• Journal of Welding and Joining
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• 제31권4호
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• pp.7-12
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• 2013

The dissimilar welding between magnesium alloy and steel sheet was required in automobile industry to increase the strength of the dissimilar joints. Laser brazing is one of the good joining processes for Mgsteel dissimilar joint. In this study, the effect of coating materials was evaluated on the laser brazing for the dissimilar joint between AZ31 and coated steels such as Zn, Sn and Ni. Diode direct laser was used to braze the lap-edge joint with Mg600 filler wire and Superior #21 flux. The wettability was best on Zn coated steel. The interlayer was formed at the interface between brazement and steel for all coating materials. The strengths of brazed specimen were 146.5N/mm, 204.6N/mm and 101.6N/mm for Zn, Sn and Ni coated steel respectively.

• 안보군사학연구
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• 통권3호
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• pp.73-120
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• 2005

Today's world is generation of Transformation. The Term "Transformation" is widely used in many nations and international organizations such as U.S. and NATO to describe the course of change undertaken by militaries to respond to the new and emerging security environment. Transformation involves all elements of the defense enterprise including Operational Environment, Operational Concepts, Doctrine, Structure and Technologies, within a supportive Cultures context. An Operational Environment is defined as "a composite of conditions, circumstances, and influences that affect the employment of military forces and bear on the decisions of the unit commander." The context for developing future military concept and capability lies essentially within the anticipated boundaries of the operational environment in a collective sense. The joint operational environment is essential to the nation's defense. It describes volatile, complex, and dangerous environment in which the military personnel. organizations, and material will operate. Implications coming forth from joint Operational Environment are but a starting point - many others exist. More and better Implications will come forth as people think about massages of Operational Environment, experiment its characteristics, learn to deal with its threats and scenarios, apply their experience and judgement, and then consider what is required of Korean military doctrine, organizations, training and education, material development, and leadership for operations in the joint Operational Environment.

• 한국보건간호학회지
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• 제14권2호
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• pp.342-354
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• 2000

This study was conducted to identify the characteristics of activities of daily living(ADU) and its influencing factors in patients with chronic arthritis. The data were obtained from 104 patients with chronic arthritis in one university hospital from May to August. 2000. For analysing data. SAS program was used for t-test. ANOVA, Schefte test. Pearson correlation. and stepwise multiple regression. The results were as follows: 1. The variables which influenced self-efficacy were duration of disease. number of painful joint, quality of sleep and alcohol drinking. 2. The variables which influenced fatigue were diagnosis and number of painful joint. 3. The variables which influenced ADL were age. duration of disease. diagnosis. number of painful joint. number of exercise and alcohol drinking. 4. ADL was positive correlation with self-efficacy and negative correlation with fatigue. And self-efficacy was negative correlation with fatigue. 5. The predictors to explain ADL were self-efficacy. number of painful joint. lupus. duration of disease and religion. These predictors explained $66.01\%$ of the activites of daily living. According to these findings. the most significant influencing factor of ADL was self-efficacy. therefore the development of nursing intervention for enhancing self-efficacy would be needed. Also. it is suggested that an exercise program should be recommended as one of useful and appropriate nursing intervention for reducing fatigue and increasing ADL.

• Geomechanics and Engineering
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• 제21권3호
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• pp.227-236
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• 2020

Non-destructive exploration using elastic waves has been widely used to characterize rock mass properties. Wave propagation in jointed rock masses is significantly governed by the characteristics and orientation of discontinuities. The relationship between spatial heterogeneity (i.e., joint spacing) and wavelength for elastic waves propagating through jointed rock masses have been investigated previously. Discontinuous rock masses can be considered as an equivalent continuum material when the wavelength of the propagating elastic wave exceeds the spatial heterogeneity. However, it is unclear how stress-dependent long-wavelength elastic waves propagate through a repetitive rock-joint system with multiple joints. A preliminary numerical simulation was performed in in this study to investigate long-wavelength elastic wave propagation in regularly jointed rock masses using the three-dimensional distinct element code program. First, experimental studies using the quasi-static resonant column (QSRC) testing device are performed on regularly jointed disc column specimens for three different materials (acetal, aluminum, and gneiss). The P- and S-wave velocities of the specimens are obtained under various normal stress levels. The normal and shear joint stiffness are calculated from the experimental results using an equivalent continuum model and used as input parameters for numerical analysis. The spatial and temporal sizes are carefully selected to guarantee a stable numerical simulation. Based on the calibrated jointed rock model, the numerical and experimental results are compared.

• The Journal of Asian Finance, Economics and Business
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• 제8권12호
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• pp.233-239
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• 2021

The objective of this study is to find out the factors affecting the employees' loyalty in private joint-stock commercial banks in Mekong Delta, Vietnam. Then, possible solutions can be proposed, which can be implemented to improve employees' engagement in private joint-stock commercial banks in Mekong Delta, Vietnam, in the future. The author conducted a survey of 300 employees at 6 private joint-stock commercial banks in 6 provinces in Mekong Delta: An Giang, Tra Vinh, Can Tho, Ben Tre, Soc Trang, and Tien Giang. The author also used the Cronbach Alpha reliability analysis method, exploratory factor analysis (EFA), and multivariate regression analysis. The results show the degree of influence of factors on employees' loyalty - according to decreasing importance: Income, Job characteristics, Working environment, Colleagues, Leadership. The authors propose some solutions based on the research findings, including focusing on assigning the right employees to the right jobs, creating a competitive and fair working environment, focusing on a reasonable income policy, and transparency in working relationships to help bank managers in the Mekong Delta, Vietnam improve human resource management to improve employee loyalty to private joint-stock commercial banks in Vietnam.

• Advances in concrete construction
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• 제14권2호
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• pp.139-151
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• 2022

Filling materials poured into precast member joint are subjected to restraint stress by the precast member and joint reinforcement. The induced stress will likely cause cracks at early ages and performance degradation of the entire structure. To prevent these issues and design reasonable joints, it is very important to analyze and evaluate the restrained shrinkage cracks of filling materials at various restraint conditions. In this study, a new time zero-that defines the shrinkage development time of a filling material-is proposed to calculate the accurate amount of shrinkage. The tensile stresses and strengths at different ages were compared through the ring test (AASHTO PP34) to evaluate the crack potential of the restrained filling materials at various restraint conditions. The mixture which contained an expansive additive and a shrinkage reducing agent exhibited high resistance to shrinkage cracking owing to the high-drying shrinkage compensation effect. The high-performance, fiber-reinforced cement composite, and ultra-high-performance, fiber-reinforced cement composite yielded very high resistance to shrinkage and cracking owing to the pull-out property of steel fibers. To this end, multiple nonlinear regression analyses were conducted based on the test results. Accordingly, a modified tensile stress equation that considered both the geometric shape of the specimen and the intrinsic properties of the material is proposed.

• 터널과지하공간
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• 제26권5호
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• pp.384-395
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• 2016

절리면의 전단거동 특성을 알아보기 위하여 암석종류와 거칠기가 서로 다른 110개의 자연 암석 절리면 시료에 대하여 거칠기 측정시험과 다단계전단시험을 실시하였다. 시험 암석은 석영반암, 석영안산암, 화강암, 편마암의 4가지 종류이고, 절리면은 JRC값에 따라 3가지 그룹으로 분류하였다. 거칠기 측정시험을 통해 절리면의 거칠기 파라미터를 분석하였으며, 다단계전단시험을 통해 암석종류, 절리면 거칠기, 수직응력의 변화가 각종 전단특성에 미치는 영향을 알아보았다. 절리면의 거칠기와 수직응력이 커질수록 최대전단강도와 전단강성은 증가하였고, 거칠기가 작고 수직응력이 커질수록 팽창각은 감소하였다. 절리면의 전단특성은 암석종류와 거의 무관한 것으로 나타나 모암의 강도보다는 거칠기와 수직응력에 더 큰 영향을 받았다. 또한 동일 암석 절리면에 대한 다단계시험과 직접전단시험의 결과를 비교분석함으로써 두 시험법의 특징을 고찰하였으며, 다단계시험으로 구한 팽창각은 시험 전반부의 낮은 수직응력수준에서 얻은 값만 유효한 것으로 나타났다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1993년도 특별강연 및 춘계학술발표 개요집
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• pp.107-110
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• 1993

• 한국방재학회:학술대회논문집
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• 한국방재학회 2009년도 정기 학술발표대회
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• pp.130.2-130.2
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• 2009

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2000년도 특별강연 및 추계학술발표대회 개요집
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• pp.198-200
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• 2000