• 제목/요약/키워드: Practical Application

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우주발사체 3축 자세제어용 단일액체추진제 추력기 -Part 2: 비행축/자세제어용 추력기의 우주발사체 적용과 국내 설계개발 (Liquid-monopropellant Thrusters for the 3-axis Attitude Control of Space Launch Vehicles -Part 2: A Practical Application of Flight-axes/Attitude Control Thrusters to the Space Launch Vehicle and Their Design Development Localization)

  • 김정수;배대석;정훈;서항석;김인태
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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    • pp.179-182
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    • 2011
  • 비행축/자세제어용 단일추진제 추력기의 우주발사체 적용과 국내 설계개발 현황을 조사/분석하였다. 탑재체의 정확한 궤도투입을 위하여 정밀한 자세제어가 요구되는 발사체 최종 단은 대부분 비추력 성능이 우수하고 높은 신뢰도 확보가 가능한 단일추진제 하이드라진 추력기시스템을 장착한다.

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A numerical simulation for reduction of rudder cavitation with gap flow blocking bars

  • Oh, Jung-Keun;Lee, Seung-Hee;Kim, Sang-Hyun;Seo, Dae-Won
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제4권2호
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    • pp.71-82
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    • 2012
  • In recent practices, a half circular prismatic bar protruding beyond the concave surface of the horn facing the gap has been formed along the centerplane of a rudder to lessen the gap flow between the horn and the movable portion of the rudder system. If a flow through the gap of a rudder is reduced considerably through this approach, previous numerical studies indicate that not only the gap flow but also the rudder cavitation can be noticeably diminished. In the present study, numerical simulations on two-dimensional rudder sections were performed to show that the blocking ability of the single centre bar can be improved by the proper choice of sectional shape. Moreover, a pair of blocking bars attached symmetric to the centerplane on the opposite convex surface of the movable portion is suggested in the study as well, to circumvent the difficulties arising from the practical application of the single centre bars. The bars are placed near the outer edges of the gap easily accessible at the maximum rudder angle to allow simple installation of the device during a maintenance period of a ship. It is found that the pair of blocking bars further improves the blocking effects and application to a practical three-dimensional rudder also backs up the fact.

모듈형 LNG 저장탱크용 자기 충전 콘크리트의 충전 성능평가 실용화 연구 (Study on Filling Capacity of Self-Consolidating Concrete for Modular LNG Storage Tank)

  • 이동규;이건우;최명성
    • 한국안전학회지
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    • 제33권6호
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    • pp.50-57
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    • 2018
  • The purpose of this study is to evaluate the practical application of the self consolidating concrete for the steel concrete pannel (SCP) in module LNG storage tank proposed in the previous research. We evaluated the physical properties and filling performance of developed concrete for the SCP module. First, a slump flow test was conducted to evaluate the performance of the proposed guidelines for the filling test. As a result, all of the concrete used showed satisfactory performance. Based on the results of the previous study, it was found that the reliability of the required time measured by the $T_{500}$ test and the rheometer results measured before and after pumping was 0.94 which means the separation and blocking should not occur. The L-box test and the U-box test were conducted before and after pumping. All of the guidelines suggested showed satisfactory performance. SCP module for LNG storage tanks was fabricated on actual size scale to evaluate the practical application at the final site. As a result, it was confirmed that satisfactory filling performance was obtained in all the specimens.

Three-dimensional numerical modelling of geocell reinforced soils and its practical application

  • Song, Fei;Tian, Yinghui
    • Geomechanics and Engineering
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    • 제17권1호
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    • pp.1-9
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    • 2019
  • This paper proposes a new numerical approach to model geocell reinforced soils, where the geocell is described as membrane elements and the complex interaction between geocell and soil is realized by coupling their degrees of freedom. The effectiveness and robustness of this approach are demonstrated using two examples, i.e., a geocell-reinforced foundation and a large scale retaining wall project. The first example validates the approach against established solutions through a comprehensive parametrical study to understand the influence of geocell on the improvement of bearing capacity of foundations. The study results show that reducing the geocell pocket size has a strong effect on improving the bearing capacity. In addition, when the aspect ratio maintains the same value, the bearing capacity improvement with increasing geocell height is insignificant. Comparing with the field monitoring and measurement in the project, the second example investigates the application of the approach to practical engineering projects. This paper provides a practically feasible and efficient modelling approach, where no explicit interface or contact is required. This allows geocell reinforced soils in large scale project can be effectively modelled where the mechanism for complex geocell-soil interaction can be explicitly observed.

의료기관 신입직원 멘토링프로그램 사례연구: A병원을 중심으로 (Case Study of New Employee Mentoring Program at Hospital A)

  • 한지영;최종일
    • 한국병원경영학회지
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    • 제29권1호
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    • pp.19-31
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    • 2024
  • Purposes: The purpose of this study is to analyze cases of development and operation of a mentoring program that provides psychological support to new employees and helps them adapt to work, thereby applying it to actual work and laying the foundation for follow-up research. Methodology: We explored the development and application process of A Hospital mentoring program by applying the mentoring program model developed according to the procedures of the ADDIE model, and confirmed the perceptions of participants who participated in the training course through analysis of activity logs and in-depth interviews. Findings: The main results of the case analysis are as follows. First, the curriculum was developed according to the stages of analysis, design, development, implementation, and evaluation. As a result of activity log and in-depth interview analysis, participants recognized that the mentoring program was helpful in forming social relationships, organizational adaptation, and preventing job turnover, and recognized difficulties in communication. Participants mentioned supplementing the operating system. Practical Implication: The results of a systematic review of the application and effectiveness of mentoring programs for new employees can serve as reference material for practical program design.

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Two-Dimensional Ordination 분석법에 의한 제초제살초 Spectrum 분류와 효과적인 사용법 (A New Approach for Practical Classification of Herbicide and for Effective Use by Two-dimensional Ordination Analysis)

  • 김순철
    • 한국응용곤충학회지
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    • 제22권2호
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    • pp.147-159
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    • 1983
  • In general, herbicides have been classified according to selectivity, mobility. time of application, methods of application, mode of action and chemical property and structure. However, there was no generally accepted classification system for practical use in the field. The primary processes affected by the majority of herbicides are the growth process through cell elongation and/or cell division, the photosynthetic process specifically the light reaction, the oxidative phosphorylation and the integrity of the membrane systems. The usual approach in the study of the mechanism by which herbicides kill or inhibit the growth of plants is to initially determine the morphological phototoxicity systems, The mechanism by which a herbicide kills a plant or suppresses its development is actually the resultant effect of primary and secondary(or side) effects. In most instances, the death of the plant is due to the secondary effects. To induce the desired response, a herbicide must be able to gain entry into the plants and once inside, to be transported within the plant to its site(s) of activity in concentrations great enough. Obstacles to the entry and movement of herbicides in plants are generally classified by leaf and soil obstacles, translocation obstacles and biochemical obstacles, and these obstacles are also strongly influenced by plant species and by environmental factors such as light, temperature, rainfall and relative humidity. And hence, in most instances, results obtained from laboratory or greenhous vary from those of field experiment. Author attempted to classify herbicides from the field experiment using the two-dimensional ordination analysis to obtain practical information for selecting effective herbicides or to choose effective herbicide combinations for increasing herbicidal efficacy or reducing the chemical cost. Based on this two-dimensional diagram, desired herbicides or combinations were selected and further investigated for the interaction effects whether these combinations are synergistic, additive or antagonistic. From the results, it was concluded that these new approach could possibly be give more comprehensive informations about effective use of herbicide than any other systems.

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우리나라 식품산업의 한-미 FTA 비즈니스 활용전략 및 모델 구축에 관한 실증연구 (A Study on the Building of Korea-USA FTA Business Model for Food Industries in Korea)

  • 김태인
    • 통상정보연구
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    • 제15권2호
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    • pp.317-344
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    • 2013
  • 본 연구는 실제 우리나라 대미 식품수출업체를 대상으로 FTA 컨설팅을 수행하고, 이를 토대로 식품산업에 알맞은 FTA 활용전략과 모델을 구축하고자 하였다. 결론적으로 식품산업의 한미 FTA 비즈니스 모델은 다음과 같이 제안할 수 있다. 첫째, 완전생산기준 적용품목은 국내산 주원료를 가공하여 FTA 체결국으로 수출하는 완전생산기준 FTA 활용전략을 구축해야 할 것이다. 03류 어류, 04류 유제품, 06류 화훼, 07류 채소, 08류 과일, 11류 쌀가루, 12류 인삼, 13류 인삼엑스, 19류 조제식료품, 20류 김치, 조미김, 주스류, 21류 가공유제품 등이 해당된다. 둘째, 세번변경기준 적용품목은 주원료를 제3국(FTA체결국)으로부터 수입하여 관세인하(원가절감) 혜택을 받고, 세번변경기준을 충족시키는 가공한 한 후 FTA 체결국으로 수출하는 세번변경기준 FTA 활용전략을 구축해야 할 것이다. 09류 건고추가루, 11류 밀가루, 15류 참기름, 21류 인스턴트커피, 16류 가공어류 및 가공젓갈, 02류 소갈비, 16류 육류조제품, 16류 삼계탕, 35류 젤라틴, 19류 면류, 21류 소스류, 22류 주류, 17류 및 18류 과자류 등이 해당된다.

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생애주기비용의 간접비용 산출을 위한 Regression Model의 개발 (Development of Regression Model to evaluate the indirect costs of Life-Cycle Costs)

  • 조효남;이종순;김충완;박경훈
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.150-156
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    • 2004
  • Though the concept of Life-Cycle Cost (LCC) itself is not new, its effectiveness for planning, design, rehabilitation and maintenance/management of civil infrastructures is becoming increasingly recognized. For the decision problems as in the case of the LCC of plant facilities, equipments, bridge decks, pavements, etc., the Life-Cycle Cost Analysis (LCCA) is relatively simple, and thus its practical implementation is rather straightforward. However, when it comes to major infrastructures such as bridge, tunnels, underground facilities, etc., the LCCA problem becomes extremely complex because lack of cost data associated with various direct and indirect losses, and the absence of uncertainty data available for the assessment as well. As a result, the LCC studies have been largely limited only to those relatively simple LCCA problems of planning or conceptual design for making decisions. Accordingly, in the recent years, the researchers have pursued extensive studies on the LCC effectiveness mostly related to LCC models and frameworks for civil infrastructures. Moreover, recently the demand on the practical application of LCC effective decisions in design and maintenance is rapidly growing unprecedently in civil engineering practice. Indirction cost is very important on LCC formulation. But that is very difficult and complicate the estimation every LCC. The objective of this paper is to suggest efficient regression model for the estimation of indirect cost approach to the practical application of LCC for the design and rehabilitation of civil. infrastructures considering traffic, traffic network, detour condition, and workzone condition. In this paper, it performed the sensitivity analysis and correlation analysis of parameter for development of regression model of inflection cost.

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대형건축물의 유출지하수 활용을 위한 평가 프로세스구축에 관한 연구 (A Study on the Evaluation Process Development for the Use of Outflowing Groundwater in Large-Scale Buildings)

  • 김재엽;이동진
    • 한국건축시공학회지
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    • 제10권3호
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    • pp.91-97
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    • 2010
  • 현재 건물 부력에 대한 보호조치로 경제성 및 효율성 측면을 고려하여 영구배수 공법의 사용이 증가하고 있다. 영구배수공법은 건축물에 접하는 지하수를 외부로 배수시켜 건축물에 작용하는 부력을 근본적으로 제거하는 공법으로, 영구배수공법 사용시 유출지하수가 발생하게 된다. 또한 우리나라는 국제인구행동연구소(PAI)에서 지정한 물 부족 국가로 지정되어 유출지하수의 활용이 요구되고 있지만 이에 대한 평가프로세스가 아직 충분하지 않다. 따라서 본 연구는 현장 적용 사례를 통해 현장 단위에서 유출되는 지하수의 활용여부를 결정할 수 있는 평가 프로세스를 구축하고 경제성을 분석하였다. 그 결과 상수도와 비교한 10년간 상수절감 비용을 통해 유출지하수의 활용이 가능한 것으로 나타났다.

기술융합이 적용된 현대장신구사례 및 응용연구 (nfc tag이 적용된 반지를 중심으로) (A Research and application of modern ornaments applied with technology convergence (focus on ring with NFC tag applied))

  • 황선욱
    • 디지털융복합연구
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    • 제18권8호
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    • pp.459-467
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    • 2020
  • 현대 장신구를 제작하는 작가의 입장에서 초연결시대속 현대장신구의 미래를 보고자 했다. 특히 그중 하나인 정보통신 기술, 그중에서도 nfc Tag을 응용한 기술융합의 실제적 방안을 찾고자 한다. 그 실제적인 접근을 위해 현재 nfc Tag기술이 활용된 상업적반지제품들의 실예를 살펴본 후 이후 공방에서 제작되는 현대장신구에도 적용가능한 실제적 방법을 찾고자 했다. 그 결과 비교적 융합이 자유롭지만 기술적 활용도가 제한되는 매몰법과 기술적 활용도는 높지만 디자인 기획 단계부터 융합을 고려해야하는 조립법의 현실적 대안을 도출하였으며 특히 그중 실제적용에 차이가 있을 수 있는 매몰법을 개념만이 아니라 샘플제작을 통해 기술적용에 있어 필요한 요소와 주의점등을 기술하였다.