• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.671-672
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• 2006

Recently Communication with using IrDA is bing used in various fields. In this paper I designed a receiver by fabricating hardware that used to be fabricated through software, so anyone who don't have knowledge on IrDA can receive Ir Signal easily. This receiver can communicate with CPU through 8 bit data and 3 bit address. Also this receiver can use user-needed CLK because this receiver embodied 16 bit CLK Prescaler.

• Journal of Communications and Networks
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• 제8권3호
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• pp.275-285
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• 2006

Suitable for multi-input multi-output (MIMO) communications, the joint beamforming space-time block coding (JBSTBC) scheme is proposed for high-speed downlink transmission. The major functionality of the scheme entails space-time block encoder and joint transmit and receive eigen-beamformer (EBF) incorporating with block-ordered layered decoder (BOLD), and its operating principle is described in this paper. Within these functionalities, the joint EBFs will be utilized for decorrelating fading channels to cause an enhancement in the spatial diversity gain. Furthermore, to fortify the capability of layered successive interference cancellation (LSIC) in block-ordered layered decoding process, this paper will develop a simple ad-hoc transmit power discrimination scheme (TPDS) based on a particular power discrimination function (PDF). To confirm the superior behavior of the proposed JBSTBC scheme employing ad-hoc TPDS, computer simulations will be conducted under various channel conditions with the provision of detailed mathematical derivations for clarifying its functionality.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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• pp.32-35
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• 2004

In this paper, we propose two novel high-rate high-performance space-time codes for multiple-input multiple-output (MIMO) systems. When $n_{T}$ transmit antennas and $n_{R}$ = $n_{T}$ receive antennas are deployed, the two proposed codes respectively offer transmission rates of ( $n_{T}$ -I) and ( $n_{T}$ - 2) symbols per channel use and diversity orders of 3 and 5. As a consequence, our proposed codes allow the MIMO systems to employ a simple detection technique based on QR decomposition. Moreover, for equal or even higher spectral efficiencies, our proposed codes always provide much better bit error rate (BER) performances than V-BLAST architecture does when $n_{R}$ = $n_{T}$. Computer simulation is given to verify performances of our proposed codes.sed codes.des.

• ETRI Journal
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• 제44권1호
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• pp.117-124
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• 2022

In this paper, the performance of precoding-aided differential spatial modulation (PDSM) systems with optimal transmit antenna subset (TAS) selection is examined analytically. The average bit error rate (ABER) performance of the optimal TAS selection-based PDSM systems using a zero-forcing (ZF) precoder is evaluated using theoretical upper bound and Monte Carlo simulations. Simulation results validate the analysis and demonstrate a performance penalty < 2.6 dB compared with precoding-aided spatial modulation (PSM) with optimal TAS selection. The performance analysis reveals a transmit diversity gain of (N_T-N_R+1) for the ZF-based PDSM (ZF-PDSM) systems that employ TAS selection with N_T transmit antennas, N_S selected transmit antennas, and N_R receive antennas. It is also shown that reducing the number of activated transmit antennas via optimal TAS selection in the ZF-PDSM systems degrades ABER performance. In addition, the impacts of channel estimation errors on the performance of the ZF-PDSM system with TAS selection are evaluated, and the performance of this system is compared with that of ZF-based PSM with TAS selection.

• 대한영양사협회학술지
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• 제18권1호
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• pp.1-15
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• 2012

The purpose of this study was to provide fundamental data for health promotion and improvement of the dietary life in students who receive school lunch support (SLS) by comparative analysis of food service satisfaction, dietary habits, and nutrition intakes according to SLS. The subjects of this study consisted of 258 boys and 233 girls at a middle school in Incheon. The students' average age was 14.9 years, average height was 161.3 cm, and average weight was 52.0 kg. The breakfast eating frequency of the No-SLS (NSLS) group was significantly greater than that of the SLS group (P<0.05). The time spent for eating breakfast in the SLS group was significantly shorter than that of the NSLS group for boys. There was no significant difference in dietary attitudes according to SLS. For satisfaction of the quantity and diversity of the school lunch menu in girls, the SLS group had higher satisfaction than the NSLS group. The daily energy intake of the SLS group was significantly lower than that of the NSLS group in both boys and girls. The majority of daily nutrients intakes in the SLS group were also significantly lower than those in the NSLS group. In summary, the female students in the SLS group were more satisfied with school lunch service than general students. However, SLS students less frequently ate breakfast and showed lower energy and nutrient intakes. Therefore, in order to improve the nutritional status and dietary life of students who receive school lunch support, consistent nutrition management and support in schools are required.

• 한국통신학회논문지
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• 제29권2A호
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• pp.202-213
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• 2004

본 논문에서는 다중 안테나 OFDM 기반의 최대 200Mbps급 차세대 무선 LAN 시스템의 프리엠블 구조와 이를 이용한 동기/채널 추정 기법을 제안한다. 제안된 프리엠블 구조를 사용할 경우 IEEE 802.11a 시스템과의 하위 호환성을 유지할 수 있을 뿐 아니라 동기 측면에서는 안테나 다이버시티(diversity) 이득으로 인해 단일 안테나 OFDM 시스템에 비해 우수한 성능을 얻을 수 있다. 또한 채널 추정 측면에서는 프리엠블의 오버헤드가 적고, 기존의 채널 추정 기법들을 적용할 경우 발생하는 시간 동기 오차에 의한 성능 저하를 주파수 영역에서의 위상 보정을 통해 최소화할 수 있다. 제안된 프리엠블 구조를 이용한 동기 및 채널 추정단은 Verilog HDL을 이용하여 하드웨어로 설계 및 검증되었으며, 그 결과 4개의 전송 안테나와 4개의 수신 안테나를 갖는 경우 동기단은 약 150K gates, 채널 추정단은 약 12K gates가 소요되었다.

• 한국통신학회논문지
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• 제33권12A호
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• pp.1147-1155
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• 2008

본 논문에서는 듀얼-홉 MIMO(Miltiple-Input Miltiple-Output) DCF(decouple-and-forward) 릴레이 시스템의 성능 분석을 위한 확률 밀도 함수를 유도한다. 확률 밀도 함수를 사용하여 정확한 BER 분석을 할 수 있다. 분석할 수 있는 안테나 조합은 (1,8,1), (8,1,8), (2,4,2), (4,2,4)이며 괄호 안의 숫자는 송신국의 송신 안테나, 릴레이 안테나, 수신국의 수신 안테나 개수이다. M-ary PSK일 때 MIMO DCF 릴레이 시스템의 모의 실험을 통해 얻은 평균 BER과 확률 밀도 함수를 통해 유도한 BER식에 의한 평균 BER이 서로 일치함을 확인할 수 있다. DCF 릴레이 시스템을 썼을 때 공간 다이버시티를 얻을 수 있다.

• 방송공학회논문지
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• 제15권6호
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• pp.749-756
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• 2010

신호 공간 다이버시티 기술은 차세대 모바일 방송의 핵심 전송 기술로 주목받고 있는 기술 중 하나이다. 기존의 DVB-T2에 사용되는 Cyclic Q-delay 방식을 MIMO 시스템에 사용할 경우에는 심볼 간 상호 의존성이 증가하여 수신기 복잡도가 크게 증가하는 반면, 이러한 문제를 해결하기 위해서 제안된 '성분 맞교환(Component-Swapping)' 기술을 적용할 경우 상호 의존성이 제한되어 수신기 복잡도가 크게 줄어든다. 본 논문에서는 DVB-T2 16K LDPC 부호를 적용한 경우에 제안된 '성분 맞교환' 기술을 컴퓨터 시뮬레이션을 통해서 분석하고, 기존 기술 대비 BER 성능 및 복잡도 면에서 이득을 가짐을 확인하였다.

• 실천공학교육논문지
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• 제11권2호
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• pp.305-311
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• 2019

많은 대학에서 학생 보상 프로그램의 일환으로 마일리지 제도를 시행하고 있다. 마일리지 제도는 교내외 비교과 프로그램에 참여한 학생들에게 마일리지를 지급하고, 획득한 마일리지에 따라 성적과 관계없이 장학금을 차등 지급하는 것이다. 본 연구는 대학 마일리지 제도에 대한 학생들의 가치지각이 충성도에 미치는 영향을 확인하고, 마일리지 혜택을 받은 집단과 그렇지 않은 집단 간 차이가 있는지 비교하고자 한다. 이를 위해 대학 마일리지에 대한 가치지각을 경제적 유용성, 심리적 유용성, 이용혜택의 다양성, 편리성, 적절성으로 구분하여 충성도 간 영향력을 실증적으로 확인하였다. 연구결과 심리적 유용성, 이용혜택의 다양성, 적절성이 충성도에 긍정적인 영향을 미치는 반면, 경제적 유용성, 편리성은 유의한 영향을 미치지 않는 것으로 확인되었다. 또한 경제적 유용성이 충성도에 미치는 영향은 마일리지 혜택을 받은 집단이 받지 않은 집단보다 높게 나타났고, 적절성이 충성도에 미치는 영향은 마일리지 혜택을 받지 않은 집단이 받은 집단보다 높게 나타났다.

• The Journal of Korean Physical Therapy
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• 제20권4호
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• pp.61-69
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• 2008

Purpose: We evaluated caregivers' understanding of patients' diseases and disuse syndrome, the understanding of exercise and massage related to rehabilitation and the necessity of education about these, the difference in education and realities of the care-giving field, and the extra services needed in the field. Methods: The survey using questionnaires was performed from June 2008 to August 2008 with 220 people participated in caregive education programme in daegu city and area near dagu city. Among the 220 submitted questionnaires, 184 which were faithfully answered were selected and they were analyzed by i-STATistics statistical program. Results: The educational focus of the first and second level caregivers, as defined by the second clause of the 29th article of the Elderly Welfare law, is on basic knowledge of diseases such as dementia, stroke, and depression. However, other diseases are not covered and the information does not include information on decreased function, complications, functional rehabilitating exercises, or preventing disuse syndrome for long term patients. The most common diseases, in order of prevalence, are stroke, dementia, diabetes mellitus, Parkinson disease, arthritis, and geriatric inertness. The general level of awareness about disuse syndrome was low, and patients, while understanding the need for massage and rehabilitative exercise, receive little education about the proper methods and therefore cannot use them. Patients also did not understand how participating in these activities could reduce medical fees, indicating that further education on massage and rehabilitative exercise is needed. Caregivers desired to include positive rehabilitation, massage, and exercise-related services in their services. Finally, differences in caregiver education and reality resulted from a lack of diversity in education. Conclusion: We suggest providing education on disuse atrophy and improving the lack of diversity in the care-giving education system.