• Journal of Astronomy and Space Sciences
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• 제20권2호
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• pp.95-100
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• 2003

This paper is for the investigation of the relationship between the geomagnetic disturbances and the relativistic electron events occurring at geosynchronous orbit. We have analyzed the electron fluxes of E > 2 MeV measured by GOES 10 satellite and the hourly Dst index for the period of April, 1999 to December, 2002. With the rigorous definition of the relativistic event, total 34 events were identified during the time period. Our statistical study showed that more than 50% of the total events occurred associated with weak (or sometimes virtually no) magnetic storms. And only ~ 20% of the events took place accompanied by a strong magnetic storm of $Dst_{min}$ < -100 nT. This result suggests that large geomagnetic storms may not be crucial for the occurrence of a relativistic event at geosynchronous orbit. We also found that there is no clear correlation between the maximum electron flux of an event and the associated minimum of Dst. Therefore any study on the physical mechanism (s) accounting for the relativistic events should take it into account that strong magnetic storms may not be necessarily required for the occurrence of a relativistic electron event at geosynchronous orbit.

• 대한인간공학회지
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• 제34권3호
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• pp.223-234
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• 2015

Objective:This study aims to investigate the correlation between office environment satisfaction levels and workers' subjective symptoms by conducting surveys asking office workers to state their subjective symptoms and office satisfaction levels. Background: The increased number of office workers and their work hours have led to new understandings of the importance of office environments including its temperature, humidity, noise levels, lighting, space arrangements, and quality of air. Method: Specific details on office work, office environment, office space satisfaction levels, workplace related symptoms, absence from work, due to workplace-related symptoms, were analyzed based on the survey answers given by 451 office workers who were the subjects of this research. Results: Office workers showed different characteristics of subjective symptoms depending on their gender, age, work experience, and time spent resting and on computers. Also, differences in symptoms were found for workers with different satisfaction levels for office environment (temperature, humidity, noise levels, quality of air, lighting) and office space arrangements (location of monitors, area and display of office space, chairs and desks). Conclusion and Application: Relationship between workers' satisfaction levels with the office environment and their subjective symptoms is expected to be serve as essential data for systematic management of the workplace.

• KIEAE Journal
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• 제10권5호
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• pp.43-55
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• 2010

This research investigated 162 residential unit plans which were located in Seoul and Gyonggi Province ranging from 58 to $118m^2$ unit net area recently. Through the investigation of unit plans, a matrix was developed based on the 5 criteria for space composition types. 5 criteria are building stock types, W/D ratio of units, unit net area, number of bay to the main orientation, and openness types. After review the matrix, 10 typical unit types were selected. At the same time, quantitative evaluation indicators were developed based on the 4 criteria such as efficiency, openness, flexibility, environmental sustainability. On each criterion, 3 indicators were developed, and measured on 162 residential unit plans. Firstly, correlation analysis were pursued on 5 criteria for space composition types and 12 quantitative evaluation indicators, and reviewed on each other. Finally, quantitative evaluation indicators of 10 typical unit types were displayed on radar charts in order to show the integrated evaluation on 4 criteria such as efficiency, openness, flexibility, environmental sustainability. From the reviews and radar chart analyses, advantages, disadvantages, and improvements on each typical unit type were presented as research results.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4184-4190
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• 2014

본 연구의 목적은 요양시설 입소노인의 일반적 특성에 따른 스트레스와 생활행동지수를 파악하고자 한다. 연구대상은 서울시 N구에 거주하는 입소노인과 강원도 횡성군 S면 거주하는 입소노인 110명 대상으로 2013년 5월 1일부터 9월30일까지 설문조사를 실시하였다. 자료 분석은 SPSS/WIN 18.0 프로그램을 이용하여 t-test, 상관분석, 다중회귀분석방법 등을 실시하였고, 실증분석은 유의수준 5%에서 검증하였다. 분석결과는 첫째, 입소 증후군은 일상적 스트레스의 가족왕래부족 스트레스와 정의 상관이 있었다. 둘째, 우울증상은 일상적 스트레스의 개인시공간부족, 가족왕래부족 스트레스와 정의 상관이 있었다. 셋째, 체중조절은 일상적 스트레스의 개인시공간부족 스트레스와만 정의 상관이 있었으며, 영양결핍증상은 일상적 스트레스의 가족왕래부족 스트레스와만 정의 상관이 있었다. 본 연구의 시사점은 입소노인의 일반적 특성에 따른 스트레스와 생활행동지수 정책의 기초자료가 될 것으로 사료된다.

• Journal of Astronomy and Space Sciences
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• 제22권4호
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• pp.431-440
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• 2005

K 지수는 특정 지역에서의 지자기 변동을 나타내는 지수로서 3시간마다 결정된다. K 지수를 결정하는 알고리즘은 태양복사의 규칙적인 일변화(Sq)를 결정하는 방법에 따라 다양하다. 그 중에서 FMI 알고리즘은 K 지수를 구하고자 하는 날과 그 전 후의 1일 자료를 포함한 총 3일 동안의 지자기 수평성분(H, D) 측정 자료를 사용하여 태양복사의 규칙적인 일변화(Sq)를 구한다. 그러나 이 알고리즘은 K 지수를 구하고자 하는 날로부터 1일 후까지의 측정 자료가 필요하기 때문에 실시간으로 K 지수를 구하는 경우에는 어려움이 있다. 본 연구에서는 준실시간으로 K 지수를 구하기 위해 미국 우주환경예보센터(NOAA/SEC)에서 제공하는 과거의 전지구적 지자기 K지수(Planetary K index: Kp)를 검색하여 최근의 Kp지수가 모두 3 이하인 지자기 활동이 조용한 날을 찾고 그 날의 지자기측정 자료를 FMI 알고리즘의 3일치 입력 자료로 사용함으로써 준실시간 K 지수를 구하는 방법을 고안하였다. 이러한 방법을 검증하기 위해 우리는 2003년 1년 동안 한국지질자원연구원에서 운용하는 경주 지자기 관측소의 FLARE+ 시스템으로 측정된 자료를 사용하고 우리의 준실시간 결정 방법을 적용하여 K 지수를 구하고 이를 일반적인 FMI 알고리즘으로 구한 K지수와 서로 비교하였다. 그 결과, 우리의 방법으로 결정된 K 지수는 일반적인 방법으로 구한 K 지수와 잘 일치하였다. 또한 준실시간 결정 방법으로 구한 K 지수를 일본 Kakioka 관측소에서 결정한 K 지수와 비교한 결과 그 상관지수(R)가 0.81 정도로 높음을 확인하였다. 본 연구의 결과는 향후 한반도 지역에서의 K 지수 변동을 준실시간으로 모니터링 하는데 활용될 수 있을 것으로 기대된다.

• 한국실내디자인학회논문집
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• 제23권3호
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• pp.48-55
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• 2014

Luis Barragan is a representative Mexican architect. He designed architectural space as a local architect in consideration of the Mexico's harsh Mediterranean climate. His manifestation of the regionality can be found mainly in his precise expression of light. Such method and concept of using light in Barragan's architecture made a huge impact on later architects but detailed studies on this issue have not been made actively. Hence, this paper intended to suggest a starting point or an orientation by illustrating the characteristics of using and expressing light in architecture through his cases of housing works. The study method was as follows. First, the general characteristics of light were identified by analyzing the elements of architectural space that dealt with light and the characteristics of expressing light shown in the architectural space. Second, the architectural background of Luis Barragan and the architectural space elements of the light expressed in his architectural space were extracted to form a hypothetical ground. Third, five of his works on the houses in his prime (after the year of 1945) were analyzed to explore the characteristics of relational representation between light and the architectural space elements in his architecture. Through this process, it was learned that, in his architectural works, light was the embodiment of the location-related, time-based, daily and illusionary experience into architecture. In addition, meditative light could be experienced by contrasting the soft and dispersed light and shadow of the inside space of Barragan's houses with the strong external light. Therefore, through the process above, this study is hoped to provide an opportunity for the contemporary architects of our era to rethink the fundamental correlation between architecture and light.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1689-1694
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• 2005

Face detection plays an important role in face recognition, video surveillance, and human computer interface. In this paper, we present a face detection system using eye detection with progressive thresholding from a digital camera. The face candidate is detected by using skin color segmentation in the YCbCr color space. The face candidates are verified by detecting the eyes that is located by iterative thresholding and correlation coefficients. Preprocessing includes histogram equalization, log transformation, and gray-scale morphology for the emphasized eyes image. The distance of the eye candidate points generated by the progressive increasing threshold value is employed to extract the facial region. The process of the face detection is repeated by using the increasing threshold value. Experimental results show that more enhanced face detection in real time.

• 천문학회지
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• 제24권1호
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• pp.117-127
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• 1991

Here I report the confirmation of a long-term modulation of a period of $92^{+21}_{-13}$ years with the "time-delay correlation" method on the sunspot data compiled over the last a total of 289 years. This periodicity better specifies the cycle which falls pretty well within Gleissberg cycle, and clearly contrasts with the 55 year grand cycle which Yoshimura (1979) claimed. It is argued that the period-amplitude diagram method. which Yoshimura used, ana lysed peak amplitudes only so that a large number of data were disregarded, and thus was more susceptible to a bias. The planetary tidal force on Sun as for the possible cause to the solar activity was investigated and its possibility was ruled out in view of no period correlation between them.

• 한국환경교육학회지:환경교육
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• 제11권2호
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• pp.252-261
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• 1998

Since 1980's during which environmental pollution became serious enough to urge various types of environmental educations in many areas. But, most emphasis has been put on theoretical education. Even field education training mostly focused on water pollution. Therefore, simple air pollution monitoring system was needed for better field education in air pollution. In this study, we evaluated Passive Sampler as an useful tool for teaching air pollution in field. Students have found passive sampler very effective tool. Recent comparative study of auto-monitoring and passive sampler networks suggested a potential use of passive sampler as an useful tool for environmental education. In this study, the correlation between two sets of values appears very high judging from the regression slope of 0.92 and correlation coefficient of 0.91 However, inexpensive Passive sampler with easy-to-operate colorimeter, has not been used in environmental education partially because large scale fluctuation in time and space characteristic to air pollution has been overlooked so that the sampler has not been tested for an effective educational tool. Passive sampler certainly deserves further in depth research as an effective air monitoring system, and better attention to its usefulness to teach students and public.

• Journal of Mechanical Science and Technology
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• 제19권8호
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• pp.1682-1691
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• 2005

Direct numerical simulation database of an axial turbulent boundary layer is used to compute frequency and wave number spectra of the wall shear-stress fluctuations in a low-Reynolds number axial turbulent boundary layer. One-dimensional and two-dimensional power spectra of flow variables are calculated and compared. At low wave numbers and frequencies, the power of streamwise shear stress is larger than that of spanwise shear stress, while the powers of both stresses are almost the same at high wave numbers and frequencies. The frequency/streamwise wave number spectra of the wall flow variables show that large-scale fluctuations to the rms value is largest for the stream wise shear stress, while that of small-scale fluctuations to the rms value is largest for pressure. In the two-point auto-correlations, negative correlation occurs in streamwise separations for pressure, and in span wise correlation for both shear stresses.