• Title/Summary/Keyword: Sky

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Comparative Evaluation of Sky-Hook Controllers for a Full Car Model with Active or Semi-Active Suspension Systems (능동과 반능동 현가장치로 된 전차량 모델에 대한 스카이훅 제어기의 비교 평가)

  • Yun, Il-Jung;Im, Jae-Pil
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.7
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    • pp.614-621
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    • 2001
  • The controllers for a full car 7-DOF model with 4 active or semi-active suspension units are designed and evaluated in this research. The control algorithms for suspension systems, such as full state feedback active, full state feedback semi-active, sky-hook active, sky-hook semi-actvie, and on-off suspension systems, are analyzed and evaluated with respect to ride comfort. The vehicle dynamic performances are expressed by response curves to a bump input, performance indices for asphalt road input, and frequency characteristic curves. Heaving, rolling, and pitching inputs are applied to the vehicle dynamic system to evaluate frequency characteristics. The simulation results show that the ride quality of the sky-hook controller approaches that the full state feedback controller more closely in semi-active suspension system than in active suspension system. For the implementation of a vehicle with sky-hook suspension control systems in this paper, 7 velocity sensors are required to measure the states.

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Cities in the Sky: Elevating Singapore's Urban Spaces

  • Samant, Swinal
    • International Journal of High-Rise Buildings
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    • v.8 no.2
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    • pp.137-154
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    • 2019
  • Singapore has seen a phenomenal and an unprecedented transformation from a swampland to a high density urban environment since its independence in 1965, made possible largely and single-handedly by the sustained efforts of its government. Indeed, urban space is a key vehicle for achieving urban social, environmental, economic, and cultural sustainability. The dense urban context in Singapore has seen an emergence and increase in elevated spaces in the form of sky-gardens, sky-bridges and sky-courts in a range of building types, seemingly seeking to tie together the different horizontal and vertical components of the city. This paper, therefore, examines the effectiveness of elevated urban spaces and pedestrian networks in Singapore and their ability to contribute to the horizontal to vertical transitions, and consequently to the urban vitality and accessibility. It does this through the analysis of two key developments: Marina Bay Sands and the Jurong Gateway. In particular, it considers the implications of certain constraints placed on urban spaces by their inherent location at height, in addition to the familiar privatization of public spaces, over-management of spaces, and their somewhat utilitarian characteristics. The paper argues that some of these issues may pose detrimental effects on the publicness of these spaces that in turn may lead to such spaces being underused and therefore adding redundancies and further stress to Singapore's urban land. Finally, the paper outlines key strategies that may help overcome the aforementioned issues, including the disjuncture associated with elevated spaces such that they may become a seamless extension of the urban spaces on ground.

A Study on Sky Light Pollution based on Sky Glow in Jeju Island (스카이글루 분석을 통한 제주도 빛공해 실태조사)

  • Lee, So-Hyun;Lim, Hong-Soo
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.4
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    • pp.83-91
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    • 2018
  • Artificial lighting contributes greatly to developing civilizations. It allows daytime activities to continue throughout the dark hours of the day and thus increasing work productivity as well as allowing people to enjoy nighttime activities. In addition, artificial lighting is used to beautify landscapes, architectural monuments, and thus highlighting the social-economic development of a given place. However, excessive and improper usage of artificial lighting can lead to light pollution. Light pollution is a serious issue that is detrimental to human health. It has been linked to a number of health conditions including sleep disorder, visual discomfort as well as cancer. The effects of light pollution extend throughout the entire ecosystem, affecting both plants and animals. Furthermore, sky-glow from light pollution hinders astronomical observation. The current paper presents a study conducted on lit environment of a nightscape. The quality of the sky was measured in 144 spots using Sky Quality Meter (SQM) devices. The measured spots were chosen on the basis of land use as well as distance from the Halla Mountain.

${\ll}$소문(素問).천원기대론(天元紀大論)${\gg}$에 대(對)한 연구(硏究)

  • Kim, Geun-Young;Yun, Chang-Yol
    • Journal of Korean Medical classics
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    • v.11 no.1
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    • pp.224-307
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    • 1998
  • The above study is based upon the Theory of Five Woon(Reasons) and Six Qi(Climates), namely Five dynamic Yin and Yang, the principle of five-six combination, the rules of ten periodically changing Woon and twelve periodically changing Qi, and its reference to the main chapters of the theory by several experts. After careful, comprehensive research and study, the followings are concluded. 1. The Theory of Five Woon and Six Qi controls all of the physical phenomena of the universe, yet it originates from Essence of the Sky that is replete and in constant motion within the abysmal expanse of the universe. So it is natural to claim that it is the Essence of the universe that is the source of the variety of phenomena in nature. 2. There is order of dynamics in the Essence and it is Yin Yang Five Movement and expressed by Five Woon and Six Qi. Therefore the Five Woon and Six Qi, which is the climatic changes of nature, is the basis and condition for all of the natural, physical occurrences including the organic phenomena of human beings. 3. Since the Sky embodied the number Five, and the Earth the number Six, Qi of the Sky itself is consequently Five Woon and Qi of the Earth itself is Six Qi. 4. In Sixty Repetition Intervals (Yuk Sip Kap Ja), the Sky took the number Six, designating the six times repetition of the ten Intervals of the Sky and the Earth chose the number Five, symbolizing five times recurrence of the twelve Intervals of the Earth. Though the number for the Sky is Five and the number for the Earth is Six, the two combine and interact in order for the Sky to exploit the number Six and for the Earth to use the number Five. This interplay implies the relationship of operation and principle of Yin in Yang and Yang in Yin. 5. There seems to be clear and intimate association between five dynamics, five bearings and five Qi' in nature and five organs, five stamina, and five emotions in physiological activities of human beings. Such an correlation apparently demonstrates the idea of climatic changes of the universe in balance among human beings, the Sky, and the Earth. 6. Because nature is of an endlessly dynamic organism itself, to have changes must mear there being movements. Thus the climatic changes in nature are the subsequent consummation of the interaction in mutual balance and unbalance of the rise and fall of the Five Woon and Six Qi. 7. The interpretation, by Chang Ji Chong of "Yin and Yang of the Sky are for birth and growth and Yin and Yang of the Earth for demise and interment" as an explanation that the first half is mainly for life and the second half for death, appears to be correct by his view that there is balance and harmony between the long and short and the strong and weak. 8. In addition to Three Yang and Three Yin, as attributes of the Intervals of the Sky and the twelve Intervals of the Earth, Five Woon and Six Qi are utilized in the annual observation of the perpetual changes of climates.

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ADVANTAGES OF THE AKARI FIR ALL-SKY MAPS

  • Doi, Yasuo;Takita, Satoshi;Ootsubo, Takafumi;Arimatsu, Ko;Tanaka, Masahiro;Morishima, Takahiro;Kawada, Mitsunobu;Matsuura, Shuji;Kitamura, Yoshimi;Hattori, Makoto;Nakagawa, Takao;White, Glenn;Ikeda, Norio
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.11-15
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    • 2017
  • We present the AKARI far-infrared (FIR) all-sky maps and describe its characteristics, calibration accuracy and scientific capabilities. The AKARI FIR survey has covered 97% of the whole sky in four photometric bands, which cover continuously 50-180 micron with band central wavelengths of 65, 90, 140, and 160 microns. The data have been publicly released in 2014 (Doi et al., 2015) with improved data quality that have been achieved since the last internal data release (Doi et al., 2012). The accuracy of the absolute intensity is ${\leq}10%$ for the brighter regions. Quantitative analysis of the relative intensity accuracy and its dependence upon spatial scan numbers has been carried out. The data for the first time reveal the whole sky distribution of interstellar matter with arcminute-scale spatial resolutions at the peak of dust continuum emission, enabling us to investigate large-scale distribution of interstellar medium in great detail. The filamentary structure covering the whole sky is well traced by the all-sky maps. We describe advantages of the AKARI FIR all-sky maps for the study of interstellar matter comparing to other observational data.

A Study on the Improvement of Classifying Method of the Sky Conditions for Application of the Daylight at Indoor - The Comparison with Cloud Amount and Measured Solar Horizontal Irradiation in Seoul - (실내 주광 활용을 위한 천공 구분 방법 개선에 관한 연구 - 서울의 전운량과 측정 일사량의 비교를 통해 -)

  • Kim, Yu-Sin;Kim, Hyun-Sun;Hong, Seong-Kwan;Park, Byoung-Chul;Choi, An-Seop
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.1
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    • pp.19-27
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    • 2010
  • Sky cover method can be used to determine sky condition by cloud amount of the Korea Meteorological Administration. And, HCI (Hourly Clearness Index) method is another method determined by measured horizontal global radiation data. The results of the HCI methods of Erbs et al. (1982), Orgill and Hollands (1977) seem to be not good enough because of the air pollution such as smog phenomenon or yellow sand phenomenon and so on. Therefore, HCI should be corrected. The aim of this study is to improve HCI. Therefore, this study is to analyze and compare on the sky conditions from Sky cover method and HCI, and then presents hourly correction factor based on Sky 채팩 method. The results of corrected HCI improved.

Efficient Dynamic Analysis of High-rise Buildings Having Belt Walls Connected by a Sky-Bridge (스카이브릿지로 연결된 벨트월이 있는 고층건물의 효율적인 동적해석)

  • Lee, Dong-Guen;Kim, Hyun-Su;Yang, Ah-Ram;Ko, Hyun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.3
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    • pp.231-242
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    • 2009
  • In the design of a sky-bridge, repetitive boundary nonlinear time history analyses are required to accurately predict dynamic behaviors of the connected buildings because the connection systems of a sky-bridge usually have high nonlinearity. If a conventional finite element model for entire high-rise buildings is used for repetitive boundary nonlinear time history analyses, computational efforts could be significant. In this study, an equivalent cantilever model considering the belt-wall effect has been proposed for an efficient dynamic analysis and a performance evaluation of vibration control of high-rise buildings connected by a sky-bridge. To verify the accuracy and efficiency of the proposed equivalent model, boundary nonlinear time history analyses of 49- and 42-story example buildings connected by a sky-bridge have been performed for wind excitation. Based on the analytical results, it has been verified that the proposed equivalent model can provide accurate dynamic responses of building structures connected by a sky-bridge with significantly reduced computational efforts.

Performance Evaluation of Vibration Control According to Installation Location of a Sky-bridge (스카이브릿지 설치위치에 따른 고층건물의 진동제어 성능평가)

  • Kim, Hyun-Su;Park, Yong-Koo;Ko, Hyun;Lee, Ui-Hyun;Lee, Dong-Guen
    • Journal of Korean Association for Spatial Structures
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    • v.10 no.3
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    • pp.65-74
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    • 2010
  • In this study, the vibration control effect according to the installation location of the sky-bridge and the difference of natural periods of the connected buildings has been investigated. To this end, 40-story and 50-story building structures connected by a sky-bridge were used as example structures and the equivalent modeling method was used. Boundary nonlinear time history analyses were performed using El Centro and Taft earthquakes to investigate the dynamic behavior of the example structures and vibration control effect of the sky-bridge. Based on numerical results, it has been shown that displacement responses can be effectively controlled as the installation floor of the sky-bridge increases and acceleration responses can be effectively reduced when the sky-bridge is installed on the mid-stories of the example building.

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Vibration Control of Adjacent Buildings using a Smart Sky-bridge (스마트 스카이브릿지를 이용한 인접건물의 진동제어)

  • Kang, Joo-Won;Chae, Seoung-Hun;Kim, Hyun-Su
    • Journal of Korean Association for Spatial Structures
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    • v.10 no.4
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    • pp.93-102
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    • 2010
  • In this study, a smart sky-bridge composed of MR damper and FPS has been proposed and vibration control performance of a smart sky-bridge for the connected buildings was investigated. To this end, 10-story and 20-story building structures connected by a smart sky-bridge were selected as example structures and El Centro and Kobe earthquakes, which have near and far fault ground motion characteristics respectively, were used for time history analyses. In order to effectively control the smart sky-bridge, fuzzy logic controller was developed and multi-objective genetic algorithm was used to optimize fuzzy logic controllers. Based on optimization results, it has been seen that there is a trade-off between seismic responses of 10-story and 20-story buildings and a suite of Pareto optimal solutions of fuzzy logic controllers for seismic response control can be obtained by multi-objective genetic algorithm. It is shown from numerical study that seismic responses of adjacent buildings can be efficiently controlled by using a smart sky-bridge.

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Region Segmentation Algorithm of Object Using Self-Extraction of Reference Template (기준 템플릿의 자동 생성 기법을 이용한 물체 영역 분할 알고리즘)

  • Lee, Gyoon-Jung;Lee, Dong-Won;Joo, Jae-Heum;Bae, Jong-Gab;Nam, Ki-Gon
    • Journal of the Institute of Convergence Signal Processing
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    • v.12 no.1
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    • pp.7-12
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    • 2011
  • In this paper, we propose the technique detecting interest object region effectively in the images from periscope of submarine based on self-generated template. First, we extract the sea-sky line, and divide it into sky and sea area from background region based on the sea-sky line. In each divided background region, the blocks which can be represented in each background region are set as a reference template. After dividing an image into several same size of blocks, we apply multi template matching to the divided search blocks and histogram template to divide the image into object region and background region. Proposed algorithm is adapted to various images in which objects exist in the background of sea and sky. We verified that proposed algorithm performed properly without given informmed prby prior learning.ropso, regardless of the slope of sea-sky line and the locmed p of object based on sea-sky line, we verified that the objects region was segmented effectively from the input image.