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무인기 기반 영상과 SVM 모델을 이용한 가을수확 작물 분류 - 충북 괴산군 이담리 지역을 중심으로 -
정찬희,고승환,박종화 한국농촌계획학회 2022 농촌계획 Vol.28 No.1
Crop classification is very important for estimating crop yield and figuring out accurate cultivation area. The purpose of this study is to classify crops harvested in fall in Idam-ri, Goesan-gun, Chungcheongbuk-do by using unmanned aerial vehicle (UAV) images and support vector machine (SVM) model. The study proceeded in the order of image acquisition, variable extraction, model building, and evaluation. First, RGB and multispectral image were acquired on September 13, 2021. Independent variables which were applied to Farm-Map, consisted gray level co-occurrence matrix (GLCM)-based texture characteristics by using RGB images, and multispectral reflectance data. The crop classification model was built using texture characteristics and reflectance data, and finally, accuracy evaluation was performed using the error matrix. As a result of the study, the classification model consisted of four types to compare the classification accuracy according to the combination of independent variables. The result of four types of model analysis, recursive feature elimination (RFE) model showed the highest accuracy with an overall accuracy (OA) of 88.64%, Kappa coefficient of 0.84. UAV-based RGB and multispectral images effectively classified cabbage, rice and soybean when the SVM model was applied. The results of this study provided capacity usefully in classifying crops using single-period images. These technologies are expected to improve the accuracy and efficiency of crop cultivation area surveys by supplementing additional data learning, and to provide basic data for estimating crop yields.
정찬희,이원영,김보연,박세은,이은정,박철영,오기원,목지오,김철희,박성우,김선우,강성구 연세대학교의과대학 2013 Yonsei medical journal Vol.54 No.3
Purpose: Considerable amount of interest has been focused on the positive relationship between inflammation and the metabolic syndrome (MS). However, few studies have been performed to evaluate the relationship between baseline white blood cell (WBC) count and future risk for developing MS. Therefore, we investigated whether the baseline plasma levels of WBC count could be associated with future risk for MS in apparently healthy Korean. Materials and Methods: A total of 1135 subjects (781 men and 354 women with a mean age of 49 years), who underwent health examinations at Kangbuk Samsung Hospital in both 2002 and 2005 were enrolled. The presence of MS was defined using the modified criteria of the National Cholesterol Education Program Adult Treatment Panel III using BMI instead of waist circumference. Results: The baseline levels of WBC count were significantly higher among incident MS cases than among subjects without MS. The relative risks of incident MS were 1.4, 3.2 and 2.7 for WBC quartiles 2, 3, and 4, respectively, when compared with the first quartile (p-value for trend <0.001). These positive associations persisted after adjustment for baseline body mass index, blood pressure, fasting glucose, high density lipoprotein-cholesterol, triglyceride and homeostatic model assessment-insulin resistance; adjusted relative risk of incident MS for the 2nd, 3rd and 4th quartile groups vs. the lowest quartile were 1.2, 2.4 and 1.7, respectively (p-value for trend =0.011). Conclusion: This retrospective cohort study suggests that an elevated WBC count could be associated with incident MS, suggesting that baseline inflammation mirrored by WBC level can impact future MS development.
정찬희,박인기,Jung, Chan-Hee,Park, In-Ki 한국군사과학기술학회 2012 한국군사과학기술학회지 Vol.15 No.5
In this study, the mathematical model of the underwater discharge system using a centrifugal pump was derived and the rotating speed profiles of the pump which satisfied the discharge performance requirements were obtained through the underwater discharge simulations. The simulation results showed that the dynamic characteristics of a projectile were greatly affected by the rotational speed of the pump, however, hardly by the discharge depth. It is anticipated that the simulation model can be used to derive the design parameters and analyze the performance concerning the underwater discharge system using a centrifugal pump.