propose an effective compression method for electrocardiogram(ECG) signals. 1-D ECG signals are reconstructed to 2-D ECG data by period and complexity sorting schemes with image compression techniques to Increase inter and intra-beat correlation. The proposed method added block division and mean-period normalization techniques on top of conventional 2-D data ECG compression methods. JPEG 2000 is chosen for compression of 2-D ECG data. Standard MIT-BIH arrhythmia database is used for evaluation and experiment. The results show that the proposed method outperforms compared to the most recent literature especially in case of high compression rate.

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The Elderly Spouses' Experiences of Providing Care for their Bedridden Patient at Home (재가 와상 환자를 돌보는 노인배우자의 경험)

  • Cho, Yeon Sil;Sohn, Sue Kyung
    • Korean Journal of Adult Nursing
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    • v.29 no.1
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    • pp.63-75
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    • 2017
  • Purpose: This study was to explore and describe the reported experiences of elderly spouses who care their bedridden spouse in the home. Methods: The participants of this study were 14 male and female elderly spouses who live in B metropolitan city and have provided care for more than six months. Data were collected from July 3 to November 6, 2014. Data analysis was done simultaneously with data collection, using the analytical methods of Strauss and Corbin for Grounded theory. Results: The core category was identified as 'going together bearing a heavy burden of care in old age.' In this study, the caring process of elderly spouses can be explained in terms of three stages such as 'a period of trial and error,' 'a period of mastering a role,' and 'a period of role transcendence'. Conclusion: The results of this study can provide an intervention framework to reduce the heavy burden of caring for an elderly spouse.

Data Analysis of Physiological Response for the Anxiety Disorder (불안증후인자의 데이터 정량분석)

  • Kim, Kwang-Joon;Lee, Yoon-Sun;Shin, Jung-Ho;Yoon, Hyung-Ro
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.11
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    • pp.51-54
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    • 1992
  • In this paper, we quantitatively evaluated the anxiety data from humans in an anxiety state. It has been reported that the electric signals of human can be correlated with their emotional state. We chose heart rate, respiration rate, temperature and skin conductance as the anxiety parameters. For experiment protocol, the subject was given exercising load to induce the anxiety state and the exercise was done using the FITRON Cycle Ergometer. We divided the data into three stages: rest period, exercise period, and recovery period. During evaluation, We counted the heart rate, slope of heart rate, temperature change, and the skin conductance.

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The Ultimate Bound of Discrete Sliding Mode Control System with Short Sampling Period for DC Motor System (DC 모터 시스템을 위한 짧은 샘플링 시간을 갖는 이산슬라이딩 모드의 최종 수렴범위)

  • Park, Heum-Yong;Jo, Young-Hun;Park, Kang-Bak
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.3
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    • pp.245-248
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    • 2010
  • Almost all of control schemes proposed so far have been designed in the continuous-time domain theoretically. Actual systems, however, have been implemented in the discrete-time domain since Micro Control Unit(MCU) and/or microprocessors have been used for the controllers. Thus, the overall system turned to be a sampled-data system, and generally speaking, the ultimate error cannot converge to zero in the actual system even though the proposed control algorithm showed the asymptotic stability in the continuous-time domain. In this paper, therefore, the ultimate error bound of a sampled data system with a short sampling period has been investigated. The ultimate error is shown to be related in the sampling period.

The establishment of the Korean government and the food situation during the Korean War (대한민국 정부수립과 한국전쟁 중의 식량사정)

  • Lee, Cherl-Ho
    • Food Science and Industry
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    • v.55 no.3
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    • pp.308-325
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    • 2022
  • The food life of Korean people during the establishment of Republic of Korea and the Korean war was reviewed. After liberation in 1945, the division of South and North Korea, the establishment of the governments, and the ensuing Korean War made Korean society extremely chaotic and transformed. Consequently, data on Korean dietary life during this period (1945-1960) are scarce and unreliable. The author tried to reveal the food situation and health and nutritional status of Koreans during this period by examining the data released by the US National Archives and other review books. Regarding the nascent period of the food industry after the Korean War, data from the recent 50-year history of the Korea Food Industry Association has been compiled.

A Study on the Standard Weather Data for Seoul (서울지방의 표준기상데이터에 관한 연구)

  • Kim, Doo-Chun
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.14 no.2
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    • pp.125-137
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    • 1985
  • Standard weather data for Seoul has been developed for use in computer calculations for energy requirements, and the 8760 sequential hourly values for seven weather elements have been placed in magnetic tape and cards. Applying the method determining average month, developed by Japanese Society of Heating, Air-Conditioning and Sanitary Engineers, the standard year data have been selected from the monthly average values for three weather elements during the 10year period of 1971 through 1980. The followings are obtained. 1. The Test Reference Year, consisting of 12 months chosen from different calendar years, has been determined, and TRY tape which contains seven weather elements has been prepared. 2. The Typical Weather Year, which means a year close to the average value, is the year of 1978 during the above 10 year period. 3. During the period, Winter Season needs the maximum heating load is from Dec. 1976 to Mar. 1977 and Summer Season needs the maximum cool ins load is from Jun. to Sep, 1978.

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Comparison of Mortality Estimate and Prediction by the Period of Time Series Data Used (시계열 적용기간에 따른 사망력 추정 및 예측결과 비교 - LC모형과 LC 코호트효과 확장모형을 중심으로 -)

  • Jung, Kyunam;Baek, Jeeseon;Kim, Donguk
    • The Korean Journal of Applied Statistics
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    • v.26 no.6
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    • pp.1019-1032
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    • 2013
  • The accurate prediction of future mortality is an important issue due to recent rapid increases in life expectancy. An accurate estimation and prediction of mortality is important to future welfare policies. The optimal selection of a mortality model is important to estimate and predict mortality; however, the period of time series data used is also an important issue. It is essential to understand that the time series data for mortality is short in Korea and the data before 1982 is incomplete. This paper divides the time series of Korean mortality into two sets to compare the parameter estimates of the LC model and LC model with a cohort effect by the period of data used. A modeling and prediction of the mortality index and cohort effect index as well as the evaluation of future life expectancy is conducted. Finally, some suggestions are proposed for the future prediction of mortality.