• 한국작물학회지
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• 제49권1호
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• pp.41-45
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• 2004

We have developed and tested a new method for nondestructive estimation of chlorophyll- and nitrogen-contents in rye leaf. It was found that the relation-ships among nitrogen, chlorophyll content and fresh weight were significantly positive correlated. Nitrogen and chlorophyll content were positively correlated whereas correlation coefficients among R, G, R-B and G-B on the basis of photo-numerical values were negative. We have found that R/(R-B) obtained from data of digital camera is the best criterion to estimate the chlorophyll content of leaves. The regression curves of the relation between R/(R-B) and chlorophyll content were also calculated from the data collected on cloudy days. The coefficients of determination ($\textrm{r}^2$) were ranged from 0.33 to 0.99. In this study, the accuracy in estimating chlorophyll content from the color data of digital camera image could be improved by correcting with R, G, and B values. It is suggested that, for practical purposes, the image values estimated with sufficient accuracy using a portable digital camera can be applied for determining chlorophyll content and nitrogen status in plant leaves.

• 대한원격탐사학회지
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• 제18권6호
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• pp.319-326
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• 2002

TRMM-PR/VIRS와 GMS 자료를 이용하여 강수량을 추정하였다. 강수량 추정의 검증에는 기상청의 AWS 관측자료를 이용하였다. 본 연구의 강수량 추정 절차는 다음과 같다: 1) TRMM-PR 자료와 AWS 자료를 이용하여 Z-R 관계식을 도출한다. 2) Z-R 관계식에 의한 추정치와 VIRS의 TBB 자료를 이용하여 강수량 추정식을 도출한다. 3) 새롭게 도출된 식의 VIRS의 TBB 대신 GMS의 TBB 자료를 대입하여 광역의 강수량을 추정한다. Z-R 관계식은 Z=303R$^{0.72}$로 나타났고 상관계수는 0.57이었다. 새롭게 제시된 강수량 추정식에 의한 결과의 상관계수는 0.67, RMSE는 17mm/hr로 나타났다. 강수량 추정식은 집중호우 때 과소추정하는 경향을 보였다.

• Journal of Forest and Environmental Science
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• 제33권3호
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• pp.187-196
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• 2017

The use of unmanned aerial vehicles (UAV) for the estimation of tree height is gaining recognition. This study aims to assess the effectiveness of tree height estimation of Pinus densiflora Sieb. et Zucc. and Pinus koraiensis Sieb. et Zucc. using digital surface model (DSM) generated from UAV-acquired imageries. Images were taken with the $Trimble^{(R)}$ UX5 equipped with Sony ${\alpha}5100$. The generated DSM, together with the digital elevation model (DEM) generated from a digital map of the study areas, were used in the estimation of tree height. Field measurements were conducted in order to generate a regression model and carry out accuracy assessment. The obtained coefficients of determination (R2) and root mean square error (RMSE) for P. densiflora (R2=0.71; RMSE=1.00 m) and P. koraiensis (R2=0.64; RMSE=0.85 m) are comparable to the results of similar studies. The results of the paired two-tailed t-test show that the two tree height estimation methods are not significantly different (p-value=0.04 and 0.10, alpha level=0.01), which means that tree height estimation using UAV imagery could be used as an alternative to field measurement.

• 한국군사과학기술학회지
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• 제24권6호
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• pp.655-663
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• 2021

In this paper, DFT-Based channel estimation with channel response mirroring is proposed and analyzed. In General, pilot symbols for channel estimation in MIMO(Multi-Input Multi-Output) OFDM(Orthogonal Frequency-Division Multiplexing) Systems have a diamond shape in the time-frequency plane. An interpolation technique to estimate the channel response of sub-carriers between reference symbols is needed. Various interpolation techniques such as linear interpolation, low-pass filtering interpolation, cubic interpolation and DFT interpolation are employed to estimate the non-pilot sub-carriers. In this paper, we investigate the conventional DFT-based channel estimation for noise reduction and channel response interpolation. The conventional method has performance degradation by distortion called "edge effect" or "border effect". In order to mitigate the distortion, we propose an improved DFT-based channel estimation with channel response mirroring. This technique can efficiently mitigate the distortion caused by the DFT of channel response discontinuity. Simulation results show that the proposed method has better performance than the conventional DFT-based channel estimation in terms of MSE.

• Journal of Information Technology Applications and Management
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• 제21권4_spc호
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• pp.345-359
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• 2014

Technological, policy and economic factors are both important variables in maximizing the results of a national R&D program and key indicators in evaluating an R&D program's eligibility for financial support. Economic analysis, in particular, is used when selecting R&D programs, setting priorities, and estimating economic effects. This paper examines a series of methodological issues related to the economic analysis of national R&D programs within the framework of the current preliminary feasibility evaluation system, and proposes alternative approaches to each of the issues discussed. The issues include the definition of R&D valuation and establishment of valuation factors; estimation of sales attributable to R&D investment; assessment of the total economic value of R&D as intellectual assets; estimation of R&D benefits and assumption of related to sales; and the application of discount rates based on the weighted average cost of capital. Finally, this study presents directions for future research on analytical procedures and methods of improving the reliability of the results of economic analysis within the national technology planning system.

• 전기학회논문지
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• 제56권7호
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• pp.1331-1338
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• 2007

A new method for detecting and eliminating the Electrocardiogram(ECG) artifact from the scalp Electroencephalogram(EEG) is proposed. Based on the single channel EEG, the proposed method consists of 4 procedures: emphasizing the R-wave of ECG artifact from EEG using the least squares acceleration(LSA) filter, detecting the R-wave from the LSA filtered EEG using the phase space method and R-R interval, generating the delayed impulse synchronized to the R-wave and elimination of the ECG artifacts based on the adaptive digital filter using the impulse and raw EEG. The performance of the proposed method was evaluated in the two separating parts of R-wave detection and, ECG estimation and elimination from EEG. In the R-wave detection, the proposed method showed the mean error rate of 6.285(%). In the ECG estimation and elimination using simulated and/or real EEG recordings, we found that the ECG artifacts were successfully estimated and eliminated in comparison with the conventional multi-channel techniques, in which independent component analysis and ensemble average method are used. From this we can conclude that the proposed method is useful for the detecting and eliminating the ECG artifact from single channel EEG and simple for ambulatory/portable EEG monitoring system.

• 기술혁신학회지
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• 제8권1호
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• pp.29-50
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• 2005

Real options provide a new and productive way to view corporate r&d investment decisions. DCF approach is well established and beloved of financial executives, but is known to systematically underestimate investment value under significant uncertainty. Though real options are not inherent in a r&d investment, they can be used to compute the investment value including managerial flexibility like option value. In this paper, we explain how the interval of option value in black-scholes model can be estimated using simulation. We also present a process framework for interval estimation of volatility and efficient of period of investment value. In such a setting, we can obtain the appropriate interval estimation of the expanded investment value.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.193-196
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• 1995

An algorithm using topological mapping has been developed for a real-time detection of the QRS complexes of ECG signals. As a measurement of QRS complex energy, we used topological mapping from one dimensional sampled ECG signals to two dimensional vectors. These vectors are reconstructed with the sampled ECG signals and the delayed ones. In this method, the detection rates of CRS complex vary with the parameters such as R-R interval average and peak detection threshold coefficient. We use mean, median, and iterative method to determint R-R interval average and peak estimation. We experiment on various value of search back coefficient and peak detection threshold coefficient to find optimal rule.

• 한국멀티미디어학회논문지
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• 제22권10호
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• pp.1149-1159
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• 2019

We present a novel deep learning architecture for obtaining a latent image from a single blurry image, which contains dynamic motion blurs through object/camera movements. The proposed architecture consists of two sub-modules: blur image restoration and optical flow estimation. The tasks are highly related in that object/camera movements make cause blurry artifacts, whereas they are estimated through optical flow. The ablation study demonstrates that training multi-task architecture simultaneously improves both tasks compared to handling them separately. Objective and subjective evaluations show that our method outperforms the state-of-the-arts deep learning based techniques.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제12권3호
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• pp.153-160
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• 2008

A size-biased Poisson distribution is defined. Its characterization by using a recurrence relation for first order negative moment of the distribution is obtained. Different estimation methods for the parameter of the model are also discussed. R-Software has been used for making a comparison among the three different estimation methods.