• Journal of Biosystems Engineering
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• 제35권2호
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• pp.77-84
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• 2010

In this study, we tried to predict tractor power output, fuel consumption rate and work performance indirectly in order to develop an eco driving system. Firstly, we developed equations which could predict tractor power output and fuel consumption rate using characteristic curves of tractor power output. Secondly, with actual engine rpm determined by initial engine rpm and work load, tractor power output and fuel consumption rate were forecasted. Thirdly, with speed signals of GPS sensor system, it was possible to foresee tractor work performance and fuel consumption rate. Lastly, precision of the eco driving system was evaluated through tractor PTO test, and effects of the eco driving system were investigated in the plowing and rotary tilling operations. Engine rpm, power output, fuel consumption rate, work performance and fuel consumption rate per plot area were displayed in the eco driving system. Predicted tractor power outputs in the full load curve were well coincided with the actual power output of prototype, but small differences, 1 to 6 ㎾, were found in the part load curve. Error of the fuel consumption rate was 0.5 L/h, 4.5%, the greatest, and 1 to 3 L/h at the part load curve. It was shown that 69% and 53% of fuel consumption rates could be reduced in plowing and rotary tilling operations, respectively, when the eco driving system was installed in tractor.

• 응용통계연구
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• 제25권1호
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• pp.15-27
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• 2012

본 논문에서는 KOSPI 시가총액기준 상위 4종목(삼성전자, 현대차, 현대모비스, POSCO)의 고빈도 거래 데이터를 바탕으로 일중 수익률의 실현변동성과 시장미시구조잡음에 대해 연구한다. Volatility signature plot을 통해 실현변동성(Realized Variance; RV)과 편의수정 실현변동성($RV_{AC_1}$)의 편의를 확인하고 시장미시구조 잡음의 특징을 실증적으로 파악한다. 또한, 잡음 대 신호비(Noise-to-Signal Ratio; NSR)를 사용하여, 평균제곱오차(Mean Square Error; MSE) 기준의 실현변동성(RV)과 편의수정 실현변동성($RV_{AC_1}$)의 최적 추출 빈도수를 추정해본다.

• Journal of Photoscience
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• 제4권3호
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• pp.97-103
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• 1997

The effect of temperature on the fluorescence quenching of 2-(4-Methoxyphenyl)-5-(1-naphthyl)-1,3,4-oxadiazole (MPNO1), 2-(4-Methoxyphenyl)-5-(2-naphthyl)-1,3,4-oxadiazote(MPNO2), by aniline, and 2-Phenylindole (2-PI) by CCk, in toluene by steady state method and in benzene by time-resolved method have been carried out in the temperature range 30 - 70$\circ$C. The Stem-Volmer (S-V) plots, I$_0$/I against quencher concentration [Q] at different temperanares show positive deviations. The fluorescence lifetimes determined at different temperatures show no systematic variations and the variations being within the experimental error, the average values of lifetimes $ $\tau$ (t) are taken for further calculations. Rate constants such as Stem-Volmer quenching constants K$_sv}$, quenching rate parameters k$_q$ and k'$_q$, static quenching constant V and kinetic distance r are determined using the modified Stem-Volmer equation and sphere of action static quenching model. In order to see whether the reactions are diffusion limited, equations k$_q$ = e$^{-Eq/RT}$ and k'$_q$ = e$^{-Eq/RT}$ are used to determine the values of E$_q$ and E'$_q$, the activation energies for collisional quenching and the values of E$_q$ are 14.53. 17.28 and 16.20 kJ mole$^{-1}$ for MPNO1, MPNO2 and 2-PI respectively and the values of E'$_q$ are 14.62 and 17.73 for MPNO1 and MPNO2 respectively. From the magnitudes of various quantities it has been concluded that the reactions are diffusion limited and the observed positive deviations in the S-V plot are due to static and dynamic quenching.

• 대한원격탐사학회지
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• 제27권3호
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• pp.303-314
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• 2011

Surface albedo is an important parameter of the surface energy budget, and its accurate quantification is of major interest to the global climate modeling community. Therefore, in this paper, we consider the direct solution of kernel based bidirectional reflectance distribution function (BRDF) models for retrieval of normalized reflectance of high resolution satellite. The BRD effects can be seen in satellite data having a wide swath such as SPOT/VGT (VEGETATION) have sufficient angular sampling, but high resolution satellites are impossible to obtain sufficient angular sampling over a pixel during short period because of their narrow swath scanning when applying semi-empirical model. This gives a difficulty to run BRDF model inferring the reflectance normalization of high resolution satellites. The principal purpose of the study is to estimate normalized reflectance of high resolution satellite (RapidEye) through BRDF components from SPOT/VGT. We use semi-empirical BRDF model to estimated BRDF components from SPOT/VGT and reflectance normalization of RapidEye. This study used SPOT/VGT satellite data acquired in the S1 (daily) data, and within this study is the multispectral sensor RapidEye. Isotropic value such as the normalized reflectance was closely related to the BRDF parameters and the kernels. Also, we show scatter plot of the SPOT/VGT and RapidEye isotropic value relationship. The linear relationship between the two linear regression analysis is performed by using the parameters of SPOTNGT like as isotropic value, geometric value and volumetric scattering value, and the kernel values of RapidEye like as geometric and volumetric scattering kernel Because BRDF parameters are difficult to directly calculate from high resolution satellites, we use to BRDF parameter of SPOT/VGT. Also, we make a decision of weighting for geometric value, volumetric scattering value and error through regression models. As a result, the weighting through linear regression analysis produced good agreement. For all sites, the SPOT/VGT isotropic and RapidEye isotropic values had the high correlation (RMSE, bias), and generally are very consistent.

• 한국토양비료학회지
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• 제49권5호
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• pp.420-428
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• 2016

For more than 50 years, satellite images have been used to monitor crop growth. Currently, unmanned aerial vehicle (UAV) imagery is being assessed for analyzing within field spatial variability for agricultural precision management, because UAV imagery may be acquired quickly during critical periods of rapid crop growth. This study refers to the derivation of growth estimating equation for highland Kimchi cabbage using UAV derived normalized difference vegetation index (NDVI) and agro-meteorological factors. Anbandeok area in Gangneung, Gangwon-do, Korea is one of main districts producing highland Kimchi cabbage. UAV imagery was taken in the Anbandeok ten times from early June to early September. Meanwhile, three plant growth parameters, plant height (P.H.), leaf length (L.L.) and outer leaf number (L.N.), were measured for about 40 plants (ten plants per plot) for each ground survey. Six agro-meteorological factors include average temperature; maximum temperature; minimum temperature; accumulated temperature; rainfall and irradiation during growth period. The multiple linear regression models were suggested by using stepwise regression in the extraction of independent variables. As a result, $NDVI_{UAV}$ and rainfall in the model explain 93% of the P.H. and L.L. with a root mean square error (RMSE) of 2.22, 1.90 cm. And $NDVI_{UAV}$ and accumulated temperature in the model explain 86% of the L.N. with a RMSE of 4.29. These lead to the result that the characteristics of variations in highland Kimchi cabbage growth according to $NDVI_{UAV}$ and other agro-meteorological factors were well reflected in the model.

• Knee surgery & related research
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• 제30권4호
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• pp.326-333
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• 2018

Purpose: To evaluate the reliability and validity of the femorotibial mechanical axis angle from radiographs in the weight bearing (WB) and supine positions compared with navigation-measured values. Materials and Methods: Sixty-eight cases of navigation-assisted total knee arthroplasty (TKA) were included. The pre- and postoperative whole leg radiographs (WLRs) in WB and supine positions were compared with the initial and final navigation values. Results: The mean mechanical axis angle from the preoperative WBWLR and navigation were not statistically different (p=0.079) and were correlated strongly with each other (intraclass correlation [ICC], 0.818). However, on postoperative measurements, although the WBWLR and navigation values were not different (p=0.098), they were not correlated with each other (ICC, 0.093). The standard error of measurement was $1.8^{\circ}{\pm}3.6^{\circ}$ for the preoperative WBWLR and $2.5^{\circ}{\pm}4.8^{\circ}$ for the postoperative WBWLR. The validity that was determined by the Bland-Altman plot was not acceptable for both pre- and postoperative measurements. Conclusions: The preoperative WBWLR could provide accurate but not precise measurement value of the femorotibial mechanical axis angle for navigation-assisted TKA, and postoperative measurements in navigation were not comparable with radiographic measurements. The lack of agreement was found between the radiographic and navigation measurements of the coronal alignment regardless of pre- or postoperative evaluation although the accuracy was found acceptable. Level of Evidence : Level 4.

• 한국ITS학회 논문지
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• 제22권1호
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• pp.103-114
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• 2023

본 연구에서는 도시부 도로의 다양한 자료를 수집하여 통행속도 변화에 대한 영향을 분석하였고, 이와 같은 빅데이터를 활용하여 GRU 기반의 단기 통행속도 예측 모형을 개발하였다. 그리고 Baseline 모형과 이중지수평활 모형을 비교 모형으로 선정하여 RMSE 지표로 예측 오차를 평가하였다. 모형 평가 결과, Baseline 모형과 이중지수평활 모형의 RMSE는 평균 7.46, 5.94값으로 각각 산출되었다. 그리고 GRU 모형으로 예측한 평균 RMSE는 5.08 값이 산출되었다. 15개 링크별로 편차가 있지만, 대부분의 경우 GRU 모형의 오차가 최소의 값을 나타내었고, 추가적인 산점도 분석 결과도 동일한 결과를 제시하였다. 이러한 결과로부터 도시부 도로의 통행속도 정보 생성 과정에서 GRU 기반의 예측 모형 적용 시 예측 오차를 감소시키고 모형 적용 속도의 개선을 기대할 수 있을 것으로 판단된다.

• 한국산림과학회지
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• 제105권3호
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• pp.342-350
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• 2016

본 연구는 우리나라 소나무림의 체계적인 경영계획 수립 및 관리목표 달성을 위해 지침이 될 수 있는 임분밀도관리도를 개발하는데 그 목적이 있다. 임분밀도관리도를 구성하는 5개의 모형을 추정하기 위하여 분석에 이용된 총 조사 표본점 수는 1,886plot이었으며, 각 표준지는 소나무의 흉고단면적이 75%이상 점유하는 임분에서 추출되었다. 유의수준 5%에서 $X{^2}_{(0.05)}$ 적합도를 검정하였으며, 허용오차율은 20% 수준으로 나타났다. 모형의 표준편차는$34.59m^3{\cdot}ha^{-1}$이었으며, 허용오차율의 최소치는 16.59%, 변동계수는 22.11%로 나타났다. 본 연구에서 제작된 소나무 임분밀도관리도는 밀도관리의 경로별 수확량과 솎아베기 과정을 예측할 수가 있어 산림경영에서 목적하는 생산재의 양과 형질에 따른 경영계획 수립이 가능할 것으로 기대하고 있다.

• 한국산림과학회지
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• 제8권1호
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• pp.11-16
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• 1968

왕죽(王竹) 및 맹종죽(孟宗竹)을 지위(地位) 상등지(上等地), 중등지(中等地), 하등지(下等地)에 따라서 생장인자(生長因子) 즉(卽) 죽고(竹高), 지하고(枝下高), 죽관장(竹冠長), 흉고주위(胸高周圍), 근경부주위(根莖部周圍)를 각각(各各) 측정(測定)하여 제(第)8표(表)를 작정(作定)하였다. 본표(本表)에 의거(依據)하여 맹종죽(孟宗竹)에서는 어느 정도(程度)의 등차(等差)를 그리고 왕죽(王竹)에서는 하등지(下等地)의 생장인자(生長因子) 특(特)히 근소(僅少)한 구티(數値)를 나타내고 있다. 다음에 상관표(相關表)를 작성(作成)하여 이에 의거(依據)한 상관계수(相關係數)를 산출(算出)하였다. 이때에 사용(使用)한 공식(公式)은 ${\mu}=\frac{{\Sigma}xy}{\sqrt{{\Sigma}X^2y^2}}$ 또 She.ppard 식(式)으로 추정(推正)할때 적욕(適用)한 공식(公式)은 ${\mu}=\frac{{\Sigma}xy}{\sqrt{({\Sigma}X^2-\frac{m}{12})({\Sigma}y^2-\frac{n}{12})}}$ 평균오차(平均誤差)의 공식(公式)은 $e=0.6745\frac{1-{\mu}^2}{\sqrt{n}}$ 상관계수(相關係數)에 따라 신뢰도(信賴度)를 좌우(左右)하는데 ${\mu}$ >0.5일때에는 상관계수(相關係數)가 있고 ${\mu}$ <0.3일때에는 상관계수(相關係數)가 없다고 하여 맹종죽(孟宗竹)에 있어서 죽고(竹高)와 흉고주위(胸高周圍) 죽고(竹高)와 근경부주위(根莖部周圍)와의 상관계수(相關係數)는 높으며 죽고(竹高)와 지하고(枝下高)와의 상관율(相關率)은 0.49로서 약(弱)한 상관관계(相關關係)가 성립(成立)되고 있다. 또한 왕중(王竹)에 있어서는 죽고(竹高)와 흉고주위죽고(胸高周圍竹高)와 근경부주위(根莖部周圍) 그리고 죽고(竹高)와 지하고(枝下高)의 상관계수(相關係數)가 0.45, 0.46, 0.48로서 높은 유의성(有意性)은 아니나 상관관계(相關關係)는 성립(成立)된다고 하겠다. 일반적(一般的)으로 지위조정(地位組定)에 있어서는 Daher 씨(氏)의 수고생장(樹高生長)을 이용(利用)하고 있으나 상술(上述)된 상관관계(相關關係)를 통(通)하여 생장인자(生長因子)인 죽고(竹高) 흉고주위(胸高周圍) 근경부주위(根莖部周圍) 및 지하고중(枝下高中) 어느 한가지만을 특정(測定)하여도 지위(地位)를 결정(決定)할수 있다는 것이 본연구(本硏究)를 통(通)하여 입증(立證)되고 있다.

• 한국토양비료학회지
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• 제50권5호
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• pp.422-433
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• 2017

Unmanned Aerial Vehicle (UAV) has several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly. And with a comparatively lower flight altitude, they can obtain good quality images even in cloudy weather. In this paper, we developed for estimating garlic growth at field scale model in major cultivation regions. We used the $NDVI_{UAV}$ that reflects the crop conditions, and seven meteorological elements for 3 major cultivation regions from 2015 to 2017. For this study, UAV imagery was taken at Taean, Changnyeong, and Hapcheon regions nine times from early February to late June during the garlic growing season. Four plant growth parameters, plant height (P.H.), leaf number (L.N.), plant diameter (P.D.), and fresh weight (F.W.) were measured for twenty plants per plot for each field campaign. The multiple linear regression models were suggested by using backward elimination and stepwise selection in the extraction of independent variables. As a result, model of cold type explain 82.1%, 65.9%, 64.5%, and 61.7% of the P.H., F.W., L.N., P.D. with a root mean square error (RMSE) of 7.98 cm, 5.91 g, 1.05, and 3.43 cm. Especially, model of warm type explain 92.9%, 88.6%, 62.8%, 54.6% of the P.H., P.D., L.N., F.W. with a root mean square error (RMSE) of 16.41 cm, 9.08 cm, 1.12, 19.51 g. The spatial distribution map of garlic growth was in strong agreement with the field measurements in terms of field variation and relative numerical values when $NDVI_{UAV}$ was applied to multiple linear regression models. These results will also be useful for determining the UAV multi-spectral imagery necessary to estimate growth parameters of garlic.