• 제목/요약/키워드: Conceptual change

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Economic Feasibility Study for CO2 Ocean Sequestration (CO2 해양격리시스템의 기술.경제적 가능성평가)

  • Park, Se-Hun;Oh, Wee-Yeong;Kwon, Moon-Sang
    • Ocean and Polar Research
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    • v.27 no.4
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    • pp.451-461
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    • 2005
  • The $CO_2$ storage in geologic and oceanic reservoirs is considered to be one of the carbon management strategies for responding to global climate change. Ocean carbon sequestration is purposeful storage acceleration into the ocean of large amounts of carbon that would accumulate in the atmosphere and naturally enter the ocean over a longer timespan. Some technologies for $CO_2$ ocean sequestrations have been developed as a nation project. However, $CO_2$ ocean sequestrations are attractive because they have the advantage of vast capacity sequestration far away from industrial areas, and offer easier monitoring whereas less economic advantage has been indicated as one of the key barriers compared with $CO_2$ geosphere sequestration, which is produced as a byproduct. In this paper, a conceptual design for $CO_2$ ocean sequestration is introduced, and the preliminary examination is described. As a result, the $CO_2$ price, US$ 24/t shows far away from the economics. The causes come from the expensive $CO_2$ recovery cost and the low $CO_2$ price. The expensive $CO_2$ recovery cost is because too much electricity and water are consumed. In order to look for an economic balance point for $CO_2$ ocean sequestration, NPV=0, it is increases the $CO_2$ price. Finally 60.4$ per ton is found to be the balance price.

Optimal Investment Strategy for Research and Development Considering Dynamic Complexity (동태적 복잡성을 고려한 최적의 연구개발 투자 전략)

  • Son, Jiyoon;Kim, Hyun Jung;Kim, Soo Wook
    • Journal of the Korean Operations Research and Management Science Society
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    • v.40 no.4
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    • pp.19-33
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    • 2015
  • Recently, interest in research and development (R&D) investment decisions have increased among Korean domestic enterprises. However, existing R&D investment studies only focused on government R&D investment policies while only a few studies investigated firm level R&D investment. Prior literatures also overlooked the feedback loop between R&D investment and firm performance. Therefore, this paper identifies a system dynamics model for R&D investment decision making in domestic electronics firms. The conceptual model is derived from R&D investment-related theories found in bodies of literature on company performance, enterprise activity, and market maturity. This study investigates the dynamic feedback between R&D activities and sales using the system dynamics model. In other words, the system dynamics model is used to explain the change in the closed feedback circulation structure in R&D investment activities including technology development, production process, and marketing that subsequently result in sales increase and re-investment into R&D from the generated revenues. There are two major results. First, a similar ratio of investment on technology development and production process derives the higher company sales. Second, regardless of market maturity, marketing investment ratio positively affects sales and R&D budget growth. This study provides a system dynamics model to find the optimal ratio for R&D investment and suggests managerial strategic implications on electronic firm R&D investment decision making under market maturity condition.

Collaborative Dispositions of Participatory Arts in Contemporary Practices -Based on Nicolas Bourriaud's Notion of Postproduction- (동시대 예술 형식의 상호성과 공유 가능성 -니콜라 부리오의 포스트프로덕션 개념을 중심으로-)

  • Baik, Youngju
    • The Journal of the Korea Contents Association
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    • v.18 no.6
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    • pp.88-101
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    • 2018
  • The collective narratives on global crisis such as the displaced, uneven distribution of resources, invasion of human rights is more than a recurring theme or polemics in the fields of contemporary arts. In the latest projects from Olafur Eliasson, Rirkrit Tiravanija and Ai WeiWei, art works are presented as performative 'platforms' for tackling these undiscriminating reality of human conditions. Here, 'the users' as driving forces of possible change, are postulated as prospective actors/players who lead and collaborate to defy the status-quo. Crossing over the on/off lines, the everyday-activities of exchanging, sharing and networking are strategically deployed and its meaning reconfigured within the context of post/production discourse. This historical, yet unsettling juncture between art and life, dystopian reality and utopian idealism has its formal-conceptual links to Russian Constructivism, Brechtian Learning-Play and Joseph Beuys' Social Sculpture. Based on Nicolas Bourriaud's notion of Postproduction, this paper aims to provide a diachronic analysis on collaborative dispositions of participatory arts practices.

Policy Plans for the Maintenance of Public Security of Living During the War (전시 국민생활안정 유지방안)

  • Kil, Byung-Ok
    • Journal of National Security and Military Science
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    • s.5
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    • pp.131-172
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    • 2007
  • Government duties in the cases of crisis are aimed at supporting efficient military operations in the fields of non-military affairs and resource mobilization, maintenance of government functions, and search for the public security of living during the war. In crisis, the government must change its functions into the total-war system with all resources available for the efficient performance of military operations, war economy, public safety and security as well as government continuance. The main contents of "Chung-Mu Plan" include the alternative measures to control the circulation of life necessities, emergency electricity, water and gas; recover public facilities from the disaster; and accommodate the wounded and refugees. Governments have practiced Ul-chi and ChungMoo exercises to improve government's management capabilities and master standard operating procedures including systematic distribution plans in the national and local level. However, such plans have not yet sufficient enough for the maintenance of public security of living. In addition to the conceptual ambiguity, major problems are the inappropriate system of the war economy, legal institutions, and administrative SOPs for the efficient maintenance of it. Thus, for the betterment of national crisis management system, the government should have the manual stated from every step and level dealing with crisis to the legal institutions. It is important to empower the National Emergency Planning Commission for the policy consistency and efficient/effective implementation. The comprehensive plans must have an integrated cooperative system of the central/local governments, military and civil society with actual practices and exercises for the maintenance of the public security of living.

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The Impact of Value Creation and Appropriation Elements on Performance (가치 창조 및 전유 요소가 기업의 성과에 미치는 영향)

  • Kim, Chul-Min;Park, Kwang-Ho
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.4
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    • pp.1-9
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    • 2017
  • Companies must capture value for sustainable growth. Capturing value is a critical task for companies, particularly when operating own businesses and organizations or starting new business. The business strategy of many companies focuses on capturing the maximum value from customers and other stakeholders. Even though a wide range of studies on value creation and appropriation has been conducted in the strategic management field, most of studies are still conceptual and theoretical. Thus more empirical studies are required to suggest future-oriented value strategy. This study reveals the value creation and appropriation elements in the aviation industry of Korea. The purpose of this study is to understand the trend of value creation and appropriation in the industry. In addition, the relationship between the elements and firm's performance are tested. The firm's performance is defined by that past and future point of views. The sample were collected from Korean Air and Asiana Air. The empirical test shows that the elements of value creation-appropriation have significant impact on firm's performance. Further, the element of value appropriation to customer has a positive impact both on firm's past and future performance. Our results show that investors acknowledge a value-based strategy as a sign of stock valuation. The results of this test correspond with the earlier one, showing that maximizing customers value rather than shareholder value does deliver impressive returns. The finding suggest that companies need to change their strategy to efficiently manage performance. With the test results, we propose a value-based strategy to maximize firm's future financial and stock performance.

An study on the ramp tabs for thurst vector control symmetrically installed at the supersonic nozzle exit (초음속 노즐 출구에 대칭적으로 설치한 추력방향제어장치인 램프 탭의 연구)

  • Kim, Kyoung-Rean;Ko, Jae-Myoung;Park, Jong-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.10 no.6
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    • pp.32-37
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    • 2007
  • Aerodynamic forces and moments have been used to control rocket propelled vehicles. If control is required at very low speed, Those systems only provide a limited capability because aerodynamic control force is proportional to the air density and low dynamic pressure. But thrust vector control(TVC) can overcome the disadvantages. TVC is the method which generates the side force and roll moment by controlling exhausted gas directly in a rocket nozzle. TVC is classified by mechanical and fluid dynamic methods. Mechanical methods can change the flow direction by several objects installed in a rocket nozzle exhaust such as tapered ramp tabs and jet vane. Fluid dynamic methods control the flight direction with the injection of secondary gaseous flows into the rocket nozzle. The tapered ramp tabs of mechanical methods are used in this paper. They installed at the rear in the rocket nozzle could be freely moved along axial and radial direction on the mounting ring to provide the mass flow rate which is injected from the rocket nozzle. In this paper, the conceptual design and the study on the tapered ramp tabs of the thurst vector control has been carried out using the supersonic cold flow system and schlieren system. This paper provides the thrust spoilage, three directional forces and moments and distribution of surface pressure on the region enclosed by the tapered ramp tabs.

Development of Korean Intensive Care Delirium Screening Tool (KICDST) (중환자 섬망 선별도구 개발)

  • Nam, Ae-Ri-Na;Park, Jee-Won
    • Journal of Korean Academy of Nursing
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    • v.46 no.1
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    • pp.149-158
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    • 2016
  • Purpose: This study was done to develop of the Korean intensive care delirium screening tool (KICDST). Methods: The KICDST was developed in 5 steps: Configuration of conceptual frame, development of preliminary tool, pilot study, reliability and validity test, development of final KICDST. Reliability tests were done using degree of agreement between evaluators and internal consistency. For validity tests, CVI (Content Validity Index), ROC (Receiver Operating Characteristics) analysis, known group technique and factor analysis were used. Results: In the reliability test, the degree of agreement between evaluators showed .80~1.00 and the internal consistency was KR-20=.84. The CVI was .83~1.00. In ROC analysis, the AUC (Area Under the ROC Curve) was .98. Assessment score was 4 points. The values for sensitivity, specificity, correct classification rate, positive predictive value, and negative predictive value were found to be 95.0%, 93.7%, 94.4%, 95.0% and 93.7%, respectively. In the known group technique, the average delirium screening tool score of the non-delirium group was $1.25{\pm}0.99$ while that of delirium group was $5.07{\pm}1.89$ (t= - 16.33, p <.001). The factors were classified into 3 factors (cognitive change, symptom fluctuation, psychomotor retardation), which explained 67.4% of total variance. Conclusion: Findings show that the KICDST has high sensitivity and specificity. Therefore, this screening tool is recommended for early identification of delirium in intensive care patients.

A Study of Conceptual Change Processes among Pre-Service Science Teachers relating to Conductor and Electrolyte as Electrified Materials (전기가 흐르는 물질로서 도체와 전해질에 대한 예비과학교사들의 개념변화 과정에 대한 연구)

  • Paik, Seoung-Hey;Kim, Kyoung-Eun
    • Journal of The Korean Association For Science Education
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    • v.33 no.6
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    • pp.1103-1118
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    • 2013
  • In this research, we analysed definitions and examples of conductor and electrolysis concept in middle school science textbooks. We also surveyed 9 senior pre-service teachers' understanding of the concept definitions and appropriate examples. From the analysis of the textbooks, we found that the possibility of misunderstanding of learners is high because of the broad definition concept and narrow list of examples. After confirming the differences among pre-service teachers' understanding of the subject through questionnaires and interviews, they also debated for a need to an agreement on scientific concepts. The pre-service teachers recognized the meaning of social constructivism and the need for an agreement process in teaching science concepts.

Medical Geography: Its Conceptual History and Historical Vision (의료지리학: 개념적 역사와 역사적 전망)

  • Lee, Jong-Chan
    • Journal of the Korean Geographical Society
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    • v.48 no.2
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    • pp.218-238
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    • 2013
  • The objective of my paper is to investigate historical change in concepts of medical geography and to present its historical vision. Modern medical geography was established in the name of medical topography in Europe where it had to control tropical diseases in the course of exploration and voyages for colonial interests. England developed medical geography in the name of sanitary reform, France did so for civilizing mission, and geomedicine prevailed in Germany. The twentieth century witnessed two traditions of medical geography, with focus on disease ecology and medical care system, respectively. In addition, the paper emphasizes the significance of cartography of disease as knowledge as power. As the identity of place becomes increasingly important in relation to health at the around of the twenty-first century, geography of health has emerged as a new promising discipline independently of medical and public health geography.

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Design and Implementation of Geographic Education Website Based on the Google Earth (구글어스 기반의 지리교육 사이트 설계 및 구현)

  • Lee, Sun-Ju;Kang, Young-Ok
    • Spatial Information Research
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    • v.18 no.2
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    • pp.13-24
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    • 2010
  • The purpose of this research is to explore the possibility of geographic education by implementing the map-based geographic education site which mashed up with Google earth by referring the various materials of geographic education which exist in on-line and off-line. In recent years map-based geographic education is required by the radical change of geoweb environments, but there have been few researches in this field. This research is folded up as follows: First, we designed the contents through the textbook analysis and then collect various data related to the contents such as pictures, video clips, conceptual map, etc. which are required to explain the concept. Second, we mashed up the collected data on the Google earth by using the Google's open API. Third, we implemented the geographic education website based on the classification of contents in textbook and the various collected data. This research is important in both that it explores the possibility of the map-based education rather than the text-based education in the geographic field which handles mainly the space and finds the best method to express the various concepts of the textbook on the geoweb environments.