• Title/Summary/Keyword: Theoretical studies

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Internal Flow Characteristics for Tangential Entry Conditions in a Swirl Injector (스월 인젝터에서 접선방향 유입구 조건에 따른 내부유동의 특성 연구)

  • Kim, Sung-Hyuk;Khil, Tae-Ock;Cho, Seong-Ho;Yoon, Young-Bin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.05a
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    • pp.115-118
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    • 2008
  • Many theoretical and experimental studies have been conducted to investigate elements of the hydrodynamic process, such as variations in liquid film thickness or air core diameter. From these studies, some theoretical relationships have been established through an approximated analytical solution of flow hydrodynamics in a swirl nozzle. However, experimental studies on elements such as internal flow have not produced conclusive results. In this study, the variations and stability of the internal flow were examined by visualizing the air core and measuring the liquid film thickness.

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A Theoretical Study on Family-Friendly Management - Dual Agenda Approach - (이중의제접근을 통한 가족친화경영)

  • Lee, Ju-Yeon;Choe, Sok-Ho
    • Journal of Family Resource Management and Policy Review
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    • v.14 no.3
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    • pp.15-36
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    • 2010
  • The purpose of this study is to review previous domestic and foreign studies and to investigate personal work-life harmonization through theoretical research on familyfriendly management using a dual agenda approach. The authors briefly identified trends and critically reviewed domestic researches on family-friendly management and foreign studies of scholars that overcame the limitations of domestic studies to present a foundation for work-life harmonization through a dual agenda approach. As a result, the existing family-friendly management was found to be compatible with work and family but was not effective in developing personal careers. The workers who actively accepted family-friendly management as part of their work-life balance were mostly female laborers who were employed part-time, had lower academic education, earned lower wages and, in general, were non-professional workers without specific skills or career aspirations. The remainder of the workers, full-time male employees, with higher education and with professional knowledge and skills, inevitably worked longer, more labor-intensive hours, due to the advent of the dual agenda approach. A new work-life harmonization program is urgently needed not only for family-friendliness but also for healthy organizations, individual career development and personal wellbeing.

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The Development of Political Economy of Communication as a Critical Scholarship and Its Theoretical Limitations (미디어 정치경제학의 학문적 지형과 이론적 과제)

  • Moon, Sang-Hyun
    • Korean journal of communication and information
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    • v.45
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    • pp.77-110
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    • 2009
  • This study explores the academic development of the Political Economy of Communication, which is pursued by reviewing academic characteristics, research subjects, key scholars, formal and informal institution as an academic hub, key articles, major academic associations and academic journals. In addition, this study examines important theoretical limitations and tasks to deal with in the future, which have been exposed through several heated debates with other research traditions such as Cultural Studies and Post Modernism.

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Internal Flow Stability for Tangential Entry Conditions in a Swirl Injector (스월 인젝터에서 접선방향 유입구 조건이 내부유동의 안정성에 미치는 영향에 대한 연구)

  • Kim, Sung-Hyuk;Khil, Tae-Ock;Cho, Seong-Ho;Yoon, Young-Bin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.12 no.6
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    • pp.30-37
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    • 2008
  • Many theoretical and experimental studies have been conducted to investigate elements of swirl injector hydrodynamics, such as variations in liquid film thickness or air core diameter. From these studies, some theoretical relationships have been established through an approximate analytical solution of flow hydrodynamics in a swirl nozzle. However, experimental studies on elements such as the stability of internal flow have not produced conclusive results. In this study, the stability of the internal flow under tangential entry conditions was examined by visualizing the formation of the air core in the swirl chamber and measuring the liquid film thickness in the orifice.

Research Trend Analysis on Research Ethics in Korea

  • LEE, Hyo-Young
    • Journal of Research and Publication Ethics
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    • v.2 no.2
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    • pp.11-16
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    • 2021
  • Purpose: The purpose of this study is to analyze the research trends of domestic research ethics and to draw implications for the limitations of existing research and future development directions through this. Research design, data and methodology: To this end, this study first examined the concept of research ethics and research area to derive an analysis frame. In addition, 72 academic papers published in domestic journals from 2000 to November 2020 were analyzed according to the research period, research area, research subject, research field, research method, and the nature of the journal. Results: As a result of the analysis, it is judged that social interest in research ethics led to academic interest after the 2005 Hwang Woo-seok incident. These characteristics show that the interest of academia is changing and increasing significantly when issues related to research ethics are raised socially. Of the 72 papers to be analyzed, 29 (40.3%) conceptual and theoretical studies on research ethics and 43 (59.7%) studies on practical measures were surveyed. Conclusions: In the case of published journals on research ethics, the proportion of publications in humanities and social sciences and pedagogical journals was high, and in research methods, literature and theoretical studies were the highest.

A Study of Establishing Culture Archiving (문화 아카이빙 정착을 위한 방향 연구)

  • Ryu, Han-jo
    • The Korean Journal of Archival Studies
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    • no.37
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    • pp.41-74
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    • 2013
  • The culture archiving has attracted the public increasingly because of interest in culture and field extension of archival science. So researches have been conducted and many attempts have been tried to in everyday life archiving and village archiving. Although many studies explain appropriateness and give examples, theoretical study is rarely conducted. This Study explains the representation of the records in theoretical ways and the process of culture archiving. Also, this study reconsiders the documenting by archivists and suggests a value-based archiving method. For proving validity of this study, reviewed the possibility of representation classification system based on cultural contents is usable. I hope that this study contributes to discussion of the development of culture archiving methods.

Capital Outflow Waves in the Korean Economy during Financial Turmoil: Its Implications and Policy Suggestions

  • Suh, Jae-Hyun
    • Journal of Korea Trade
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    • v.23 no.7
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    • pp.113-127
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    • 2019
  • Purpose - This paper investigates whether financial crises could be the indicators of capital outflow waves or vice versa in Korea. Korea has experienced two severe financial crises, which are the Asian Crisis and the global financial crisis. Although there were many variables associated with these two remarkable events, one notable variable was gross capital outflows, which had significantly increased around them. Motivated by existing literature which built theoretical frameworks explaining the relationship between capital flight and financial crises, we examine the empirical evidence for this relationship. Design/methodology - We use panel data from 61 countries including Korea from 1980 to 2009 to study the associations between capital flight and diverse financial crises such as banking, currency, debt, and inflation crises. To be specific, we use the complementary log-log model to see whether capital outflow waves are reliable indicators for domestic financial crises. Findings - The results show, first, that banking, currency, and inflation crises are associated with capital flight. Second, debt crises are also associated with capital flight, but the result is not robust to different specifications. And, third, the positive associations between capital flight and crises are mainly driven by banking flows rather than FDI and portfolio flows. Originality/value - This paper is one of a few studies that investigates domestic (not foreign) investors' behavior during financial turmoil. Furthermore, theoretical studies which provide contradictory explanations on the movements of gross capital outflows during financial crises emphasizes the importance of empirical evidence in this paper.

Theoretical Study of C-H σ-Bond Activation and Related Reactions

  • Sakaki, Shigeyoshi
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.829-831
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    • 2003
  • Various theoretical studies of σ-bond activation of organic molecules by transition metal complexes arereviewed. In the homolytic σ-bond activation, the d orbital energy level of the central metal is an importantfactor, as well known. At the same time, the electron-withdrawing substituent which stabilizes the sp3 orbitalaccelerates the homolytic σ-bond activation. In the heterolytic C-H σ-bond activation of RH by $MXL_n$, the XHbond formation is an important driving force, where $MRL_n$ and HX are formed as products. The heterolytic σ-bond activation is also understood in terms of the electrophilic attack of the metal center to the substrate.

Theoretical Study for Hydrogen Production from an Integrated Gasification Combined Cycle System

  • Lee, Sang-Sup
    • Environmental Engineering Research
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    • v.16 no.1
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    • pp.35-39
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    • 2011
  • An integrated gasification combined cycle (IGCC) system has been attracting attention due to its increased energy conversion efficiency and ability to treat various carbonaceous materials. IGCC is also expected to play an important role in the future supply of hydrogen energy. The use of a palladium-based membrane to separate the hydrogen from the synthesis gas stream has been intensively studied due to its exceptional hydrogen-separating capability. However, theoretical research on hydrogen separation is still an unfamiliar area in Korea. First-principle density functional theory was applied in this study to investigate the dissociative adsorption of hydrogen onto a palladium surface. The stability of hydrogen on the surface was theoretically evaluated with various adsorption configurations, partial pressures and temperatures. Further theoretical and experimental studies were also suggested to find a more hydrogen-selective material.

Composite action of notched circular CFT stub columns under axial compression

  • Ding, Fa-xing;Wen, Bing;Liu, Xue-mei;Wang, Hai-bo
    • Steel and Composite Structures
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    • v.24 no.3
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    • pp.309-322
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    • 2017
  • This paper conducted both numerical and theoretical studies to investigate the composite action of notched circular concrete-filled steel tubular (CFT) stub columns under axial compression and established a theoretical method to predict their ultimate bearing capacity. 3D finite element (FE) analysis was conducted to simulate the composite action and the results were in good agreement with experimental results on circular CFT stub columns with differently oriented notches in steel tubes. Parametric study was conducted to understand the effects of different parameters on the mechanical behavior of circular CFT stub columns and also the composite action between the steel tube and the core concrete. Based on the results, a theoretical formula was proposed to calculate the ultimate bearing capacity of notched CFT stub columns under compression with consideration of the composite action between the steel tube and the core concrete.