• 대기
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• 제28권3호
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• pp.317-324
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• 2018

In this study, we review the ground-based whole-sky camera (WSC), which is developed to continuously capture day and night cloud images using the illumination data from a precision Lightmeter with a high temporal resolution. The WSC is combined with a precision Lightmeter developed in IYA (International Year of Astronomy) for analysis of an artificial light pollution at night and a DSLR camera equipped with a fish-eye lens widely applied in observational astronomy. The WSC is designed to adjust the shutter speed and ISO of the equipped camera according to illumination data in order to stably capture cloud images. And Raspberry Pi is applied to control automatically the related process of taking cloud and sky images every minute under various conditions depending on illumination data from Lightmeter for 24 hours. In addition, it is utilized to post-process and store the cloud images and to upload the data to web page in real time. Finally, we check the technical possibility of the method to observe the cloud distribution (cover, type, height) quantitatively and objectively by the optical system, through analysis of the captured cloud images from the developed device.

• 한국주거학회논문집
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• 제17권3호
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• pp.99-109
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• 2006

The purpose of this study was to analyze the characteristic of each view in an apartment unit in terms of the quality. This study was accomplished by two research methods; the field survey on 181 apartment complexes in Daegu, and the preference evaluation on 24 cases sampled in the sense of its location, i.e. inside or outside of a complex. In the field survey, view targets were categorized into various items such as a building, a road, a mountain, a tree, another apartment, the sky, and so on, and the characteristics of the distance from a viewer to view targets and view of the level in an apartment were analyzed. In the preference evaluation, 24 cases, each one has one of the follows; the natural view, the artificial view, and the combined view of the both, were chosen and those were evaluated by 167 interviewees. As a result, the conclusions from the study were drawn as follows; 1) The view, the combination of buildings, roads, mountains, trees, apartments, and the sky, is usually seen in an apartment unit. 2) The type of view target is more significant to a person than its location. 3) The natural and combined view are preferred to the artificial one. 4) In the case of the same outside view, a person likes the open view more than the somewhat covered one.

• 한국산학기술학회논문지
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• 제14권6호
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• pp.3068-3073
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• 2013

근래에 스카이브릿지를 활용하여 연결된 고층구조물의 진동제어성능을 개선하고자 하는 연구가 수행되고 있다. 본 논문에서는 스카이브릿지로 연결되는 두 구조물의 고유진동주기의 차이와 스카이브릿지 설치위치가 진동제어성능에 미치는 영향에 대해서 분석하여 보았다. 이를 위하여 40층과 50층 구조물을 연결된 예제구조물로 선택하였고 두 구조물의 고유진동주기 차이를 1.0배에서 1.5배까지 순차적으로 변경하면서 해석모델을 구성하였다. 각각의 해석 모델에 대하여 KBC2009를 기반으로 생성한 인공지진하중을 입력 하중으로 생성하여 시간이력해석을 수행하였다. 수치해석결과 두 구조물의 고유진동주기차이가 증가할수록, 연결된 층의 높이가 높아질수록 변위 및 속도응답에 대해서 일반적으로 우수한 제어성능을 나타내는 것을 알 수 있었다. 그러나 가속도응답의 경우에는 이러한 경향과 반대되는 제어성능변화를 나타내었다.

• 천문학논총
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• 제30권2호
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• pp.675-677
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• 2015

A data simulator and reduction package for the Devasthal Optical Telescope Integral Field Spectrograph (DOTIFS) has been developed. Since data reduction for the Integral Field Spectrograph (IFS) requires complicated procedures due to the complex nature of the integral spectrograph, common reduction procedures are usually not directly applicable for such an instrument. Therefore, the development of an optimized package for the DOTIFS is required. The data simulator observes artificial object and simulates CCD images for the instrument considering various effects; e.g. atmosphere, sky background, transmission, spectrograph optics aberration, and detector noise. The data reduction package has been developed based on the outcomes from the DOTIFS data simulator. The reduction package includes the entire processes for the reduction; pre-processing, flat-fielding, and sky subtraction. It generates 3D data cubes as a final product, which users can use for science directly.

• 한국지구과학회지
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• 제40권5호
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• pp.464-475
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• 2019

대부분의 중 고등학교가 도심지에 위치하며 사용할 수 있는 천문 관측 장비에 제한이 있다는 점을 고려하여 DSLR 카메라와 교육용 소형 망원경을 결합하여 도심지 밤하늘 밝기를 측정하였다. DSLR 카메라의 다양한 설정은 ISO 설정 외에는 원본 파일에 영향을 주지 않았으며, 필터 변환까지 고려한 일반적인 측광 정밀도는 대략 0.1 등급이다. 밤하늘 밝기는 천정 부근의 경우 B, V, r 필터에서 각각 약 17.5, 17.1, $16.9mag\;arcsec^{-2}$으로 측정되었다. 이를 통해 도심지의 대략적인 한계등급은 B 필터에서 17.5 등급, V와 r 필터에서 17등급으로 추정할 수 있다. 관측지점과 가까운 대규모 인공 조명은 고도와 필터에 무관하게 밤하늘 밝기를 약 $0.6mag\;arcsec^{-2}$ 증가시킴으로써 관측 환경을 악화시키는 주요인으로 나타났다.

• Architectural research
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• 제1권1호
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• pp.31-40
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• 1999

In this age of "Information", many people consider it a deterrent to information flow to provide a hierarchy with private rooms in a modern office layout. There are others, however, who insist that visual and acoustical privacy are more important than any other design factor in achieving higher productivity. The debate may never end, but the partitioned open plan, which is a new form of the vast open plan, has merits of each concept - open and closed layout. Consequently, office design has dramatically shifted to partitioned open planning, with shorter, temporary walls or partitions, originally intended for increasing privacy and diminishing hierarchy, yet still keeping flexibility in spatial organization. The introduction of low-level partitioned spaces in an office layout, however, produces a complicated lighting design problem. Obviously, accurately predicted daylighting performance data are needed not only for daylighting design but for artificial lighting system design. Scale models of 12 sets of unit partitioned spaces are constructed and extensive scale model measurements of both daylight and reflected sunlight have been performed within an artificial sky simulator. The prototype-building interior is modeled with different partition configurations, each of which is modeled using the different envelope geometry and exterior configurations, and then the variations in interior light levels are estimated. The result indicates that partitioned spaces employed in an open plan of modern offices still offer a large potential for daylighting and energy saving as well. Much of the savings may derive from the cumulative effect of reflected sunlight. Optimal design for building envelope geometry and exterior configuration promises additional savings.

• 환경영향평가
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• 제28권1호
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• pp.63-70
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• 2019

인공조명은 필수적인 부분이지만, 불필요하거나 과도한 빛의 사용으로 인해 빛공해를 유발시킨다. 빛공해는 전력낭비, 인체의 건강상 악영향, 생태계 파괴 등과 같은 부정적인 영향으로 국 내외에서 법적인 규제를 하고 있다. 하지만 현재는 조명기구 설치 이후의 방법으로만 관리하기 때문에 사전에 빛공해가 유발될 우려가 있는 지역을 효과적으로 관리하고 영향을 저감시키기 위한 빛공해분야 영향평가지침을 제안하고자 한다. 영향평가작성지침을 수립하여 작성자 및 검토자의 혼란을 방지하고 중장기적으로 국내의 빛공해 관리를 효과적으로 수립하는데 활용하고자 한다.

• 인간식물환경학회지
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• 제24권1호
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• pp.85-94
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• 2021

Background and objective: This study examined, compared, and analyzed the tree vitality of the trees growing on the artificial ground of Seoullo 7017 that transformed the overpass that was to be demolished into a "sky garden" using portable tree pots. Methods: Based on the summer season when the metabolic activity of plants is most active, this study measured the cambial electrical resistance in four directions(east, west, south and north), using the Shigometer (model OZ-93, Osmose) and compared the location and analysis of pots according to their means and standard errors. Results: Meanwhile, according to the analysis, vitality was relatively superior in pots with a big diameter, trees planted individually than in groups, trees of the ramp section rather than the bridge section, and in the southwest direction of the cambium. Conclusion: This study revealed the improper condition of the planting plan and implementation on the site, where various species of trees are displayed in a poor environment. Despite the significant assessment of the vitality of various trees introduced within Seoullo 7017 for the first time, this study is limited in that the data used were measured only once in summer. In this regard, it raised the need for continuous interest in and monitoring of a special plant environment and development of proper maintenance and management techniques, along with follow-up research on seasonal and temperature conditions, soil moisture and root development conditions to supplement this research.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.34-37
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• 2005

An efficient and robust neural network-based scheme is introduced in this paper to perform automatic cloud detection. Unlike many existing cloud detection schemes which use thresholding and statistical methods, we used the artificial neural network methods, the multi-layer perceptrons (MLP) with back-propagation algorithm and radial basis function (RBF) networks for cloud detection from Geostationary satellite images. We have used a simple scene (a mixed scene containing only cloud and clear sky). The main results show that the neural networks are able to handle complex atmospheric and meteorological phenomena. The experimental results show that two methods performed well, obtaining a classification accuracy reaching over 90 percent. Moreover, the RBF model is the most effective method for the cloud classification.

• 수면정신생리
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• 제27권1호
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• pp.1-7
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• 2020

Mobile digital devices are very familiar and useful devices in the daily life of modern people, and are used for various tasks such as communication, reading, writing, and playing media. As the use of mobile digital devices has become more prevalent, user time has also been increasing. In particular, the number of people who use digital devices before sleep is growing. The light pollution associated with these devices is classified into four categories: urban sky glow, glare, light trespass, and clutter. The pattern in which modern people use digital devices corresponds to light pollution caused by light trespass and clutter from light exposure to artificial light at night. The light pollution caused by digital devices can cause melatonin secretion suppression, delayed sleep onset, reduction of sleepiness before bedtime, and periodic rhythm and cognitive function disturbances. In addition, a study of children and adolescents showed there may be disturbances in the sleep-wake cycle and circadian rhythm, deterioration of sleep quality, and daytime fatigue due to light pollution caused by artificial light at night from mobile digital devices. A multi-faceted research effort is also necessary to investigate the healthy use of mobile digital devices based on research evidence and insights with an accurate evaluation of the influence of mobile digital devices as a form of light pollution.