• 제목/요약/키워드: reflectance model

검색결과 331건 처리시간 0.026초

근적외선(NIR) 분광법에 의한 수삼의 성분 측정 (Measurement of the proximate components of fresh ginseng (Panax ginseng C.A Meyer) using Near-Infrared Reflectance Spectroscopy)

  • 장규섭;이의석;이규희
    • 농업과학연구
    • /
    • 제28권2호
    • /
    • pp.116-124
    • /
    • 2001
  • 종래의 화학적 방법에 의한 일반 분석으로 수분, 전분, 회분, 조섬유, 칼슘, 마그네슘 등의 성분 분석 결과 수치와 근적외 분광 분석기를 이용하여 검량선을 작성한 결과, 결정계수 ($R^2$)는 전분(0.951), 칼슘(0.933), 수분(0.918), 회분(0.897), 조섬유(0.728), 마그네슘(0.390)의 순으로 높았고, 조섬유와 마그네슘의 경우는 결정계수 값이 다소 떨어지는 경향이 있었지만, 기존의 분석 방법과 유사한 경우를 얻었다. 향후 계속적인 시료의 보강과 모집단 분석을 이용한 체계적인 확충을 통해 얻어진 개량된 검증식을 사용하게 된다면 앞으로 수삼의 분석을 효과적으로 수행할 수 있을 것으로 사료된다.

  • PDF

열화상카메라를 이용한 블랙아이스 특성 연구 (Characteristics of Black Ice Using Thermal Imaging Camera)

  • 김승준;윤원섭;김연규
    • 한국산업융합학회 논문집
    • /
    • 제24권6_2호
    • /
    • pp.873-882
    • /
    • 2021
  • In this study, a study was conducted to develop a system for predicting/responding to black ice occurring on roads in winter. Tests conditions were studied by making models of cement concrete pavement and asphalt concrete pavement. In order to freeze water on the manufactured model package, an tests was conducted at a temperature below zero using a freezer, and the freezing process was photographed using a thermal imaging camera. Black ice is generated when water is present on the road surface and the temperature is below freezing or the road surface temperature is below the dew point temperature. Under sub-zero conditions, the pavement, water, and ice were classified with a thermal imaging camera. As a result of the tests, it was possible to distinguish with a thermal imaging camera at a temperature below freezing in the same freezer due to the difference in the emissivity of the packaging, water, and ice. In the process of changing from water to ice during the tests, it was analyzed that ice and water were clearly distinguished by the thermal imaging camera due to the difference in emissivity and reflectance, so black ice could be predicted using the thermal imaging camera.

분해 심층 학습을 이용한 저조도 영상 개선 방식 (Low-light Image Enhancement Method Using Decomposition-based Deep-Learning)

  • 오종근;홍민철
    • 전기전자학회논문지
    • /
    • 제25권1호
    • /
    • pp.139-147
    • /
    • 2021
  • 본 논문에서는 저조도 영상을 개선하기 위한 영상 분해 기반 심층 학습 방법 및 분해 채널 특성에 따른 손실함수를 제안한다. 기존 기법들의 문제점인 색신호 왜곡 및 할로 현상을 제거하기 위해, 입력 영상의 휘도 채널을 반사 성분과 조도 성분으로 분해하고, 반사 성분, 조도 성분 및 색차 신호를 신호 특성에 적합한 심층학습 과정을 적용하는 분해 기반 다중 구조 심층 학습 방법을 제안한다. 더불어, 분해 채널들의 특성에 따른 혼합 놈 기반의 손실함수를 정의하여 복원 영상의 안정성을 증대하고 열화 현상을 제거하기 위한 기법에 대해 기술한다. 실험 결과를 통해 제안한 방법이 다양한 저조도 영상을 효과적으로 개선하였음을 확인할 수 있었다.

Size and Crystal Structure Dependence of Photochromism of Nanocrystalline WO3 and MoO3 Prepared by Acid-Precipitation Method

  • Jun Young, Kwak;Young Hee, Jung;Yeong Il, Kim
    • 대한화학회지
    • /
    • 제67권1호
    • /
    • pp.33-41
    • /
    • 2023
  • Nanocrystallne WO3 and MoO3 with several different sizes and crystal structures were prepared by simple acid precipitation and subsequent heat treatment. The photochromic (PC) properties of these samples were comparatively investigated in powder state by monitoring diffuse reflectance spectral changes after bandgap irradiation. The PC effect of hexagonal WO3 and monoclinic WO3 strongly depended upon crystallite size rather than crystal structure. The smaller the crystallite size, the better the PC effect. However, orthorhombic WO·H2O and MoO3 having hexagonal and orthorhombic structures did not follow this trend. One consistent result for all WO3 and MoO3 samples is that the heat treatment in air, which changes crystallinity, whether it changes the crystal structure or only the crystallite size, reduces the PC effect. Since the thermal treatment reduces the surface oxygen defect sites, we believe that the PC effect of WO3 and MoO3 depends critically on the surface oxygen defect sites that serve as deep trap sites for photogenerated electrons and oxygen radical holes. We also found that the proton insertion claimed by double charge injection model is not critical for the PC effect.

DEVELOPMENT OF AN INTEGRATED GRADER FOR APPLES

  • Park, K. H.;Lee, K. J.;Park, D. S.;Y. S. Han
    • 한국농업기계학회:학술대회논문집
    • /
    • 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
    • /
    • pp.513-520
    • /
    • 2000
  • An integrated grader which measures soluble solid content, color and weight of fresh apples was developed by NAMRI. The prototype grader consists of the near infrared spectroscopy and machine vision system. Image processing system and an algorithm to evaluate color were developed to speed up the color evaluation of apples. To avoid the light glare and specular reflection, an half-spherical illumination chamber was designed and fabricated to detect the color images of spherical-shaped apples more precisely. A color revision model based on neural network was developed. Near-infrared(NIR) spectroscopy system using NIR reflectance method developed by Lee et al(1998) of NAMRI was used to evaluate soluble solid content. In order to observe the performance of the grader, tests were conducted on conditions that there are 3 classes in weight sorting, 4 classes in combination of color and soluble solid content, and thus 12 classes in combined sorting. The average accuracy in weight, color and soluble solid content is more than about 90 % with the capacity of 3 fruits per second.

  • PDF

Google Earth Engine 기반 도시화에 따른 식생 생장기간 변화 (Analyzing the impact of urbanization on vegetation growing season length using Google Earth Engine)

  • 손소영;김지현;김연주
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2022년도 학술발표회
    • /
    • pp.198-198
    • /
    • 2022
  • 최근 도시화에 따른 토지 피복 변화와 열섬현상 등의 원인으로 상승하는 도시의 기온이 식물 계절에 미치는 영향에 관한 연구들이 다수 진행되고 있다. 본 연구는 수도권인 서울과 경기도 지역을 대상으로 도시 내 열섬현상으로 인한 기온 상승과 도시 지역 내 식생 생장기간 변화의 관계성을 분석하였다. 식물계절 모니터링에 사용한 개량식생지수(Enhanced Vegetation Index, EVI)는 Google Earth Engine (GEE)에서 제공하는 30 m 해상도의 2000-2021년 NASA-USGS Landsat 위성(TM5, ETM+7, OLI8)의 지표면 반사율(surface reflectance, SR) 자료에서 도출하여 생장기간 산정에 사용하였다. 또한 PRISM (Parameter-elevation Regressions on Independent Slopes Model)을 각 기상관측지점의 일별 지상 기온 자료에 적용하여 30 m 해상도로 생성한 격자형 지표면 온도의 공간적 패턴을 분석하였다. 연구 지역 내 도시화 정도(magnitude)를 도심으로부터의 거리와 환경부 토지피복도 및 인구 밀도를 종합하여 특정하였고, 최종적으로 기후변화 및 도시화 정도와 생장기간 변화의 특징을 분석하였다. 비선형 로지스틱 회귀를 사용하여 EVI 데이터를 종합하여 분석한 결과, 수도권 지역에서 전반적으로 식물계절 개엽일(Start of Season)은 앞당겨지며 낙엽일(End of Season, EOS)은 늦춰져 생장기간(Length of Growing Season, LOS)이 길어짐을 발견하였다.

  • PDF

Yield Prediction of Chinese Cabbage (Brassicaceae) Using Broadband Multispectral Imagery Mounted Unmanned Aerial System in the Air and Narrowband Hyperspectral Imagery on the Ground

  • Kang, Ye Seong;Ryu, Chan Seok;Kim, Seong Heon;Jun, Sae Rom;Jang, Si Hyeong;Park, Jun Woo;Sarkar, Tapash Kumar;Song, Hye young
    • Journal of Biosystems Engineering
    • /
    • 제43권2호
    • /
    • pp.138-147
    • /
    • 2018
  • Purpose: A narrowband hyperspectral imaging sensor of high-dimensional spectral bands is advantageous for identifying the reflectance by selecting the significant spectral bands for predicting crop yield over the broadband multispectral imaging sensor for each wavelength range of the crop canopy. The images acquired by each imaging sensor were used to develop the models for predicting the Chinese cabbage yield. Methods: The models for predicting the Chinese cabbage (Brassica campestris L.) yield, with multispectral images based on unmanned aerial vehicle (UAV), were developed by simple linear regression (SLR) using vegetation indices, and forward stepwise multiple linear regression (MLR) using four spectral bands. The model with hyperspectral images based on the ground were developed using forward stepwise MLR from the significant spectral bands selected by dimension reduction methods based on a partial least squares regression (PLSR) model of high precision and accuracy. Results: The SLR model by the multispectral image cannot predict the yield well because of its low sensitivity in high fresh weight. Despite improved sensitivity in high fresh weight of the MLR model, its precision and accuracy was unsuitable for predicting the yield as its $R^2$ is 0.697, root-mean-square error (RMSE) is 1170 g/plant, relative error (RE) is 67.1%. When selecting the significant spectral bands for predicting the yield using hyperspectral images, the MLR model using four spectral bands show high precision and accuracy, with 0.891 for $R^2$, 616 g/plant for the RMSE, and 35.3% for the RE. Conclusions: Little difference was observed in the precision and accuracy of the PLSR model of 0.896 for $R^2$, 576.7 g/plant for the RMSE, and 33.1% for the RE, compared with the MLR model. If the multispectral imaging sensor composed of the significant spectral bands is produced, the crop yield of a wide area can be predicted using a UAV.

Artificial Neural Network-based Model for Predicting Moisture Content in Rice Using UAV Remote Sensing Data

  • Sarkar, Tapash Kumar;Ryu, Chan-Seok;Kang, Jeong-Gyun;Kang, Ye-Seong;Jun, Sae-Rom;Jang, Si-Hyeong;Park, Jun-Woo;Song, Hye-Young
    • 대한원격탐사학회지
    • /
    • 제34권4호
    • /
    • pp.611-624
    • /
    • 2018
  • The percentage of moisture content in rice before harvest is crucial to reduce the economic loss in terms of yield, quality and drying cost. This paper discusses the application of artificial neural network (ANN) in developing a reliable prediction model using the low altitude fixed-wing unmanned air vehicle (UAV) based reflectance value of green, red, and NIR and statistical moisture content data. A comparison between the actual statistical data and the predicted data was performed to evaluate the performance of the model. The correlation coefficient (R) is 0.862 and the mean absolute percentage error (MAPE) is 0.914% indicate a very good accuracy of the model to predict the moisture content in rice before harvest. The model predicted values are matched well with the measured values($R^2=0.743$, and Nash-Sutcliffe Efficiency = 0.730). The model results are very promising and show the reliable potential to predict moisture content with the error of prediction less than 7%. This model might be potentially helpful for the rice production system in the field of precision agriculture (PA).

Prediction of Chemical Organic Composition of Manure by Near Infrared Reflectance Spectroscopy

  • Amari, Masahiro;Fukumoto, Yasuyuki;Takada, Ryozo
    • 한국근적외분광분석학회:학술대회논문집
    • /
    • 한국근적외분광분석학회 2001년도 NIR-2001
    • /
    • pp.1265-1265
    • /
    • 2001
  • The organic materials included in excreta of livestock are important resources for organic manure and for improving soil quality, although there is still far from effective using. One reason for this is still unclearly standard of quality for evaluation of manure made from excreta of livestock. Therefore, the objective of this study is to develop rapid and accurate analytical method for analyzing organic compositions of manure made from excreta of livestock, and to establish quality evaluation method based on the compositions predicted by near infrared reflectance spectroscopy (NIRS). Sixteen samples of manure, each eight samples prepared from two treatments, were used in this study. The manure samples were prepared by mixing 560 kg feces of swine,60 kg sawdust with moisture content was adjusted to be 65%. The mixture was then keep under two kinds of shelter, black and clear sheets, as a treatment on the effect of sunlight. Samples were taken in every week (form week-0 to 7) during the process of manure making. Samples were analyzed to determine neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) by detergent methods, and organic cell wall (OCW) and fibrous content of low digestibility in OCW (Ob) by enzymatic methods. Biological oxygen demand (BOD) was analyzed by coulometric respirometer method. These compositions were carbohydrateds and lignin that were hardly digested. Spectra of samples were scanned by NIR instrument model 6500 (Pacific Scientific) and read over the range of wavelength between 400 and 2500nm. Calibration equations were developed using eight manure samples collected from black sheet shelter, while prediction was conducted to the other eight samples from clear sheet shelter. Accuracy of NTRS prediction was evaluated by correlation coefficients (r), standard error of prediction (SEP) and ration of standard deviation of reference data in prediction sample set to SEP (RPD). The r, SEP and RPD value of forage were 0.99, 0.69 and 7.6 for ADL, 0.96, 1.03 and 4.1 for NDF, 0.98, 0.60 and 4.9 for ADF, 0.92, 1.24 and 2.6 for Ob, and 0.91, 1.02 and 7.3 for BOD, respectively. The results indicated that NIRS could be used to measure the organic composition of forage used in manure samples.

  • PDF

초분광 항공원격탐사 테스트베드 구축 및 시험자료 획득 (Construction and Data Analysis of Test-bed by Hyperspectral Airborne Remote Sensing)

  • 장안진;김용일;최석근;한동엽;최재완;김용민;한유경;박홍련;왕표;임희창
    • 대한원격탐사학회지
    • /
    • 제29권2호
    • /
    • pp.161-172
    • /
    • 2013
  • 분광 영상의 효과적인 테스트베드 구축은 초분광 영상의 다양한 활용을 위하여 선행되어야한다. 본 연구에서는 다양한 연구 분야에 적용할 수 있는 테스트베드의 구축 방법 및 효용성에 대한 기초 연구를 수행하였다. 이를 위하여, 기존의 국내 외 테스트베드 생성 방법을 분석하고, 이를 바탕으로 하여 항공기 기반 초분광 센서의 촬영을 위한 테스트베드를 설계하였다. 구축된 테스트베드를 촬영한 영상에서 기준자료를 생성시키기 위하여, 본 연구에서는 대리보정에 의한 전처리 기법을 적용하고, 이에 대한 효용성을 분석하였다. 실험결과, 대리보정은 타프를 이용하는 것이 가장 이상적이지만, 상황에 따라서 분광반사율이 일정하거나, 변화폭이 상대적으로 적은 물질을 이용하는 것이 가능하다는 것을 확인하였다. 본 연구에서 촬영한 테스트베드 자료는 국내 외의 초분광 영상 처리 연구에 참조자료로 사용될 수 있을 것으로 사료된다.