• Title/Summary/Keyword: Sky Conditions

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Evaluation of Thermal and Visual Environment for the Glazing and Shading Device in an Office Building with Installed of Venetian Blind (베네시안 블라인드가 적용된 오피스 건물의 외피 투과체 계획을 위한 열·빛 환경 평가에 대한 연구)

  • Kim, Chul-Ho;Kim, Kang-Soo
    • KIEAE Journal
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    • v.15 no.6
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    • pp.101-109
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    • 2015
  • Purpose: Glazing and shading devices influence a lot on the thermal and visual environment in office buildings. Solar heat and daylight are contrary concept, therefore proper arrangement of thermal and optical performance is needed when designing a glazing and shading devices. The purpose of this study is to examine the conditions of the glazing and shading devices available for promoting the reduction of cooling loads + lighting loads and the improvement in thermal comfort and visual comfort for the summer season in an office building installed with venetian blind. Method: This study established 12 simulation cases which have different glazings and the positions of venetian blind for evaluating different thermal and optical performance. And by using EnergyPlus v8.1 and Window v7.2 program, we quantitatively analyzed cooling loads + lighting loads, thermal comfort and visual comfort in an office building installed with the glazing and shading devices. Result: Consequently, Case 9(Double Low-E+Exterior Blind) is the best arrangement of solar heat gain and daylight influx, thereby becomes the most excellent case of reducing cooling+lighting loads(46.8%) and simultaneously becomes the enhancement case in thermal comfort. Also, DGI(Daylight glare index) under clear sky conditions in summer was evaluated to be 19.6, and thereby satisfied the recommendation level of allowing visual comfort.

ANALYSIS OF IRSIGNAL CHARACTERISTICS OF A SHIP FOR NON-UNIFORM ATMOSPHERIC CONDITIONS (비균일 대기상태를 고려한 함정의 적외선 신호 특성 분석)

  • Choi, J.H.;Kim, D.H.;Han, K.I.;Ha, N.K.;Jang, H.S.;Lee, S.H.;Kim, D.G.;Kim, T.K.
    • Journal of computational fluids engineering
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    • v.22 no.1
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    • pp.88-94
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    • 2017
  • The IR signal entering into a sensor is composed of the following components: the self-emitted component directly from the object surface, the reflected components of the solar and sky irradiance at the object surface, and the scattered component by the atmosphere without reference to any object surfaces. The self-emitted and reflected components from the object can be lowered by the atmospheric layer between the object and the IR sensor. The principle factors influencing the atmospheric transmittance are the air temperature, the relative humidity and the observation distance. Previous studies on IR signal transmission through the atmosphere are focused on uniform atmospheric conditions and the non-uniform nature of the atmosphere was not properly treated in modeling. In this study, we use the local atmospheric transmittance to simulate the non-uniform atmosphere in analyzing the IR signal from the object surface. The results show that the nonuniform analysis of the atmosphere becomes more important as the wavelength of IR signal increases.

Study on Hyungsang in Nei Ching (형상에 관한 문헌 고찰 -내경을 중심으로-)

  • Kang Kyung Hwa;Baek Geun Gi;Kim Kyung Chul;Lee Yang Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.3
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    • pp.424-434
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    • 2002
  • In Jang-Sang theory, ‘Sang’ indicates ‘Hyung Sang’. The internal organs appear it's shapes(Hyung Sang) outward. ‘Hyung Sang’ is concept that was used on 「the book of changes」(周易) and 「Nei Ching」(內經) to means a thing's shapes and conditions. ‘Hyung’ is the shape, an organization composing a thing and ‘Sang’ is the symptom, an essence(a seed) immanenting a thing. To observe Hyung Sang, it have to apply the principle that ‘the sky and man correspond each other(天人相應)’. Usually ‘Hyung’ appears as shapes and ‘Sang’ appears as colors and conditions. Diagnosis on the basis of Hyung Sang put first the external expression of the five Jang six Bu organs and Jung-Ki-Shin-Hyul(精氣神血). So a doctor has to unite shapes, colors, pulse and symptoms(形, 色, 脈, 症) when diagnosis a patient. The theory of Hyung Sang includes the basic theories of the oriental medicine, the theory for Yin-Yang and the five element(陰陽五行論), organ picture(Jang-Sang), meridians(經絡學說), the five circuit phases and the six atmospheric influences(運氣學說), physical constitution(體質學說). I think that treatment based on Hyung Sang is shown the essence of the oriental medicine well. In the future, I think, we need to study more about the theory of Hyung Sang.

Evaluation of Overall Heat Transfer Coefficient of Different Greenhouse Thermal Screens Using Building Energy Simulation (BES를 이용한 온실용 보온커튼의 관류열전달계수 산정)

  • Rasheed, Adnan;Lee, Jong Won;Lee, Hyun Woo
    • Journal of Bio-Environment Control
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    • v.27 no.4
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    • pp.294-301
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    • 2018
  • In winter, thermal screens are widely used to reduce heat loss from greenhouse to save energy. Unfortunately, not much data are available to the farmer to compare thermal screens while selecting the one that meets their specific requirements. Thus, there is a need to investigate the thermal performance of thermal screens. To address this issue, the Building Energy Simulation (BES) model of a hot box was used to calculate the overall heat transfer coefficient (U-value) of the thermal screens. To validate the model, computed and experimental U-values of single-and double-layered polyethylene (PE) material were compared. This validated model was used to predict the U-values of the selected thermal screens under defined weather conditions. We quantified the U-values of each selected material and significant changes in their U-values were noted in response to different weather conditions. Notably, the thermal properties of the tested screens were taken from the previous literature to calculate U-values using the BES model. The U-values of the thermal screens can help researchers and farmers evaluate their screens and make pre-design decisions that suit their investment capabilities.

Model Calculation of Total Radiances for KOMPSAT-2 MSC (다목적실용위성 2호 MSC 총복사량의 모델 계산)

  • 김용승;강치호
    • Korean Journal of Remote Sensing
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    • v.17 no.3
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    • pp.211-218
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    • 2001
  • We have performed the calculation of total radiances for the KOMPSAT-2 Multispectral Camera (MSC) using a radiative transfer model of MODTRAN and examined its results. To simulate four seasonal conditions in the model calculation, we used model atmospheres of mid-latitude winter and summer for calculations of January 15 and July 15, and US standard for April 15 and October 15, respectively. Orbital parameters of KOMPSAT-2 and the seasonal solar zenith angles were taken into account. We assumed that the meteorological range is the tropospheric aerosol extinction of 50 km and surface albedo is the global average of clear-sky albedo of 0.135. MSC contract values are found to be considerably greater in the MSC spectral range than the total radiances calculated with the above general conditions. It is also shown that the spectral behavior of model results with the constant surface albedo differs from the pattern of MSC contract values. From these results, it can be inferred that the forthcoming MSC images would be somewhat dark.

An analysis of the production conditions for small-sized women's jacket products - Focusing on young contemporary brands for spring/summer 2021 - (여성복 스몰사이즈 재킷 제품 생산실태- 2021년 S/S 영컨템포러리 브랜드를 중심으로 -)

  • Lee, Yujin;Jang, Jeongah
    • The Research Journal of the Costume Culture
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    • v.29 no.6
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    • pp.849-864
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    • 2021
  • This study analyzed product conditions in terms of "size system," "clothing construction depending on fit," "details," "colors," and "prices," with an emphasis on young contemporary brands for spring/summer 2021, in order to provide basic data for the development of small-sized women's jackets. Out of 96 domestic and foreign brands, the study analyzed 254 small-sized jacket products from 23 brands that produce size-XS jackets. First, when examining the sizes for women's jackets, we found that 8 out of the 23 brands offer a size-XXS option. After conducting tree analysis to analyze the factors affecting the production of size-XXS, the study found significant results in the areas of "distinction between domestic and foreign brands" and "product price." Second, after categorizing small-sized women's jackets into 3 categories-fit-slim, basic, and straight-the study analyzed clothing construction elements depending on fit. This seasons mainly feature straight-fit's hip-line length jacket, a 4-panel pattern, and a panel without a waist dart. Third, the study, through the analysis of the colors of small-sized women's jackets, found a higher frequency of colors in the order of black (23.0%), white (13.3%), and beige tones (10.1%), with additional colors such as sky blue, rose pink, and aquamarine in production, which exhibit the senses of the seasons. Price analysis revealed that small-sized jackets constituted a price range at the mid-to-low end, as in ₩50,000-100,000 (30.3%), ₩100,000-150,000 (19.3%), and ₩150,000-200,000 (11.8%).

Analysis of Weather Records in Admiral Yi Sun-sin's Nanjung Ilgi (이순신장군의 난중일기에 기록된 기상자료의 분석)

  • Suh, Myoung-Seok;Cha, So-Yeong
    • Atmosphere
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    • v.31 no.5
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    • pp.539-551
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    • 2021
  • In this paper, the weather records in 'Nanjung Ilgi' were investigated and the weather characteristics of the southern coast of Korea (SC_Korea) was discussed. The Nanjung Ilgi is a personal diary written by admiral Yi Sun-sin from January 1592 to November 1598 during the 7-year war caused by the Japanese invasion. He is a respected great leader in the history of world naval warfare, winning all 23 battles against the Japanese. Of the 1593 days of diaries currently preserved, only 42 days have no weather records. Weather was recorded in detail, including sky conditions, precipitation, wind characteristics and others. Weather records were extracted from the diary, converted to the solar calendar, and compared with the meteorological data of Yeosu. The average annual precipitation day is about 90 days, which is similar to the current 95~100 days. As in the current climate, precipitation frequently occurs for about 30 days in summer, but less than 15 days in other seasons, and the rainy season starts from June 14 to 21 and ends from July 6 to 17. It seems that the abnormal cold and heat phenomena, which deviate significantly from the seasonal average climate, occurred on 6 and 21 days, respectively, over 7 years. This means that the weather records of Nanjung Ilgi can be used as valuable data on the climate of SC_Korea in the late 16th century. The fact that he recorded the weather even in such extreme battle conditions shows that he clearly recognized the importance of weather in warfare.

Relationship between Low-level Clouds and Large-scale Environmental Conditions around the Globe

  • Sungsu Park;Chanwoo Song;Daeok Youn
    • Journal of the Korean earth science society
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    • v.43 no.6
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    • pp.712-736
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    • 2022
  • To understand the characteristics of low-level clouds (CLs), environmental variables are composited on each CL using individual surface observations and six-hourly upper-air meteorologies around the globe. Individual CLs has its own distinct environmental conditions. Over the eastern subtropical and western North Pacific Ocean in JJA, stratocumulus (CL5) has a colder sea surface temperature (SST), stronger and lower inversion, and more low-level cloud amount (LCA) than the climatology whereas cumulus (CL12) has the opposite characteristics. Over the eastern subtropical Pacific, CL5 and CL12 are influenced by cold and warm advection within the PBL, respectively but have similar cold advection over the western North Pacific. This indicates that the fundamental physical process distinguishing CL5 and CL12 is not the horizontal temperature advection but the interaction with the underlying sea surface, i.e., the deepening-decoupling of PBL and the positive feedback between shortwave radiation and SST. Over the western North Pacific during JJA, sky-obscuring fog (CL11), no low-level cloud (CL0), and fair weather stratus (CL6) are associated with anomalous warm advection, surface-based inversion, mean upward flow, and moist mid-troposphere with the strongest anomalies for CL11 followed by CL0. Over the western North Pacific during DJF, bad weather stratus (CL7) occurs in the warm front of the extratropical cyclone with anomalous upward flow while cumulonimbus (CL39) occurs on the rear side of the cold front with anomalous downward flow. Over the tropical oceans, CL7 has strong positive (negative) anomalies of temperature in the upper troposphere (PBL), relative humidity, and surface wind speed in association with the mesoscale convective system while CL12 has the opposite anomalies and CL39 is in between.

Combining Conditional Generative Adversarial Network and Regression-based Calibration for Cloud Removal of Optical Imagery (광학 영상의 구름 제거를 위한 조건부 생성적 적대 신경망과 회귀 기반 보정의 결합)

  • Kwak, Geun-Ho;Park, Soyeon;Park, No-Wook
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1357-1369
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    • 2022
  • Cloud removal is an essential image processing step for any task requiring time-series optical images, such as vegetation monitoring and change detection. This paper presents a two-stage cloud removal method that combines conditional generative adversarial networks (cGANs) with regression-based calibration to construct a cloud-free time-series optical image set. In the first stage, the cGANs generate initial prediction results using quantitative relationships between optical and synthetic aperture radar images. In the second stage, the relationships between the predicted results and the actual values in non-cloud areas are first quantified via random forest-based regression modeling and then used to calibrate the cGAN-based prediction results. The potential of the proposed method was evaluated from a cloud removal experiment using Sentinel-2 and COSMO-SkyMed images in the rice field cultivation area of Gimje. The cGAN model could effectively predict the reflectance values in the cloud-contaminated rice fields where severe changes in physical surface conditions happened. Moreover, the regression-based calibration in the second stage could improve the prediction accuracy, compared with a regression-based cloud removal method using a supplementary image that is temporally distant from the target image. These experimental results indicate that the proposed method can be effectively applied to restore cloud-contaminated areas when cloud-free optical images are unavailable for environmental monitoring.

Realtime Visibility Measurement Using Moving Area Filter and Image Contrast (이동영역 필터와 영상대비를 이용한 실시간 시정측정)

  • Kim, Bong-Keun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.3
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    • pp.35-45
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    • 2008
  • Realtime visibility measurement using camera is a new method which can collect some realtime visibility data similar to those of the human eyes, and can replace the existing methods using the expensive optical equipment. There have been a few attempts to measure visibility by extracting depth and three-dimensional structure under bad weather conditions. However, if there are many movements of objects in the image, these approaches seem to be inappropriate. In addition, the realtime visibility measurement will require a relatively simple and fast processing. Typically the contrast degrades exponentially in the bad weather. Therefore, in this paper we propose an easy and quick method that extract contrast from images using a moving area filter and measure visibility by mathematically modelling of the relationship between image contrast and visibility. The moving area filter is used for removing the area of the sky and moving objects that affect visibility measurement on images. The method proposed here can make possible not only realtime visibility measurement from images taken by CCD cameras, but also steady visibility measurement by using the moving area filter in case of much traffic on the road.

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