• 한국안전학회지
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• 제14권1호
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• pp.33-40
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• 1999

In this paper, a damaged example of hanging guide frame used in the lifting of shore protection caisson was investigated. An examination of the stress and stability of members was carried out by structural analysis and the causes of damages was investigated. The stability analysis considering local and global stress buckling was performed. As a result of stability analysis. the first structure was unstable structure. Therefore improved structure was examined and the best effective methodology was the reassignment of wire.

• 대한치과기공학회지
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• 제38권3호
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• pp.151-156
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• 2016

Purpose: The dental implant should be enough to endure chewing load and it's required to have efficient design and use of implant to disperse the stress into bones properly. This study was to evaluate the stress distribution on a supporting bone by lengths and diameters of the implant fixture. Methods: The modeling and analysis of stress distribution was used for the simple molar porcelain crown model by Solidworks as FEM program. It was designed on applying with tightening torque of 20 Ncm of a abutment screw between a cement retained crown abutment and a fixture. The fixtures of experimental model used 10, 13mm by length and 4, 5mm by diameter. A external vertical loading on the two buccal cusps of crown and performed finite element analysis by 100 N. Results: The maximum von Mises stress(VMS) of all supporting bone models by fixture length and diameter were concentrated on the upper side of supporting compact bone. The maximum stress of each model under vertical load were 164.9 MPa of M410 model, and 141.2 MPa of M413 model, 54.3 MPa of M510 model, 53.6 MPa of M513 model. Conclusion: The stress reduction was increase of fixture's diameter than it's length. So it's effective to use the wider fixture as possible to the conditions of supporting bone.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.24-31
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• 1993

In the design of column, computation of effective length factor for calculation of allowable compressive stress is inevitable. In this study. computer code which automatically generates effective length factor in the finite element analysis is developed. The program is developed to be used for orthogonal and nonorthogonal frame structure. Some i1lustrative examples verify that the computation results we correct for various cases.

• Steel and Composite Structures
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• 제39권4호
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• pp.435-451
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• 2021

Shear lag effect was a significant mechanical behavior of steel-concrete composite beams, and the effective flange width was needed to consider this effect. However, the effective flange width is mostly determined by static load test. The cyclic vehicle loading cases, which is more practical, was not well considered. This paper focuses on the study of shear lag effect of the concrete slab in the negative moment region under fatigue cyclic load. Two specimens of two-span steel-concrete composite beams were tested under fatigue load and static load respectively to compare the differences in the negative moment region. The reinforcement strain in the negative moment region was measured and the stress was also analyzed under different loads. Based on the OpenSees framework, finite element analysis model of steel-concrete composite beam is established, which is used to simulate transverse reinforcement stress distribution as well as the variation trends under fatigue cycles. With the established model, effects of fatigue stress amplitude, flange width to span ratio, concrete slab thickness and shear connector stiffness on the shear lag effect of concrete slab in negative moment area are analyzed, and the effective flange width ratio of concrete slab under different working conditions is calculated. The simulated results of effective flange width are compared with calculated results of the commonly used specifications, and it is found that the methods in the specifications can better estimate the shear lag effect in concrete slab under static load, but the effective flange width in the negative moment zone under fatigue load has a large deviation.

• 한국생산제조학회지
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• 제7권5호
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• pp.120-126
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• 1998

Second step shot peening was applied on both smooth specimen and U-notch specimen in order to investigate the stress distribution and the improvement in fatigue strength. Various experiments and measurements such as rotary bending fatigue test and the measurement of compressive residual stress were performed. The results showed that the fatigue strength of second step shot peened specimens increased by 34 percent compared to that of unpeened ones. Compressive residual stress also considerably increased, which resulted in the increase of fatigue strength. finite element analysis showed that shot peening is effective in decreasing the bending stress by external force. The effectiveness of shot peening in reducing the compressive residual stress was anticipated by the superposition of the concentrated stress and the compressive residual stress.

• 간호행정학회지
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• 제17권4호
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• pp.508-515
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• 2011

Purpose: The purposes of this study were to understand correlation of parenting stress and turnover intention of nurses, and to provide basic data for effective nursing management. Methods: Subjects included 287 nurses who had children and worked in hospitals. Data were collected through organized questionnaires from September 1st to 30th 2010. Collected data was analyzed with descriptive statistics, t-test, ANOVA, correlation analysis using PASW statistics 18 program. Results: The average score for parenting stress of the participants was 3.12 out of 5. Nurture stress was statistically different depending on age, job position, shift work, night duty and stages of family development. The average score for turnover intention of the participants was 3.34 out of 5. Turnover intention was statistically different depending on age, number of children and stages of family development. As a result of correlation analysis of parenting stress and turnover intention, turnover intention showed positive correlation with daily stress, stress caused from taking parent role and average parenting stress. Conclusion: This study indicates that parenting stress is related with turnover intention, nursing managers should make efforts to decrease parenting stress in order to reduce turnover intention of nurses.

• 한국콘텐츠학회논문지
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• 제17권9호
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• pp.466-475
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• 2017

스트레스는 매일 살아가면서 사소한 일부터 큰 충격을 받는 삶의 주요한 사건까지 다양한 요인으로부터 온다. 이는 어느 한 시기에만 나타나는 것이 아니라, 생애에 거쳐 나타나므로 지속적으로 스트레스를 관리할 수 있는 연구가 필요하다. 본 연구에서는 사용자 스스로 스트레스를 진단, 관리할 수 있는 홍채 분석기반 시스템을 개발하였다. 그리고 홍채진단에 의한 스트레스 지수와 설문기반의 스트레스 지수의 상관성을 분석한 후, 사용자의 스트레스 지수를 정량화하였다. 본 연구에서 제안하는 시스템은 사용자가 쉽게 현재 자신이 느끼고 있는 스트레스 정도를 알 수 있고, 이에 상응하여 예측되는 질병에 대한 조기 진단 및 질병예방의 하나의 방법으로 사용할 수 있을 것이다.

• 한국지진공학회논문집
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• 제20권6호
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• pp.401-412
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• 2016

On Tuesday, January 17, 1995, an earthquake of magnitude 7.2 struck the Port of Kobe. In effect, the port was practically destroyed. After a hazard investigation, researchers reached a consensus to adopt a performance-based design in port and harbor structures in Japan. A residual displacement of geotechnical structures after an earthquake is one of the most important engineering demands in performance-based earthquake-resistant design. Thus, it is essential to provide reliable responses of geotechnical structures after an earthquake through various techniques. Today, a nonlinear explicit response history analysis(NERHA) of geotechnical structures is the most efficient way to achieve this goal. However, verification of the effective stress analysis, including post liquefaction behavior, is difficult to perform at a laboratory scale. This study aims to rigorously verify the NERHA by using well-defined field measurements, existing numerical tools, and constitutive models. The man-made, Port Island, in Kobe provides intensive hazard investigation data, strong motion records of 1995 Kobe earthquake, and sufficient engineering parameters of the soil. Two dimensional numerical analysis was conducted on the caisson quay wall section at Port Island subjected to the 1995 Kobe earthquake. The analysis result matches very well with the hazard investigation data. The NERHA procedure presented in this paper can be used in further studies to explain and examine the effects of other factors on the seismic behavior of gravity quay walls in liquefiable soil areas.

• 한국지반공학회논문집
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• 제20권1호
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• pp.121-129
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• 2004

본 연구에서는 균질 단순사면의 안정검토 시 간편하게 이용할 수 있는 사면안정도표를 제안하였다. 기존의 사면안정도표는 대부분 한계평형해석에 근거하고 있으나 잘 알려진 바와 같이 한계평형해석은 역학적으로 엄밀한 해석기법이 아니다. 반면 가상일방정식과 소성이론의 경계정리를 이용한 한계해석은 계산이 간단하면서도 역학적 엄밀성이 보장되어 사면과 같은 지반구조물의 안정해석에 적합한 해석기 법이다. 특히 유한요소와 최적화기법을 적용한 수치한계해석은 다양한 사면조건을 반영할 수 있을 뿐 만 아니라 안정해의 최적값을 효율적으로 산정할 수 있는 장점이 있다. 본 연구에서는 유효응력 개념의 수치한계해석기법을 개발하고 다양한 사면조건에 대한 해석을 수행하여 역학적으로 엄밀한 사면안정도표를 제안하였다. 유효응력해석을 위한 간극수압의 영향은 기존의 사면안정도표와 같이 간극 수압비를 적용하여 고려하였다. 제안된 안정도표와 Spencer 안정도표를 비교한 결과 Spence. 안정도표를 적용하여 사면설계를 수행할 경우 안전측 설계가 됨을 알 수 있었다.

• 한국융합학회논문지
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• 제11권2호
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• pp.361-373
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• 2020

본 연구의 목적은 국내에서 혈액투석환자를 대상으로 적용된 스트레스 중재프로그램을 메타분석하여 스트레스 중재프로그램의 효과를 확인하고, 스트레스 중재 방법의 특성과 경향을 파악하기 위함이다. 분석대상연구는 총 10편으로 MINORS를 사용하여 문헌의 질평가를 실시하였으며, Comprehen sive Meta Analysis Version 3.0 및 Review manager version 5.3을 활용하여 자료를 분석하였다. 연구의 질 평가 점수는 21.2점이었으며, 중재프로그램의 심리적 스트레스에 대한 효과크기는 -.72, 생리적 스트레스 중 코티졸의 효과크기는 -.52로 보통의 효과를 보였다. 하위그룹 분석에서 음악요법, 아로마요법, 투석 중 중재, 개인중재, 1회당 60분 이상의 중재, 총 10~20회기 중재의 효과가 더 컸다. 본 연구 결과를 활용하여 추후 효과적인 스트레스 중재프로그램을 구성할 수 있을 것이며, 추후 혈액투석환자를 대상으로 한 무작위배정 실험연구가 더 필요하다.