• 제목/요약/키워드: Partial likelihood

검색결과 102건 처리시간 0.026초

정교화 가능성 모형에 의한 IT 피교육자 신용 믿음 변화의 종단분석 (An Longitudinal Analysis of Changing Beliefs on the Use in IT Educatee by Elaboration Likelihood Model)

  • 이웅규
    • Asia pacific journal of information systems
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    • 제18권3호
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    • pp.147-165
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    • 2008
  • IT education can be summarized as persuading the educatee to accept IT. The persuasion is made by delivering the messages for how-to-use and where-to-use to the educatee, which leads formulation of a belief structure for using IT. Therefore, message based persuasion theory, as well as IT acceptance theories such as technology acceptance model(TAM), would play a very important role for explaining IT education. According to elaboration likelihood model(ELM) that has been considered as one of the most influential persuasion theories, people change attitude or perception by two routes, central route and peripheral route. In central route, people would think critically about issue-related arguments in an informational message. In peripheral route, subjects rely on cues regarding the target behavior with less cognitive efforts. Moreover, such persuasion process is not a one-shot program but continuous repetition with feedbacks, which leads to changing a belief structure for using IT. An educatee would get more knowledge and experiences of using IT as following an education program, and be more dependent on a central route than a peripheral route. Such change would reformulate a belief structure which is different from the intial one. The objectives of this study are the following two: First, an identification of the relationship between ELM and belief structures for using IT. Especially, we analyze the effects of message interpretation through both of central and peripheral routes on perceived usefulness which is an important explaining variable in TAM and perceived use control which have perceived ease of use and perceived controllability as sub-dimensions. Second, a longitudinal analysis of the above effects. In other words, change of the relationship between interpretation of message delivered by IT education and beliefs of IT using is analyzed longitudinally. For achievement of our objectives, we suggest a research model, which is constructed as three-layered. While first layer has a dependent variable, use intention, second one has perceived usefulness and perceived use control that has two sub-concepts, perceived ease of use and perceived controllability. Finally, third one is related with two routes in ELM, source credibility and argument quality which are operationalization of peripheral route and central route respectively. By these variables, we suggest five hypotheses. In addition to relationship among variables, we suggest two additional hypotheses, moderation effects of time in the relationships between perceived usefulness and two routes. That is, source credibility's influence on perceived usefulness is decreased as time flows, and argument quality's influence is increased. For validation of it, our research model is tested empirically. With measurements which have been validated in the other studies, we survey students in an Excel class two times for longitudinal analysis. Data Analysis is done by partial least square(PLS), which is known as an appropriate approach for multi-group comparison analysis with a small sized sample as like this study. In result. all hypotheses are statistically supported. One of theoretical contributions in this study is an analysis of IT education based on ELM and TAM which are considered as important theories in psychology and IS theories respectively. A longitudinal analysis by comparison between two surveys based on PLS is also considered as a methodological contribution. In practice, finding the importance of peripheral route in early stage of IT education should be notable.

성상도 집합 그룹핑 기반의 적응형 병렬 및 반복적 QRDM 검출 알고리즘 (Adaptive Parallel and Iterative QRDM Detection Algorithms based on the Constellation Set Grouping)

  • 마나르모하이센;안홍선;장경희;구본태;백영석
    • 한국통신학회논문지
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    • 제35권2A호
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    • pp.112-120
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    • 2010
  • 본 논문에서는 집합 그룹핑을 이용한 APQRDM (adaptive parallel QRDM) 알고리즘과 AIQRDM (adaptive iterative QRDM) 알고리즘을 제안한다. 제안된 검출 알고리즘은 집합 그룹핑을 이용하여 QRDM 알고리즘의 트리 검색 단계를 PDP (partial detection phases) 로 분할하여 수행한다. 기존 QRDM 알고리즘의 트리 검색 단계가 4개의 PDP로 나누어질 때, APQRDM 알고리즘은 기존 QRDM 알고리즘의 1/4 에 해당하는 검출 지연(latency) 을 가지며, AIQRDM 알고리즘은 기존 QRDM 알고리즘의 약 1/4에 해당하는 하드웨어 요구량을 가진다. 모의실험 결과는 $4{\times}4$ 시스템의 경우, APQRDM 알고리즘은 12dB의 Eb/N0에서 기존 QRDM 알고리즘의 약 43%에 해당하는 연산 복잡도를 가지며, AIQRDM 알고리즘은 0dB의 Eb/N0에서 기존 QRDM 알고리즘의 54%, AQRDM 알고리즘의 10%에 해당하는 연산 복잡도를 가짐을 보인다.

Pathologic conditions associated with impacted third molars: A retrospective study of panoramic radiographs in a Southern Brazilian population

  • Gabriela Brum Cardoso;Gleica Dal' Ongaro Savegnago;Waneza Dias Borges Hirsch;Mariana Boessio Vizzotto;Gabriela Salatino Liedke
    • Imaging Science in Dentistry
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    • 제53권4호
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    • pp.303-312
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    • 2023
  • Purpose: This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions. Materials and Methods: Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05). Results: The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2±11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar. Conclusion: The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

BD 기록기를 위한 전단 시스템에 관한 연구 (A Study of Front-end System for BD Recorder)

  • 최광석
    • 대한전자공학회논문지SD
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    • 제44권6호
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    • pp.28-33
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    • 2007
  • BD-R/RE/ROM을 2배속으로 기록하고 재생할 수 있는 전단 시스템을 개발하였다. 시스템의 재생능력은 PR(a,b,c,d,e)형 5탭 PRML을 채택함으로써 향상되었다. 제안된 PRML덕분에 2배속 25GB 디스크에서 ${\mp}0.6{\circ}$ 이상의 라디알 및 탄젠셜 틸드 마진을 가지고도 $2{\times}10^{-4}$이하의 BER을 얻을 수 있었다. 최적파워레벨이 다른 다양한 BD-R/RE의 안정적인 기록을 위해 OPC 방법에 대해서도 제안하였다. 개발한 시스템은 $0.18-{\mu}m$ CMOS공정으로 $60mm^2$ 면적에 1,400만 트랜지스터를 칩에 집적하였다.

경주지역 일부 중학생의 건강관련 위험행동 (A Survey of the Health Risk Behaviors of Middle School Students in Kyungju)

  • 한영란
    • 지역사회간호학회지
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    • 제12권2호
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    • pp.468-481
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    • 2001
  • The purpose of this study was to collect basic data to develop school health policy and health promotion program. This survey measured the levels of risk behaviors in six categories in a middle school students in Kyungju(n=490). The data was collected from November to December 2000. It was done using a 1999 version of the Youth Risk Behavior Survey of CDC, which was translated and make a partial modification. The major results were as follows. Many middle school students engaged in behaviors that will increase the likelihood of death or illness. 1) A high percentage of middle school students engaged in behaviors that contribute to unintentional injuries and school-related violence (42.1 -78%) 2) Students who perceived their school life are happy experienced more depression(p=.000) and Students who perceived their school and family life are so-and-so seriously considered attempting suicide(p = .000) than other subgroup. 3) In spite of they were normal weight, 14.5% of students considered themselves overweight. 4) There was significantly difference or correlation between health risk behaviors and grade, parents educational level perception of school life and performance, perception of family life and religion. Based on this results of study, it is necessary to develop school health program and school health policy to prevent health risk behaviors and improve health promotion especially considering characteristics of middle school students.

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고밀도 비선형 광 저장장치를 위한 새로운 부분응답 최대유사도 신호 검출기 구현 (Implementation of a PRML Detection for Asymmetric High-density Optical Storage System)

  • 이규석;이재진
    • 한국통신학회논문지
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    • 제31권11C호
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    • pp.1052-1057
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    • 2006
  • 본 논문에서는 고밀도 광기록 장치에서 발생하는 디스크 기울임 현상으로 인한 검출 성능 저하를 방지하기 위해서 디스크 기울임 분석기를 갖는 적응 등화 PRML 검출 방법을 VerilogHDL을 이용하여 구현하였다. 디스크 기울임의 분석을 위하여 고정된 패턴으로 일정한 간격마다 반복되는 동기 데이터를 이용하여 분석된 디스크의 기울임 정도를 측정하여 ROM에 저장된 등화기 계수값과 가지 메트릭의 기준값을 갱신한다. 이러한 방법은 지속적으로 계수값을 계산하여 갱신시켜줘야 하는 기존의 적응등화 방법에 비해 간단하게 각각의 계수값을 갱신시킬 수 있다. Hynix $0.35{\mu}m$ STD cell library로 회로를 합성한 결과 35K 정도의 게이트를 필요로 하고 최대동작속도 140MHz의 성능을 보였다.

인터넷을 활용한 표본조사 방법에 관한 사례연구 (Methodology for Internet Survey: Case Study)

  • 윤은성;김영원
    • 한국조사연구학회지:조사연구
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    • 제3권1호
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    • pp.25-51
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    • 2002
  • 본 연구에서는 설문지 형태 등 다양한 요인들이 인터넷 조사의 응답률 및 신뢰성에 미치는 영향을 고찰하기 위해 숙명여자대학교 재학생960명을 표본으로 추출하여 전자우편조사를 실시하였다. 조사 결과 53.9%의 응답률을 얻었으며, 이를 통해 인터넷조사에서 단일스크린 형태와 다중스크린형태, 사전통보, 응답 재요청 등의 요인에 따른 응답률을 분석하였다. 또한 사례연구를 통해 비확률추출법인 자발적 참여에 의한 인터넷조사와 확률추출법인 전자우편조사 결과를 비교했을 경우 전자우편조사에서 보다 성실한 응답을 얻을 수 있다는 결론을 얻었다. 비록 제한적인 모집단을 연구대상으로 했지만 과학적인 확률추출을 적용한 신뢰성 있는 인터넷조사방법의 구현이 무엇보다 중요하고, 아울러 특정 집단을 모집단으로 하는 경우 확률추출에 의한 인터넷조사 방법의 구현이 현실적으로 가능하다는 사실을 확인할 수 있었다.

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인터넷 쇼핑 사이트의 사용성 및 신뢰성과 고객 충성도간의 관계에서 인터넷 쇼핑 관여도의 조절효과 (The Moderating Effects of Internet Shopping Involvement on the Relationship between Usability, Trust of Internet Shopping Sites and Customer Loyalty)

  • 서건수
    • 한국IT서비스학회지
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    • 제7권3호
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    • pp.1-30
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    • 2008
  • This paper proposes an integrated model of customer loyalty in the context of Internet shopping based on a review of two competing perspectives - transactional and relational views. The research model suggests that the usability and trust associated with an Internet shopping site are key determinants of customer loyalty. In this paper, factors such as promotion, ease of use/navigation, and purchase facilitation are posited as major determinants of usability. Trust, on the other hand, is assumed to be influenced by the quality of communication, social shopping service, and safety level associated with an Internet shopping site. This paper also asserts that the lack of consideration for individual differences is one of the key reasons for the inconsistent and mixed research findings in user acceptance literature. In this regard, the elaboration likelihood model (ELM) is considered to be appropriate referent theory as it may theoretically explain why a particular information technology (IT) related message has varying influences on different adopters. The research model comprising 11 hypotheses was derived from and validated through a survey involving 271 university students. The partial least square(PLS) method was used to test the suitability of the research model and its hypotheses. Overall, the results suggest that the usability and trust associated with an Internet shopping site play an important role in acquiring loyal customers. In particular, the user's Internet shopping involvement is found to moderate the relationship between trust and customer loyalty.

고밀도 비선형 광 저장장치를 위한 새로운 부분응답 최대유사도 신호 검출 기술 (PRML Detection for Asymmetric High-density Optical Storage System)

  • 이규석;이재진
    • 한국통신학회논문지
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    • 제31권10C호
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    • pp.927-932
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    • 2006
  • 본 논문은 고밀도 광 기록 저장장치에서 오류의 주 원인이 되는 tangential tilt의 문제를 해결하기 위한 개선된 부분응답최대유사도 신호 검출 방법을 제안한다. 틸트의 변화에 따라 등화기 계수와 비터비 디코더의 가지 기준값을 적응적으로 갱신하여 채널의 변화에 잘 적응하도록 하였다. 채널의 변화를 감지하는 요소로 주기적으로 반복되는 데이터의 동기패턴을 이용하여 누적 평균을 취한 후 변화량에 해당되는 등화기 계수값과 비터비 디코더의 가지 기준값을 동시에 갱신한다. 제안된 방법을 적용한 결과 기존의 PRML 검출기에 비해 비트 오류율 10-6에서 최대 4dB이상 성능이 향상되는 것을 확인할 수 있었다.

Super-RENS Disc의 Random 신호 특성 (Random Signal Characteristics of Super-RENS Disc)

  • 배재철;김주호;김현기;황인오;박창민;박현수;정문일;노명도
    • 정보저장시스템학회:학술대회논문집
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    • 정보저장시스템학회 2005년도 추계학술대회 논문집
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    • pp.119-123
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    • 2005
  • We report the random pattern characteristics of the super resolution near field structure(Super-RENS) write once read-many(WORM) disc at a blue laser optical system(laser wavelength 405nm, numerical aperture 0.85) and the Super-RENS read only memory(ROM) disc at a blue laser optical system(laser wavelength 659nm, numerical aperture 0.65). We used the WORM disc of which carrier-to-noise ratio (CNR) of 75nm is 47dB and ROM disc of which carrier-to-noise ratio (CNR) of 173nm is 45dB. We controlled the equalization (EQ) characteristics and used advanced partial-response maximum likelihood (PRML) technique. We obtained bit error rate (bER) of 10-3 level at 50GB WORM disc and bite error rate of 10-4 level at 50GB level ROM disc. This result shows high feasibility of Super-RENS technology for practical use.

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