• 한국농공학회지
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• 제33권2호
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• pp.120-129
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• 1991

This study refers to temporal variation of physical properties of tilled soil under natural rainfalls. Field measurements of porosity, average hydraulic conductivity and average capillary pressure head on a tilled soil were conducted by soil sampler and air-entry permeameter respectively at regular intervals after tillage. Temporal variation of these physical properties were analysed by cumulative rainfall energy since tillage. Field experiment was conducted on a sandy loam soil at Suwon durging April~July in 1989. The followings are a summary of this study results ; 1. Average porosity just after tillage was 0.548cm$^3$/cm$^3$. As cumulative rainfall energy were increased in 0.1070, 0.1755, 0.3849 J/cm$^2$, average porosity were decreased in 0.506, 0.4]95, 0.468m$^3$/cm$^3$ respectively. 2. Average hydraulic conductivity just after tillage was 45.42cm/hr. As cumulative rainfall energy were increased in 0.1755, 0.2466, 0.2978, 0.3849J/cm$^2$ average hydraulic conductivity were decreased in 15.34, 13.47, 9.58, 8.65cm/hr respectively. 3. As average porosity were decreased in 0.548, 0.506, 0.495, 0.468cm$^3$/cm$^3$ average capillary pressure head were increased in 6.1, 6.7, 6.9, 7.4cm respectively. 4. It was found that temporal variation of porosity, average hydraulic conductivity on a tilled soil might be expressed as a function of cumulative rainfall energy and average capillary pressure head might be expressed as a function of porosity. 5. The results of this study may be helpful to predict infiltration into a tilled soil more accurately by considering Temporal variation of physical properties of soil.

• Journal of the Korean Statistical Society
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• 제23권2호
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• pp.325-340
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• 1994

Effects of temporal aggregation on estimation for ARMA models are studied by investigating the Hannan & Rissanen (1982)'s procedure. The temporal aggregation of autoregressive process has a representation of an autoregressive moving average. The characteristic polynomials associated with autoregressive part and moving average part tend to have roots close to zero or almost identical. This caused a numerical problem in the Hannan & Rissanen procedure for identifying and estimating the temporally aggregated autoregressive model. A Monte-Carlo simulation is conducted to show the effects of temporal aggregation in predicting one period ahead realization.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.196-199
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• 2005

이 논문에서는 과학적 응용에서 발생하는 군집을 이루는 시간 데이터를 관리하는 방법을 제안한다. 먼저, 시간데이터를 구분하는 경계값 LB와 RB를 정의하고 과거, 현재, 미래 세그먼트에 각각 저장되는 개체버전을 정의하였다. 또한 Hotspot 분포를 가지는 시간 데이터에 대하여 각 세그먼트 사이에 이동하는 알고리즘을 나타내었다. 이 논문에서 제안하는 최소중복을 이용한 이동 방법과 기존방법에 대하여 성능을 비교하였다. 질의에 대한 평균 응답 시간에서는 기존의 방법과 비슷한 결과를 보였다. 제안한 이동 방법은 세그먼트 사이에 중복해서 저장되는 데이터 수를 적게 하므로 공간 이용율 측면에서는 기존의 이동 방법보다 효율적이었다.

• 한국농공학회지
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• 제35권3호
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• pp.36-46
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• 1993

The purposes of this study are to develop three-layered Green-Ampt infiltration model considering temporal variation of physical properties of soil and to evaluate the model with field experiment on bare-tilled and soybean-growing soil plots under natural rainfalls. Infiltration tests were conducted on a sandy loam soil. The model has three-layered soil profile including a surface crust, a tilled layer, a subsoil and considers temporal variation of porosity, hydraulic conductivity, capillary pressure head on a tilled layer by natural rainfalls and canopy density variation of crop. Field measurement of porosity, average hydraulic conductivity and average capillary presure head on a tilled layer were conducted by soil sampler and air-entry permeameter at regular intervals-after tillage. It was found that temporal variation of porosity and average hydraulic conductivity might be expressed as a function of cumulative rainfall energy and average capillary pressure head might be expressed as a function of porosity of a tilled soil. The model was calibrated by an optimization technique, Hooke and Jeeves method using hourly surface runoff data. With the calibrated parameters, the model was verified satisfactorily.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.680-683
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• 1987

The speech signal processing in the auditory system can be analysized based on two representations : Average discharge rate and Temporal discharge pattern. But the average discharge rate representation is restricted by the narrow dynamic range because of the rate saturation and the two tone suppression phenomena, and the temporal discharge pattern representation needs a sophisticate frequency analysis and synchrony measure. In this paper, a simple representation is proposed : using a model considering the interaction of Cochlear fluid-BM movement and a haircell model, the feature of speech signals (formant frequency and pitch of vowels) is easily estimated in the Average Synchronized Rate.

• Archives of Plastic Surgery
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• 제32권2호
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• pp.214-218
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• 2005

The anatomy and distribution of the superficial temporal vessels are known to follow regular patterns, with few exceptions in previous studies. But these previous studies of the anatomy and distribution of the superficial temporal vessels were based, only on the cadaver studies. Authors evaluated the anatomy of these vessels in the operative field of the living body from December 1997 to June 2001, The superficial temporal vessels were surgically exposed from the zygomatic arch extending to the superior temporal line through a preauricular incision in 18 patients(20 cases), who underwent reconstructive surgery using these vessels in the operative field. The authors measured and analyzed; the distribution, branching and diameters of the superficial temporal vessels. The results were obtained as follows; 1.In 19 cases, STV(superficial temporal vein) runs posterior to STA(superficial temporal artery) at the upper border of the zygomatic arch. 2. There was no frontal or parietal branches in 2 cases and vena comitante existed along with STA in one case. 3. The external diameter of STA and STV was measured at the lower border of the zygomatic arch. The external diameter of STA ranged from 1.5 mm to 3.0 mm(average 2.1 mm) and those of STV ranged from 1.3 mm to 3.5 mm (average 2.0 mm). This study can be helpful in the reconstructive surgery using the superficial temporal vessels, for the results of our study are based on the true anatomy of the living body.

• Journal of the Korean Statistical Society
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• 제22권2호
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• pp.271-282
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• 1993

Unit root test for temporally aggregated first order autoregressive process is considered. The temporal aggregate of fist order autoregression is an autoregressive moving average of order (1,1) with moving average parameter being function of the autoregressive parameter. One-step Gauss-Newton estimators are proposed and are shown to have the same limiting distribution as the ordinary least squares estimator for unit root when complete observations are available. A Monte-Carlo simulation shows that the temporal aggregation have no effect on the size. The power of the suggested test are nearly the same as the powers of the test based on complete observations.

• 품질경영학회지
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• 제43권4호
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• pp.521-532
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• 2015

Purpose: The purpose of this study is to compare two multivariate cumulative sum (MCUSUM) charts designed for spatio-temporal surveillance in terms of not only temporal detection performance but also spatial detection performance. Method: Experiments under various configurations are designed and performed to test two CUSUM charts, namely SMCUSUM and RMCUSUM. In addition to average run length(ARL), two measures of spatial identification accuracy are reported and compared. Results: The RMCUSUM chart provides higher level of spatial identification accuracy while two charts show comparable performance in terms of ARL. Conclusion: The RMCUSUM chart has more flexibility, robustness, and spatial identification accuracy when compared to those of the SMCUSUM chart. We recommend to use the RMCUSUM chart if control limit calibration is not an urgent task.

• 한국환경과학회지
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• 제13권1호
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• pp.27-36
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• 2004

Present study analyzed the temporal and spatial characteristics of PM10 pollution in Metropolitan Daegu area based on air pollution monitoring station data and measurements of PM10 concentrations in background area in order to provide essential data for efficient PM10 pollution management. The significant variation of spatial and temporal PM10 concentrations in Daegu area was observed during the study years. The highest maximum PM10 concentration(332 $\mu\textrm{g}$/㎥), average concentration(88 $\mu\textrm{g}$/㎥) and frequency exceeding PM10 daily standard(150 $\mu\textrm{g}$/㎥) were all observed in Namsandong located near a major roadway. The hourly and weekly variations of PM10 concentrations had different pattern for the measurement sites. The monthly and seasonal concentrations exhibited a notable characteristic： the maximum concentration was obtained in spring season, most likely due to Yellow sand effects. Furthermore, this temporal variation of PM10 pollution varied with study site. Meanwhile, the PM10 values measured at the monitoring site, Manchondong, were comparable with those of a control site. The average PM10 concentration ranged from 23 $\mu\textrm{g}$/㎥ to 115 $\mu\textrm{g}$/㎥ with a mean value of 53 $\mu\textrm{g}$/㎥ in the former site and from 22 $\mu\textrm{g}$/㎥ to 91 $\mu\textrm{g}$/㎥ with a mean value of 45 $\mu\textrm{g}$/㎥ in the latter site.

• 한국정보통신학회논문지
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• 제9권4호
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• pp.877-882
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• 2005

과학적 응용에서 발생하는 각종 실험 데이터의 관리에 대한 관심이 높아지고 있으나 체계적인 관리 방법에 대한 연구가 많지 않다. 이 논문에서는 과학적 응용에서 발생하는 군집을 이루는 시간 데이터를 관리하는 방법을 제안한다. 먼저, 시간 데이터를 구분하는 경계값 LB와 RB를 정의하고 과거, 현재, 미래 세그먼트에 각각 저장되는 개체 버전을 정의하였다. 또한 Hotspot 분포를 가지는 시간 데이터에 대하여 각 세그먼트 사이에 이동하는 알고리즘을 나타내었고, 제안하는 최소중복을 이용한 이동 방법과 기존방법에 대하여 성능을 비교하였다. 질의에 대한 평균 응답 시간에서는 기존의 방법과 비슷한 결과를 보였다. 제안한 이동 방법은 세그먼트 사이에 중복해서 저장되는 데이터 수를 적게 하므로 공간 이용율 측면에서는 기존의 이동 방법보다 효율적이었다.