• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.68.2-68.2
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• 2011

KVN은 2008년말에 3 대의 망원경 구축을 완료하고, 2009년에는 22/43 GHz 수신기를 각 망원경에 설치하였으며, 2009년말부터는 이 망원경들을 이용한 단일안테나 연구관측 및 VLBI 시험관측에 착수하였다. 2010년에는 86 Hz 수신기 1 대를 도입하였고, 129 GHz 수신기의 경우 믹스 개발을 완료한 후 현재 수신기 1대를 조립하고 있다. 적어도 1 set의 86/129 Hz 수신기가 금년 내에 연세망원경에 설치되어 시험관측이 수행될 예정이다. 2010년에는 또한 안테나의 크래딩 작업을 완료하여 지향성을 개선하였으며, 단일 안테나 연구관측 결과를 논문으로 생성하기도 하였다. 2011년말부터는 VLBI 연구관측에 착수할 예정이며, 관측시간의 50 %를 일본의 VERA와 공동관측에 활용할 예정이다. 2010년말에는 동아시아VLBI센터 건물의 건설이 착수되었으며, 2012년 6월경에 완공될 예정이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.296-303
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• 2008

Co-existence of various wireless systems may cause frequency interference problem. For this reason, frequency sharing studies play a very important role in order to use limited spectrum resources efficiently. Especially, because a satellite system covers a global area in nature, the frequency sharing between the satellite system and terrestrial systems is essential. For satellite systems using Ka bands, we can increase spectrum efficiency by considering off-axis angles of earth station antenna. In this paper, we demonstrate the analysis result of separation distance between the satellite earth station and a terrestrial repeater, and the presented results can be used to design and implement Ka band wireless systems.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.169-184
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• 2002

In order to extract bearing information from the directional sensors of DIFAR(directional frequency analysis and recording) that is a kind of passive sonobuoy, the cardioid beamforming algorithm applicable to DIFAR system was studied in the frequency domain. the algorithm uses narrow-band signals propagated though the media from the acoustic sources such as ship machineries. The proposed algorithm is expected to give signal to noise ratio of 6dB when it uses the maximum response axis(MRA) among the Cardioid beams. The estimated bearings agree very well with those from GPS data. Assuming the bearings from GPS data to be real values, the estimation errors are analyzed statistically. The histogram of estimation errors in each frequency have Gaussian shape, the mean and standard deviation dropping in the ranges -1.1~$6.7^{\circ}$ and 13.3~$43.6^{\circ}$, respectively. Estimation errors are caused by SMR degradation due to propagation loss between the source and receiver, daily fluctuating geo-magnetic fields, and non-stationary background noises. If multiple DIFAR systems are employed, in addition to bearing, range information could be estimated and finally localization or tracking of a target is possible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.1
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• pp.71-77
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• 1998

In this Paper, the training principles and the control method of adaptive array antennas using the LMS and CMA algorithms for the $\pi$/4 QPSK signal is showed and the convergence characteristics, the adaptivity of directional pattern SINR and the replication of desired signal of adaptive arrays are compared and discussed each other. Computer simulation results showed that the SINR of LMS adaptive array was 13.8［dB］, and that of CMA was 12.8［dB］, and also the convergence characteristics of LMS was fast a little than that of CMA. The LMS adaptive array was also performed null point well for the interference signal direction than that of the CMA adaptive array.

• Journal of Sensor Science and Technology
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• v.8 no.5
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• pp.377-387
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• 1999

A piezoelectric flextentional deep-water sonar transducer has been designed using a coupled FE-HEM. The dynamics of the sonar transducer is modelled in three dimensions and is analyzed with external electrical excitation conditions. Different results are available such as steady-state frequency response for TX displacement modes, directivity patterns, resonance frequencies, TVRs. While the conventional barrel-stave typed sonar transducer of the piezoelectric material is designed, the external surface of the transducer is modified in order to allow the same hydrostatic pressure to be applied onto the inner and the outer surfaces of the transducer. With this modification for deep-water application, a new resonance mode is generated at lower frequency. This lower resonance mode can be adjusted according to the degree of the outer surface modification.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.6
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• pp.654-664
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• 2003

The purpose of this study was to segment consumers based on sales promotion orientation and examine the differences between the consumer segments on shopping styles and demographics. A total of 462 responses collected from a questionnaire survey to subjects aged over 20 were analyzed. Cluster analysis on sales promotion orientation identified four groups including rational group(21%), active group(28%), insensitive group(22.1%), and interest group(28.9%) of sales promotion. MANOVA, ANOVA and $\chi$$^2$-test revealed significant differences among the four groups on shopping styles(high-quality prone, value prone, price prone. brand prone, fashion prone, hedonic shopping prone, and loyalty) and 4 demographic characteristics(i.e., age, marital status. occupation, and education). The rational group showed lower brand proneness than did other groups while the active group showed higher price and brand proneness. The interest group showed high value, brand, and hedonic shopping proneness while the insensitive group was the least engaged in shopping styles. The study developed a profile of each segment and provided marketing implications.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.9
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• pp.1407-1417
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• 2008

This study intended to compare the effects of fashion emotional and relationship experience of middle and old aged women on their long-term relationship orientation. The survey was conducted in September and October in 2006 on 579 middle old aged women whose age varied from 40 to 70 years old, who lived in Seoul and the metropolitan area and had experienced fashion shopping. The SPSS 12.0 was used to do an analysis of frequency, an exploratory factor analysis, and a multi-regression analysis and Lisrel 8.14 was applied to make a path analysis. The result of this study was as follows: Comparing the two age groups, the most important fact was that fashion related experience had more affective on long-term relationship orientation for old aged than middle aged women. Secondly, the effects of fashion emotional experience of middle and old aged women affected the long-term relationship orientation were the same. This analysis suggested that intensive marketing strategy effort of emotional experience for middle aged women and relational experience for old aged women should be more effective in fashion market.

• Journal of Korea Technology Innovation Society
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• v.12 no.4
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• pp.840-864
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• 2009

At the time of so-called localization, the start-up and successful management of NTVs (New technology ventures) might be a key factor of regional economic development. The research investigated the factors influencing the performance of NTVs South-western Area. According to the research result, the capability of CEO and R&D cooperation, supply chain integratim, information searching activities, market orientation are the factors which have positive correlation with the performance of NTVs in a statistically significant way in this region.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.51-56
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• 2009

This paper presents the design of high sensitive/broadband tag antenna for Radio Frequency Identification (RFID) in Ultra High Frequency(UHF) band. A proposed tag antenna size is $60\;mm\;{\times}\;10\;mm\;{\times}\;1\;mm$. The resonant frequency is 910MHz and bandwidth is about 900 MHz at -10 dB below. The measured return loss and directional pattern have been confirmed a good agreement with the calculation results. The read range of proposed tag antenna with chip is observed about 6.5 m and proposed tag antenna has been observed an average 0.5 m for more than read range of the commercial tag antenna.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1115-1125
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• 2010

This study is to examine how POS(perceived organization support) would affect trust in her/his superior and organization, organization commitment and customer orientation. The effect of demographic variables differences on independent and dependent variables was examined. Data for this study was collected by questionnaire from a sample of 277 employees of 9 hospitals in Korea. The findings show that POS is significantly influence trust in her/his superior and organization, organization commitment, and customer orientation. Variables like gender and type of employment have a significant difference. However there is no difference in the type of occupation.