• Journal of Communications and Networks
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• 제8권2호
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• pp.151-157
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• 2006

In a continuously expanding wireless world, the number of radio systems increases every day and efficient spectrum usage becomes a more significant requirement. Ultra-wideband (UWB) and cognitive radio are two exciting technologies that offer new approaches to the spectrum usage. The main objective of this paper is to shed the first light on the marriage of these two important approaches. The strength of orthogonal frequency division multiplexing (OFDM) based UWB in co-existing with licensed systems is investigated. The opportunity concept is defined, and the requirements of the opportunistic spectrum usage are explained. It is proposed to take the UWB-OFDM from the current underlay implementation, and evolve it to a combined underlay and opportunistic spectrum usage technology, leading to cognitive UWB-OFDM. This way, we aim at making UWB more competitive in the wireless market with extended range, higher capacity, better performance, and a wide variety of applications.

• 대한건축학회논문집:구조계
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• 제34권7호
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• pp.27-34
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• 2018

The energy consumption of apartment houses is affected by various factors. The criteria for assessing current energy usage are area, region and purpose. The purpose of this study is to obtain the reliability of the method of evaluating the existing energy consumption certificate and to derive usable evaluation factors according to the correlation of factors affecting energy consumption. The research process collects energy usage data for apartment houses in Daegu and calculates statistical results through correlation analysis and multiple regression analysis. As a result, it was found that the power energy is influenced by the yearly factor of physical characteristics, and the heat energy and total energy usage are influenced by the energy source which is energy characteristic factor.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권4호
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• pp.1489-1503
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• 2018

Spectrum reuse has attracted much concern of researchers and scientists, however, the dynamic spectrum access is challenging, since an individual secondary user usually just has limited sensing abilities. One key insight is that spectrum usage forecasting among secondary users, this inspiration enables users to obtain more informed spectrum opportunities. Therefore, spectrum usage forecasting is vital to cognitive radio networks (CRNs). With this insight, a spectrum usage forecasting model for the occurrence of primary users prediction is derived in this paper. The proposed model is based on auto regressive enhanced primary user emergence reasoning (AR-PUER), which combines linear prediction and primary user emergence reasoning. Historical samples are selected to train the spectrum usage forecasting model in order to capture the current distinction pattern of primary users. The proposed scheme does not require the knowledge of signal or of noise power. To verify the performance of proposed spectrum usage forecasting model, we apply it to the data during the past two months, and then compare it with some other sensing techniques. The simulation results demonstrate that the spectrum usage forecasting model is effective and generates the most accurate prediction of primary users occasion in several cases.

• 기술혁신학회지
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• 제13권4호
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• pp.772-793
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• 2010

본 논문은 공표데이터들(산업연관표, 관련미시통계)을 이용하여 2005년 우리나라의 방사선이용의 경제규모를 추정하였다. 방사선이용의 경제규모는 방사선 이용이 국민들의 후생과 복지 중진에 기여하는 부분적 정량적으로 도출한 것이므로 경제체제 내의 방대한 분야에서 다양한 형태로 사용되는 방사선이용의 전체 모습을 보여준다. 추정결과에 따르면 2005년의 방사선이용의 경제규모는 6조 2,971억원이며, 이는 GDP(851조 9,822억원)의 0.74%에 해당한다. 이는 미국 또는 일본의 방사선이용의 규모와 비교하면 낮은 수준이다. 분야별 방사선이용의 경제규모는 공업분야에서 5조 7,753억원(GDP 대비 0.68%), 농업분야에서 1,705억원(GDP 대비 0.020%), 의학 의료분야에서 3,513억원(GDP 대비 0.04%)이다. 공업분야에서 방사선이 가장 활발하게 이용되는 것으로 추정되었다. 그러나 우리나라의 연구구조의 변화를 고려할 때에 의학 의료분야에서의 이용이 보다 증가할 것으로 예상된다. 우리나라의 GDP에서 방사선이용의 경제규모가 차지하는 비중이 0.74%에 이른다는 추정 결과는 방사선이용이 국민생활에 기여하고 있는 정도를 새롭게 인식시킨다. 방사선이 이용되는 분야를 규명하고, 방사선이 국민의 후생을 향상시키는 것에 기여한다는 것을 명확하게 하는 것은 국민들이 방사선에 대해서 갖고 있는 부정적 이미지를 경감시키고 수용성을 높이는 것에 기여한다.

• 한국IT서비스학회지
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• 제14권2호
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• pp.1-14
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• 2015

As mobile distribution environment is changing rapidly and competition is more intensive in businesses today, technology based self service have been changed and developed. Among the change, financial institutes and consumers are interested in mobile banking services. This study attempted to investigate the impact of service convenience value on customer satisfaction and re-usage intention, and investigated the moderate effect of technology anxiety in the relationship between service convenience value and mobile banking service usage. For this study, data were gathered from respondents who have experience using mobile banking service and analyzed by structural equation model. A convenience value affected consumer satisfaction and re-usage intention toward mobile banking service. Also, this study found that the more technology anxiety, the less re-usage intention. The results show that management and investment to improve convenience value and to reduce technology anxiety make consumers' satisfaction and re-usage intention toward mobile banking service.

• 영어어문교육
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• 제16권3호
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• pp.101-117
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• 2010

This study examines whether English users at a U.S. university apply avoidance strategy in using English articles. All participants had learned English for at least 10 years and had used English for at least 15 years at the time of the data collection, so they made an ideal sample to examine the differences between native speakers of English and non-native speakers of English, in terms of avoidance strategy usage of English articles. To examine whether non-native speakers avoid using a certain feature when unsure of the correct usage, the mean differences of each article usage between NS and NNS groups were calculated and compared. On the basis of results showing that there are no statistically significant differences in terms of article usage between the groups, it is concluded that the highly advanced level participants did not use avoidance strategy in English articles, and that the type of English article and the task type did not affect learners' avoidance strategy usage. This research is expected to provide teachers and researchers with information about highly advanced level L2 language speakers' usage patterns with regards to avoidance strategy.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2014년도 추계학술발표대회
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• pp.1136-1138
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• 2014

Recently, predicting personality with the help of smartphone usage is become very interesting and attention grabbing topic in the field of research. At present there are some approaches towards detecting a user's personality which uses the smartphones usage data, such as call detail records (CDRs), the usage of short message services (SMSs) and the usage of social networking services application. In this paper, we focus on the predicting user attitude based on MBTI theory by using their smartphone usage data. We used Naïve Bayes and SVM classifier for classifying user personalities by extracting some features from smartphone usage data. From analysis it is observed that, SVM classifier works well as compared to Naïve Bayes.

• 인터넷정보학회논문지
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• 제21권4호
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• pp.77-85
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• 2020

본 연구는 학생들의 성장에 따른 미디어 교육 활용 특성 종단적 변화를 알아보고자 하였다. 이를 위해 미디어의 교육적 활용 특성을 학습이용, 정보이용, 그리고 게임이용으로 구분하였다. 잠재성장모형을 적용하여 학습이용, 정보이용, 게임이용의 종단적 변화를 탐색하였다. 이후 3가지 미디어 교육적 활용 특성의 종단적 변화에서 성별 차이를 검증하였다. 한국청소년패널조사(KYPS)의 중등2패널을 활용하여 4년간 반복 추적 조사한 3,499명의 데이터를 분석하였다. 연구결과 (a) 학년이 증감함으로써 미디어의 학습이용과 정보이용의 변화율은 증가하는 경향을 나타내었다. (b) 여학생의 미디어 학습이용과 정보이용의 초기치와 변화율이 높은 것으로 나타났다. (c) 학년이 증가함으로써 미디어의 게임이용은 변화율이 감소하는 것으로 나타났다. (d) 미디어 게임이용에서는 초기치에는 남학생이 여학생보다 높은 것으로 나타났으나, 변화율에는 유의한 차이가 없는 것으로 나타났다.

• 한국IT서비스학회지
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• 제6권3호
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• pp.1-26
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• 2007

In this paper, we identified factors that affect the usage of UCC, which is becoming increasingly popular in our society and throughout the globe. Four hypotheses were tested using a new integrative model of UCC usage, which is built up by incorporating the TAM and the PA(pleasure-arousal)model. We analyzed the data collected in our survey of 258 individual UCC users during the period from Oct 2006 to Dec 2006. We found that pleasure and arousal showed a strong significant effect on individual's UCC usage, supporting the findings of the exiting research on TAM. To be specific, arousal had an effect on the UCC usage through its effect on pleasure and self efficacy. Pleasure affected the UCC usage in two ways: First, pleasure affected UCC usage through increasing the ease of UCC service. At the same time, pleasure had a direct effect on the UCC usage. Contrary to what the prior research on technology acceptance suggested, we found ease of use and social influence had no significant effect on individual’s UCC usage. We suggest that this finding of no effect of ease of use and social influence has an important implication in understanding the UCC usage. That is, the UCC usage may be motivated by different factors than those which inspire other technology acceptance behavior. The UCC users may be engaging in a creative activity enjoying the sheer pleasure of creating UCC, self expression, and sharing what they want to tell. Intrinsic motivation rather than extrinsic motivation seems to click this new type of technology users.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2007년도 International Conference
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• pp.80-86
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• 2007

In this paper, we identified factors that affect the usage of UCC, which is becoming increasingly popular in our society and throughout the globe. Four hypotheses were tested using a new integrative model of UCC usage, which is built up by incorporating the TAM and the PAD(pleasure-arousal-dominace)model. We analyzed the data collected in our survey of 258 individual UCC users during the period from Oct 2006 to Dec 2006. We found that pleasure and arousal showed a strong significant effect on individual's UCC usage, supporting the findings of the exiting research on TAM. To be specific, arousal had an effect on the UCC usage through its effect on pleasure and self efficacy. Pleasure affected the UCC usage in two ways: First, pleasure affected UCC usage through increasing the ease of UCC service. At the same time, pleasure had a direct effect on the UCC usage. Contrary to what the prior research on technology acceptance suggested, we found ease of use and social influence had no significant effect on individual's UCC usage. We further found that such effects of the ease of use and pleasure factors are more positive in the entertainment-based UCC than in the relationship-based UCC.