http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Rathnayaka, Pathum,Baek, Seung-Hae,Park, Soon-Yong Hindawi Limited 2017 Journal of sensors Vol.2017 No.-
<P>We present two simple approaches to calibrate a stereo camera setup with heterogeneous lenses: a wide-angle fish-eye lens and a narrow-angle lens in left and right sides, respectively. Instead of using a conventional black-white checkerboard pattern, we design an embedded checkerboard pattern by combining two differently colored patterns. In both approaches, we split the captured stereo images into RGB channels and extract R and inverted G channels from left and right camera images, respectively. In our first approach, we consider the checkerboard pattern as the world coordinate system and calculate left and right transformation matrices corresponding to it. We use these two transformation matrices to estimate the relative pose of the right camera by multiplying the inversed left transformation with the right. In the second approach, we calculate a planar homography transformation to identify common object points in left-right image pairs and treat them with the well-known Zhangs camera calibration method. We analyze the robustness of these two approaches by comparing reprojection errors and image rectification results. Experimental results show that the second method is more accurate than the first one.</P>
E.J.M.P.T.K. Rathnayaka,박두산 사단법인 한국정밀농업학회 2024 정밀농업과학기술지 Vol.6 No.1
This research introduces an automatic gate-controlling system explicitly tailored for sustainable paddy cultivation in Sri Lanka. Paddy fields, critical to the nation's food security, often face water management and resource efficiency challenges. Given the pressing concerns of water scarcity and the need for efficient resource utilization in Sri Lanka's agricultural landscape, the automatic gate-controlling system emerges as a cutting-edge solution. This research explores the transformative potential of this technology in revolutionizing traditional irrigation practices. It provides a detailed examination of the system's components and functionalities, emphasizing the integration of smart sensors to gather real-time data on soil moisture levels, weather conditions, and crop water requirements. This data is then processed through advanced analytics, facilitating informed decision-making for the automated control of irrigation gates. These data inputs are then processed by an intelligent control system that automates the operation of water gates. By precisely regulating water flow, the system minimizes water wastage and mitigates over-irrigation risks, contributing to sustainable paddy cultivation practices. The automated nature of the system reduces the dependency on manual labor, providing farmers with an efficient and reliable tool for water management. By adopting this technology, the study envisions increased yields in paddy cultivation while promoting responsible use of water resources. This research marks a significant stride towards sustainable agriculture in Sri Lanka, particularly in the crucial paddy cultivation sector.
Calibration of a Stereo Radiation Detection Camera Using Planar Homography
Baek, Seung-Hae,Rathnayaka, Pathum,Park, Soon-Yong Hindawi Limited 2016 Journal of sensors Vol.2016 No.-
<P>This paper proposes a calibration technique of a stereo gamma detection camera. Calibration of the internal and external parameters of a stereo vision camera is a well-known research problem in the computer vision society. However, few or no stereo calibration has been investigated in the radiation measurement research. Since no visual information can be obtained from a stereo radiation camera, it is impossible to use a general stereo calibration algorithm directly. In this paper, we develop a hybrid-type stereo system which is equipped with both radiation and vision cameras. To calibrate the stereo radiation cameras, stereo images of a calibration pattern captured from the vision cameras are transformed in the view of the radiation cameras. The homography transformation is calibrated based on the geometric relationship between visual and radiation camera coordinates. The accuracy of the stereo parameters of the radiation camera is analyzed by distance measurements to both visual light and gamma sources. The experimental results show that the measurement error is about 3%.</P>
Analysis of online food purchasing behavior: a study of Sri Lankan consumers
Piyumi Wijesinghe,Shashika D. Rathnayaka,Niranga Bandara,허정민,Dinesh D. Jayasena 충남대학교 농업과학연구소 2023 Korean Journal of Agricultural Science Vol.50 No.4
Online shopping has been undergoing significant developments in the South Asian region in the last decade. Using a representative sample of Sri Lankan consumers, this study explored online food purchasing behavior in Sri Lanka, a developing nation and island in South Asia. Data were collected from 562 respondents from all nine provinces in Sri Lanka using an online survey. Consumer attitudes were evaluated using factor analysis, and factor scores were added as explanatory variables to the final model. An ordered logistic regression model was used to examine the impact of consumer demographics, economic variables, and consumer attitudes on online food purchases. Online food purchasing intensity was categorized into four groups that suited ordinal rankings: zero for never, low for rarely, medium for occasionally, and high for regularly. Results indicated that age, income, education, and living in urban areas affect the online food purchasing behavior of Sri Lankan consumers. In addition, trust, convenience, and attitudes toward price were powerful drivers of online food purchasing. The findings have a number of significant managerial ramifications for creating strategies to promote online food purchases in developing South Asian nations like Sri Lanka. Moreover, promoting online shopping could be a potential solution for traffic congestion, ultimately helping to mitigate the negative externalities associated with it, such as carbon emissions and air pollution.