• 정신신체의학
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• 제25권2호
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• pp.111-119
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• 2017

연구목적 본 연구는 메르스(Middle East Respiratory Syndrome, MERS(Middle East Respiratory Syndrome, 이하 MERS) 사태 발생 당시에 받은 스트레스가 사회심리적 건강에 미치는 영향을 알아보고, 회복탄력성이 매개효과로서 사회심리적 건강에 영향을 주는지를 알아보고자 하였다. 방 법 MERS가 발생한 병원의 병원종사자 156명과 일반인 127명을 대상으로 스트레스 자각척도, 사회심리적 건강측정 도구, 코너-데이비슨 리질리언스 척도를 시행하였다. 스트레스가 사회심리적 건강에 미치는 영향 및 회복탄력성의 매개효과를 확인하기 위해 피어슨 상관관계분석과 위계적 다중회귀분석을 실시하였다. 결 과 병원종사자와 일반인 모두에서 지각된 스트레스가 높을수록 사회 심리적 건강이 좋지 않음을 보였고, 지각된 스트레스가 높을수록 낮은 회복탄력성을 나타냈으며, 스트레스와 사회심리적 건강 사이의 관계에서 회복탄력성이 부분 매개를 하는 것으로 나타났다. 결 론 본 연구는 MERS 사태로 인해 받은 스트레스가 사회심리적 건강에 영향을 미침에 있어서 개인의 회복탄력성의 정도가 간접적으로 사회심리적 건강에 긍정적 효과를 끼칠 수 있고, 회복탄력성 강화를 목표로 한 임상적 개입 및 사회심리적 접근방법이 위기 발생시 정신건강을 유지하는데 중요함을 시사한다.

• 콘크리트학회지
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• 제6권1호
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• pp.89-100
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• 1994

프리스트레스 프리텐숀 보의 전달길이를 위하여 콘크리트의 변형율에 의하여 부착력을 계측하는 간접적인 방법을 일반적으로 사용하여 왔다. 이 트랜스퍼 실험은 실제 보에서 행하여지므로, 실제 상태의 정착부착력을 계측할 수 있다는 장점이 있으나, 최대 정착부착응력과 부착강비를 구하기 난해하며, 그 결과가 매우 분산되어 있으므로, 구조 설계자가 안전한 적정기준을 이해하고 선택하기 어렵다. 콘크리트의 변형을 측정하지 않아도 PS 강선의 정착부착 성능을 얻을 수 있는 대안을 소개하였다. 실제 보에서 PS강재의 긴장을 풀 때와 유사한 상황에서 정축부착 응력을 직접 구하였다. 하중재하부에서 풀려진 PS강선의 긴장력은 하중재하부쪽 강선의 단면증가를 가져오고, 콘크리트 블록에 정착부착력을 발생시키며, 다른 방향(고정부 쪽)으로 슬립을 유발시킨다. 두 개의 중공 로드셀로 양단하중을 최대 부착응력 또는 전면슬립이 일어날 때까지 계측하였다. 프리텐션 콘크리트보의 정착부착 길이를 구하기 위하여 이 방법을 기존의 트랜스퍼 실험방법과 병행하여 사용할 것을 제안한다.

• 가정과삶의질연구
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• 제27권2호
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• pp.255-268
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• 2009

The purpose of this study was to deepen our understanding about mothers' parenting stress in multi-cultural families. The study was conducted through in-depth interviews of 6 mothers from Mongolia, Philippines, and Japan who were living in Seoul. The findings of this study were as follows. First, mothers of multi-cultural families had difficulties of giving birth and child rearing, especially in the earliest years of their children. They were not fully adapted to the ways of living in Korea with little social support from family members and neighbors. Second, they were worried about their children's development, particularly language development due to their lack of understanding and fluency in Korean. Third, they were concerned about the cultural and racial discrimination against their children. They expected their children to be treated and respected equally like ordinary Korean children. Fourth, they were anxious about the fact that their children might not acquire the basic academic skills before they enter the elementary schools. Furthermore, they were worried that their children might not get as much educational support as they want. Fifth, despite the burden of mother's role in Korea, they wished to get a job to support their children for better education. In conclusion, the marriage immigrant mothers experienced the stress due to the lack of social support, the discrimination against immigrants, the possibilities of their children's delays in development, the disparity in the level of support for educating their children and the high expectations about their children's education in Korean society. Therefore it is necessary for the policy makers to consider more practical support system for the multi-cultural families in order for the marriage immigrant mothers to build up self-confidence in child rearing and educating their children.

• 한국식품영양학회지
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• 제30권1호
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• pp.83-95
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• 2017

This study examined the socioeconomic factors that affect self-rated health (SRH) in healthy adults, and the relationship of SRH to health-related habits, serum biochemical indices, and nutritional intakes. Subjects consisted of 1,154 healthy adults without any known disease, aged 19 to 65 years (average age of 36.7), whose information was obtained from the 2013 Korean National Health and Nutritional Examination Survey data. Of these subjects, 73 rated themselves as 'very healthy,' 460 indicated that they were 'healthy,' 568 self-identified as 'ordinary', and 53 put themselves in the 'unhealthy' category. The proportion of subjects who chose 'unhealthy' was significantly increased with higher frequencies of disruptions in their daily lives (p<0.05), regret after drinking (p<0.05), smoking (p<0.001), and higher levels of stress (p<0.001). On the other hand, the proportion of subjects reported as 'very healthy' was significantly higher with regular intense (p<0.001) or moderate physical activities (p<0.05), regular walking (p<0.05), a perception of being 'normal' in their body image (p<0.01), a decrease of body weight more than 3 kg in the past year (p<0.05), and without risk factors for metabolic syndrome (p<0.05). Serum triglyceride level was lower, and 25-(OH) vitamin D content was significantly higher, in the 'very healthy' group as compared to the 'unhealthy' group (p<0.05). Dietary fiber and vitamin C intakes were significantly higher in the 'very healthy' group than 'unhealthy' group (p<0.05). The overall results suggest that a healthy lifestyle, including regular exercise, non-smoking, good stress management, and higher intakes of fiber and vitamin C, may be potential factors that affect one's positive perception of health.

• 한국건축시공학회지
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• 제2권4호
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• pp.145-152
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• 2002

High fluid concrete unlike OPC concrete is made with various material, and the phase of fresh concrete is considerably different. In order to understand fluidity phase and mix properties of high fluid concrete, concrete is required to access as suspension structure which consists of aggregate and paste. The focus of this paper is to analyze the test results and quantify the effect of mix proportions of mortar and fineness modulus of sand on the properties of fresh mortar. The effect of water-binder ratio. sand-binder ration. contents of ggbs (by mass of total cementitious materials). and various contents of water reducing agent on the yield stress and plastic viscosity of the mix is studied. Based on the experimental results, the fellowing conclusions can be drawn: (1) The mixing time needed for high fluid mortar was approximately two times more than that of ordinary portland mortar. (2) The fluidity phase of mortar could be explained by yield stress of mix and the fluidity of mortar. (3) As the content of ggbs increased, yield stress of mortar was decreased and plastic viscosity of it was increased. (4) For the high fluid mortar, it was appeared that sand-binder ratio should be below 1.5.

• Structural Engineering and Mechanics
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• 제47권4호
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• pp.531-544
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• 2013

Compared with pavement structures of ordinary road sections, pavement structures in the intersection are exposed to more complex traffic characteristics which may exacerbates pavement distresses such as fatigue-cracking, shoving, shear deformation and rutting. Based on a field survey about traffic characteristics in the intersection conducted in Shanghai China, a three dimensional dynamic finite-element model was developed for evaluating the mechanistic responses in the pavement structures under different traffic characteristics, namely uniform speed, acceleration and deceleration. The results from this study indicated that : (1) traffic characteristics have significant effects on the distributions of the maximum principal strain (MPS) and the maximum shear stress (MSS) at the pavement surface; (2) vehicle acceleration or deceleration substantially impact the MPS and MSS at pavement surface and could increase the magnitude of them by 20 percent to 260 percent; (3) in the vertical direction, with the increase of vehicle deceleration rate, the location of the MPS peak value and the MSS peak value changes from the sub-surface layer to the pavement surface.

• 대한기계학회논문집A
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• 제31권12호
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• pp.1214-1220
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• 2007

The vertical roller mill, which performs the grinding and partly blending of raw material, is the one of the important machine to produce ordinary portland cement. It has been reported that an unexpected fatigue failure occurred in a table liner in the course of grinding portland cement. The life of table liner is estimated to $4{\times}10^7$ cycles in the design stage, but at the field, when its operating time reaches to $2{\times}10^6{\sim}8{\times}10^6$ cycles, the fracture of table liner begins to be found. The fracture of table liner is initiated from the outside edge of grinding path contacting with the grinding roller. Its maintenance normally take 30 % of the total maintenance costs of the roller mill. Therefore, this study shows the clarification of the reasons occurring the fatal destruction of the table liner by fatigue fracture analysis utilizing fracture mechanics and by the finite element method. And, the results from Goodman diagram illustrate relationship of including information on the transition between tensile and bending fatigue strength in the fatigue characterization of table liner.

• Structural Engineering and Mechanics
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• 제61권2호
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• pp.209-220
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• 2017

The purpose of this paper is to study the geometrically nonlinear free vibration of functionally graded nano/micro beams (FGNBs) based on the modified couple stress theory. For practical applications, some analytical expressions of nonlinear frequencies for FGNBs on a nonlinear Pasternak foundation are developed. Hamilton's principle is employed to obtain nonlinear governing differential equations in the context of both Euler-Bernoulli and Timoshenko beam theories for a comprehensive investigation. The modified continuum theory contains one material length scale parameter to capture the size effect. The variation of two-constituent material along the thickness is modeled using Reddy's power-law. Also, the Mori-Tanaka method as an accurate homogenization technique is implemented to estimate the effective material properties of the FGNBs. The results are presented for both hinged-hinged and clamped-clamped boundary conditions. The nonlinear partial differential equations are reduced to ordinary differential equations using Galerkin method and then the powerful method of homotopy analysis is utilized to obtain the semi-analytical solutions. Eventually, the presented analytical expressions are used to examine the influences of the length scale parameter, material gradient index, and elastic foundation on the nonlinear free vibration of FGNBs.

• Steel and Composite Structures
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• 제22권5호
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• pp.1193-1214
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• 2016

In this paper, the 3D stress state and inter-laminar stresses in a rotating thin laminated cylinder shell are studied. The thickness of the cylinder is supposed to be thin and it is made of laminated composite material and can have general layer stacking. The governing equations of the cylindrical shell are obtained by employing the Layerwise theory (LWT). The effect of rotation is considered as rotational body force which is induced due to the rotation of the cylinder about its axis. The Layerwise theory (LWT), is used to discrete the partial differential equations of the problem to ordinary ones, in terms of the displacements of the mathematical layers. By applying the Free boundary conditions the solution of the governing equations is completed and the stress state, the inter-laminar stresses, and the edge effect in the rotating cylindrical shells are investigated in the numerical results. To verify the results, LWT solution is compared with the results of the FEM solution and good agreements are achieved. The inter-laminar normal and shear stresses in rotating cylinder are studied and effects of layer stacking and angular velocity is investigated in the numerical results.

• 한국재난정보학회 논문집
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• 제11권4호
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• pp.534-541
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• 2015

본 연구는 양단이 단순지지된 조건을 갖는 다층 원통쉘을 해석하는 방법을 제시하였고, 3차원 응력 특성을 규명한 것이다. 지배방정식은 편미분방정식을 상미분방정식으로 변환을 가정한 유한요소 개념을 이용하여 유한대판법 해석법을 이용하여 수치해서하였다. 특히 단순지지 조건을 갖는 3차원 다층원통쉘에 대해서는 시행함수로서 삼각함수로 구성되는 보의 고유함수로 구성되는 경우에 대해 해석하였다. 층 재료는 강재 또는 콘크리트로하고 층두께, 원통길이 등 파라메터를 다양하게 변화시켜 다층원통쉘에 미치는 영향을 검토한다.