• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2000년도 특별강연 및 추계학술발표대회 개요집
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• pp.114-117
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• 2000

• 한국지반환경공학회 논문집
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• 제11권11호
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• pp.47-54
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• 2010

최근 쓰레기 매립장에 보강 및 보호 목적으로 토목섬유가 널리 사용되고 있다. 최근 연구결과, 토목섬유-흙 접촉면에서는 진행성 파괴가 발생할 수 있는데 이는 토목섬유-흙 접촉면에서 함수비, 연직응력, 화학적 요소의 영향 등 고유물성에 기인한다. 본 연구에서는 침출수 내의 산성 및 염기성과 같은 성분의 영향이 진동하중 상태에서 토목섬유-흙 접촉면의 전단강도 감소에 미치는 영향을 실내 시험을 통하여 분석하였다. 다기능 접촉면 시험기를 새로 구축하고 서로 다른 pH 조건에서 수침시킨 토목섬유와 흙시료를 이용하여 진동 직접전단시험을 수행하여 접촉면 전단두께와 화학적 요소에 의한 접촉면의 전단강도 감소를 확인하였다. 또한 접촉면 전단강도 감소를 정량적으로 표현하기 위하여 교란상태개념에 기초하여 동하중 하의 화학적 인자들에 의한 토목섬유-흙 접촉면의 정규화 교란도 함수를 파악하고 전단강도 감소 특성을 확인하였다.

• 한국직업건강간호학회지
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• 제18권2호
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• pp.205-218
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• 2009

Purpose: The purpose of this study was to learn the affective factors of case managers' occupational stress. Method: A total of 986 participants responded to a self-administered questionnaire that included 24 items of Korean Occupational Stress Questionnaire Short Form (KOSQSF), job satisfaction index, health behaviors, general characteristics, and variables related to work. The data collection of research was done from 17th to 21th of September, 2007. The data were analysed by t-test, ANOVA, and multiple regression with SPSS 11.1 package program. Result: The results of this study were as follows: The overall job satisfaction rate of men and women was highly than that of the Korean worker's standard. There were statistically significant differences in occupational stress in work place, work department, work position, smoking, treatment in out-patient clinic, subjective & relative health-status, work load, supervisor's review on work-ability, and job satisfaction. According to the multi-variate analysis, occupational stress(47.6%) was related to job satisfaction, workload, individual work-ability, supervisor's review on work-ability, health status and gender. Conclusion: Occupational stress varied depending on the ten variables and was influenced by job satisfaction(35.7%) and 5 other variables. The results suggest that further follow-up study on case managers is necessary to relieve their occupational stress.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.83-84
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• 2008

The primary water stress corrosion cracking (PWSCC) of dissimilar metal weld based on Alloy 82/182 is one of major issues in material degradation of nuclear components. It is well known that the crack initiation and growth due to PWSCC is influenced by material's susceptibility to PWSCC and distribution of welding residual stress. Therefore, modeling the welding residual stress is of interest in understanding crack formation and growth in dissimilar metal weld. Currently in Korea, a numerical round robin study is undertaken to provide guidance on the welding residual stress analysis of dissimilar metal weld. As a part of this effort, the present paper investigates distribution of welding resisual stress of a ferritic low alloy steel nozzle with dissimilar metal weld using Alloy 82/182. Two-dimensional thermo-mechanical finite element analyses are carried out to simulate multi-pass welding process on the basis of the detailed design and fabrication data. The present results are compared with those from other participants, and more works incorporating physical measurements are going to be performed to quantify the uncertainties relating to modelling assumptions.

• The Plant Pathology Journal
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• 제29권2호
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• pp.201-208
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• 2013

Drought stress is one of the major yield affecting factor for pepper plant. The effects of PGPRs were analyzed in relation with drought resistance. The PGPRs inoculated pepper plants tolerate the drought stress and survived as compared to non-inoculated pepper plants that died after 15 days of drought stress. Variations in protein and RNA accumulation patterns of inoculated and non-inoculated pepper plants subjected to drought conditions for 10 days were confirmed by two dimensional polyacrylamide gel electrophoresis (2D-PAGE) and differential display PCR (DD-PCR), respectively. A total of six differentially expressed stress proteins were identified in the treated pepper plants by 2D-PAGE. Among the stress proteins, specific genes of Cadhn, VA, sHSP and CaPR-10 showed more than a 1.5-fold expressed in amount in B. licheniformis K11-treated drought pepper compared to untreated drought pepper. The changes in proteins and gene expression patterns were attributed to the B. licheniformis K11. Accordingly, auxin and ACC deaminase producing PGPR B. licheniformis K11 could reduce drought stress in drought affected regions without the need for overusing agrochemicals and chemical fertilizer. These results will contribute to the development of a microbial agent for organic farming by PGPR.

• 여성건강간호학회지
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• 제17권5호
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• pp.447-453
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• 2011

Purpose: The purpose of this research was to identify levels of parenting stress, depression and family support of immigrant women and to investigate the moderating effect of family support on the relationship between parenting stress and depression of immigrant women. Methods: The research was carried out with 86 immigrant women who were registered in multi-cultural support centers and receiving education in three cities South Jeolla Province. Data were collected using structured questionnaires and analyzed using descriptive statistics, correlation analysis and hierarchical regression analysis with SPSS/WIN 17.0. Results: The level of parenting stress perceived by the immigrant women was moderate and the level of depression was slightly high. The level of family support as perceived by the wives was slightly high as well. There was a positive correlation between depression and parenting stress but no correlation with family support. Effects of parenting stress on depression were moderated by family support. Conclusion: Results indicate that family support provided to immigrant women moderated effects of parenting stress on depression. Accordingly, as family support is critical to immigrant women, education and other programs need to be provided to promote understanding of family support as a help for immigrant women.

• The Journal of Asian Finance, Economics and Business
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• 제9권1호
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• pp.177-187
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• 2022

Theoretical literature agrees on the interaction between financial instability and economic activity but explains it's dynamic in two points of view: one is that the transmission mechanism occurs in one unique regime and the other reckons a shift of regime leads to the alteration of the transmission mechanism. This study aims to find evidence of the multi-regime transmission for ASEAN developing countries. The author employs the technique of Threshold vector auto regression using the financial stress index standing for financial instability. Monthly data is collected, covering a period long enough with many episodes of high stress in recent decades. There are two conclusions: (1) A financial shock has a negative and stronger impact on economic activity during a high-stress period than it does during a low-stress period; (2) the response of economic activity to a negative financial shock during high-stress periods is stronger than it is during normal times. The findings point to the importance of the financial stress index as an additional early warning indicator for the real economy sector, as well as the positive effect that a reduction in financial stress may have on economic activity, implying the importance of "unconventional" monetary policy in times of high financial stress.

• 한국도로학회논문집
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• 제9권2호
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• pp.63-76
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• 2007

본 연구에서는 콘크리트 포장에 덧씌우기를 하였을 때 다축차륜하중에 의한 응력분포특성을 분석하기 위하여 변환영역에서의 해석법을 개발하였다. 덧씌우기는 기존의 슬래브와 완전히 부착이 되었을 경우와 전혀 부착이 되지 않았을 때의 두 가지 극한 조건을 기준으로 분석을 하였다. 차륜하중은 복륜단축, 복륜복축, 복륜삼축 등 복륜다축하중을 고려하였으며 덧씌우기의 두께, 탄성계수, 포아송비 등이 응력분포에 미치는 영향을 분석하였다. 변환영역에서의 해석법을 이용하여 덧씌우기 포장을 분석하는 방법에 대하여 상세히 설명하였으며 해석결과의 정확성은 유한요소법을 이용한 해석결과와 비교하여 검증하였다. 해석을 수행한 결과 덧씌우기의 두께, 탄성계수, 포아송비의 증가는 기존 슬래브 하부의 최대인장응력을 감소시키며 감소 정도는 부착 덧씌우기가 비부착 덧씌우기에 비해 더 큰 것을 알 수 있었다. 또한 덧씌우기의 포아송비가 응력에 미치는 영향은 그리 크지 않은 것을 알 수 있었으며 부착과 비부착 덧씌우기 포장에서 덧씌우기의 두께 및 탄성계수의 증가에 따른 기존슬래브의 최대응력 감소특성도 분석하였다. 그리고 하중의 축수에 따른 부착과 비부착 덧씌우기 포장의 응력분포 및 최대응력특성도 분석하였다.

• Structural Engineering and Mechanics
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• 제66권4호
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• pp.505-513
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• 2018

Steam flooding is widely used in heavy oil reservoir with coupling effects among the formation temperature change, fluid flow and solid deformation. The effective stress, porosity and permeability in this process can be affected by the multi-physical coupling of thermal, hydraulic and mechanical processes (THM), resulting in a complex interaction of geomechanical effects and multiphase flow in the porous media. Quantification of the state of deformation and stress in the reservoir is therefore essential for the correct prediction of reservoir efficiency and productivity. This paper presents a coupled fluid flow, thermal and geomechanical model employing a program (MATLAB interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators for coupled THM processes in multiphase reservoir modeling. In each simulation cycle, time dependent reservoir pressure and temperature fields obtained from three dimensional compositional reservoir models were transferred into finite element reservoir geomechanical models in ABAQUS as multi-phase flow in deforming reservoirs cannot be performed within ABAQUS and new porosity and permeability are obtained using volumetric strains for the next analysis step. Finally, the proposed approach is illustrated on a complex coupled problem related to steam flooding in an oil reservoir. The reservoir coupled study showed that permeability and porosity increase during the injection scenario and increasing rate around injection wells exceed those of other similar comparable cases. Also, during injection, the uplift occurred very fast just above the injection wells resulting in plastic deformation.

• Journal of Advanced Marine Engineering and Technology
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• 제11권3호
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• pp.45-52
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• 1987

Generally the factors affected largely by the cold cracking sensitivity of the weld are the quantity of the diffusible hydrogen, the brittleness and hardness of the bond area and the tensile restraint stress. These factors have relation each other, and if we can reduce one of these factors, it becomes instrumental to the root cracks prevention of weld. This study deals with the gravity type-underwater-welding of KR Grade A-3 marine steel plate using E4303 welding electrode in order to compare wet-underwater-welding with in-air- welding, resulting in obtaining the tensile restraint characteristics, the hardness distribution, the quantity of diffusible hydrogen and the macro- and micro-crack properties in both underwater and in-air welds. The main results obtained are as follows: 1) The quantity of diffusible hydrogen measured for 48 hours is about 18cc/100g-weld-metal for the in-air-weld of one pass and about 48cc/100g-weld-metal for the underwater-weld of one pass which is about 3 times penetration of diffusible hydrogen compairing with the case of the in-air-weld. However, it was experimentally confirmed that, by the multi-pass welding of 2 to 5 passes, the diffusible hydrogen in the underwater weld metal can be reduced as much as 27 to 49%. 2) The hardness of the weld metal indicates the highest value in the heat affected zones of underwater weld for more rapid cooling rate, resulting in the higher sensitivity of cold cracking. So, it is desirable to soften the higher hardness in the HAZ by tempering effect such as the multi-pass welding in the underwater welding. 3) At the bond vicinity of the underwater weld HAZ, micro cracks were found as resulted by both more rapid cooling rate and more diffusible hydrogen and also by the stress corrosion cracking under the tensile restraint stress in the underwater. But this could be prevented by the tempering effect of the following weld bead such as the multi-pass welding.