• 제목/요약/키워드: Preliminary study

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항공용 가스터빈 연소기 기본 설계 프로그램 개발 : Part 2 - 공기 유량 배분 (Preliminary Design Program Development for Aircraft Gas Turbine Combustors : Part 2 - Air Flow Distribution)

  • 김대식;유경원;황기영;민성기
    • 한국연소학회지
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    • 제18권3호
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    • pp.61-67
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    • 2013
  • This study introduces the design methods for air flow distribution at the level of preliminary design, and reviews the typical combustion process and main functions of sub-components of aircraft gas turbine combustors. There are lots of design approaches and empirical equations introduced for air flow distributions at the combustors. It is shown that a decision on which design approaches work for the combustor development is totally dependent upon the objective of engine design, target performance, and so on. The current results suggested for preliminary air flow distributions need to be validated by combustor geometry checkups and performance evaluations for future works.

고압 산소 치료기에 대한 예비위험분석 (Preliminary Hazard Analysis for a Hyperbaric Oxygen Chamber)

  • 전태보
    • 산업기술연구
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    • 제33권A호
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    • pp.3-8
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    • 2013
  • Reduction of risk plays a pivotal role in the development of medical instruments. A hyperbaric oxygen chamber, as a medical device, is known to help medical therapy for diversity of diseases through provision of high purity oxygen. The use of hyperbaric oxygen is expected to increase in the future and study to rigorously examine reliability and safety is needed. We have performed risk assessment for a newly developed hyperbaric oxygen chamber in this study. We first briefly discussed the system structure and concept of risk assessment for the study. Based on the hazards identified, we performed preliminary hazard analysis for the chamber.

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청소년 성발달 평가척도 개발을 위한 예비연구 (A Preliminary Study on the Sexual Development Assessment Scale for Adolescents)

  • 하은혜;유미숙;조유진
    • 아동학회지
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    • 제26권1호
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    • pp.279-297
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    • 2005
  • The purpose of this preliminary study was to test the validity and reliability Sexual Development Assessment Scale for Adolescents. Subjects were 579 middle school and 504 high school students in Seoul and Gyeonggido. Statistical analyses were by factor analyses, Cronbach's ${\alpha}$, $x^2$ value and Cramer's V. Construct validity was composed with 10 factors on sexual Development Assessment Scale for middle school students and 12 factors for high school students. Reliability of each subscale was high and the item discrimination, $x^2$ value and Cramer's V were also meaningful.

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발코니 확장의 합법화에 대한 인식 및 선호 (Recognition and Preference of Legalized Expansion of Living Space to Balcony)

  • 박경옥;이상운
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2006년도 추계학술발표대회 논문집
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    • pp.97-102
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    • 2006
  • The purpose of this study is to suggest complementary measures to the statute legalizing the expansion of living space to balcony, by means of survey on the recognition and preference of preliminary applicants for new apartments. The survey was done on 130 preliminary applicants who visited 3 model houses opened in Cheongju in June to July, 2006. Conclusions are as follows. (1) Most of preliminary applicants knew that the expansion of living space to balcony were legalized, but were not quite aware of legal details, so that more active publicity is needed by the government. In addition, if the government has a plan to impose tax to expanded space, it has to make clear the definition of the balcony space. (2) Preliminary applicants wanted space expansion of living room, main bed room and children's bed room in order, which implies that constructors have to suggest variety of expansion plans overpassing simple space expansion. (3) Preliminary applicants attached importance on the safety of expanded space. The management office is recommended to have the right to superintend its safety after construction.

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Mechanical evolution law and deformation characteristics of preliminary lining about newly-built subway tunnel closely undercrossing the existing station: A case study

  • Huijian Zhang;Gongning Liu;Weixiong Liu;Shuai Zhang;Zekun Chen
    • Geomechanics and Engineering
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    • 제35권5호
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    • pp.525-538
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    • 2023
  • The development of a city is closely linked to the construction and operation of its subway system. However, constructing a new subway tunnel under an existing station is an extremely complex task, and the deformation characteristics and mechanical behavior of the new subway tunnel during the excavation process can greatly impact the normal operation of the existing station. Although the previous studies about the case of underpass engineering have been carried out, there is limited research on the condition of a newly-built subway tunnel that closely undercrossing an existing station with zero distance between them. Therefore, this study analyzes the deformation law and mechanical behavior characteristics of the preliminary lining of the underpass tunnel during the excavation process based on the real engineering case of Chengdu Metro Line 8. This study also makes an in-depth comparison of the influence of different excavation methods on this issue. Finally, the accuracy of numerical simulation is verified by comparing it with on-site result. The results indicate that the maximum bending moment mainly occurs at the floor slab of the preliminary lining, while that of the ceiling is small. The stress state at the ceiling position is less affected by the construction process of the pilot tunnel. Compared to the all-in-one excavation method, although the process of partial excavation method is more complicated, the deformation of preliminary lining caused by it is basically less than the upper limit value of the standard, while that of the all-in-one excavation method is beyond standard requirements.

Top Management Commitment in Enterprise Resource Planning Implementation Success : Preliminary Study in Indonesian State-Owned Enterprises

  • Hartijasti, Yanki
    • Journal of Information Technology Applications and Management
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    • 제18권3호
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    • pp.41-59
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    • 2011
  • This preliminary study held in two Indonesian state-owned enterprises (SOEs) showed empirical evidence that top management commitment was perceived to be the most important critical factor contributing to enterprise resource planning (ERP) implementation success, compared to top management support and top management involvement. Therefore, top management and middle management must continually show commitment during the ERP implementation process. This finding could serve as a reference for further study in a larger number of Indonesian SOEs.

한국 간호사의 직업존중감 측정도구 개발 (Development of Job-Esteem Scale for Korean Nurses)

  • 최현주;정귀임
    • 대한간호학회지
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    • 제50권3호
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    • pp.444-458
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    • 2020
  • Purpose: The purpose of this study was to develop the Job Esteem Scale for Korean Nurses (JES-KN) and verify its validity and reliability. Methods: Preliminary items were based on the attributes and indicators elicited from a concept analysis study on Korean nurses' job-esteem. The final preliminary tool for the main survey was confirmed through the content validity test of 10 experts and preliminary survey of 20 hospital nurses. The final preliminary scale was used on 350 hospital nurses in the scale testing phase for the main survey designed to test the validity and reliability of the scale. Results: The final scale consisted of 28 items and 6 factors, these factor explained 66.6% of the total variance. The correlation between the total score and factors ranged from .64 and .84, validating that each sub-factor is suitable to explain job esteem. The correlation coefficient between this scale and the Job Satisfaction Scale for Clinical Nurses ranged from .41 to .70, and the internal consistency for the scale using Cronbach's α for the total items was .94. Conclusion: The JES-KN is a valid and reliable tool that reflects the reality of clinical sites accordingly. The JES-KN may well be used effectively to assess and evaluate the job esteem of Korean nurses.

인공위성 궤도의 추적과 예보의 기술개발(I) -예비궤도 결정법에 관한 연구- (A Study on the Tracking and Position Predictions of Artificial Satellites(I) - A Study on the Methods of the Preliminary Orbit Determination-)

  • 김천휘;신종섭;박필호;김두환;이병선;조중현;이정숙;박상영;최규홍
    • Journal of Astronomy and Space Sciences
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    • 제5권1호
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    • pp.45-51
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    • 1988
  • 지주주위를 선회하는 안공위성의 예"1궤도를 결정하는 대부분의 모든 땅뱀을을 채조사하였다. 조사판 앙법들을 이용하켜 기상위성 NOAA-10호의 예비궤도릎 결청하였고 그 결과들을 NASA에서 계산된 NOAA-10호 위성의 평균궤도요소와 비교하였다. 이 비교를 통하여 Ga-uss형 방법들에 의하여 결정된 예비궤도요소들이 Laplace형 방법들에 의한결과보다NASA의 평균궤도요소에 더 가깝게 계산되었다. 우리의 결과는 Gauss방법에 대한 Taff(l984) 의 비판이 재고되어야 함을 보여 주며 따라서 Marsden ( 1985 )의 견해를 뒷받침한다.

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Study on the Preliminary Design of ARGO-M Operation System

  • Seo, Yoon-Kyung;Lim, Hyung-Chul;Rew, Dong-Young;Jo, Jung-Hyun;Park, Jong-Uk;Park, Eun-Seo;Park, Jang-Hyun
    • Journal of Astronomy and Space Sciences
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    • 제27권4호
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    • pp.393-400
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    • 2010
  • Korea Astronomy and Space Science Institute has been developing one mobile satellite laser ranging system named as accurate ranging system for geodetic observation-mobile (ARGO-M). Preliminary design of ARGO-M operation system (AOS) which is one of the ARGO-M subsystems was completed in 2009. Preliminary design results are applied to the following development phase by performing detailed design with analysis of pre-defined requirements and analysis of the derived specifications. This paper addresses the preliminary design of the whole AOS. The design results in operation and control part which is a key part in the operation system are described in detail. Analysis results of the interface between operation-supporting hardware and the control computer are summarized, which is necessary in defining the requirements for the operation-supporting hardware. Results of this study are expected to be used in the critical design phase to finalize the design process.