• 제목/요약/키워드: Stability number

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재순환역을 수반하는 동축분류예혼합화염에 관한 연구 (Stability of premixed double concentric jets flame with a recirculation zone)

  • 이등헌일;송규근
    • 대한기계학회논문집
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    • 제11권1호
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    • pp.145-153
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    • 1987
  • 본 논문에서는 예혼합동축분류화염에 있어서 재순환역 안으로의 기체(공기, 연료, 혼합기) 주입과 2차공기의 족회가 화염안정성, 화염형상 및 재순환역에 미치는 영향을 명확히 하였다.

산불의 영향을 고려한 산지사면의 안정성 평가 (Safety Evaluation of Mountain Slopes Considering the Effect of Forest Fire)

  • 김종민;정봉훈;최준성;박덕근
    • 한국방재학회 논문집
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    • 제4권1호
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    • pp.57-64
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    • 2004
  • 최근의 엘리뇨와 라니냐 등 이상기온현상과 이에 따른 산불발생빈도의 증가는 산지사면의 안정성에 대한 산불의 영향을 고려해보게 되는 계기가 되고 있다. 본 논문에서는 산불로 인한 식생의 파괴에 따른 자연사면 안정성에 미치는 정도를 규명하고, 산불에 따른 사면의 안정성을 평가하는 방법을 제시하여 산불로 인하여 발생될 수 있는 피해를 최소화하는데 그 목적이 있다. 본 논문에서는 산불로 인한 산지사면 식생의 변화가 사면 안정성에 미치는 영향을 정량적으로 분석하였고, 그 결과로 산불의 영향을 고려한 사면안정도표를 제안하였다.

임플란트 일차 안정성에 있어서 골질에 따른 osteotome 술식의 효과 (The Effect of Osteotome Technique on Primary Implant Stability according to Bone Quality)

  • 백승재;이재관;박찬진
    • Journal of Periodontal and Implant Science
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    • 제35권3호
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    • pp.777-788
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    • 2005
  • The primary stability of implants is an important factor to predict the osseointegration. Recently, the resonance frequency analysis has been used to measure the primary stability. It is an objective method to monitor the stability of implants during healing phase. This study is to validate the differences in the effect of the osteotome method according to the bone quality as well the thickness of cortical bone. Two hundred seventy implants of 3.75mm in diameter(Neoplant, Neobiotech, Korea) were placed in 135 bovine ribs. The bone quality is classified into 3 classes according to the number of bone marrow spaces which implants would be placed, and then classified into 9 subclasses after the ribs were trimmed. Two implants were placed in 15 specimens of each class. The conclusion were as follows: 1. In case of less dense cancellous bone, the oseotome method is more effective in primary stability rather than the drilling method(p <0.05). 2. If there was cortical bone, it is more advantagous to get stronger primary stability. 3. If cancellous bone is more dense or if cortical bone exists, there is no statistical significance between drilling and osteotome method(p <0.05).

국내 어선 복원성 규정 분석 및 개선 기준안 연구 (Analysis of Domestic Fishing Vessel Stability Regulations and Research on their Criteria Amendment for Improvement)

  • 오경근;임남균
    • 해양환경안전학회지
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    • 제28권2호
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    • pp.290-296
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    • 2022
  • 전 세계 해상 선박사고 건수는 감소하고 있지만, 국내 해상 사고 건수는 증가하고 있다. 이러한 이유에서 국내 선박의 해양 사고를 줄이기 위한 한 가지 방법으로 사고 건수가 가장 많은 어선과 낚시어선을 대상으로 하는 어선복원성기준에 관한 연구를 수행한다. 국제해사기구(IMO)와 국내 그리고 일본, 중국, 캐나다 해외 3개국의 어선복원성기준을 각각 조사하고, 상호 비교 분석한 결과외국의 기준들 대비 국내 기준이 가장 완화된 기준임을 알 수 있었다. 비교 분석 결과를 토대로 국내 어선복원성 기준을 보완하기 위한 어선복원성기준 개정(안)을 5가지 평가항목에 대해서 제안했다.

강널말뚝 흙막이벽으로 시공된 굴착연약지반의 안정성 (The Stability of Excavated Soft Ground Supported by Sheet-pile Walls)

  • 홍원표;김동욱;송영석
    • 한국지반공학회논문집
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    • 제21권1호
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    • pp.5-14
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    • 2005
  • 인천국제공항 공사현장의 흙막이 굴착단면에서 계측된 자료를 검토하여 연약지반에 설치된 강널말뚝 흙막이벽의 수평변위와 굴착주변지반의 변형에 대한 상관관계를 조사하였다. 벽체의 지지방식에 따른 강널말뚝 흙막이벽의 수평변위는 앵커지지, 복합지지, 버팀보지지 순으로 작게 나타났으며, 각각의 지지방식에 따른 최대수평변위 발생위치도 서로 다르게 발생하였다. 흙막이벽의 최대수평변위 및 최대수평변위속도는 굴착지반의 안정수가 ${\pi}$이하일 경우 각각 굴착깊이의 $1\%$, 1mm/day이하로 발생되고, 안정수가 ${\pi}+2$ 이하일 경우 각각 굴착깊이의 $2.5\%$, 2mm/day이하로 발생되며, 안정수가 ${\pi}+2$ 이상일 경우 급격하게 증가한다. 또한, 굴착저면에서의 N치가 감소함에 따라 흙막이벽의 최대수평 변위는 증가하며, N치가 약 10이하일 경우 흙막이벽의 최대수평변위는 급격하게 증가함을 알 수 있다. 한편, Terzaghi(1943)에 의해 제안된 히빙에 대한 안전율이 감소함에 따라 흙막이벽의 최대수평변위는 증가하며, 히빙의 안전율이 2.0일 경우 흙막이벽의 최대수평변위는 급속하게 증가함을 알 수 있다. 따라서, 국내 연약지반 강널말뚝 흙막이벽의 경우 히빙에 대한 안전율은 2.0으로 제안할 수 있다.

무치악 환자 에서 Neutral Zone 방법을 적용한 임상 증례 (Treatment of Edentulous Patient with Neutral Zone Technique : A Clinical Case)

  • 김용식;이병욱
    • 구강회복응용과학지
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    • 제17권2호
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    • pp.107-112
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    • 2001
  • The prosthodontic treatment of severely resorbed edentulous patients has been one of the frustrating areas due to extensive loss of tissues. The integrated neuromuscular balance among tongue, lip, and cheek is compromised. The retention, stability, and support are the three major factors to influence the clinical outcome. Fish described a denture as having three surface, with each surface playing an independent and important role in the over all fit, stability, and comfort of the denture. He recommended that the polished surface should be a series of inclines so that pressure from muscular activity will retain dentures. Within the denture space there is an area that has been termed the neutral zone. The neutral zone is that area in the mouth where, during function, the forces of the tongue pressing outward are neutralized by the forces of the cheeks and lips pressing inward. According to Jacobson and Krol, neuromuscular control interacts to provide retention and the relationship of polished surface of denture base to the surrounding muscular structure of orofacial capsule facilitates the stability and retention. This neutral zone concept has been demonstrated with various modification by a number of authors. The theory used to develop the denture base contours is based on the belief that the muscle should functionally mold not only the border but the entire polished surface. Lott and Walsh reported the clinical success on complete mandibular dentures with application of neutral zone concept. A number of studies demonstrated that denture stability and retention are more dependent on correct position of the teeth and correct contour of external surfaces of the denture in a severely resorbed alveolar ridge. This article presents a prosthodontic approach to treatment of a edentulous patient using neutral zone technique to improve the retention and stability of the prosthesis.

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지역 금융포용 수준이 새마을금고의 경영지표에 미치는 영향 (The Effect of Regional Financial Inclusion Level on Financial Cooperatives' Management Indicators)

  • 윤상용;김진희;박순홍
    • 아태비즈니스연구
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    • 제13권4호
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    • pp.91-107
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    • 2022
  • Purpose - This study quantitatively examines the level of financial inclusion of a microfinance institution in each region and how this is changing recently, and examines the level of financial inclusion by region and various financial characteristic factors related to it. It was empirically verified what kind of significant impact actually has on the institution's major management performance indicators (stability, profitability, efficiency, and public interest). Design/methodology/approach - It was confirmed that the institution's financial inclusion index declined rapidly after 2015 as a whole, although there were some differences by region depending on regional characteristics. However, considering the fact that the number of branches per 100,000 adult population is steadily increasing nationwide, it was found that, contrary to what is known, the simple decrease in the number of branches of the institution was not the main cause. Findings - The analysis results of this study show that the institution's efforts for financial inclusion have a positive impact on profitability, stability, efficiency, and public interest, and that the institution pursues profitability, efficiency, stability, and public interest. showed that some trade-offs exist. In other words, overall, it was analyzed that profitability of the institution has a positive effect on efficiency, and efficiency has a positive effect on stability and public interest. Research implications or Originality - Since the institution's efforts to improve its profitability do not have a negative impact on its stability and public interest, it is judged that it is important to take a strategic stance, so excessive loan supply that exceeds the scope of the institution's own control needs to be avoided as much as possible. More detailed financial supply strategies and business management capabilities that enhance the asset soundness and management efficiency of safes need to be demonstrated.

신호 포획현상을 가지는 알로하 시스템의 안정성 고찰 (A Stability Issue on Controlled ALOHA System with Capture Channel)

  • 곽경섭
    • 한국통신학회논문지
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    • 제18권12호
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    • pp.1855-1869
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    • 1993
  • 기존의 알로하 시스템은 불안정한 시스템으로 알려져있다. 또한 포획현상을 가지는 알로하 시스템도 불안정하다는 것이 증명되었다. 본 논문에서는 신호, 포획현상을 가지는 알로하 시스템에 전송 제어 알고리즘을 적용하고, 새로운 Lyapunov 함수를 도입하여 다차원 바르코프 연쇄 모델의 안정성을 증명하였다. 부가적으로 시스템의 전송효율을 구하고, 또한 시뮬레이션을 통하여 패킷 전송지연을 분석하였다.

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이중 동전기 휠에 의해 반송되는 도전성 환봉의 공간 안정성 (A Spatial Stability of the Conductive Rod Conveyed by Double Electrodynamic Wheels)

  • 정광석
    • 한국정밀공학회지
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    • 제29권8호
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    • pp.873-878
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    • 2012
  • Putting a conductive rod between rotating axial electrodynamic wheels composed of repetitive permanent magnets, three-axial magnetic forces generate on the conductive rod. It is possible to levitate and transfer the rod on space with the forces. However, the forces vary in direction and magnitude for a position of the rod between the electrodynamic wheels. Thus, the position influences the stability of the rod also. To guarantee the stability of a levitated object, the force acting on the object should have negative stiffness like a spring. So, we analyze the stable operating range of the conductive rod levitated by the axial wheels with the commercial finite element tool in this paper. Specially, as the pole number and the radial width of permanent magnets has much influence on the generated force and thereby the stable region, their sensitivities are analyzed also. The analytic result is compared with experimental result.

케이블의 비선형 가동효과를 고려한 사장교 강거더의 좌굴 안전성 평가 (Buckling Stability in the deck Steel Girder of Cable stayed Bridge Considered Nonlinear Behavior of Stay Cable)

  • 최학재
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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    • pp.129-139
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    • 2005
  • The focused topic according to be slender and longer of cable stayed bridge's main span is as follows (1) Aerodynamic stability (2) Lateral movement of stiffening girder caused by wind force during and after construction (3) Global bucking of stiffening girder caused by axial force Among this, the number 3 has not received much attention in the past due to high buckling safety factor of stiffening girder. However, according to be slender of stiffening girder, the topic of buckling stability of girder is not any more unconcerned subject. The purpose of this paper is to examine the effect of stay cable's nonlinear behavior on the buckling stability of cable-stayed bridge.

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