• Computers and Concrete
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• v.7 no.5
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• pp.437-453
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• 2010

CFRP has been widely used for strengthening reinforced concrete members in last decade. The strain transfer mechanism from concrete face to CFRP is a key factor for rigidity, ductility, energy dissipation and failure modes of concrete members. For these reasons, determination of the effective CFRP bonding length is the most crucial step to achieve effective and economical strengthening. In this paper, generalizations are made on effective bonding length by increasing the amount of test data. For this purpose, ANSYS software is employed, and an experimentally verified nonlinear finite element model is prepared. Special contact elements are utilized along the concrete-CFRP strip interface for investigating stress distribution, load-displacement behavior, and effective bonding length. Then results are compared with the experimental results. The finite element model found consistent results with the experimental findings.

• Child Health Nursing Research
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• v.13 no.1
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• pp.73-80
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• 2007

Purpose: As a result of dramatic advances in the medical and surgical management of congenital heart disease (CHD), many babies born with cardiac anomalies today can expect to reach adulthood. The main purpose of this study was to examine the relationship between parenting stress and personal resources of mothers of children with CHD. Method: Fifty-one mothers of children with CHD were recruited at the pediatric cardiac outpatient clinic from July 14th to September 25th 2006. Abidin's parenting stress index/short form (PSI/SF) and Brandt and Weinert's personal resource questionnaire (PRQ) were used. PSI has 3 sub-concepts; parental role distress, dysfunctional parent-child interaction, and difficult child. PRQ has 4 sub-concepts; intimacy, social integration, worth, and assistance. Data were analyzed using SPSS 13.0 version. Results: Correlation analysis showed that parenting stress was significantly related to 'intimacy', 'social integration', and 'worth' of mothers. Multiple regression analysis showed that parenting stress was significantly related to personal resource of mother and information by internet. Conclusion: Mothers who felt they had supportive friends and family, high self esteem, and social integration reported lower parenting stress. Also, internet may be an effective method to provide information and share experience for mothers of children with CHD.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.116-126
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• 2009

The use of short implants has been accepted risky from biomechanical point of view. However, short implants appear to be a long term viable solution according to recent clinical reports. The purpose of this study was to investigate the effect of different diameter and length of implant size to the different type of bone on the load distribution pattern. Stress analysis was performed using 3-dimensional finite element analysis(3D-FEA). A three-dimensional linear elastic model was generated. All implants modeled were of the various diameter(${\phi}4.0$, 4.5, 5.0 and 6.0 mm) and varied in length, at 7.0, 8.5 and 10.0 mm. Each implant was modeled with a titanium abutment screw and abutment. The implants were seated in a supporting D2 and D4 bone structure consisting of cortical and cancellous bone. An amount of 100 N occlusal load of vertical and $30^{\circ}$ angle to axis of implant and to buccolingual plane were applied. As a result, the maximum equivalent stress of D2 and D4 bones has been concentrated upper region of cortical bone. As the width of implant is increased, the equivalent stress is decreased in cancellous bone and stress was more homogeneously distributed along the implants in all types of bone. The short implant of diameter 5.0mm, 6.0mm showed effective stress distribution in D2 and D4 bone. The oblique force of 100N generated more concentrated stress on the D2 cortical bone. Within the limitations of this study, the use of short implant may offer a predictable treatment method in the vertically restricted sites.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3833-3838
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• 2010

Brainwave can be the most effective means of detecting the state of the brain that changes moment by moment. Since brain has closed relations with hormones which are a foundation of metabolism, it needs to examine closely the mutual relationship between brainwave and hormone. We examined the possibility to find out such information about metabolism by comparing brainwave with cortisol hormone. The major variables are anti-stress quotient of brainwave and cortisol density which give stress information of the working women, to measure from March 3 to May 28, 2007. To find out the relationship between them, we performed such statistical analysis about the before and after of brainwave training as t-test, correlational analysis and regression analysis. We obtained following results: First, considerable changes of variables is shown by brain-wave training. Second, there exist a correlation between variables. Third, according to regression analysis, influence between variables is verified. Thus, we found that stress information of hormone analytical level can be obtined only through brainwave analysis.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.343-349
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• 2014

The dental osseointegration implant should be enough to endure occlusion load and it's required to have efficient design and use of implant to disperse the stress into bones properly. Solidworks as a finite element analysis program for modeling and analysis of stress distribution was used for the research. The simple crown model was designed on applying conjoined condition with tightening torque of 20 Ncm of a abutment screw between a cement retained implant abutment and a fixture. A $45^{\circ}$ oblique loading from lingual to buccal side on buccal cusps of crown and performed finite element analysis by 100 N of external load. The results by a analysis for stress distribution of supporting bones of fixture were as below. The von Mises stress was concentrated on the upper side of supporting compact bone regardless of the diameters and lengths of fixture, and the efficiency result of stress reduction was increase of fixture's diameter than it's length. Therefore, it's effective to use wider fixture as possible to the conditions of supporting jaw bone.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.205-210
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• 1998

The strength and dimension of recent constructed subway box structures are increased considerably. These increases are resulting in much initial cracks by hydration heat and thermal stress. According to previous studies, decrease of cement amount by using superplasticizer and L/H value is the best way to eliminate hydration heat and stress. The analyses using finite element model were performed. By the result of analysis, the use of superplasticizer and the decrease of the change of longitudinal placing length are proved to be more effective for elimination thermal cracks. By ACI Code, for longitudinal placing length 25 m, the amount of wall temperature reinforcement is always lack despite of concrete mix proportion. With analytical result and the inducing crack joint, the in-site test were performed and the analytical results proved to be effective. However, the inducing crack joint is not effective if it is a small size.

• Earthquakes and Structures
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• v.6 no.3
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• pp.251-266
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• 2014

Dynamic analyses for a suite of ground of motions were conducted on concrete gravity dam sections to examine the earthquake induced stresses and effective damping. For this purpose, frequency domain methods that rigorously incorporate dam-reservoir-foundation interaction and time domain methods with approximate hydrodynamic foundation interaction effects were employed. The maximum principal tensile stresses and their distribution at the dam base, which are important parameters for concrete dam design, were obtained using the frequency domain approach. Prediction equations were proposed for these stresses and their distribution at the dam base. Comparisons of the stress results obtained using frequency and time domain methods revealed that the dam height and ratio of modulus of elasticity of foundation rock to concrete are significant parameters that may influence earthquake induced stresses. A new effective damping prediction equation was proposed in order to estimate earthquake stresses accurately with the approximate time domain approach.

• Child Health Nursing Research
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• v.5 no.1
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• pp.5-17
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• 1999

This study was designed to determine the schemata and their characteristics of stress experience the subjectivity of stress experience(structure of subjectivity) would be a basic step for the effective clinical education through the stress management for characteristics of these types. Q-methodological method was used for that purpose. The research method statements were collected prior to the study through indepth interviews. For the study, 31 Q-statements were selected. There were 34 nursing students as subjects for the research. The 34 nursing students sorted the 31 statements using the principal of forced normal distribution. The principle of forced normal distribution, which has 9 scales to measure the individual opinions, was called. Q-factor analysis by using PC QUANL program supply the material. According to the outcomes of this study, there were 3 types of special opinion about the stress experience of clinical practice. The first type is called 'Influence of practical atmosphere type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The second type is called 'conflict of nursing role type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The third type is called 'Lack of confidence type'. Members of this type experienced stress because of a lack of confidence for their own nursing knowledge and skill. As a result, we now need further study to identify individual psychological aspects of stress for clinical practice. The findings will guide the development in effective approaches for clinical education. Finally, the result of the study will provide us the need for developing systematic and integrated practice education program for students and active involvement of clinical instructor.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2050-2054
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• 2007

This study numerically and experimentally investigated on thermal strain analysis of aluminum alloy casting mold using metal foundry. To predict the numerical result of thermal strain in Al alloy casting mold during the cooling process, it is performed the investigation of temperature distribution, stress and displacement based on the physical properties of Al alloy. In results of this study, Al alloy casting mold represented rapidly cooling graph during initial 20minutes after beginning cooling process, therefore value of stress and displacement is rapidly changed during initial 20minutes after beginning cooling process. In addition to, temperature distribution obtained by experiment confirmed corresponding pattern then compared numerical analysis with experiment. These results are distribute to make the effective and the high precision casting mold.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.247-250
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• 2006

The growing demand for more fuel-efficient vehicles to reduce energy consumption and air pollution is a challenge for the automotive industry. The characteristic properties of aluminum, high strengrth stiffness to weight ratio, good formability, good corrosion resistence, and recycling potential make it the ideal candidate to replace heavier materials in the car to respond to the weight resuction demand within the automotive industry. In this paper, A series of compression test was carried out to find the flow stress of A6082 at 300, 400 and $500^{\circ}C$, then we tried to estimate weldability, extrusion load and effective stress of die in the aluminum extrusion process through the 3D FE simulation at non-steady state for aluminum automotive parts.