• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.3-8
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• 2014

Recently, a spectrum sensing technique employing the maximum value of a received power spectrum as a test statistic has been presented in the literature for the purpose of detecting a wireless microphone signal in TV bands This detects the presence of a primary user by comparing the test statistic with some threshold, which depends on the background noise power level as well as a target false alarm rate. Therefore its performance may deteriorate when the noise power uncertainty occurs. As a means to mitigate this difficulty, we present a spectrum sensing strategy adopting the ratio of the maximum and the minimum value of the power spectrum as a test statistic and analyze its performance of spectrum sensing.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.02a
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• pp.173-178
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• 2008

본 연구에서는 영상음향의 사운드디자인 구조의 차이가 수용자에게 어떠한 감응도 변화가 있는가를 알아 보았다. 실험은 60초의 TV광고음향을 음악으로만 디자인한 음향트랙과(A), 음향효과와 음악으로 디자인한 음향트랙(B)을 청취하게 하여, 어떠한 사운드 구조가 감응도(주의력, 활성도, 감성도)에 더 유의한 영향을 미치는가를 알아 보았다. 실험은5명씩의 남.여 대학생을 대상으로 이루어 졌고 안정상태와 Fp1, Fp2를 중심으로 한 전두엽측정방식으로 한 뉴로피드백(Neuro feedback)뇌파측정방법으로 측정하였다. 그 결과, 음악으로만 디자인한 A음향트랙에서의 감응도는 주의((ATQ)와 활성도(ACQ), 감성도(EQ)모두가 증가했으나 B트랙보다는 낮았다. 음악+효과음으로 디자인한 B트랙에서는 주의력(ATQ), 활성도(ACQ),는 A트랙보다 증가하였으나 EQ(감성도)는 반대로 A트랙보다 낮았다. 결과적으로 영상에서 음향은 주의력과 활성도 에는 기본적으로 뇌의 변화에 작용하나 정서적인 면은 역시 음악이 유효한 것으로 나타났다. 그러나 강한 효과음들은 음악보다 주의력과 집중도를 높이기는 하나 스트레스적(SQ)지수는 오히려 높은 것으로 나타났다. 본 연구를 통하여 방송과 영화 등의 사운드구조는 영상과의 호흡을 기본으로 하지만 실제로 시각정보와 청각정보가 동시에 합쳐져서, 심리적으로 어떠한 영향을 미치는가를 뇌신경측정으로 고찰한 것에 의의가 있다.

• Korean Journal of Cognitive Science
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• v.22 no.2
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• pp.123-143
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• 2011

At what point in the process of speech production are gestures involved? According to the Lexical Retrieval Hypothesis, gestures are involved in the lexicalization in the formulating stage. According to the Information Packaging Hypothesis, gestures are involved in the conceptual planning of massages in the conceptualizing stage. We investigated these hypotheses, using the game situation in a TV program that induced the players to involve in both lexicalization and conceptualization simultaneously. The transcription of the verbal utterances was augmented with all arm and hand gestures produced by the players. Coverbal gestures were classified into two types of gestures: lexical gestures and motor gestures. As a result, concrete words elicited lexical gestures significantly more frequently than abstract words, and abstract words elicited motor gestures significantly more frequently than concrete words. The difficulty of conceptualization in concrete words was significantly correlated with the amount of lexical gestures. However, the amount of words and the word frequency were not correlated with the amount of both gestures. This result supports the Information Packaging Hypothesis. Most of all, the importance of motor gestures was inferred from the result that abstract words elicited motor gestures more frequently rather than concrete words. Motor gestures, which have been considered as unrelated to verbal production, were excluded from analysis in many gestural studies. This study revealed motor gestures seemed to be connected to the abstract conceptualization.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11C
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• pp.1095-1101
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• 2007

For the cognitive radio (CR) systems sharing the spectrum with narrowband primary devices, this paper presents a fractional bandwidth (FBW) mode utilizing a variable portion of the system band to avoid the interference to or from the primary devices. For the method, the preamble and FBW mode detection algorithm are provided to obtain the FBW mode information during the synchronization. Simulation results in wireless regional area network (WRAN) environments reveal that the FBW mode can be detected reliably without any deterioration of the synchronization performance.

• Journal of Korean Academy of Nursing
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• v.37 no.1
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• pp.105-113
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• 2007

Purpose: The purpose of this study was to identify the effects of a multi agent obesity control program in obese school children. This program was composed of strategies to modify diet and exercise habits and to change cognitive behavior variables(stress, coping, and self-efficacy). Method: The subjects were 40 obese school children who participated in our project voluntarily via homepage, TV, newspaper, public paper and school official documents. The program was implemented daily for 4 sessions per day for ten days from August 16 to 26, 2004. The daily program consisted of exercise therapy, dance therapy, cognitive behavior therapy and aroma therapy. The data was analyzed by paired t-test using the SPSSWIN program. Result: There was a significant decrease in children's waist-hip ratio(p=.04) and in children's stress(p=.00) after the program. There was a significant increase in children's self-confidence after the program(p=.02) and a significant decrease in children's diet habit after the program(p=.02). Conclusion: This study provides evidence that a multiagent obese control program is effective in changing waist-hip ratio, stress, self-confidence, and diet habits in obese school children.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.122-139
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• 2015

Though the digital transition of terrestrial TV has been completed, the transmission system for terrestrial radio has not been determined and terrestrial radio still keeps its analog transmission. This study, under coorientation model, aims to explore the cognitive difference in recognizing important factors to be considered in deciding the digital radio transmission system between the employees of terrestrial broadcasters and then crucial issues related to the factors are driven. It has been found that the most big cognitive difference among the employees of three major terrestrial broadcasters lies in selecting frequency band for digital radio transmission. But there was little difference of opinion on simultaneous production-transmission, efficiency of frequency usage, broadcast quality and standards of service. The most disputable point in transition to digital radio broadcasting is selecting the frequency band for digital radio between the frequency bands used for FM radio broadcast (88-108MHz), terrestrial DMB (VHF Ch7~13) and FM radio adjacent broadcast band (76~88MHz: VHF Ch5~6). So, the question concludes into the selection issue between DAB+, HD-Radio, and DRM+. To improve the quality of radio broadcasting service and enhance the satisfaction of listeners, it is desirable to allow to operate both production system and transmission station, to enhance high transmission efficiency with minimum transmission facility, and to permit new entrance of broadcasters.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.50-64
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• 2016

Nowadays, smart meter (SM) technology is widely effectively used. In addition, power allocation (PA) and channel selection (CS) are considered problems with many proposed approaches. In this paper, we will suggest a specific scenario for an SM configuration system and show how to solve the optimization problem for transmission between SMs and the data concentrator unit (DCU), the center that collects the data from several SMs, via simulation. An efficient CS with PA scheme is proposed in the TV white space system, which uses the TV band spectrum. On the basic of the optimal configuration requirements, SMs can have a transmission schedule and channel selection to obtain the optimal efficiency of using spectrum resources when transmitting data to the DCU. The optimal goals discussed in this paper are the maximum capacity or maximum channel efficiency and the maximum allowable power of the SMs used to satisfy the quality of service without harm to another wireless system. In addition, minimization of the interference to the digital television system and other SMs is also important and needs to be considered when the solving coexistence scenario. Further, we propose a process that performs an interference analysis scheme by using the spectrum engineering advanced Monte Carlo analysis tool (SEAMCAT), which is an integrated software tool based on a Monte-Carlo simulation method. Briefly, the process is as follows: The optimization process implemented by genetic evolution optimization engines, i.e., a genetic algorithm, will calculate the best configuration for the SM system on the basis of the interference limitation for each SM by SEAMCAT in a specific configuration, which reaches the solution with the best defined optimal goal satisfaction.

• 한국정보교육학회:학술대회논문집
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• 2010.01a
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• pp.209-212
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• 2010

오늘날 학교 현장에서 교실에 비치된 TV를 통한 멀티미디어 자료 제시를 빼놓고는 수업을 진행할 수 없을 정도로 멀티미디어 자료는 큰 역할을 하게 되었고, 그런 관계로 멀티미디어 자료와 아동의 학성성취도의 연관관계를 분석하는 많은 연구가 이루어지고 있다. 그 중 멀티미디어 학습자료 제시 유형이 학생의 학업성취도에 미치는 영향에 대한 분석이 있다. 여러 가지 논문에서 애니메이션 학습자료는 텍스트보다 녹음자료와 함께 사용되는 것이 아동의 학업성취에 유리하다는 결론을 내리고 있다. 하지만 정확하게 읽고 텍스트를 해독하는 능력이 뛰어난 아동들, 즉 읽기 유창성이 뛰어난 아동들에게서 어떤 결과가 나오는지 분석된 결과는 없다. 따라서 본 논문에서는 읽기 유창성이 우수한 집단과 그렇지 않은 집단과의 비교 결과를 통해 과거의 분석된 결과가 그대로 유의미한지를 검증할 것이며 이러한 결과를 통해 좀 더 효율적인 멀티미디어 학습 자료의 쓰임을 제시하는데 많은 도움을 줄 수 있을 것이다.

• Information and Communications Magazine
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• v.24 no.9
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• pp.15-21
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• 2007

유비쿼터스 사회의 도래에 따른 전파자원의 부족현상을 해결하고 스펙트럼 이용효율을 증가시키기 위해 cognitive radio(CR) 기술을 이용하여 전파특성이 우수한 V/UHF 주파수 자원을 공유하는 기술이 최근에 각광을 받고 있다. 본 논문에서는 CR기술에 대한 소개와 더불어 IEEE802.22 WRAN working group에서 검토되고 있는 CR기술을 이용한 V/UHF 대역의 주파수 자원 공유를 통해 얻을 수 있는 스펙트럼 이용효율을 분석하였다. DTV 및 WRAN 시스템 파라미터와 제안된 공유 시나리오를 바탕으로 시뮬레이션을 통해 분석한 결과, CR 기술 도입시 스펙트럼 효율은 수백 배 이상이 향상되고, 커버리지 효율도 배 이상 향상됨을 알 수 있었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.11
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• pp.779-789
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• 2014

Cognitive radio (CR) technology based on geo-location database access approach and/or wideband spectrum sensing approach is absolutely vital in order to recognize available frequency bands in white spaces (WSs), and efficiently utilize shared spectrums. This paper presents a new structure for the TVWS database access protocol implementation based on Internet Engineering Task Force (IETF) Protocol to Access WS database (PAWS). A wideband compressive spectrum sensing (WCSS) scheme using a modulated wideband converter is also proposed for the TVWS utilization. The developed database access protocol technology which is adopted in both the TV band device (TVBD) and the TVWS database operates well in the TV frequency bands. The proposed WCSS shows a stable performance in false alarm probability irrespective of noise variance estimation error as well as provides signal detection probabilities greater than 95%. This paper also investigates Federal Communications Commision (FCC) regulatory requirements of TVWS database as well as European Telecommunications Standards Institute (ETSI) policy related to TVWS database. A standardized protocol to achieve interoperability among multiple TVBDs and TVWS databases, which is currently prepared in the IETF, is discussed.