• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.7
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• pp.81-88
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• 2020

The geometry and the defect of the groove of the part provoke a sudden change of stress in a local region. The objective of this paper is to investigate the effects of the geometry and the imperfection of a small groove on stress distributions in the vicinity of the joined region for the ABS part with a thin wall using a three-dimensional finite element analysis (FEA). Several types of groove are designed to improve joining characteristics in the vicinity joined region. The imperfection model of the small-sized groove is obtained from observation of deposition characteristics of a fused deposition modeling process. Local stress distributions in the vicinity of the joined region are predicted by the FE model with refined meshes. The influence of the angle and the imperfection of the groove on appearance regions of the maximum stress and distributions of the defined principal stress for different loading conditions is examined using the results of FEAs. Finally, a proper design of the groove is proposed to improve joining characteristics between the substrate and the ABS part.

• Journal of Convergence for Information Technology
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• v.9 no.3
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• pp.146-151
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• 2019

This study performed to identify the relationship between job stress and self-efficacy based on the related research review and text network analysis. For the literature review, we performed the search process at three domestic and one foreign database using key words, 'nurse', 'stress', 'self-efficacy'. A total of 18 papers were selected as the target literature. Nine of these studies reported a statistically significant negative correlation between nurses' job stress and self-efficacy. It was difficult to compare between studies' results because of the optional usage of the questionnaires. In addition, a text network analysis was conducted by extracting keywords from the 18 papers. The keyword with the highest frequency of appearance was job stress, and the main words with high frequency of emergence were self-efficacy, hospital, and correlation. To clarify the relationship between the keywords, it is proposed to perform a survey on the influence factors through the development of Korean version measurement.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.580-592
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• 2021

This study was conducted on mothers with infants to identify the relevant factors affecting parenting stress and depression, and to verify the effectiveness of the beauty therapy program on parenting stress and depression. After conducting a self-administered survey of 450 mothers with infants under 36 months old in Busan city from May 1 to 20 May, 2018 through convenient sampling method, the final analysis of 402 women. In addition, experimental research through one group pretest-posttest design was also conducted on 17 people to verify the effectiveness of the beauty therapy program on parenting stress and depression. The multiple regression analysis showed that the higher appearance-management behavior, the less parenting stress and depression. Also, parenting stress and depression after participating in beauty therapy programs are significantly reduced compared to those before participating in beauty programs. This study could confirm that beauty therapy program is one of the effective measures to improve women's mental health and self-esteem.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.190-197
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• 2002

In this thesis, ZnO varistors with various formulation, such as A∼E, were fabricated according to ceramic fabrication method. The microstructure, electrical properties, and surge characteristics of ZnO varistors were investigated according to ZnO varistors with various formulation. In the microstructure, A∼E\`s ZnO varistor ceramics sintered at 1130$\^{C}$ was consisted of ZnO grain(ZnO), spinel phase (Zn$\_$2.33/Sb$\_$0.67/O$\_$4/), Bi-rich phase(Bi$_2$O$_3$) and intergranuler phase, wholly. Lightning impulse residual voltage of A, B, C and E\`s ZnO varistors suited standard characteristics, below 12kV at current of 5kA. On the contrary, D\`s ZnO varistor exhibited high residual voltage as high reference voltage. In the accelerated aging test, leakage current and watt loss of B, C and D\`s ZnO varistors increases abruptly with stress time under the first a.c. stress(115$\^{C}$/3.213kV/300h). Consequently, C varistor exhibited a thermal run away. On the contrary, leakage current and watt loss of A and C\`s ZnO varistors which show low initial leakage current exhibited constant characteristics. After high current impulse test, A\`s ZnO varistor has broken the side of varistor but impulse current flowed. On the contrary, E\`s ZnO Varistor exhibited good discharge characteristics which the appearance of varistor was not wrong such as puncture, flashover, creaking and other significant damage. After long duration impulse current test, E\`s ZnO varistor exhibited good discharge characteristics which the appearance of varistor was not wrong such as puncture, flashover, creaking and other significant damage. After high current impulse test and long duration impulse current test, E\`s ZnO varistor exhibited very good characteristics which variation rate of residual voltage is 1.4% before and after test.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.218-231
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• 2005

Statement of problem. In the partially edentulous patients, removable partial dentures have been working as a important treatment modality. Clasps, a kind of direct retainers, received some amount of stresses during the insertion and removal of partial denture on the abutment tooth. Purpose. The study is to investigate stresses of the different clasps. Material and methods. In order to investigate the degree of stresses, maxillary partial edentulism (Kennedy Class II modification I) was assumed and removable partial dentures were designed on it with three kinds of metallic materials; cobalt-chromium alloy, type IV gold alloy and commercially pure (c.p.) titanium. Aker's clasp was applied on the left second molar. RPA (mesial rest-proximal plate-Aker's) clasp was on the left first premolar and wrought wire clasp was on the right first premolar. Three dimensional, non-linear, dynamic finite element analysis method was run to solve this process. Results. 1. Cobalt-chromium alloy had the highest von Mises stress value and c.p. titanium had the lowest one irrespective of the types of clasps. 2. In the Aker's clasps, stress on the retentive tips was shown shortly after the appearance of stresses of the middle and minor connector areas. These time lag was much shorter in the RPA clasps than in the Aker's clasp. 3. In general. retentive tips of wrought wire clasps had much less amount of stress than other clasps. Conclusion. The amount of stress was the highest in the RPA clasp and the lowest in the wrought wire clasp, in general.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.23-29
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• 2009

The hybrid composite materials are recently used in many field as an advanced material due to their high resistance to fracture. However, hybrid composite materials have several problems, especially delamination, compared with homogeneous materials such as an aluminum alloy, etc. In this study, we carried out the tensile test to study the tension failure appearances and tensile ultimate strength of CFRP/Al/CFRP hybrid composite materials. The CFRP material used in the experiment is a commercial material known as CU175NS in unidirectional carbon prepreg. Also Al/CFRP/Al hybrid composites with three kind length of a single edge crack were investigated for the relationship between an aluminium volume fraction and a crack length. The crack length was measured by a traveling microscope under a universal dynamic tester. Futhermore the stress intensity factor behavior was examined according to a volume fraction and an initial crack length ratio to a width.

• Journal of The Korea Institute of Healthcare Architecture
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• v.13 no.3
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• pp.7-14
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• 2007

The concept and spatial composition of office have endlessly changed according to social trend. And according to social change, members of office, namely, concept of organization has been changed. Presently, our society finds and needs appearance of office suitable for our society. According to a concept of ecological environment and a concept laying stress on human, various trials have been performed but still, stress of salaried men is treated as social issue. By having connection between psychological healing theory of Max $L{\ddot{\bar{u}}}scher$ and spatial expression elements (content : refuge, self-esteem : prospect, confidence : flow, liberty : void) as a theory, we discussed possibility of aesthetic office landscape could be developed to a type of office which could control emotion that can be a cause of stress and we intended to examine limitation and possibility through case analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.456-467
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• 2018

Appearance has become an important means of expressing oneself in modern society, and women often desire to lose weight. Therefore, this study examined the diets of female college students with high weight loss needs and analyzed the effects of their body image, sociocultural attitude, body stress and diet behavior on intake weight loss products. Data were collected from 220 Korean female college students from June to July using an online survey program. The questionnaires included body image scale, Sociocultural Attitude Towards Appearance Questionnaire (SATAQ), Body Attitudes Questionnaire (BAQ) and diet behaviors scale. Data were analyzed by descriptive statistics, the $x^2$-test, Pearson's correlation coefficients, and logistic regression analysis using the SPSS 22.0 program. There were significant differences in body image, SATAQ, obesity stress and diet behavior between groups. All variables were significantly correlated with each other. Factors influencing weight loss products intake by female university students were SATAQ (OR=1.15, CI=1.03-1.29), obesity stress (OR=1.13, CI=1.06-1.20), diet behaviors (OR=1.21, CI=1.10-1.33), and knowledge regarding the side effects of weight loss products (OR=3.86, CI=1.62-9.20). Thus, it is necessary to teach female college students to recognize healthy weight control methods. Moreover, if weight loss products are needed, appropriate information should be provided regarding the ingredients and side effects of the product.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.489-500
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• 2016

This study examined the influencing factors of depression on the physical appearance satisfaction and the trends of personal relationships in Korean nursing college students. A total of 247 subjects between 17 and 27 years of age were selected through random sampling. Data were collected using a self-reported questionnaire from November 1, 2012 to March 30, 2013. The depression acceptance differed significantly according to rank between siblings, religion, school record, socioeconomic status, cohabitation, and stress resolving methods. There was a positive correlation between depression and the appearance satisfaction and the trends of personal relationship. 26.8% variance in depression was explained by the appearance, socioeconomic status, sympathy-acceptance, resistance-mistrust, body figure, and cohabitation. These findings may be useful for understanding depression in nursing college students and developing more specific personal interrelationship and depression programs.

• The Plant Pathology Journal
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• v.32 no.4
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• pp.300-310
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• 2016

Pathogen infection in plants induces complex responses ranging from gene expression to metabolic processes in infected plants. In spite of many studies on biotic stress-related changes in host plants, little is known about the metabolic and phenotypic responses of the host plants to Pseudomonas cichorii infection based on image-based analysis. To investigate alterations in tomato plants according to disease severity, we inoculated plants with different cell densities of P. cichorii using dipping and syringe infiltration methods. High-dose inocula (${\geq}10^6cfu/ml$) induced evident necrotic lesions within one day that corresponded to bacterial growth in the infected tissues. Among the chlorophyll fluorescence parameters analyzed, changes in quantum yield of PSII (${\Phi}PSII$) and non-photochemical quenching (NPQ) preceded the appearance of visible symptoms, but maximum quantum efficiency of PSII ($F_v/F_m$) was altered well after symptom development. Visible/near infrared and chlorophyll fluorescence hyperspectral images detected changes before symptom appearance at low-density inoculation. The results of this study indicate that the P. cichorii infection severity can be detected by chlorophyll fluorescence assay and hyperspectral images prior to the onset of visible symptoms, indicating the feasibility of early detection of diseases. However, to detect disease development by hyperspectral imaging, more detailed protocols and analyses are necessary. Taken together, change in chlorophyll fluorescence is a good parameter for early detection of P. cichorii infection in tomato plants. In addition, image-based visualization of infection severity before visual damage appearance will contribute to effective management of plant diseases.