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.

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.

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.

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.

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.

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.

페이스북(Facebook)에서 뉴스 댓글이 이용자들의 여론 인식, 책임귀인 및 정책 의견에 미치는 영향

최수정(Soojung Choi),정세훈(Se-Hoon Jeong) 사이버커뮤니케이션학회 2017 사이버 커뮤니케이션 학보 Vol.34 No.3

본 연구는 페이스북에서 뉴스의 댓글을 통해 전달되는 댓글 귀인(내적귀인/외적귀인)과 사회적 승인단서(있음/없음)가 이용자들의 여론 지각, 책임 귀인 및 정책 의견에 미치는 영향에 대해서 알아보고자 하였다. 이를 위해 20-59세 성인 남녀 369명을 대상으로 실험 연구를 진행하였다. 그 결과 여론 인식에 대한 댓글 귀인(내적귀인/외적귀인)의 효과가 발견되었다. 구체적으로, 외적 귀인 댓글(중독의 원인이 상황이나 환경 및 외부적 요인에 있다고 보는 댓글)에 노출된 뉴스 이용자들은 타인들이 외적 귀인을 할 것(스마트폰 중독의 원인으로 외부 환경을 탓할 것)으로 여론을 인식하는 경향이 나타났으며, 이러한 여론 인식은 자신의 귀인 방식 (외적 귀인)을 통해 궁극적으로 사회적 해결을 지지하는 정책 의견(스마트폰 이용습관 관련 미디어 교육 강화, 스마트폰 이용문화 개선 캠페인 실시 등)으로 이어지는 것으로 나타났다. 이 과정에서 사회적 승인단서의 상호작용은 나타나지 않았다. 본 연구는 스마트폰 중독처럼 내적 귀인 (이용자 개인)과 외적 귀인 (미디어 산업)으로 논쟁이 되고 있는 이슈를 선정하여, 이에 대한 이용자들의 책임귀인 및 정책의견을 알아보고자 했다는 점에서 뉴미디어 효과, 헬스커뮤니케이션 및 PR 연구 등에 중요한 함의를 가진다고 할 수 있다. This study aims to investigate the effect of news comments on users’ perceived public opinion, attribution, and policy opinion, particularly in Facebook. In this process, the influence of comments on perceived public opinion is examined based on exemplification theory, and the influence of perceived public opinion on attribution and policy opinion is explained by attribution theory. 369 adults were randomly assigned to messages with news comments that made internal vs. external attribution for smartphone addiction. Results showed that the main effect of attribution in news comments on percieved public opinion was found. Perceived public opinion influenced one’s policy opinions mediated by individual attribution. Social endorsement cues did not moderate the effects. By examining the public’s attribuions and policy opinions regarding smartphone addiction, this research has important implications for health communication and PR research.

신채호의 << 꿈하늘 >> , << 용과 용의 대격전 >> 연구

최수정(Su Jeong Choi) 한국언어문화학회 2001 한국언어문화 Vol.19 No.-

Shin chae-ho is famous of a historian. Also he handed down a number of literary works. But literary research to him have been careless, and drawn by his nationalist thought and strife. I anaysised constructing feature and fantasy mechanism. Heavens in Dream is divided metamorphosis/non-metamorphosis of characters. The latter is way which theme is transmitted simply. The former is way which theme is transmitted association of idea by chain of metamorphosis. The latter lead to single line of time, stability of space. The former produce new spatial sense and totality by partial of body represented superfluously The Fierce Strife between two Dragons is marked of `0`(zero) and sound. These related to good dragon. `0` imply status which can`t representation itself. came, came, Dragon came at last. Now is the last day of Heaven sound. This is based on hearing sense, gradation. The conclusion as a form of Dragon is not in sight at the narrative end, only that sound is catching character`s ears. Interpretative difference of North Korea and South Korea occur at this point. Such difference can be examined at version of a phenomenon of reading. Two work maintain idea and sense which keep autonomy. This due to material imagination, and this materiality is due to his strict knowledge and counter passion to his times. Ethical nature is situated between knowledge and passion. The real gave `Otherness` to his idealist disposition. The Other facilitated imagination.

휴대용 및 Bench-Top X-선 형광 분석기를 이용한 오일 시료 중 마찰 금속의 비교 분석

최수정(Soo-Jung Choi),김종혁(Chong-Hyeak Kim),이석근(Sueg-Geun Lee),김동표(Dong-Pyo Kim) 한국분석과학회 2009 분석과학 Vol.22 No.5

Critical Literacy in the EFL Classroom: Perspectives of Undergraduates on Reading beyond the Text

최수정(Soo Joung Choi) 한국영어어문교육학회 2016 영어어문교육 Vol.22 No.3

This paper reports on a qualitative case study that explored the possibility of developing critical literacy within a general English reading program at the collegiate level in Korea. Conducted in the context of a mandatory English class with a novice instructor and 39 freshmen, the study aimed to bring to light the way critical literacy was closely related to the students ability to read beyond the text. Data were collected from classroom observations, a student reflection paper, and instructor interviews, and were analyzed qualitatively. The findings illustrated that the critical approach to literacy offered students an opportunity to situate their reading practices within the larger sociopolitical world and to develop critical consciousness through collaboration. Dissatisfied with the traditional cognitively oriented and teacher-centered approach to reading, the students spoke highly of the critical literacy approach as it allowed them to reflect critically on the issues presented in the text, which were relevant to their lives, to form and express their own opinions, and to search for ways to bring about changes. Although students had positive experiences in the critical literacy class overall, they encountered some challenges as well. Implications for successful implementation of critical literacy are suggested.