디지털 멀티미디어 방송(DMB)에서 클라이언트 요구 기반의 데이터 캐러셀 스케줄링

최수정,박익현,강상혁,Choi, Sujeong,Park, Ik-Hyun,Kang, Sang-Hyuk 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.2B

이 논문에서는 DMB에서의 주문형 데이터 방송을 위한 새로운 데이터 캐러셀 스케줄링 알고리듬을 제안한다. 클라이언트로부터 리궤스트를 받으면 서버는 그 리궤스트에 대한 통계치를 이용하여 아이템을 두 집합으로 나눈다. hot 아이템을 한 캐러셀 내에서 여러 번 반복하여 방송하도록 하여 그 아이템에 대한 클라이언트의 대기시간을 줄이도록 하였으며, hot 아이템의 방송회수에 상한선을 두어 cold 아이템의 방송 기회를 늘이도록 하여 클라이언트의 리퀘스트에 대한 응답 성공률을 높이도록 하였다. 모의실험을 통해 캐러셀 기반의 다른 알고리듬과 비교하였을 때 원하는 결과를 얻어낼 수 있었다. We propose a new data carousel scheduling algorithm for on-demand data broadcasting in DMB. The server divides data items into two sets named hot and cold, according to request statistics from clients. When constructing a data carousel, hot items are placed periodically with their upper limit of broadcasting frequency. If there are empty slots after placing hot items, cold items with high request ratio are placed until the carousel is full. A cold item is broadcast only once in the caroulsel. For the response on clients' requests, our proposed scheme is shown to have high success ratio with short waiting time.

온라인 시장 활성화를 위한 간편결제 특성에 관한 연구

최수정,김창식,곽기영,김희웅,Choi, Sujung,Kim, Changsik,Kwahk, Keeyoung,Kim, Heewoong 디지털산업정보학회 2016 디지털산업정보학회논문지 Vol.12 No.3

This study develops an extended model to predict customer satisfaction in easy payment systems based on information systems success model. Our data was collected from easy payment systems users and analyzed using PLS. This study selected four variables as easy payment systems characteristics(convenience, variety, security, speed) along with gender being used as a moderating variable. The results showed that convenience and security are turned out to affect customer satisfaction. Additionally, the test of difference in gender revealed that with respect to gender, moderating effects exist in security and speed. This implies that this study can provide different promotion strategies according to gender. Overall, the proposed model could be used to predict customers' willingness to pay on the easy payment systems.

만성불면증 환자에게 적용한 단기 인지행동중재의 효과

최수정,이영희,Choi, Su-Jung,Yi, Young-Hee 한국중환자간호학회 2008 중환자간호학회지 Vol.1 No.1

Purpose: This study was conducted to exam the effects of the Abbreviated Cognitive Behavioral Therapy(ACBT) on chronic insomnia. Methods: Study was one-group interrupted time series study that involved 13 adults(mean age=51.7, aged 25-77 years) with chronic primary insomnia who visited sleep disorder clinic of S Hospital from November 2004 to October 2005. The subjects received 2-session individual ACBT with 2 week-interval($1^{st}$: 1.5- 2hrs, $2^{nd}$: 20-30min). To measure the subjective insomnia severity and sleep patterns, 3 times of insomnia severity index and sleep logs were completed(before ACBT, after ACBT, and 3-month after ACBT). The main outcomes were subjective insomnia severity and sleep patterns(sleep onset latency, waking after sleep onset, and total sleep time, sleep efficiency). The data were analyzed with SPSS 10.0 version program by Friedman test, Wilcoxon signed rank test with Bonferroni correction. Results: There were statistically significant decrease in insomnia severity index, sleep onset latency, and waking after sleep onset, and increase total sleep time and sleep efficiency. Conclusion: ACBT was effective in reducing subjective insomnia severity and improving sleep patterns. Sleep improvement was better sustained over time with ACBT.

저장매체 스트리밍에서 substream에 기초한 비순차 패킷 스케줄링

최수정,안희준,강상혁,Choi Su Jeong,Ahn Hee June,Kang Sang Hyuk 한국통신학회 2004 韓國通信學會論文誌 Vol.29 No.10C

이 논문에서는 스트리밍 미디어에 대해 속도 대비 왜곡을 최적화하는 패킷 스케줄링 알고리듬을 제안한다. 수신단은 패킷을 받으면 ACK를 보내는데, 주기적으로 관측한 채널 throughput을 함께 보낸다. 비디오 패킷의 중요도는 움직임 백터, 텍스처 필드, 시간계층화를 고려하여 GOP 내에서의 위치에 의해 결정되며, 이것을 이용하여 서브스트림을 정의한다. 서버는 수신단으로부터 온 응답 정보와 비디오의 통계적 특징을 사용하여 임의의 시점에서 전송하고자 하는 최적의 서브스트림을 결정한다. 이를 위해 스트리밍 시스템을 류잉 시스템으로 모델링하고, 각 서브.스트림에 있는 프레임의 복호화 실패을을 체감대역폭을 이용하여 계산하고 그 시점에 전송할 최적의 서브스트림을 선택한다. 수신단이 주기적으로 기록하고 전송한 채널정보에 대해, 송신단은 최적의 서브스트림을 새로이 계산하는데, 그때까지 서브스트링의 데이터는 Earliest Deadline First(EDP)방식으로 전송핀다. 이 때, 전송 순서는 원래의 재생 순서와 다르게 된다. 그리고, 실제 비디오 데이터를 사용한 실험에서, 제안한 스케줄링이 기존의 순차적인 전송보다 성능이 좋다는 것을 보여준다. We propose a packet scheduling algorithms for streaming media. We assume that the receiver periodically reports back the channel throughput. From the original video data, the importance level of a video packet is determined by its relative position within its group of pictures, taking into account the motion-texture discrimination and temporal scalability. Thus, we generate a number of nested substreams. Using feedback information from the receiver and statistical characteristics of the video, we model the streaming system as a queueing system, compute the run-time decoding failure probability of a Same in each substream based on effective bandwidth approach, and determine the optimum substream to be sent at that moment in time. Since the optimum substream is updated periodically, the resulting sending order is different from the original playback order. From experiments with real video data, we show that our proposed scheduling scheme outperforms the conventional sequential sending scheme.

NaNO₃, NaHCO₃ 농도가 Arthrospira platensis 생장에 미치는 영향

최수정,하종명,이재화,Choi, Soo-Jeong,Ha, Jong-Myung,Lee, Jae-Hwa 한국생물공학회 2015 KSBB Journal Vol.30 No.6

Arthrospira platensis (A. platensis) is one of the most explored cyanobacteria and has been studied for proteins, vitamins, pigment (chlorophyll and carotenoids) and fatty acid. In this study, we tested the effect of $NaHCO_3$ and $NaNO_3$ on the microalgae growth under photoautothrophic culture in A. platensis. As a result, cell growth and dry cell weight were increased in proportion to the $NaHCO_3$ and $NaNO_3$ concentration. Pigment (chlorophyll and carotenoids) contents of A. platensis were increased with proportion to $NaHCO_3$ concentration. But, the content of pigment (chlorophyll and carotenoids) in 100% $NaNO_3$ medium of A. platensis was the highest, 40%, 140% and 200% $NaNO_3$ medium with pigment content of A. platensis was reduced. In conditions of $NaHCO_3$ (50%) or $NaNO_3$ (40%) limitation, A. platensis could accumulate lipids to high as 1.7-fold and 1.3-fold.

이러닝시스템의 매체풍부성, 매체유용성, 매체경험이 학습자 만족에 미치는 영향

최수정,강경준,고일상,Choi, Su-Jeong,Kang, Kyung-Jun,Ko, Il-Sang 한국데이터전략학회 2007 Journal of information technology applications & m Vol.14 No.2

In an effort to apply IT to practices of learning, universities are trying to implement e-Learning systems and expanding the extent of their usage. Nowadays, e-Learning systems are not only used for conducting web-based distance learning, but also used for supporting traditional classes education by encouraging communication and information sharing between instructors and learners or among the learners. There is relatively lack of studies on the exploitation of e-Learning systems in the traditional classes, in comparison with a distance education. Specifically, howe-Learning systems could support the traditional class and/or which benefits e-Learning systems could offer in the classes are among the important issues. In this study, we suggest that e-Learning systems would be the rich media to communicate and exchange information among people who participate in a class. We derive key variables like media richness and media experience from Media Richness Theory and from Channel Expansion Theory. Moreover, Media usefulness and Satisfaction of a learner with e-Learning system is drawn from the literature on IS success. We examine the effects of perceived media richness, media usefulness, and media experience on leaner's satisfaction with e-Learning systems. In addition, we also investigate learner's media usefulness perception which is positively related to media richness and media experience. Finally, learner's experience with e-Learning systems affects perceived media richness. Based on the results of an empirical test. we first suggest that perceived media richness with e-Learning systems contributes to increase media usefulness and satisfaction of a learner. Second, media experience is an important predictor of media richness and media usefulness perception. Consequently, the result can support Channel Expansion Theory. Finally, media usefulness perception affects learner's satisfaction with e-Learning systems.

대지미술에서 해석한 공간적 요소의 조경활동 접목에 관한 연구

최수정 ( Soo Jung Choi ),유진형 ( Jin Hyung Yoo ) 한국기초조형학회 2008 기초조형학연구 Vol.9 No.5

모바일 간편결제에 대한 지속사용의도: 개인의 혁신성, 신뢰 및 네트워크 효과를 고려한 UTAUT모형 시각에서의 접근

최수정 ( Sujung Choi ),강영선 ( Yeong Seon Kang ) 정보통신정책학회 2016 정보통신정책연구 Vol.23 No.4

본 연구는 최근 급성장 하고 있는 모바일 간편결제에서 어떤 요인들이 이를 이용하는 사용자들의 지속사용의도에 영향을 미쳤는지 살펴보았다. 구체적으로 개인의 혁신성, 모바일 간편결제에 대한 지각된 신뢰, 네트워크 효과에 대한 기대가 사용자들의 지속사용의도에 미치는 영향을 분석하였다. 이를 위해, 본 연구에서는 Venkatesh et al. (2003)의 UTAUT모형(Unified Theory of Acceptance and Use of Technology)을 적용하여 새로운 기술을 수용하는 사용자의 지속사용의도를 설명하고자 한다. 207명의 대학생을 대상으로 설문을 실시했으며, smartPLS를 통해 분석한 결과, UTAUT모형으로부터 성과기대, 노력기대, 사회적영향이 모바일 간편결제 사용자의 지속사용의도에 긍정적인 영향을 미치는 것으로 나타났으며, 본 연구를 통해 추가된 지각된 신뢰, 네트워크 효과에 대한 기대가 모바일 간편결제 사용자의 지속사용의도에 긍정적인 영향을 미치는 것으로 나타났다. 하지만, 모바일 간편결제 사용자의 혁신성은 지속사용의도에 유의한 영향을 미치지 않는 것으로 나타났다. In this study, we investigate various factors affecting technology acceptance by smartphone users (i.e., perceived trust, perceived network effects, and users` innovativeness) in relation to mobile payment services, which have recently been introduced in Korea. For this purpose, we employ the unified theory of acceptance and use of technology (UTAUT; Venkatesh et al., 2003) to explain the process of technology adoption and user experience in the case of the new mobile payment services. A smartPLS-software analysis based on a survey of 207 undergraduate students indicates that five factors including performance expectations, effort expectations, social influence, perceived network effects, and users` innovativeness influence the intention of smartphone users to use mobile payment services continuously.

대학의 교실수업에서 이러닝시스템 이용의 활성화에 관한 연구: 사회적, 기술적, 개인적 특성

최수정 ( Su Jeong Choi ) 한국정보시스템학회 2008 情報시스템硏究 Vol.17 No.4

集合債權讓渡擔保의 해석을 둘러싼 諸問題 : 대법원 2003.9.5., 2002다40456 판결

崔秀貞(Choi, Su-Jeong) 한국민사법학회 2004 民事法學 Vol.26 No.-

Bei der Entscheidung des obersten Gerichtshofs, die in diesem Aufsatz besprochen worden ist, handelt es sich um eine Globalzession. Unter Globalzession ist eine Sicherungsabtretung gegenwärtiger und künftiger Forderungen mit der Besonderheit, daß eine Vielfalt oder Gesamtheit von Forderungen unter einer Gesamtbezeichnung abgetreten wird, zu verstehen. Wie stets bei Vorausabtretungen, gewinnt bei der Globalzession das Bestimmtheitserfordernis besondere Bedeutung. Die praktischen Wirksamkeitsprobleme der Globalzession liegen eher bei der die Interessen des Globalzessionars übermäßig begünstigenden Reichweite. In Betracht kommt also eine Sittenwidrigkeit wegen wirtschaftlicher Knebelung, Beeinträchtigung der wirtschaftlichen Betätigungsfreiheit und Benachteiligung der übrigen Gläubiger. Und strengere Maßstäbe werden bei formularmäßiger Abtretung auf der Grundlage von §§6,11 Nr.3 AGBG an die Angemessenheit der Sicherung gelegt. Einerseits hat der oberste Gerichtshof den Globalzessionsvertrag, der A und der Kläger abgeschlossen hatten, als Vorvertrag qualifiziert. Aber diese Entscheidung ist mit dem Parteiwillen, der durch die Vertragsauslegung erleuchtet wird, nicht zu vereinbaren und aus dem rechtspolitischen Gesichtspunkt sehr bedenklich. Andererseits bei der Abtretung bedarf es der vom Zedent gemachten Mitteilung an den Schuldner oder der Annahme vom Schuldner, damit der Zessionar die abgetretene Forderung geltend macht. Es steht gleich, wenn die Abtretung aufgelöst wird, die Parteirolle daher umgekehrt wird. Die Mitteilung kann mit dem Zustimmung desjenigen, der Zessionar war, zurückgenommen werden. Ohne solche Mitteilung oder gerechte Zurücknahme kann der Zedent vom Schuldner eine Leistung nicht fordern. Aber der Schuldner kann den Leistungsanspruch des früheren Zessionars stets verweigern, denn er hat nun keinen Rechtsgrund dafür. Die Entscheidung des obersten Gerichtshofs, der die Klage des früheren Zessionars (Klägers) abgewiesen hat, ist selbst nicht ungerecht, aber ihre Begründung hat ins klare gebracht zu werden.