• Title/Summary/Keyword: error measurement

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An Analysis of Global Solar Radiation using the GWNU Solar Radiation Model and Automated Total Cloud Cover Instrument in Gangneung Region (강릉 지역에서 자동 전운량 장비와 GWNU 태양 복사 모델을 이용한 지표면 일사량 분석)

  • Park, Hye-In;Zo, Il-Sung;Kim, Bu-Yo;Jee, Joon-Bum;Lee, Kyu-Tae
    • Journal of the Korean earth science society
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    • v.38 no.2
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    • pp.129-140
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    • 2017
  • Global solar radiation was calculated in this research using ground-base measurement data, meteorological satellite data, and GWNU (Gangneung-Wonju National University) solar radiation model. We also analyzed the accuracy of the GWNU model by comparing the observed solar radiation according to the total cloud cover. Our research was based on the global solar radiation of the GWNU radiation site in 2012, observation data such as temperature and pressure, humidity, aerosol, total ozone amount data from the Ozone Monitoring Instrument (OMI) sensor, and Skyview data used for evaluation of cloud mask and total cloud cover. On a clear day when the total cloud cover was 0 tenth, the calculated global solar radiations using the GWNU model had a high correlation coefficient of 0.98 compared with the observed solar radiation, but root mean square error (RMSE) was relatively high, i.e., $36.62Wm^{-2}$. The Skyview equipment was unable to determine the meteorological condition such as thin clouds, mist, and haze. On a cloudy day, regression equations were used for the radiation model to correct the effect of clouds. The correlation coefficient was 0.92, but the RMSE was high, i.e., $99.50Wm^{-2}$. For more accurate analysis, additional analysis of various elements including shielding of the direct radiation component and cloud optical thickness is required. The results of this study can be useful in the area where the global solar radiation is not observed by calculating the global solar radiation per minute or time.

Developing an On-Line Monitoring System for a Forest Hydrological Environment - Development of Hardware - (산림수문환경(山林水文環境) 모니터링을 위(爲)한 원거리(遠距離) 자동관측(自動觀測)시스템의 개발(開發) - 하드웨어를 중심(中心)으로 -)

  • Lee, Heon Ho;Suk, Soo Il
    • Journal of Korean Society of Forest Science
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    • v.89 no.3
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    • pp.405-413
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    • 2000
  • This study was conducted to develop an on-line monitoring system for a forest hydrological environment and its meteorological condition, such as temperature, wind direction and speed, rainfall and water level on V-notch, electrical conductivity(EC), potential of hydrogen(PH) by the motor drive sensor unit and measurement with a single-chip microprocessor as controller. These results are summarized as follows ; 1. The monitoring system consists of a signal process unit, motor drive sensor unit, radio modem unit and power supply. 2. The motor drive sensor unit protects the sensor from swift current or freezing and can constantly maintain fixed water level during measurements. 3. This monitoring system can transfer the data by radio modem. Additionally, this system can monitor hydrological conditions in real time. 4. The hardware was made of several modules with an independent CPU. They can be mounted, removed, repaired and added to. Their function can be changed and expanded. 5. These are the result of an accuracy test, the values of temperature, EC and pH measured within an error range of ${\pm}0.2^{\circ}C$, ${\pm}1{\mu}S$ and ${\pm}0.1pH$ respectively. 6. This monitoring system proved to be able to measure various factors for a forest hydrological environment in various experimental stations.

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An Intelligent Monitoring System of Semiconductor Processing Equipment using Multiple Time-Series Pattern Recognition (다중 시계열 패턴인식을 이용한 반도체 생산장치의 지능형 감시시스템)

  • Lee, Joong-Jae;Kwon, O-Bum;Kim, Gye-Young
    • The KIPS Transactions:PartD
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    • v.11D no.3
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    • pp.709-716
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    • 2004
  • This paper describes an intelligent real-time monitoring system of a semiconductor processing equipment, which determines normal or not for a wafer in processing, using multiple time-series pattern recognition. The proposed system consists of three phases, initialization, learning and real-time prediction. The initialization phase sets the weights and tile effective steps for all parameters of a monitoring equipment. The learning phase clusters time series patterns, which are producted and fathered for processing wafers by the equipment, using LBG algorithm. Each pattern has an ACI which is measured by a tester at the end of a process The real-time prediction phase corresponds a time series entered by real-time with the clustered patterns using Dynamic Time Warping, and finds the best matched pattern. Then it calculates a predicted ACI from a combination of the ACI, the difference and the weights. Finally it determines Spec in or out for the wafer. The proposed system is tested on the data acquired from etching device. The results show that the error between the estimated ACI and the actual measurement ACI is remarkably reduced according to the number of learning increases.

Growth curve estimates for wither height, hip height, and body length of Hanwoo steers (Bos taurus coreanae)

  • Park, Hu-Rak;Eum, Seung-Hoon;Roh, Seung-Hee;Sun, Du-Won;Seo, Jakyeom;Cho, Seong-Keun;Lee, Jung-Gyu;Kim, Byeong-Woo
    • Korean Journal of Agricultural Science
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    • v.44 no.3
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    • pp.384-391
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    • 2017
  • Growth curves in Hanwoo steers were estimated by Gompertz, Von Bertalanffy, Logistic, and Brody nonlinear models using growth data collected by the Hanwoo Improvement Center from a total of 6,973 Hanwoo (Bos taurus coreanae) steers 6 to 24 months old that were born between 1996 and 2015. The data included three parameters: A, mature size of body measurement; b, growth ratio; and, k, intrinsic growth rate. Nonlinear regression equations for wither height according to Gompertz, Von Bertalanffy, Logistic, and Brody models were $Y_t=144.7e^{-0.5869e^{-0.00301t}}$, $Y_t=145.3(1-0.1816e^{-0.00284t})^3$, $Y_t=143.1(1+0.7356e^{-0.00352t})^{-1}$, and $Y_t=146.8(1+0.4700e^{-0.00249t})^1$, respectively, while those for hip height were $Y_t=144.5e^{-0.5549e^{-0.00312t}}$, $Y_t=145.0(1-0.1724e^{-0.00295t})^3$, $Y_t=143.1(1+0.6863e^{-0.00360t})^{-1}$, and $Y_t=146.2(1+0.4501e^{-0.00263t})^1$, respectively. Equations for body length $Y_t=174.1e^{-0.8342e^{-0.00289t}}$, $Y_t=175.8(1-0.2500e^{-0.00265t})^3$, $Y_t=170.0(1+1.1548e^{-0.00363t})^{-1}$, and $Y_t=180.3(1+0.6077e^{-0.00215t})^1$, respectively, for the same models. Among the four models, the Brody model resulted in the lowest mean square error, with mean square errors of 31.79, 30.57, and 42.13, respectively, for wither height, hip height, and body length. Also, an estimated birth wither height, birth hip height, and birth body length (77.98, 80.57, and 70.97 cm, respectively) were lower in the Brody model than in other models. An inflection point was not observed during the growth phase of Hanwoo steer according to the growth curves calculated using Gompertz, Von Bertalanffy, and Logistic models. Based on the results, we concluded that the regression equation using the Brody model was the most appropriate among the four growth models. To obtain more accurate parameters, however, using data from a wider production period (from birth to shipping) would be required, and the development of a suitable model for body conformation traits would be needed.

Case Study on Big Data Sampling Population Collection Method Errors in Service Business (서비스 비즈니스의 빅데이터 모집단 산정방식 오류에 관한 사례연구)

  • Ahn, Jinho;Lee, Jeungsun
    • Journal of Service Research and Studies
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    • v.10 no.2
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    • pp.1-15
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    • 2020
  • As big data become more important socially and economically in recent years, many problems have been derived from the indiscriminate application of big data. Big data are valuable because it can figure out the meaning of informative information hidden within the data. In particular, to predict customer behavior patterns and experiences, structured data that were extracted from Customer Relationship Management (CRM) or unstructured data that were extracted from Social Network Service(SNS) can be defined as a population to interpret the data, during which many errors can occur. However, those errors are usually overlooked. In addition to data analysis techniques, some data, which should be considered in the analysis, are not included in the population and thus do not show any meaningful patterns. Therefore, this study presents the measurement and interpretation of the data generated when the cause of error in the population setting is strong relationship and interaction between people or a person and an object. In other words, it will be shown that if the relationship and interaction are strong, it is important to include data collected from the perspective of user experience and ethnography in the population by comparing various cases of big data application, through which the meaning will be derived and the best direction will be suggested.

A Study On Design & Implementation of An Attitude Control System of a Lot of Legs Robots (다족형 로봇의 자세 제어 시스템 설계 및 구현에 관한 연구)

  • Nam, Sang-Yep;Hong, Sung-Ho;Kim, Suk-Joong
    • 전자공학회논문지 IE
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    • v.45 no.4
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    • pp.11-18
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    • 2008
  • This study is implementation of attitude control system(ACS - Attitude Control System). for a multi legs robot. This study designs H/W of Inertial Measurement Unit (IMU) and attitude control algorithm S/W. Compare performance with Mtx and MTx in order to verify action performance of this system after implementation, and will verify a system integrated IMU of a multi-legs robot. ACS uses Gyro and an accelerometer and an earth magnetism sensor, and it is a system controlling a roll, pitch angle attitude of an object. Generally, low price MEMS is difficult to calculate a correct situation of an object as an error occurs severely the Inertial sensor. This study implements IMU in order to develop ACS as use MEMS, accelerometer, Gyro sensor and earth magnetism sensor. Design algorithm each a roll, pitch, yaw attitude guaranteeing regular performance, and do poling in a system as include an attitude calculation program in an IMU system implemented. Mixed output of Gyro and an accelerometer, and recompensed a roll, pitch angle, and loaded in this study on a target platform in order to implement the ACS which guaranteed performance more than a continuously regular level, and operated by real time, and did porting, and verified.

Research on Measurement Condition Establishment of a Liquid Scintillation Counter System (액체섬광계수기 장비의 계측조건 확립에 관한 연구)

  • Park, Eung-Seop;Han, Sang-Jun;Lee, Seung-Jin;Kim, Hee-Gang;Lee, Na-Young;Mun, Ji-Yeon
    • Journal of Radiation Protection and Research
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    • v.31 no.3
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    • pp.155-164
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    • 2006
  • It is judged that there could be certainty in every process of analyzing environmental samples using Liquid Scintillation Counter. Therefore, this study focuses on quantitative evaluation on uncertainty in an effort to analyze comparatively accurately environmental samples. For this, after parameters which can have an effect on uncertainty was derived, the evaluation on each parameter was tamed out. The results of analysis of each parameter showed that the effect according to the weight difference of Teflon vial did not appear, and that standard deviations of SQP(E) averages reached saturation point at $75{\sim}90$ sec at the result of making increases step by step the irradiation time of External standard, and that values measured by repeat method produces good results compared with replicate. Also, conclusion was derived that analysis on sample after it is left in cold and dark room at least above 1,000 minutes have to be carried out, and the result of carrying out verification on results measured as well as equipment itself using radioactivity-error-analysis and chi-square test, resonable result was derived.

A Study of The Determinants of Turnover Intention and Organizational Commitment by Data Mining (데이터마이닝을 활용한 이직의도와 조직몰입의 결정요인에 대한 연구)

  • Choi, Young Joon;Shim, Won Shul;Baek, Seung Hyun
    • Journal of the Korea Society for Simulation
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    • v.23 no.1
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    • pp.21-31
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    • 2014
  • In this article, data mining simulation is applied to find a proper approach and results of analysis for study of variables related to organization. Also, turnover intention and organizational commitment are used as target (dependent) variables in this simulation. Classification and regression tree (CART) with ensemble methods are used in this study for simulation. Human capital corporate panel data of Korea Research Institute for Vocation Education & Training (KRIVET) is used. The panel data is collected in 2005, 2007, and 2009. Organizational commitment variables are analyzed with combined measure variables which are created after investigation of reliability and single dimensionality for multiple-item measurement details. The results of this study are as follows. First, major determinants of turnover intention are trust, communication, and talent management-oriented trend. Second, the main determining factors for organizational commitment are trust, the number of years worked, innovation, communication. CART with ensemble methods has two ensemble CART methods which are CART with Bagging and CART with Arcing. Comparing two methods, CART with Arcing (Arc-x4) extracted scenarios with very high coefficients of determination. In this study, a scenario with maximum coefficient of determinant and minimum error is obtained and practical implications are presented. Using one of data mining methods, CART with ensemble method. Also, the limitation and future research are discussed.

Effective PPG Signal Processing Method for Detecting Emotional Stimulus (감성 자극 판단을 위한 효과적인 PPG 신호 처리 방법)

  • Oh, Dong-Gi;Min, Byung-Seok;Kwon, Sung-Oh;Kim, Hyun-Joong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.5C
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    • pp.393-402
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    • 2012
  • In this study, we propose a signal processing algorithm to measure the arousal level of a human subject using a PPG(Photoplethysmography) sensor. From the measured PPG signals, the arousal level is determined by PPI(Pulse to Pulse Interval) and discrete-time signal processing. We ran psychophysical experiments displaying visual stimuli on TV display while measuring PPG signal from a finger, where the nature landscape scenes were used for restorative effect, and the urban environments were used to stimulate the stress. However, the measured PPG signals may include noise due to subject movement and measurement error, which results in incorrect detections. In this paper, to mitigate the noise impact on stimulus detection, we propose a detecting algorithm using digital signal processing methods and statistics of measured signals. A filter is adopted to remove a high frequency noise and adaptively designed taking into account the statistics of the measured PPG signals. Moreover we employ a hysteresis method to reduce the distortion of PPI in decision of emotional. Via experiment, we show that the proposed scheme reduces signal noise and improves stimulus detection.

Compensation Method for Occluded-region of Arbitrary-view Image Synthesized from Multi-view Video (다시점 동영상에서 임의시점영상 생성을 위한 가려진 영역 보상기법)

  • Park, Se-Hwan;Song, Hyuk;Jang, Eun-Young;Hur, Nam-Ho;Kim, Jin-Woong;Kim, Jin-Soo;Lee, Sang-Hun;Yoo, Ji-Sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.12C
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    • pp.1029-1038
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    • 2008
  • In this paper, we propose a method for an arbitrary-view image generation in multi-view video and methods for pre- and post-processing to compensate unattended regions in the generated image. To generate an arbitrary-view image, camera geometry is used. Three dimensional coordinates of image pixels can be obtained by using depth information of multi-view video and parameter information of multi-view cameras, and by replacing three dimensional coordinates on a two dimensional image plane of other view, arbitrary-view image can be reconstructed. However, the generated arbitrary-view image contains many unattended regions. In this paper, we also proposed a method for compensating these regions considering temporal redundancy and spatial direction of an image and an error of acquired multi-view image and depth information. Test results show that we could obtain a reliably synthesized view-image with objective measurement of PSNR more than 30dB and subjective estimation of DSCQS(double stimulus continuous quality scale method) more than 3.5 point.