• Journal of the Korean Ceramic Society
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• v.56 no.4
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• pp.394-398
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• 2019

In this paper, the joining characteristics of GDC-LSM ceramics with Crofer 22 APU metal alloys was investigated at different brazing temperatures and holding times by reactive air brazing. Brazing was performed using Ag-10 wt% CuO filler, at three different temperatures (1000, 1050, and 1100℃ for 30 minutes) as well as for three different holding times (10, 30, and 60 minutes at 1050℃). The interfacial microstructures were examined by scanning electron microscopy and the joining strengths were assessed by measuring shear strengths at room temperature. The results show that with increasing brazing temperature and holding time, joint microstructure changed obviously and shear strength was decreased. Shear strength varied from a maximum of 100±6 MPa to a minimum of 18±5 MPa, depending on the brazing conditions. These changes were attributed to an increase in the thickness of the oxide layer at the filler/metal alloy interface.

• Journal of Ecology and Environment
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• v.38 no.2
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• pp.249-256
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• 2015

Islands are often habitats to unique species because they have different environmental conditions from the mainland and other islands. Another characteristic of islands is their limited natural resources, which has led island residents to heavily rely on traditional ecological knowledge (TEK) and use resources sustainably. The so-called "Maeul landscape" shows the interrelationship of biological species and people's use of natural resources. Shinan-gun is an administrative district located in the southwestern part of Korea that forms an archipelago with huge tidal flat areas. Since long ago, people's use of these tidal flats shows a high degree of biocultural diversity. Maeul landscapes also show humans' adaptation to the natural environment. For instance, strong winds blowing mainly from the northwest have led people in Shinan-gun to create "Ushil," a windbreak forest with stone blocks to block wind from their villages and agricultural fields. At present, the transfer of TEK to future generations is at stake due to socio-economic changes that cause island populations to shrink and age rapidly. Islands are often regarded as good destinations for tourism, but attention should also be given to sustainable development due to the environmental characteristics of islands. International organizations are making efforts to curb the threats of global environmental problems especially on small islands. Their activities are aimed at seeking solutions that stress the central role of biocultural diversity in establishing the sustainable use of natural resources on islands. Joint efforts oflocal people and government authorities to protect and conserve the Maeul landscape should be encouraged.

• Journal of Families and Better Life
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• v.4 no.2
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• pp.89-101
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• 1986

This study sought to investigate the presence and characteristics of postulated variables(involvement & empathy) that may moderate the need for overt conflict - resolving behavior when husbands and wives disagree on a certain purchasing subdecision and that may explain husband - wife decision - making patterns. For the above purpose, the analyses of this study are based on response of 180 husbands and wives(90 couples) to questions concerning 11 subdecisions of house and sofa-set purchasing decisions. The results are summarized as follows; 1) Income, education, and wives job do not significantly differenciate the levels of involvement and empathy except that education does the levels of wives involvement and empathy and that wives job does the levels of husbands involvement. 2) Husbands and wives indicate significantly different levels of involvement and empathy on most subdecisions. i. e., wives regard all subdecisions importantly. and on 3 subdecisions of joint decision - making pattern, they have the higher consideration for their husband's preferences. 3) Incongruency in husband - wife responses to the questions of decision - making patterns are moderate. 4) Husbands and wives involvement / empathy discriminate well the patterns of decision - making on various subdecisions within 2 product classes. Wives empathy accounts for much discriminating power in both instances. Thus, the need to add these involvement and empathy variables to models of family decision - making is sugguested.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.2
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• pp.90-94
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• 1998

This study aims at analyzing to treeing in the solid-solid interface which is insulation type of cable junction parts, the proceeding of tree-growth and electrical breakdown were research in the study. Interface was made artificially to detect how it influenced the insulating ability of the whole system, the specimen were XLPE generally used in cable. The interface conditions were divided into two parts. First condition being the one focused on the surface of interface, it was treated with sand paper (#80, #600, #1200). For the second condition, the pressure of interface was varied as the value of 1, 5, 10 [$kg/cm^2$]. Using above conditions, treeing and breakdown properties on tree-growth were respectively compared in details. As a result, breakdown time was shorter for the full range of supplied voltage in the case of interface existed in the joint than non-existed interface. In the case of existed interface, the interface which had high-interface pressure and painted with silicon insulating oil was the best in the aspect of breakdown characteristics.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.73-78
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• 2008

The paper presents the characteristics of mechanical properties within the heat affected zone (HAZ) of dissimilar metal weld between SA508 Gr.1a and F316 stainless steel (SS) with Alloy 82/182 filler metal. Tensile tests were performed using small-size specimens taken from the HAZ regions close to both fusion lines of weld, and the micro-structures were examined using optical microscope (OM) and transmission microscope (TEM). The results showed that significant gradients of the yield stress (YS), ultimate tensile stress (UTS), and elongations were observed within the HAZ of SA508 Gr.1a. This was attributed to the different microstructures within the HAZ. In the HAZ of F316 SS, however, the welding effect dominated the YS and elongation rather than UTS, and TEM micrographs conformed the strengthening in the HAZ of F316 SS was associated with a dislocation-induced strain hardening.

• Korean Journal of Adult Nursing
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• v.26 no.1
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• pp.67-77
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• 2014

Purpose: The purpose of this study is to investigate the prevalence of metabolic syndrome and its components and to examine the related factors in urban and rural community, South Korea. Methods: The data from the 5th Korea National Health and Nutrition Examination Survey (KNHANES-V) conducted in 2010 were utilized in this study. The subjects were 5,760 adults 20 years or over. The data were consisted with health survey questionnaire and health examination. $x^2$-test and logistic regression was used for the analysis SAS 9.3 applying sampling weights. Results: The prevalence of metabolic syndrome based on the latest definition proposed the joint scientific meeting was 23.4% and 29.0% respectively in urban and rural community. Rural community showed higher prevalence of abdominal obesity (29.9% vs 38.5%), elevated blood pressure (31.3% vs 38.5%), elevated blood glucose (24.3% vs 28.4%) than urban community. The related factors were age, marital status, high risk drinking, obesity in urban community and age, marital status high risk drinking, severe physical activity, obesity in rural community. Conclusion: This study showed there was difference in prevalence and the related factors of metabolic syndrome and these findings have important implications to prevent and manage metabolic syndrome in public health field.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.29-35
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• 2020

This paper studies the main parameters of tube-to-bar dissimilar material and shape friction welding for piping materials. The weldability of joint parts was investigated with respect to tensile tests, micro-Vickers hardness, the bond of area, and optical microstructure. The specimens are tested as-welded. Optimal welding conditions are n = 2000 rpm, HP = 50 MPa, UP = 100 MPa, HT = 5 sec, and UT = 10 sec when the metal loss (Mo) is 11 mm. Moreover, the same two materials for friction welding are strongly mixed with a well-combined structure of micro-particles without any molten material, particle growth, or defects. Therefore, the expected result of dissimilar material friction welding includes a reduction of cost and material in the welding process.

• Journal of Construction Engineering and Project Management
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• v.5 no.4
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• pp.1-6
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• 2015

Due to unique characteristics of small construction companies, safety management is comprised of complex problems. This paper aims to better understand the complexity and dynamics of safety management in small construction companies. A system dynamics (SD) model was built in order to capture the causal interdependencies between factors at different system levels (regulation, organization, technical and individual) and their effects on safety outcomes. Various tests were conducted to build confidence in the model's usefulness to understand safety problems facing small companies from a system dynamics view. A number of policies were analyzed by changing the value of parameters. The value of a system dynamics approach to safety management in small construction companies is its ability to address joint effects of multiple safety risk factors on safety performance with a systems thinking perspective. By taking into account feedback loops and non-linear relationships, such a system dynamics model provides insights into the complex causes of relatively poor safety performance of small construction companies and improvement strategies.

• Journal of Distribution Science
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• v.13 no.10
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• pp.51-56
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• 2015

Purpose - This study examines Chinese P2P investment decision processes from a behavioral economics approach. Research design, data, and methodology - We analyze the online P2P investment product purchase decisions of 241 respondents in China, March 2015 to May 2015. T-tests were conducted to determine whether the framing effect influenced investor investment preferences. The Association Rule was used to identify the framing effect of respondent demographic characteristics on joint decisions regarding stable or risky investment products. Results - There are significant differences between the two groups (positive framing and negative framing) and their product-choosing behavior. In the positive framing group, female investors, young investors, investors with non-financial occupations and with limited or no experience, preferred stable P2P investment products. In contrast, in the negative framing group, investors with extensive investment experience preferred risky investment products. Conclusions - The framing effect influences investor choices in online P2P investment products. It is necessary to implement comprehensive supervision and full information disclosure regarding P2P investment products. P2P investment websites can also adopt different marketing strategies according to investor gender and age.

• Journal of Korean society of Dental Hygiene
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• v.18 no.5
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• pp.763-770
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• 2018

Objectives: The purpose of this study was to investigate the relationship between mental healthlevel,usual lifestyle, and thelevelofsubjectivesymptoms of some adults. Methods: From 17 September-28 November 2017, 260 adults living in Seoul, Gyeonggi, and Incheon comple tedaquestionnaireconsistingofgeneral characteristics (6 items), mental health level (14 items), usual lifestyle (9 items), and subjective symptoms level (9 items) on a 5-point scale. Results: In the mental health level, there was a significant difference in sex, age, marital status, education level, andexistenceofstress, and there were differences in age, marital status, occupation, and existence of stress in usual lifestyle. There were statistically significant differences in age, marital status, occupation, and existenceofstress in the subjective symptoms of temporomandibular disorders. Conclusions: It is necessary to develop a program that can be applied in parallel with counseling therapy related to mental health during the clinical treatment of temporomandibular disorders.