• 제목/요약/키워드: Conceptual change

검색결과 525건 처리시간 0.027초

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

  • 박세헌;오위영;권문상
    • Ocean and Polar Research
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    • 제27권4호
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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.

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

  • 손지윤;김현정;김수욱
    • 한국경영과학회지
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    • 제40권4호
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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.

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

  • 백영주
    • 한국콘텐츠학회논문지
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    • 제18권6호
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    • pp.88-101
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    • 2018
  • 본고는 니콜라 부리오(Nicolas Bourriaud)의 포스트프로덕션(Postproduction) 개념에 토대하여 동시대 예술 형식의 상호성과 공유 가능성을 통시적 관점에서 분석하였다. 표본 사례로 예시한 올라퍼 알리아슨(Olafur Eliasson), 리크리트 티라바니자(Rirkrit Tiravanija,), 아이 웨이웨이(Ai WeiWei)의 근작에서 예술은 전지구적 현안에의 관여를 유도하는 실행 체계이자 협업 시스템으로서 제시된다. 이러한 형식주의 작업 양상은 탈중심을 넘어 사용자 중심으로 재편되고 있는 동시대 IT 네트워크 환경과 경험을 투영한다. 예술과 비예술의 경계가 모호해진 시장주의 현실에 대한 대응 방안으로서 예술가들은 공유와 확장성을 지향하는 사용자 문화를 적극 포용하고 있다. 작품의 생산과 유통 과정에 수용자가 직접 개입할 수 있도록 작업체계는 분산적으로 구축되는데, 이는 기존의 관객 참여형 예술과 궤를 함께 하면서도 매체 실험을 넘어서는 것이다. 여기서 온오프라인을 넘나들며 탈정형적 연대를 추구하는 사용자들이 서로에게 잠재된 가능성을 일깨워내는 쇄신 주체로 상정된다. 참여 양식이 집단 지성에 대한 상호 신뢰를 토대로 유무형의 자원 공유와 네트워킹에 기반하면서, 예술은 대안적 현실을 모색하는 공론장이자 플랫폼으로 제시되고 있다.

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

  • 길병옥
    • 안보군사학연구
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    • 통권5호
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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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가치 창조 및 전유 요소가 기업의 성과에 미치는 영향 (The Impact of Value Creation and Appropriation Elements on Performance)

  • 김철민;박광호
    • 산업경영시스템학회지
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    • 제40권4호
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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.

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

  • 김경련;고재명;박종호
    • 한국유체기계학회 논문집
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    • 제10권6호
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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.

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

  • 남애리나;박지원
    • 대한간호학회지
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    • 제46권1호
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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.

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

  • 백성혜;김경은
    • 한국과학교육학회지
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    • 제33권6호
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    • pp.1103-1118
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    • 2013
  • 이 연구에서는 중등학교 과학 교과서에서 도체와 전해질에 대한 정의와 사례를 분석하고, 4학년 예비교사 9명을 대상으로 도체와 전해질의 정의와 적절한 사례에 대한 이해를 알아보았다. 교과서 분석을 통해 개념의 정의보다 사례는 협소하게 제시되어 있어서 학습자가 사례로부터 제한된 정의로 이해할 가능성이 높음을 확인하였다. 예비교사들에 대한 설문과 면담을 통해서 도체와 전해질 개념에 대한 이해가 서로 다름을 확인하고, 토론을 통해 과학 개념을 합의해 나가는 과정을 경험하였다. 이러한 경험을 통해 예비과학교사들은 사회적 구성주의의 의미를 깨닫고, 교사로서 학생들을 지도할 때 과학 개념을 합의해 나가는 과정이 필요함을 인식하게 되었다.

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

  • 이종찬
    • 대한지리학회지
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    • 제48권2호
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    • pp.218-238
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    • 2013
  • 한국 지리학계에서 보건의료에 대한 지리학적 연구가 증가되고 있는 양상에 비추어 볼 때, 의료지리학이 개념적으로 어떻게 발달해왔는지에 대한 역사적인 인식이 요청된다. 이 글의 목적은 의료지리학의 개념적 역사를 탐구하고 향후 의료지리학의 역사적 전망을 제시하는 데 있다. 근대 의료지리학은 유럽이 열대 식민지를 통치하는 과정에서 필연적으로 직면하게 되었던 열대 질병을 통제하는 과정에서 의료지형학의 이름으로 형성되었다. 영국에서는 환경위생 개혁의 명분으로, 프랑스에서는 문명화 사명의 구호 아래, 독일에서는 지리의학의 개념으로 각각 발달해왔던 의료지리학은 20세기에 크게 질병 생태학과 의료체계의 두 가지 흐름으로 발달되었다. 본 논문은 질병의 지도에 함축된 권력의 의미를 강조하면서, 의료지리학, 보건지리학, 건강지리학의 공통 지점과 서로 다른 지향점을 제시하였다는 데 의의가 있다.

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

  • 이선주;강영옥
    • Spatial Information Research
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    • 제18권2호
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    • pp.13-24
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    • 2010
  • 본 연구의 목적은 온라인과 오프라인 공간에 다양하게 존재하는 지리 관련 학습 자료를 지도를 기반으로 매쉬업한 지리교육사이트를 구현해 봄으로써 지도를 기반으로 한 지리교육의 가능성을 탐색해보고자 하였다. 최근 지오웹환경의 급격한 변화는 지리교육에 있어서도 지도에 기반한 다양한 변화가능성을 제안하고 있지만, 지리교육분야에서 그와 관련된 연구는 매우 제한적이었다. 그러나 본 연구에서는 첫째, 교과서 분석을 통하여 콘텐츠를 설계하고, 그 개념을 설명하기 위한 사진, 영상, 개념도 등 다양한 관련자료를 수집하였으며, 둘째, 수집된 자료를 구글의 오픈 API를 활용하여 지도기반으로 매쉬업하였으며, 셋째, 교과서 분석에 따른 내용분류와 수집된 자료를 바탕으로 지리교육사이트를 구축하였다. 본 연구는 공간을 다루는 지리교육에서 텍스트위주가 아닌 지도기반으로 교육을 할 수 있는 가능성을 탐색하고, 지오웹환경에서 교과서의 다양한 개념을 가장 잘 표현할 수 있는 방안을 모색하였다는데 의의가 있다.