• 제목/요약/키워드: Previous study

검색결과 21,266건 처리시간 0.044초

열손실에 의한 확산-열 불안정성의 가속화 (Acceleration in Diffusive-thermal Instability by Heat Losses)

  • 박준성;박정;김정수
    • 한국연소학회지
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    • 제12권2호
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    • pp.34-41
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    • 2007
  • The dynamic behaviors of counterflow non-premixed flame have been investigated experimentally to study effects of heat losses and Lewis number on edge flame oscillation, which result from the advancing and retreating edge flame motion of outer flame edge at low strain rate flame. For low strain rate flame, lateral conduction heat loss in addition to radiation heat loss could be more remarkable than the others. Oscillatory instabilities appear at fuel Lewis number greater than unity. But excessive lateral conduction heat loss causes edge flame instability even at fuel Lewis number less than unity. The excessive heat loss caused by the smaller burner diameter in which the flame length is an indicator of lateral conduction heat loss extends the region of flame oscillation and accelerates oscillatory instability in comparison to the previous study with the burner diameter of 26mm. Extinction behaviors quite different from the previous study are also addressed.

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열박음 공정이 케이스의 온도분포 및 변형에 미치는 영향(II) - 변형 계측 및 변형 해석 모델 정립 - (A Study on the Temperature Distribution and Deformation of Case in Shrinkage Fit Process(II) - Deformation Measurement and Deformation Analysis Model -)

  • 장경복;정진우;강성수;최규원;박찬우;조상명
    • Journal of Welding and Joining
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    • 제19권5호
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    • pp.492-498
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    • 2001
  • In the previous study, temperature monitoring of case about shrinkage fit process was performed and heat transfer model was developed in detail by feedback and tuning among monitoring result, process investigation, and analysis result. The gap element in contact between case and core was effectively used in analysis model. In present study, following things are performed to solve deformation of case due to shrinkage fit process on the basis of previous result. Above all, mechanical material properties of case are measured by case specimen for deformation analysis considering weldment of case. Deformation of case before and after shrinkage fit process is measured, too. Three dimensional deformation model is developed by the comparison and inspection between these experimental data and analysis results. Deformation analysis is simulated with the result of heat transfer analysis, in other words, non-coupled analysis is used. Finally the countermeasure for deformation is brought up through those.

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Improving visual relationship detection using linguistic and spatial cues

  • Jung, Jaewon;Park, Jongyoul
    • ETRI Journal
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    • 제42권3호
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    • pp.399-410
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    • 2020
  • Detecting visual relationships in an image is important in an image understanding task. It enables higher image understanding tasks, that is, predicting the next scene and understanding what occurs in an image. A visual relationship comprises of a subject, a predicate, and an object, and is related to visual, language, and spatial cues. The predicate explains the relationship between the subject and object and can be categorized into different categories such as prepositions and verbs. A large visual gap exists although the visual relationship is included in the same predicate. This study improves upon a previous study (that uses language cues using two losses) and a spatial cue (that only includes individual information) by adding relative information on the subject and object of the extant study. The architectural limitation is demonstrated and is overcome to detect all zero-shot visual relationships. A new problem is discovered, and an explanation of how it decreases performance is provided. The experiment is conducted on the VRD and VG datasets and a significant improvement over previous results is obtained.

IS 프로젝트 선택에 있어서의 편견에 대한 재고찰 (Reexamining Organizational Bias In Selecting IS Projects)

  • 홍성완
    • Asia pacific journal of information systems
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    • 제3권2호
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    • pp.55-73
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    • 1993
  • The importance of IS project selection process has been recognized by many IS researchers as well as IS practitioners. The ideal selection process should provide an organization with best IS project from many competing proposals. However, researchers have found that some organizational biases exist in making the selection decisions. This means different selection mechanisms favor projects with different characteristics. The purpose of this study is to reexamine previous findings to determine if the biases still exist in rapidly changing IS environment. An exploratory case study was conducted to gain deeper understanding of the actual IS project selection process. Then scenario approach was used for the empirical study. Some conflicting findings from the previous studies are discussed.

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A Comprehensive Review on r-Learning: Authentic r-Learning Beyond the Fad of New Educational Technology

  • Jung, Sung Eun;Han, Jeonghye
    • International journal of advanced smart convergence
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    • 제9권2호
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    • pp.28-37
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    • 2020
  • We conducted a comprehensive review on the previous research on r-Learning. By reviewing 843 previous studies about r-Learning published from 2004 to 2015, this study investigated 1) the trend of research on r-Learning over time, 2) the characteristics of targeted students in r-Learning, 3) the educational activities implemented for r-Learning, and 4) the types of educational robots used for r-Learning. The study found that the research on r-Learning has rapidly and steadily increased and the types of educational activities and educational robots has been diversified. Relying on the findings of this review, this study suggests 1) ensuring growth in both the quality and the quantity of research on r-Learning, 2) broadening the target student population of r-Learning beyond the age-limited boundaries, 3) enhancing educational activities of r-Learning, and 4) recognizing the necessity for systematic and clear concepts of types of educational robots.

흑백영상처리장치를 이용한 과실선별기 개발에 관한 연구(II) - 잔상의 영향 및 선별성능 - (Development of a Fruit Grader using Black/White Image Processing System(II) - Effects of Blurring and Performance of the Fruit Grader -)

  • 노상하;이종환;이승훈
    • Journal of Biosystems Engineering
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    • 제17권4호
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    • pp.363-369
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    • 1992
  • The aim of this study was to examine the blurring effects on performance of the experimental fruit grader in grading Fuji apples by size and coloration of the whole surface of individual apples. The grader consisted of a black/white image prcessing system, one camera, and utilized the algorithm developed for high speed sorting in the previous study. The results are summarized as follows : 1. With the algorithm developed in the previous study, it took 0.27~0.33 second in analyzing the size and coloration of an apple, and relative errors were within 3% for size and 1.3% for coloration. 2. The effect of blurring increased linearly with the conveying speed of apple and showed more significant effect on detection of coloration than on determining of size. 3. Considering the blurring effect, capacity of the experimental fruit grader was estimated to 7,500 apples per hour.

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포털사이트의 지각된 서비스 품질이 후속 행동에 미치는 영향에 관한 연구 (The Effect of Perceived Service Quality of Web Portal Site on Trust, Satisfaction and Revisit Intention)

  • 이승희;김혜경
    • 디지털융복합연구
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    • 제6권1호
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    • pp.75-82
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    • 2008
  • This paper is aimed to exam factors in the perceived service quality of web portal site and to analyze their effects on customer satisfaction. And this paper analysis satisfaction effects on revisit intention. To accomplish this purpose, this study examined previous studies and summarized core factors of service quality. Form literature survey, we drawn core factors. They are convenience, technologies, valuable of contents and service, communication, positioning. These core factors will affect on customer trust, satisfaction and satisfaction will affect on revisit intention. This study examined previous studies and summarized core factor in perceived service quality of web portal site. Fourteenth hypothesis were developed. Data for empirical testing were collected through survey to portal sites user. The results of this study are as follows; First, we find that service, communication and positioning have positive influence on the trust. Second, convenience, valuable of contents and postioning factors have a positive influence on the satisfaction. Third, it is shown that satisfaction have a positive influence on the revisit intention.

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교사효능감의 개념, 측정, 효과, 영향요인에 대한 연구동향 (Review of Researches in Concept, Measurement, Effect, and Influence Factor of Teacher Efficacy)

  • 주동범
    • 수산해양교육연구
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    • 제21권4호
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    • pp.489-498
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    • 2009
  • The purpose of the study is to review research in concept, measurement, effect, and influence factor of teacher efficacy. Through the review of previous research, the study shows that the concept of teacher efficacy is likely to be situation-specific rather than teacher characteristic. And the study represents that the measurement of teacher efficacy is related to the development of measurement instrument and the extraction of construct. The effect of teacher efficacy concerns the relationship between teacher efficacy and the student's academic achievement and affective traits such as motivation, interests, and attitude, and the relationship between teacher efficacy and teacher. And the influence factor of teacher efficacy concerns the influence of job environment related to teacher. The four things mentioned above are discussed in detail based on the previous research.

커피전문점에서 전환장벽을 고려한 고객만족과 충성의 관계 (Moderating effect Switching Barrier on Coffee-shop customer Satisfaction and Loyalty)

  • 김판수;한장협
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2011년도 추계학술대회
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    • pp.683-694
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    • 2011
  • This study analysed impact of service quality on customer satisfaction and loyalty in the take-out coffee shop. The switching barrier was also studied as a moderating effect. Particularly, this study focused on relationships between customer loyalty and switching barriers. A lot of previous studies interest only in customers satisfaction. This study also analysed relationships among service quality, customer satisfaction, switching barriers and brand loyalty. Eventually, service quality significantly affects customer satisfaction, moderating effects, brand loyalty and marketing performance. SERVQUAL model which was established by PZB (1988) was used as a service quality factors. The impact on customer satisfaction was analysed using multiple regression analysis. Simple regression analysis was used to find effects of customer satisfaction and customer loyalty. Additional factors of switching barriers was classified based on previous studies. Hierarchical multiple regression analysis was used to find factors of customer loyalty among switching barriers. In the result, we can find that the importance of tangibles, responsiveness in service quality factors and contract cost, search cost and continuous cost in moderating effects.

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창조적 리더십의 질적인 분석에 관한 연구 (A Study on the Qualitative Analysis of Creative Leadership)

  • 이상범
    • 디지털융복합연구
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    • 제7권4호
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    • pp.21-30
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    • 2009
  • Public and private sectors are experiencing a worldwide economic depression originated from the failure of U.S. financial system. At a harsh time like this, policy-makers need to understand more about the effects of the creative leadership in the digital era. However, there haven't been enough studies performed on this field in Korea. This study aims to fill the blank and learn more about the correlation between creative leadership and organizational effectiveness. To achieve this goal, various previous leadership studies have been reviewed in terms of organizational behaviors, comparative culture studies, and etc. In the end, this study argues previous qualitative studies' weaknesses and limitations, and tries to suggest new aspect of qualitative research method of creative leadership.

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