• Title/Summary/Keyword: VISIBLE AREA

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Visible Project Area for Korean Child (Six Years Old) in Radiant Enclosures (한국 어린이를 위한 복사 공간에서의 투사 면적에 관한 연구)

  • 손철수;최민권
    • Journal of the Korean housing association
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    • v.11 no.4
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    • pp.77-84
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    • 2000
  • The purpose of this paper is to find a visible project area for an average six year old Korean child in radiant enclosures having standing pose. The results using this method will be necessary to find effective radiation area, effective radiation area factor, form factor, and mean radiant temperature for an average six years old Korean child consists of 3012 triangles. The methods to find visible project area of an average six years old Korean at arbitrary view point will be presented. The visible project area for Korean child is needed for evaluating thermal comfort for six years old Korean child. The biggest visible project area of an average six years old Korean is $\textrm{cm}^2$$2.061.0\textrm{cm}^2$ at the view point of alfa 0.0 degree and beta 0.0 degree, and the smallest visible real area of an average six years old Korean is $567.1\textrm{cm}^2$ at the view point of alfa 15.0 degree and beta 90.0 degree.

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Implementation of a Relay Module for Coverage Extension in Visible Light Communication (가시광 통신의 커버리지 확장을 위한 릴레이 모듈 구현)

  • Lee, Sang-Gwon;Lee, Jong-Sung;Oh, Chang-Heon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.738-740
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    • 2017
  • Visible light communication is a communication method using light, and it has advantage of ensuring security in a single space as compared with RF communication. However, in the area outside the visible line of the light, communication disconnection occurs. Therefore, this paper proposes a relay module to overcome the coverage extension and communication disconnection phenomenon of visible light communication. The proposed relay module transmits and receives data of visible light communication by sequentially transmitting data packets including target ID through adjacent visible light module. Through experimentation of data transmission, we confirmed the extension of the transmission range and the data reception in the area outside the line of sight.

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A Simulation Study of MAC Protocol Based on Beacon Mode for Considering IEEE 802.15.7 Star Topology Visible Personal Area Network System (IEEE 802.15.7 스타 토폴로지 VPAN 시스템을 고려한 비콘 모드 기반 MAC 프로토콜 성능 평가)

  • Hwang, Junho;Yoo, Myungsik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.4
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    • pp.247-256
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    • 2013
  • According to the complete standard document for PHY/MAC layer of visible light communication through the IEEE 802.15.7 WG on Sept. 2011, visible light communication lays a good foundation for developing a variety of application services. Thus, visible light communication moves to the advanced research period for developing application services, but most of applications are limited only to PtP service model. However, PtMP communication environment for VLC is required to accommodate more various applications. In this paper, we analyze an effect of key parameters on network performance in the star topology based visible personal area network system. We implement a simulator with considering attributes of PHY and MAC layer which are defined by IEEE 802.15.7 standard documents, and analyze the VLC performance.

Kinetic Study of the Visible Light-Induced Sonophotocatalytic Degradation of MB Solution in the Presence of Fe/TiO2-MWCNT Catalyst

  • Zhang, Kan;Oh, Won-Chun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1589-1595
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    • 2010
  • In order to effective degradation of organic dye both under visible light or ultrasonic irradiation, the MWCNTs (multiwalled carbon nanotube) deposited with Fe and $TiO_2$ were prepared by a modified sol-gel method. The Fe/$TiO_2$-MWCNT catalyst was characterized by surface area of BET, scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) and ultraviolet-visible (UV-vis) spectroscopy. The low intensity visible light and low power ultrasound was as an irradiation source and the methylene blue (MB) was choose as the model organic dye. Then degradation experiments were carried out in present of undoped $TiO_2$, Fe/$TiO_2$ and Fe/$TiO_2$-MWCNT catalysts. Through the degradation of MB solution, the results showed the feasible and potential use of Fe/$TiO_2$-MWCNT catalyst under visible light and ultrasonic irradiation due to the enhanced formation of reactive radicals as well as the possible visible light and the increase of ultrasound-induced active surface area of the catalyst. After addition of $H_2O_2$, the MB degradation rates have been accelerated, especially with Fe/$TiO_2$-MWCNT catalyst, in case of that the photo-Fenton reaction occurred. The sonophotocatalysis was always faster than the respective individual processes due to the more formation of reactive radicals as well as the increase of the active surface area of Fe/$TiO_2$-MWCNT catalyst.

Analysis on Visibility Range of Forest Fire Detection Facilities for Forest Fire Prevention (산불예방을 위한 감시시설 가시범위 분석에 관한 연구)

  • Lee, Si-Young;An, Sang-Hyun
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.157-160
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    • 2008
  • This study analyzed on the area of Samcheok, Kangwondo about forest fire alarming area and enlargement of the area. Then, visible area by unattended watching camera and watchtower for forest fire which were run by Samcheok was cross-checked with geographic information system, and it could be whether effective on watching the area where the forest fire risk was high enough and also it could be expanded to larger forest fire. The result of study, the visible area by watching facilities only holds for 13.4% of the whole forest fire alarming area, but the forest fire can be observed even though it is occurred in small valley because of smoke and all the forest fire have been occurred in daytime. Therefore, it can be determined that watching area will be extended around 50.3% while the observation radii of watching facilities raise by 4km. However, Samcheok has much greater area of mountain area in compared to any other cities or counties, watching facilities should be installed and run additionally for extinguishing the forest fire from the beginning.

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A Noisy Infrared and Visible Light Image Fusion Algorithm

  • Shen, Yu;Xiang, Keyun;Chen, Xiaopeng;Liu, Cheng
    • Journal of Information Processing Systems
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    • v.17 no.5
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    • pp.1004-1019
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    • 2021
  • To solve the problems of the low image contrast, fuzzy edge details and edge details missing in noisy image fusion, this study proposes a noisy infrared and visible light image fusion algorithm based on non-subsample contourlet transform (NSCT) and an improved bilateral filter, which uses NSCT to decompose an image into a low-frequency component and high-frequency component. High-frequency noise and edge information are mainly distributed in the high-frequency component, and the improved bilateral filtering method is used to process the high-frequency component of two images, filtering the noise of the images and calculating the image detail of the infrared image's high-frequency component. It can extract the edge details of the infrared image and visible image as much as possible by superimposing the high-frequency component of infrared image and visible image. At the same time, edge information is enhanced and the visual effect is clearer. For the fusion rule of low-frequency coefficient, the local area standard variance coefficient method is adopted. At last, we decompose the high- and low-frequency coefficient to obtain the fusion image according to the inverse transformation of NSCT. The fusion results show that the edge, contour, texture and other details are maintained and enhanced while the noise is filtered, and the fusion image with a clear edge is obtained. The algorithm could better filter noise and obtain clear fused images in noisy infrared and visible light image fusion.

The Analysis of Coastal Landscape according to Development of Woljeong-ri Village in Jeju (제주 월정리 해안변 개발에 따른 해안경관 실태 분석 연구)

  • Seong, Da-Jeong;Park, Chung-Keun
    • Journal of the Regional Association of Architectural Institute of Korea
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    • v.20 no.6
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    • pp.33-40
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    • 2018
  • The coastal village in Woljeong-ri, Jeju is highly preferred by tourists because of its unique natural landscape different from inland areas. Especially, the number of buildings in the coastal area of the village is increasing due to escalating commercial value. Buildings are densely developed, along the seaside, resulting in privatization of coastal landscape. This results in blocking of landscape and psychological exchanges between the coastal village and coast. This study analyzed the actual conditions of coastal landscape before and after 2010, when the number of tourists and demand for development were increased in the coastal area of the coastal village in Woljeong-ri, Jeju. In this study, open index, visible horizontal index, elevation angle, elevation blockage and visible facade index were used to compute objective indicators of coastal landscape status. The analysis reveals visible facade index, a complex landscape assessment indicator, was increased by 7 times after 2010 as compared with before 2010. As such, there are many coastal villages in Jeju similar to Woljeong-ri that have a high landscape value and are in need of management. A comprehensive measure including a system for management of coastal landscape is urgently required to create narrative landscape in Jeju.

A Study on Framing Techniques of Landscape Assessment Using the Analytic Hierarchy Process - The Assessment on the Landscape Control Points - (AHP 기법을 활용한 경관평가법 작성에 관한 연구 - 경관통제점에서의 평가 -)

  • Suh Joo-Hwan;Yang Hee-Seung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.4
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    • pp.94-104
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    • 2004
  • This study creates the LCP (Landscape Control Point) through the survey of spot sites for the quality of landscape assessment, which is based on an objective and departmentalized data base; the landscape assessment was achieved by production of weight value with the AHP (Analytic Hierarchy Process) technique, selection of requisites for the landscape assessment with the IVERSON method and visual area analysis with GIS (Geographic Information System). Futhermore, validity of the landscape assessment was verified by analysis of the correlation between physical amount and aesthetic amount. The purpose of this study is to suggest the basic essential data for landscape assessment and landscape planning by the characteristics of landscape based on verification of the suggested landscape assessment methods. The results of this study are summarized below. 1. In the adaptation of landscape assessment using GIS, the landscape assessment points of LCP 18, 17 and 16, which have more visible elements such as hill area, mountain area, and forest and farm land, were indicated to be higher than the others. In contrast, the landscape assessment points of LCP 13, 6 and 10, which have less visible elements, were relatively lower than the others. 2. In the visible preference measuring method, LCP 4, 14, and 16 showed high points of landscape assessment with 3.46, 3.4, and 3.18 each. With the more natural environments such as hill area, mountain area, and forest and farm land, higher results were shown. In contrast, LCP 7, 1, and 9 showed low points of landscape assessment with 2.24, 2.36, and 2.53 each. 3. In this study, a coefficient of 0.746 was gained by the analysis of correlation between the points of landscape assessment method and the points of visual preference from a slide show. This has 99 percent of probability in statistical data. 4. In conclusion, with the demonstration of the correlation between the landscape assessment method based on the AHP technique and the aesthetic amount (preference proportion), the practical use of landscape assessment can be demonstrated by the suggested landscape assessment method.

The Characteristics of Visible Reflectance and Infra Red Band over Snow Cover Area (적설역에서 나타나는 적외 휘도온도와 반사도 특성)

  • Yeom, Jong-Min;Han, Kyung-Soo;Lee, Ga-Lam
    • Korean Journal of Remote Sensing
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    • v.25 no.2
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    • pp.193-203
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    • 2009
  • Snow cover is one of the important parameters since it determines surface energy balance and its variation. To classify snow and cloud from satellite data is very important process when inferring land surface information. Generally, misclassified cloud and snow pixel can lead directly to error factor for retrieval of surface products from satellite data. Therefore, in this study, we perform algorithm for detecting snow cover area with remote sensing data. We just utilize visible reflectance, and infrared channels rather than using NDSI (Normalized Difference Snow Index) which is one of optimized methods to detect snow cover. Because COMS MI (Meteorological Imager) channels doesn't include near infra-red, which is used to produce NDSI. Detecting snow cover with visible channel is well performed over clear sky area, but it is difficult to discriminate snow cover from mixed cloudy pixels. To improve those detecting abilities, brightness temperature difference (BTD) between 11 and 3.7 is used for snow detection. BTD method shows improved results than using only visible channel.