• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.88-88
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• 2022

Detection of stress responses in crops is important to diagnose crop growth and evaluate yield. Also, the multi-spectral sensor is effectively known to evaluate stress caused by nutrient and moisture in crops or biological agents such as weeds or diseases. Therefore, in this experiment, multispectral images were taken by an unmanned aerial vehicle(UAV) under field condition. The experiment was conducted in the long-term fertilizer field in the National Institute of Crop Science, and experiment area was divided into different status of NPK(Control, N-deficiency, P-deficiency, K-deficiency, Non-fertilizer). Total 11 vegetation indices were created with RGB and NIR reflectance values using python. Variations in nutrient content in plants affect the amount of light reflected or absorbed for each wavelength band. Therefore, the objective of this experiment was to evaluate vegetation indices derived from multispectral reflectance data as input into machine learning algorithm for the classification of nutritional deficiency in rice. RandomForest model was used as a representative ensemble model, and parameters were adjusted through hyperparameter tuning such as RandomSearchCV. As a result, training accuracy was 0.95 and test accuracy was 0.80, and IPCA, NDRE, and EVI were included in the top three indices for feature importance. Also, precision, recall, and f1-score, which are indicators for evaluating the performance of the classification model, showed a distribution of 0.7-0.9 for each class.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.107-120
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• 2017

There are many wildfire risk indices worldwide, but objective comparisons between such various wildfire risk indices and surface dryness indices have not been conducted for the wildfire cases in Korea. This paper describes a sensitivity analysis on the wildfire risk indices and surface dryness indices for Korea using LDAPS(Local Analysis and Prediction System) meteorological dataset on a 1.5-km grid and MODIS(Moderate-resolution Imaging Spectroradiometer) satellite images on a 1-km grid. We analyzed the meteorology-based wildfire risk indices such as the Australian FFDI(forest fire danger index), the Canadian FFMC(fine fuel moisture code), the American HI(Haines index), and the academically presented MNI(modified Nesterov index). Also we examined the satellite-based surface dryness indices such as NDDI(normalized difference drought index) and TVDI(temperature vegetation dryness index). As a result of the comparisons between the six indices regarding 120 wildfire cases with the area damaged over 1ha during the period between January 2013 and May 2017, we found that the FFDI and FFMC showed a good predictability for most wildfire cases but the MNI and TVDI were not suitable for Korea. The NDDI can be used as a proxy parameter for wildfire risk because its average CDF(cumulative distribution function) scores were stably high irrespective of fire size. The indices tested in this paper should be carefully chosen and used in an integrated way so that they can contribute to wildfire forecasting in Korea.

• Journal of Korean Academy of Nursing
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• v.34 no.6
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• pp.1014-1024
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• 2004

Purpose: The purpose of this study was to develop a tool for nutritional assessment, so that home care nurses can make early assessment of patients' nutritional status. Method: The study was done in two parts first a tool was developed to assess nutrition, and second the content validity and clinical validity of the categories and indices were verified. Result: The results of this study are summarized in two ways. First, the nutritional assessment tool was classified into 3 areas, physical measurement, nutritional survey and clinical survey, and into 11 categories with 22 indices. Second, when 5 of the 11 categories were positive, nutritional status was considered to be poor. Conclusion: By developing a clinically useful nutritional assessment tool for patients receiving home care, which was developed in this study, the quality of life for these patients will improve and contribution to the development of a more effective clinical home nursing practice will occur.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.9-15
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• 2010

As catenary supply electric power directly to the railway system, it is very important to prevent an accident of a catenary for appropriate train operation. This paper proposed the assessment the outage data for "British Catenary Safety Analysis Report" and Korean data to compare the reliability of the railway system. The analyzed data were applied to Event Tree and Fault Tree algorithm to calculate the reliability indices of railway system. Event tree is created and gate results of fault tree analysis are used as the source of event tree probabilities. Fault tree represents the interaction of failures and basic events within a system. Event Tree and Fault Tree analysis result is helpful to assess the reliability to interpreted. The reliability indices can be used to determine the equipment to be replaced for the entire system reliability improvement.

• 전기의세계
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• v.22 no.1
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• pp.28-34
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• 1973

This paper treats with the sub-optimal control problem of noninear systems by approximation method. This method involves the approximation by linearization which provides the sub-optimal solution of non-linear control problems. The result of this work shows that, in the problem in which the controlled plant is characterized by an ordinary differential equation of first order, the solution obtained by this method coincides with the exact solution of problem. In of case of the second or higher order systems, it is proved analytically that this method of linearization produces the sub-optimal solution of the given problem. It is also shown that the sub-optimality of solution by the method can be evaluated by introducing the upper and lower bounded performance indices. Discussion is made on the procedure with some illustrative examples whose performance indices are given in the quadratic forms.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.12 no.2
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• pp.84-95
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• 2008

Background and purpose: Health is characterized by variability and a loss variability is associated with aging and disease. Normal healthy respiratory patterns are characterized by breath to breath variability. The aim of this study is to analyze Correlation Analysis of 10 respiratory indices(include breath to breath variability) and K-POMS factors score. Method: Respiratory data were measured during 15 minutes and transferred to text file. We calculated 10 respiratory parameters in use of MATLAB7.1. After then do correlation analysis of 10 respiratory indices and K-POMS factors score. Result and conclusion: Respiratory variability is showed significant correlation with vigor factor. Respiratory rate is showed significant correlation with depression factor.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.81.2-81.2
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• 2010

Based on Yonsei Evolutionary Population Synthesis (YEPS), we have investigated the effect of horizontal branch stars (HBs) on the age-dating of simple stellar populations (SSPs). A detailed comparison of YEPS SSP with H_beta of M31 globular clusters (GCs) reveals (1) that the age dating without HB prescription gives ~5 Gyr younger ages for metal-poor M31 GCs, and (2) the age dating with HB prescription does not need any age gap between metal-poor and metal-rich GCs. This result is parallel to the well-known discrepancy in ages derived from integrated Balmer strengths and isochrone fittings of Milky Way GCs (MWGCs). Without a synthetic blue HB model, we cannot explain strong Balmer indices of metal-poor and old MWGCs. Our results suggest that the SSP model with well calibrated HBs should be used for the age-dating of SSPs to avoid a serious underestimation of ages due to the strong Balmer indices.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.417-422
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• 2002

Comparison studies of the Quantitative Structure Activity Relationship (QSAR) methods with new imidazo-quinolinedione derivatives were conducted using Comparative Molecular Field Analysis (CoMFA), Comparative Molecular Similarity Indices Analysis (CoMSIA), and the Hologram Quantitative Structure Activity Relationship (HQSAR). When the CoMFA crossvalidation value, q2, was 0.625, the Pearson correlation coefficient, r2, was 0.973. In CoMSIA, q2 was 0.52 and r2 was 0.979. In the HQSAR, q2 was 0.501 and r2 was 0.924. The best result was obtained using the CoMSIA method according to a comparison of the calculated values with the real in vitro cytotoxic activities against human ovarian cancer cell lines.

• Journal of Korean Society for Quality Management
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• v.28 no.2
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• pp.103-122
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• 2000

Process capability indices (PCI) $C_p\;C_{pk},\;C_m,\;and\;C_{pmk}$ are widely used to evaluate the process performance. The PCI's have been evolved to consider the 'off targetness' more adequately. However, all of these indices are found to be inconsistent with the proportion of nonconforming items, in some cases. That is, the PCI for a process may result in higher value even when the proportion of defectives increases. For these reasons, we propose a new capability index, $c_{pd}$, which is consistent with the defect rate. The characteristics of the new PCI, $c_{pd}$ are investigated with respect to the existing PCI's. Some statistical properties of an estimator for $c_{pd}$ are also investigated by a Monte Carlo simulation. Sensitivity study under minor deviation from normality is also performed to show the robustness of $c_{pd}$. A good estimator for $c_{pd}$ is under study.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.91-95
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• 2001

In this study, we estimated the behavior of the diversity of physiological responses under varied physical environmental factors by measuring variations of heart rate variability (HRV), an index of activity of cardiac autonomic control. Seven healthy young male adults consented and participated in the study. The environmental conditions consisted of thermal, lighting, and acoustic conditions. Two components of HRV were measured. one was the low frequency (LF) component of HRV, which provided a quantitative index of the sympathetic and parasympathetic (vagal) activities controlling the heart rate (HR). The other component measured was the high frequency (HF) component, which provided an index of the vagal tone. The percent contribution of physical environmental factors to the variations in HRV indices were calculated by ANOVA. The contribution of physical environmental factors to the variations in HR was higher than the contribution of HF and LF. However, the contribution of these factors was lower than the contribution related with individual difference in all indices. This result showed that the individual diversity of physiological responses is not a negligible quantity.