• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.45-54
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• 2002

The purpose of this study was to describe the gait pattern and parameters of the healthy elderly over 65years of age by the GATERite system. The subjects were sorted into two groups, depending on their sex: male and female. And female subjects were sorted into three groups, depending on their age. From time parameters and space parameters of gait cycle, between groups, the following results were made. The time parameters such as cadence, velocity, step time, single support and double support were the less the male than the female. And the higher age, the lower value except 80 age group, while no statistically significant. The space parameters(step length and stride length) were the longer the male than the female, and the higher age, the lower value while no statistically signigicant. The functional ambulation profile was high correlation with time and space parameters statistically significant.

• Communications for Statistical Applications and Methods
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• 제10권1호
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• pp.19-30
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• 2003

Spatiotemporal statistical models are used for analyzing space-time data in many fields, such as environmental sciences, meteorology, geology, epidemiology, forestry, hydrology, fishery, and so on. It is well known that classical spatiotemporal process modeling requires the estimation of space-time variogram or covariance functions. In practice, the estimation of such variogram or covariance functions are computationally difficult and highly sensitive to data structures. We investigate a Bayesian hierarchical model which allows the specification of a more realistic series of conditional distributions instead of computationally difficult and less realistic joint covariance functions. The spatiotemporal model investigated in this study allows both spatial component and autoregressive temporal component. These two features overcome the inability of pure time series models to adequately predict changes in trends in individual sites.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.874-879
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• 2014

This study is aimed to evaluate the acoustic performances of outdoor apartment complex and to analyze acoustic performances change based on greening conditions. The object space located in Seoul, Yangcheon-gu, Sinjung-dong and classified according to type of space-form. The measurement reverberation time at 500 Hz is 0.86~1.84sec. The simulated reverberation time at 500 Hz is decreased from 1.57sec to 0.57sec in ㅁshape type of 69% treatment with greening and 1.7sec to 0.89sec in ㄷshape type of 70% treatment and 1.05sec to 0.53sec in ㄴshape type of 61.6% treatment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2341-2350
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• 2012

Face detection is the first step of vision-based driver fatigue detection method. Traditional face detection methods have problems of high false-detection rates and long detection times. A space-time restrained Adaboost method is presented in this paper that resolves these problems. Firstly, the possible position of a driver's face in a video frame is measured relative to the previous frame. Secondly, a space-time restriction strategy is designed to restrain the detection window and scale of the Adaboost method to reduce time consumption and false-detection of face detection. Finally, a face knowledge restriction strategy is designed to confirm that the faces detected by this Adaboost method. Experiments compare the methods and confirm that a driver's face can be detected rapidly and precisely.

• 한국산업정보학회논문지
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• 제23권5호
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• pp.1-8
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• 2018

본 논문은 시공간 블록 코딩 알고리즘을 위한 간단한 암호화 기법을 제안한다. 시공간 블록 코딩 알고리즘은 데이터를 전송하는데 두 개의 안테나를 사용하며, 전송 데이터는 원래의 데이터와 수신기에서 결합하기 위하여 변형된 데이터로 구성된다. 이러한 종류의 두 개의 송신 안테나 데이터는 각각 상대방의 안테나와 교환되어 전송될 수 있으며, 이러한 방법은 간단한 암호화 알고리즘으로 사용될 수 있다. 암호화 시간 제어 정보는 송신기와 수신기 사이에서 미리 공유되어야 한다. 제안된 구조는 암호화 알고리즘이 없는 경우와 비교하여 성능이 향상됨을 제시하였다.

• ETRI Journal
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• 제28권5호
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• pp.680-683
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• 2006

One objective in developing the next generation of wireless communication systems is to increase data rates and reliability. A promising way to achieve this is to combine multiple-input and multiple-output signal processing with a space-time coding scheme, which offers higher coding and diversity gains and improves the spectrum efficiency and reliability of a wireless communication system. It is noted, however, that time delay differences and phase differences among different channels increase symbol interference and degrade system performance. In this letter, we investigate phase differences and their effects on multiple-input and multiple-output systems, and propose a compensation algorithm for the Rayleigh fading model to minimize their effects.

• Journal of Communications and Networks
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• 제9권2호
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• pp.177-184
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• 2007

Alamouti space-time code (STC) is a part of the UMTS-WCDMA standard. However, up to the best of our knowledge no exact closed-form outage and bit error probability (BEP) formulas for this famous code exists. Evaluating its performance through simulations is time-consuming and therefore, there should be analytical performance graphs to serve as a reference which are derived in this paper for coherently MPSK-modulated data. Additionally, analytical results take into account different channel fading levels from transmit antennas to receive ones.

• 천문학회보
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• 제44권2호
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• pp.60.2-60.2
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• 2019

Based on our experience on exoplanet transit observation, we propose the exoplanet science cases with Small Telescope Network. One is the follow-up observation for validation of exoplanet candidates. TESS(Transiting Exoplanet Survey Satellite) is pouring out exoplanet candidates in bright stars(V<15) on all the sky. Since Small Telescope Network will consist of 0.5-1m telescopes, we will expect to produce promising outcomes from the follow-up observation of bright candidates. Next is the transit time observation. By spectroscopy of space and large telescopes during transit event, it can be possible to find the bio signatures in exoplanet atmosphere. So, in terms of cost, it is critical to determine the exact time of transit event. In addition, detecting the variation of transit time can reveal another exoplanet and exomoon in the system. In order to determine the transit time and its variation, the accumulation of transit event data is more important than the quality of photometric data. We expect that it can be a challenging project of Small Telescope Network.

• Journal of Astronomy and Space Sciences
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• 제31권1호
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• pp.67-72
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• 2014

The next generation small satellite-1 (NEXTSat-1) program has been kicked off in 2012, and it will be launched in 2016 for the science missions and the verification of space core technologies. The payloads for these science missions are the Instrument for the Study of Space Storms (ISSS) and NIR Imaging Spectrometer for Star formation history (NISS). The ISSS and the NISS have been developed by Korea Advanced Institute of Science and Technology (KAIST) and Korea Astronomy and Space science Institute (KASI) respectively. The ISSS detects plasma densities and particle fluxes of 10 MeV energy range near the Earth and the NISS uses spectrometer. In order to verify the spacecraft core technologies in the space, the total of 7 space core technologies (SCT) will be applied to the NEXTSat-1 for space verification and those are under development. Thus, the operation modes for the ISSS and the NISS for space science missions and 7 SCTs for technology missions are analyzed for the required operation time during the NEXTSat-1's mission life time of 2 years. In this paper, the operational concept of the NEXTSat-1's science missions as well as the verification of space core technologies are presented considering constraints of volume, mass, and power after launch.

• 한국실내디자인학회논문집
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• 제26권6호
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• pp.3-12
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• 2017

As the quality of life has improved today, there is a growing desire among consumers for new space and interest in spending their valuable time in 'the third space' has tended to increase. Cafes have been integrated with sales and exhibition space as the representative third space. For example, it's cafe type automobile exhibition centers. The purpose of this study is to examine the characteristics of 'the third space' in cafe type automobile exhibition centers and suggest a plan for effective spatial characteristics. It checked the necessity of the third space' in automobile exhibition centers by analyzing automobile consumption trends of the 21st century according to industry change and restructures a checklist by grasping cafe type automobile exhibition centers and the concept and characteristics of 'the third space' based on the precedent studies. A questionnaire is made through the checklist drawn and a survey is conducted targeting users of the target areas of cases. The target areas of cases are 4 cafe type automobile exhibition centers opened in Korea since 2014. The analytical results of the target areas of cases that reflected the characteristics of 'the third space' are as follow: First, cafe type automobile exhibition centers must be built to make customers enter the space and at the same time, receive information on automobiles and space naturally. Second, in order to increase satisfaction with the space and brands, there is the necessity to arouse their interest through various experiences including test driving cars directly. Third, revisit intention can be found to be more influenced by spatial design than brand satisfaction. Fourth, partitions or interior for dividing the space need to be improved. In the next studies, specific research on plans about creating design to improve corporate image and brands and induce customers to revisit cafe type automobile exhibition centers by applying the characteristics of 'the third place' to them is required.