• Structural Engineering and Mechanics
• /
• 제61권6호
• /
• pp.747-754
• /
• 2017

Exact solutions for stresses for an infinite rectangular plate perforated by two circular holes of different radii subjected to uni-axial or bi-axial uniform loads are investigated using the Airy stress function. The hoop stresses occurring at the edge of the circular hole are computed and plotted. Comparisons are made for the stress concentration factors for several types of loading conditions.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집A
• /
• pp.854-859
• /
• 2000

When the round bar with step is twisted and bent, stress concentration is occurred in the irregular geometric parts. Two dimensional axisymmetric stress analysis is carried out according to the geometric change of the stress-concentrated part of round bar with step. Three dimensional cases are also investigated.

• 한국콘텐츠학회논문지
• /
• 제16권3호
• /
• pp.760-770
• /
• 2016

본 연구에서는 다문화청소년들의 스트레스와 학업태도 간의 관계를 분석하고, 스트레스 대처와 사회적 지원, 심리적 안녕감의 매개관계를 파악하여 보다 효율인 지도를 위한 기초 자료를 제공하고자 요인 간의 관계 검증을 위해 구조방정식 모델을 설정하고, 체계적인 분석을 통해 모형의 적합도 및 변인 간 관계성을 검증하였다. 본 연구의 결과는 다음과 같다. 첫째, 다문화청소년의 인구통계학적 변인에 따른 스트레스 요인 간에 차이를 검증하였다. 학년과 가족의 월평균 수입에 따른 스트레스의 차이는 나타나지 않았다. 하지만 거주기간에 따른 스트레스에 대한 차이는 인간관계와 수업참여에 대한 스트레스에서 유의미한 차이가 나타났다. 둘째, 다문화청소년의 스트레스는 스트레스 대처와 심리적 안녕감에는 음(-)의 영향을 미쳤다. 하지만 사회적 지원, 스트레스 대처, 심리적 안녕감 모두 스트레스와 학업태도 간의 관계에서 정(+)의 매개효과가 있음이 나타났다.

• 한국주거학회논문집
• /
• 제20권6호
• /
• pp.1-10
• /
• 2009

Rapid social change affects residential environments and this in turn creates new stimuli to which people have to adapt. These stimuli have been seen to increase stress levels. Therefore, dwellers in these environments try to reduce stress through various methods. The purpose of this paper is to: 1) identify the general trends of coping styles about residential environmental stress, 2) analyze the differences in socio-demographic characteristics and how the physical characteristics of buildings affect stress, find out how personal backgrounds affect stress levels and the ability to get rid of environmental-related stress. The subjects in this study consisted of people living in multi-family housing in Gwangju. The city is divided into 5 districts and used quota sampling. 324 housewives were surveyed from the households by self-administered questionnaires. The survey was conducted in December, 2006, after the questionnaire was revised based on the results of preliminary survey. After all the questionnaires were collected, the data was coded and analyzed using the SPSS 12.0 program. This study confirmed that the manner in which those in multi-family housing coped with stress. Especially, we need a policy which seriously considers residents who are of low social-economic standing. As well as being exposed to residential environmental stress, they also have no means to deal with it. The age of a building had a strong impact on coping styles about residential environmental stress. We have to make special studies about the adaptive reuse of buildings for the reduction of residential environmental stress and to greatly improve coping styles. In conclusion, it emphasized the importance of education, information, and economic aid. Reasonable housing management would surely lead to a rise in residential satisfaction and the promotion of residential welfare.

• 융합정보논문지
• /
• 제10권2호
• /
• pp.116-125
• /
• 2020

본 연구는 경기도 다문화가정 청소년들이 인식하는 자아탄력성과 가족기능 및 문화적응 스트레스가 정신건강에 미치는 영향을 알아보고 이들의 정신건강 증진을 위한 효과적인 원조방안을 제시하고자 하는데 그 목적이 있다. 이를 위해 경기도에 거주하는 다문화가정 중학생 304명을 대상으로 기술통계분석, T검증과 일원분산분석, 위계적 회귀분석을 실시하였다. 연구결과, 다문화가정 청소년들이 문화적응 스트레스 하위변인인 과정스트레스를 높게 지각할수록, 자아탄력성의 하위변인인 감정조절을 낮게 지각할수록 우울불안이 높아져 정신건강 수준이 낮아지는 것을 알 수 있었다. 본 연구결과를 토대로 다문화가정 청소년의 정신건강을 증진시키기 위한 자아탄력성을 고취시킬 수 있는 다양한 심리정서 프로그램의 개발과 문화적응 과정의 스트레스를 극복할 수 있는 지원방안 마련, 다문화가정을 지원할 수 있도록 관련 법률의 제도적 보완 등을 논의하고 제언하였다.

• 한국해양공학회지
• /
• 제32권5호
• /
• pp.297-309
• /
• 2018

After an accident involving mooring link failures in an offloading buoy, verification of the fatigue safety in terms of the out-of-plane bending (OPB) and in-plane bending (IPB) moments has become a key engineering item in the design of various floating offshore units. The mooring links for an 8 MW floating offshore wind turbine were selected for this study. To identify the OPB stiffness (OPB moment versus interlink angle), a numerical simulation model, called the 3-link model, is usually composed of three successive chain links closest to the fairlead or chain hawse. This paper introduces two numerical simulation techniques for the 3-link analyses. The conventional and advanced approaches are both based on the prescribed rotation approach (PRA) and direct tension approach (DTA). Comparisons of the nominal stress distributions, OPB stiffnesses, hotspot stress curves, and stress concentration curves are presented. The multiple link analyses used to identify the tension angle versus interlink angle require the OPB stiffness data from the 3-link analyses. A convergence study was conducted to determine the minimum number of links for a multi-link analysis. It was proven that 10 links were sufficient for the multi-link analysis. The tension angle versus interlink angle relations are presented based on multi-link analyses with 10 links. It was found that the subsequent results varied significantly according to the 3-link analysis techniques.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.1433-1435
• /
• 2003

Very decisive progress was made in advancing fundamental POL-IN-SAR theory and algorithm development during the past decade. This was accomplished with the aid of airborne & shuttle platforms supporting single -to-multi-band multi-modal POL-SAR and also some POL-IN-SAR sensor systems, which will be compared and assessed with the aim of establishing the hitherto not completed but required missions such as tomographic and holographic imaging. Because the operation of airborne test-beds is extremely expensive, aircraft platforms are not suited for routine monitoring missions which is better accomplished with the use drones or UAVs. Such unmanned aerial vehicles were developed for defense applications, however lacking the sophistic ation of implementing advanced forefront POL-IN-SAR technology. This shortcoming will be thoroughly scrutinized resulting in the finding that we do now need to develop most rapidly POL-IN-SAR drone-platform technology especially for environmental stress-change monitoring with a great variance of applications beginning with flood, bush/forest-fire to tectonic-stress (earth-quake to volcanic eruptions) for real-short-time hazard mitigation. However, for routine global monitoring purposes of the terrestrial covers neither airborne sensor implementation - aircraft and/or drones - are sufficient; and there -fore multi-modal and multi-band space-borne POL-IN-SAR space-shuttle and satellite sensor technology needs to be further advanced at a much more rapid phase. The existing ENVISAT with the forthcoming ALOSPALSAR, RADARSAT-2, and the TERRASAT will be compared, demonstrating that at this phase of development the fully polarimetric and polarimetric-interferometric modes of operation must be viewed and treated as preliminary algorithm verification support modes and at this phase of development are still not to be viewed as routine modes.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제10권2호
• /
• pp.129-140
• /
• 2018

A residual stress generated in the steel structure is broadly categorized into initial residual stress during manufacturing steel material, welding residual stress caused by welding, and heat treatment residual stress by heat treatment. Initial residual stresses induced during the manufacturing process is combined with welding residual stress or heat treatment residual stress, and remained as a final residual stress. Because such final residual stress affects the safety and strength of the structure, it is of utmost importance to measure or predict the magnitude of residual stress, and to apply this point on the design of the structure. In this study, the initial residual stress of steel structures having thicknesses of 25 mm and 70 mm during manufacturing was measured in order to investigate initial residual stress (hereinafter, referred to as initial stress). In addition, thermal elastic plastic FEM analysis was performed with this initial condition, and the effect of initial stress on the welding residual stress was investigated. Further, the reliability of the FE analysis result, considering the initial stress and welding residual stress for the steel structures having two thicknesses, was validated by comparing it with the measured results. In the vicinity of the weld joint, the initial stress is released and finally controlled by the weld residual stress. On the other hand, the farther away from the weld joint, the greater the influence of the initial stress. The range in which the initial stress affects the weld residual stress was not changed by the initial stress. However, in the region where the initial stress occurs in the compressive stress, the magnitude of the weld residual compressive stress varies with the compression or tension of the initial stress. The effect of initial stress on the maximum compression residual stress was far larger when initial stress was considered in case of a thickness of 25 mm with a value of 180 MPa, while in case of thickness at 70 mm, it was 200 MPa. The increase in compressive residual stress is almost the same as the initial stress. However, if initial stress was tensile, there was no significant change in the maximum compression residual stress.

• 한국콘텐츠학회논문지
• /
• 제12권2호
• /
• pp.222-231
• /
• 2012

본 연구는 다문화가족의 남성배우자의 이중문화스트레스 및 의사소통과 결혼만족도와의 관계를 파악하고자 전국에 있는 결혼이민자 지원센터, 건강가정지원센터의 프로그램 참가자와 지역사회복지관의 다문화 프로그램을 이용하는 결혼이주여성의 배우자를 대상으로 실시하였다. 첫째, 이중문화스트레스는 하위영역 중 문화충격(M= 4.32)이 가장 높고, 지각된 적대감의 평균값이 가장 낮은 것으로 조사되었는데, 점수가 높을수록 이중문화스트레스가 높은 것으로 볼 수 있다. 둘째, 이중문화스트레스에 따른 결혼만족도는 이중문화스트레스가 높은 집단이 낮은 집단보다 높았다. 셋째, 의사소통에 따른 결혼만족도는 의사소통이 높은 집단이 낮은 집단보다 높았다. 넷째, 의사소통은 이중문화스트레스가 결혼만족도에 미치는 영향을 매개함을 알 수 있다.

• Computers and Concrete
• /
• 제20권5호
• /
• pp.555-562
• /
• 2017

The accuracy and integrity of stress data acquired by bridge heath monitoring system is of significant importance for bridge safety assessment. However, the missing and abnormal data are inevitably existed in a realistic monitoring system. This paper presents a data reconstruction approach for bridge heath monitoring based on the wavelet multi-resolution analysis and support vector machine (SVM). The proposed method has been applied for data imputation based on the recorded data by the structural health monitoring (SHM) system instrumented on a prestressed concrete cable-stayed bridge. The effectiveness and accuracy of the proposed wavelet-based SVM prediction method is examined by comparing with the traditional autoregression moving average (ARMA) method and SVM prediction method without wavelet multi-resolution analysis in accordance with the prediction errors. The data reconstruction analysis based on 5-day and 1-day continuous stress history data with obvious preternatural signals is performed to examine the effect of sample size on the accuracy of data reconstruction. The results indicate that the proposed data reconstruction approach based on wavelet multi-resolution analysis and SVM is an effective tool for missing data imputation or preternatural signal replacement, which can serve as a solid foundation for the purpose of accurately evaluating the safety of bridge structures.