• 제목/요약/키워드: Stability criteria

검색결과 809건 처리시간 0.023초

지역 간 고용격차와 고용경쟁력 분석에 관한 연구 (A Study on the Analysis of Regional Disparity and Competitiveness on Employment in Korea)

  • 박홍철;이주형
    • 한국산학기술학회논문지
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    • 제14권5호
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    • pp.2207-2214
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    • 2013
  • 본 연구는 지역 간 고용격차를 파악하고, 고용경쟁력 평가지표를 통해 지역현황 및 특성을 분석하기 위한 연구이다. 첫째, 지역 간 고용격차는 심화되고 있는 것으로 나타났으며, 질적 측면과 안정성 측면에서의 격차가 더욱 심각한 것으로 나타났다. 둘째, 지역별 고용경쟁력은 충남, 서울, 울산, 경북, 대전 등의 순으로 나타났으며, 부산은 고용위험 지역으로 분류되었다. 셋째, 고용경쟁력에 가장 많은 영향을 미치는 요인은 안정성 측면의 지표들인 것으로 분석되었다. 따라서 지역 간 고용격차를 완화하고 고용경쟁력을 강화하기 위해서는 양질의 안정적인 일자리를 창출하기 위한 노력이 필요하며, 특히 고용위험 지역의 경우에는 지속적인 모니터링이 요구된다.

동적재료모델을 활용한 티타늄합금의 고온성형성 고찰 (Hot Workability Characterization of Ti Alloys Using Dynamic Material Model)

  • 염종택;현용택;나영상;박노광
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.301-304
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    • 2001
  • Hot-compression tests were carried out to investigate the hot workability of Ti64 and Ti6246 alloys at different temperatures and strain rates. Processing maps were developed on the basis of the dynamic material model unifying the relationship among constitutive behavior, hot workability and microstructure development. Stable regions, defined on the basis of four stability criteria 0${\delta}log(m)/\frac{\bot}{\varepsilon})<0$, s<1 and ${\delta}log(s)/\frac{\bot}{\varepsilon})<0$, were found to be associated with dynamic recovery and recrystallization.

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Consumer Dissatisfaction Factors and Purchase Behaviors of Backpacks

  • Kim, Mi-Sook;Kim, So-Young
    • The International Journal of Costume Culture
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    • 제3권2호
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    • pp.147-160
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    • 2000
  • The purposes of the present study were to investigate the factors of consumer dissatisfaction with backpacks and to examine if the levels of dissatisfaction with the factors differ significantly among the groups determined by demographic characteristics and purchase behaviors. The differences in the purchase behaviors of backpacks were also tested among the groups determined by demographic characteristics. Data collection was consisted of two pilot tests and the final test. The questionnaire was distributed to 40 students of universities in Seoul from July 1 to 13 in 2000 and 351 were usable. Data were analyzed by factor analysis, t-test, χ²analysis, MANOVA, ANAOVA, Duncan's multiple range tests using SPSS PC/sup +/ Program. Five factors were formulated : durability, ease-of-care/color fastness, dimensional stability, wearability and design. Subjects were most dissatisfied with the dimensional stability of backpacks. Different demographic characteristics and purchase behaviors resulted in significantly different levels of dissatisfaction with selected factors. Significant differences were also found in selected selection criteria and purchase behaviors among groups determined by some demographic characteristics.

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뉴트럴 네트워크 제어 시스템의 안정도 분석 및 퍼지 제어기 설계 (Stability Analysis and Stabilization for Neutral Networked Control System)

  • 송민국;박진배;김진규;주영훈
    • 한국지능시스템학회논문지
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    • 제20권2호
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    • pp.159-164
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    • 2010
  • 본 논문에서는 뉴트럴 타입 시간 지연을 갖는 네트워크 제어 시스템의 안정도 분석 및 제어기 설계에 대해서 논의한다. 네트워크상에서 발생하는 뉴트럴 타입 시간 지연을 모델링하며, 전체 네트워크 제어 시스템은 뉴트럴 타입 시간 지연을 가지는 비선형 시스템이 된다. 시간 지연 분산 방법을 이용하여 기존과 다른 새로운 안정도 조건을 유도한다. 리아프노푸 함수를 이용하여 제안된 네트워크 제어 시스템을 안정화 시키는 퍼지 제어기 설계를 위한 충분조건을 유도한다. 제안된 충분조건을 선형 행렬 부등식의 형태로 나타내고, 해를 통하여 퍼지 제어기의 이득 값을 설계한다. 예제를 통하여 제안된 이론의 타당성을 확인한다.

풍속 증가에 따른 풍하중이 컨테이너 크레인의 구조 안정성에 미치는 영향 (Analyzing the effect on a Structural Stability of a Container Crane according to an Increased Wind velocity)

  • 권순규;한근조;한동섭;이성욱
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.373-374
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    • 2006
  • This study is carried out to analyze the stability of a container crane in according to the change of a wind direction and a machinery house location when a wind load of a wind velocity, 75m/s was applied on the state stowing a container crane by a heavy wind. A design wind load applied to this study was calculated in observance of 'Load Criteria of Building Structure'. And we analyzed the reactions of each supporting points according to appling a wind direction to an interval of $10^{\circ}\;in\;0^{\circ}{\sim}180^{\circ}$ and the structure stability of a container crane according to changing a machinery house. location occupying 15% of a container crane weight. From a results of this study, we presented a design criteria of an overturning disturbance equipment, tie-down.

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절리암반사면의 안정해석 방법에 관한 비교연구 (A Comarative study on slope stability modeling of highly fractured rock slopes)

  • 유충식;김선빈;양기호;정하승
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 춘계 학술발표회
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    • pp.434-443
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    • 2009
  • Slope stability analysis is an essential part of rock slope design. For highly fractured rock, the limit equilibrium method (LEM) based slope stability analysis with a circular failure surface is often carried out assuming the rock mass behaves more or less as a continuum. This paper examines first, the applicability of the finite-element method (FEM) based shear strength reduction (SSR) technique for highly fractured rock slope, and second the use of Mohr-Coulomb (MC) failure criterion in conjunction with generalized Hoek-Brown (HB) failure criterion. The numerical results on a number of cases are compared in terms of the factor of safety (FS). The results indicated that the FEM-based SSR technique yields almost the same FSs from LEM, and that the MC and HB failure criteria yield almost identical FSs when the strength parameters for MC failure criterion are obtained based on the modified HB failure criterion if and only if value of the Hoek-Brown constant $m_i$ is smaller than 10 and slope angle is smaller than 1:1, otherwise MC failure criteria over-estimate the factor of safety.

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ON APPROXIMATIONS TO FLOQUET SYSTEMS

  • Zaghrout, A.A.S.;Ragab, A.A.
    • Kyungpook Mathematical Journal
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    • 제27권1호
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    • pp.55-60
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    • 1987
  • A linear system $\dot{x}= A(t)x$, with A(t+w)=A(t) is considered. A step function approximation of a periodic matrix is constructed. The stability criteria is discussed.

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원자력 발전소 배관에 대한 파단전누설 개념 적용기준의 수정 (Modification of Current Leak Before Break Criteria for Nuclear Piping System)

  • 유영준;김영진
    • 대한기계학회논문집A
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    • 제20권6호
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    • pp.1862-1871
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    • 1996
  • The puopose of this paper is sto modify the current LBB criteria. The validity of current LBB criteria and current standard LBB analysis mehtod are evaluated using linear elastic fracture mechanics and elastic-plastic fracture mechanics. The results of evaluation demonstrate that the current LBB driteria are very conservative and some level of margins already exist in the standard LBB analysis method. Thus, the margin on load .root. and margin on crack size 2 can be eliminated to extend LBB application for the samller diameter pipe.