• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2011년도 한국우주과학회보 제20권1호
• /
• pp.20.2-20.2
• /
• 2011

The NASA Antarctica balloon experiment CREAM has successfully collected the data of energetic cosmic rays during flights in past years. We will present the recent analysis results of the CREAM experiment. We will also report on the launch and recovery process of the latest flight. The silicon charge detector of the CREAM has played the key role in the precision measurement of the charge constitution of energetic cosmic rays. We proposed the upgrade of the CREAM experiment with the installment of a new large silicon charge detector on top of the CREAM instrument. The charge measurement of the large silicon detector with no material in front is expected to improve the accuracy of the CREAM charge measurement drastically when combined with the measurement of the existing double layer silicon detector. We will present the fabrication of the large silicon detector and its performance in the radiation source test as well as in the beam test.

• 한국항공우주학회지
• /
• 제46권10호
• /
• pp.798-805
• /
• 2018

본 연구에서는 극초음속 충격파 풍동시험에 대한 적응적 실험 계획법 기반 접근법을 소개한다. 원뿔형 모델의 피치 모멘트를 받음각과 피치 각속도에 대한 함수로 모델링하기 위해 일련의 실험들을 수행하였다. 또한 다수의 시계열 실험 데이터를 효과적으로 분석하기 위해 초고속 카메라를 통해 획득한 실험 이미지로부터 실험 모델의 궤적을 구성하기 위한 알고리즘을 개발하였다. 해당 알고리즘을 활용해 이전 실험에 대한 분석 결과를 토대로 다음 실험점을 결정하는 적응적 실험 계획법을 제안한다.

• 한국정보통신학회논문지
• /
• 제11권8호
• /
• pp.1596-1603
• /
• 2007

본 논문에서는 음성인식 시스템을 구현함에 있어 중요한 특징 파라미터와 학습, 인식 알고리즘의 선택을 위한 제안을 하기 위하여 각각 세 가지의 방법을 조합하여 인식 실험을 수행하고 검토하였다. 두 종류의 실험을 통하여 하드웨어 장치로 구현할 경우 보다 효과적인 음성 인식 시스템을 제안한다. 첫 번째로는 특징 파라미터의 성능을 평가하기 위하여 기존의 MFCC와 MFCC를 PCA와 ICA를 이용하여 특징 공간을 변화시킨 새로운 특징 파라미터를 제안하여 총 3종류의 특징파라미터에 대한 인식 실험을 수행하였으며, 두 번째로는 학습데이터 수에 따른 HMM, SVM, RVM의 인식 성능을 실험하였다. 이상의 실험에 의하여 ICA에 의한 특징 파라미터가 특징 공간상에서의 높은 선형 분별성에 의해 MFCC와 비교하여 평균 1.5%의 성능향상을 확인할 수 있었으며 학습데이터의 감소에 따른 인식실험에서는 HMM과 비교하여 RVM에서 최고 3.25%의 성능향상을 확인하였다. 이에 근거하여 TI사의 DSP(TMS320C32)를 사용하여 음성 인식기를 구현하여 실시간으로 실험하여 시뮬레이션과 비교하였다. 이와 같은 결과로서 본 논문에서 제안하는 음성인식시스템을 위한 효과적인 방법은 ICA를 이용한 특징 파라미터를 추출하고 RVM을 이용하여 인식을 수행하는 것이라 판단한다.

• 한국항공우주학회지
• /
• 제38권11호
• /
• pp.1067-1074
• /
• 2010

본 연구에서는 이중 쐐기형 초음속 흡입구의 압력회복률에 대한 신뢰성 최적설계를 수행하였다. 주어진 설계영역에서 다양한 설계변수의 불확실성을 고려하여 흡입구의 압력회복률을 확률적으로 모델링하였으며, 목적함수로는 흡입구 항력을 선정하였다. 신뢰성 최적설계에 앞서 전산해석비용을 줄이기 위해 실험계획법과 크리깅 모델을 이용하여 적절한 설계공간을 탐색하였다. 신뢰성 기법의 정확도 검증을 위해 몬테카를로 시뮬레이션을 수행하였으며 이 결과를 신뢰성 기법 결과가 잘 추종함을 확인하였다. 신뢰성 기반 최적설계를 수행한 결과, 설계변수의 불확실성을 고려함으로써 시스템의 신뢰성을 확보하였다. 시스템 설계의 다양한 불확실성을 고려하기 위해서는 신뢰성 기반 최적설계가 유용한 접근방법임을 확인할 수 있었다.

• 디자인학연구
• /
• 제15권3호
• /
• pp.167-180
• /
• 2002

작은 화면에서 방대한 규모의 정보를 보기 위해서는 정보구조가 잘 조직화되어야 하고, 항해 보조장치가 적절하게 제공되어야 한다. 본 연구는 위계적인 구조(Hierarchical structure)를 지닌 정보공간을 작은 디스플레이 공간(small screen)에서 제시할 때 사용자가 실제 공간 구조차 유사하게 내적 모형(internal model)을 형성하도록 하기 위하여 어떻게 항해 단서(navigation cue)를 제공하는 것이 효과적인지를 밝히고자 하는데 그 목적이 있다. 본 연구에서는 색을 중심으로 연구내용이 이루어 졌으며, 이는 색이 가지고 있는 속성과 색공간 개념이 위계구조의 정보공간과 잘 맵핑될 수 있다고 판단되었기 때문이다. 정보공간을 위한 색공간은 색상과 톤 개념을 기반으로 정의되었다. 1차 사전 설문조사가 진행되었고, 2차 본 실험을 통해서 색 단서(color cue) 제공이 사용자의 공간구조 이해 및 항해 성과(navigation performance)에 미치는 영향을 실증적으로 검증하였다. 실험 결과는 첫째, 카테고리 구분을 위해 사용된 색상은 정보공간의 개념을 이해하는데는 도움이 되지만, 항해 성과에는 부정적인 영향을 주었다. 둘째, 톤으로 제공된 정보 깊이에 대한 단서는 정보공간의 개념 이해에도 별 도움이 되지 않았으며, 항해 성과에도 역시 부정적인 영향을 주었다. 본 연구는 연구결과의 제한점과 향후 연구에 대한 기술로 마무리하였다.

• 대한건축학회논문집:구조계
• /
• 제36권3호
• /
• pp.159-167
• /
• 2020

For modern people who spend most of their time indoors, the indoor environment is very important. The efficiency of work depends on the amenity level of the occupants who use the office space. Therefore, the experiment was conducted to derive the proper illuminance according to the amenity level of the occupants. The experiment was conducted in an office in Chilgok County for 6 days. The illuminance of the indoor was changed every day, the feeling brightness of the occupants was measured every 10 minutes, the eye fatigue was measured every 30 minutes, and the overall illuminance and the work surface illuminance were measured every hour. Experimental results show that the feeling brightness is different depending on the position of the occupants. Also, it was found that the brightness survey preferred by the occupants required more proper illuminance than the brightness. In addition, it is considered that there is a correlation with indoor temperature and humidity as the eye fatigue of occupants. Brightness preference by time of day was analysis from feeling brightness of occupants and preference brightness of occupants, and then it was analyzed like eye fatigue to derive proper illuminance per hour. Based on these results, it can be utilized for improvement of eye amenity existing office space.

• 한국실내디자인학회논문집
• /
• 제21권4호
• /
• pp.87-95
• /
• 2012

This study is for the analysis to which element of space the users observing the lobby at a public space pay more attention for their visual perception. It is focused on the typology process of observation characters. The subjects, in the observation process, came to be interested in the circumstantial clues for space perception and the detailed characters drawing their interest. I could analyze the observation characters of the subjects observing the space by the comprehension and typology of their observation characters. First, from the viewpoint of successive 9 times of observations, each subject observed for 0.32 second to get the visual perception in the applied space, but spent another 0.39 second for the exploration of another observation object or the space roaming. The observation character of the subjects at the lobby of the public space selected for this experiment was that they spent more time on space exploration than on concentration on a point in the space. Second, I analyzed the typology process through the time range. Since the subjects' frequency varied depending on the way to set up the time range, the necessity was proposed that the time range for the analysis of observation characters should be set up more objectively. Third, in case of analyzing the observation characters by 10-second-unit time range, the concentration in the beginning and the middle was 25%, and that in the beginning and the final 41.7%, which showed that 75% of the subjects concentrated in the beginning of the observation time when the concentration in the beginning is added to it. Fourth, the type 3 categorized as "concentration in the beginning and the middle" is the group 47.1 percent of the subjects belong to, and each subject concentrated 1.1 times in the beginning and 2.1 times in the final, which showed that the concentration in the final was 1.75 times as high as that in the beginning.

• 천문학논총
• /
• 제28권3호
• /
• pp.95-100
• /
• 2013

A fiber-optic reference signal transmission system, which transmits the 1.4 GHz reference signal from H-maser to receiver cabin in radio telescopes, was adopted for compensating the phase changes due to temperature variation and antenna movement. At the first experiment, the remote signal's phase changed more than 15 degrees at 1.4 GHz. We found unstable components in sub-system experiments and replaced them. The main cause of unstable phase stability was the unaligned polarization axis between Laser Diode and Mach-Zehnder Modulator (MZM). The improved system stability showed $1{\times}10^{-16}$ allan standard deviation at 1,000 sec integration time with the antenna fixed. When the antenna moves in the azimuth axis, the 1.4 GHz remote signal showed the phase change smaller than 0.2 degrees.

• International Journal of Aeronautical and Space Sciences
• /
• 제3권1호
• /
• pp.61-73
• /
• 2002

This paper addresses the conceptual design results of the HAUSAT-1 (Hankuk Aviation University SATellite-1), developed by Space System Research Lab. of Hankuk Aviation Univ., which is a new generation picosatellite. This project has been funded by Korean Government for the purpose of developing the space core technology. This is the first attempt at the level of university in Korea to develop the satellite weighing less than 1kg and accelerates opportunities with low construction, low launch cost space experiment platforms. The purpose of the HAUSAT-1 project is to offer graduate and undergraduate students great opportunities to be able to understand the design process of satellite development as a team member. Its mission objectives are to track its position by the GPS receiver system, to deploy the thin film solar cell panel to generate extra power, and to measure plasma density and temperature with the plasma sensor. The HAUSAT-1 will orbit at the altitude of 650 km with 65 degree inclination angle with 12 months of design mission life. It is planned to be launched on November 2003 by Russian launch vehicle "Dnepr".

• 한국실내디자인학회논문집
• /
• 제21권5호
• /
• pp.145-152
• /
• 2012

Since 1966 when James Turrell completed his studies on Art, he has been working on the consistent theme of Art. For the 46 years of time, site contexts, scales, methods of light have been changed and they made Turrell's unique 'project series'. Each series has different spatial, visual-perceptual forms and characteristics from other series. The differences were caused by the given situations, but also Turrell intentionally pursued it. However, there are essential theme of art that has not changed in most of Turrell's projects. Target of this paper is to study the unchanged theme as well as the differences. The study starts with three questions: first, what is the geometrical space composition?, second, what is the visual-perceptual phenomenon?, third, what is the hidden consistent theme? This research focuses on three case projects: Wedgework, Space Division Constructions, Skyspaces. These project series are in between the early small object-like installations and the late mega-scale outdoor projects. The study found that geometrical space composition has important role to give visual-perceptual dynamism to the viewer. The phenomenological perception is connected to the questions of relationship between human and space, ultimately human and the world. Although the Merleau-Ponty's philosophy has been related to the work of Turrell in various previous studies, Cartesian 3-dimensional geometry has also crucial role to experiment a viewer's perceptual boundaries. Image of infinity is another aspect of three cases, especially Space Division Constructions and Skyspaces. Through these structure, Turrell's work lead to an ultimate question of meaning for human existence in infinite space. It is hoped that this paper is helpful for Architecture and Interior design field in which light and space are essential.