• Journal of Families and Better Life
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• v.23 no.3 s.75
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• pp.197-215
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• 2005

The purpose of this study is to examine how the causal relationships between independent variables, marital communication decision making participation and family life satisfaction of elderly in couple household. The survey was conducted from May 26 to July 21, 2003. Total 394(male: 186, female: 208) samples were used for the analysis. Using SPSS/PC WIN program, data were analyzed by frequencies, percentages, mean, standard deviation, Cronbach'a, Pearson's correlation, t-test, and multiple regression. The major findings were as follows: 1) The findings showed that there were high level of the communication between the elderly males and females. In the decision making participation the finding showed that both elderly males and females generally made joint decisions with no gender differences. The elderly males and females reported overall family life satisfaction; and the elderly males were more likely satisfied with their family lives than the elderly females. 2) The path analysis on family life satisfaction presented that several variables had direct/indirect effects on family life satisfaction through communication and decision making participation. Among the moderate variables, communication agreement and communication openness had significant effects on family life satisfaction. Specifically, the elderly men were more likely satisfied when they participated in decision making on leisure: the elderly women were more likely satisfied when they participated in decision making on family life.

• Journal of Hydrogen and New Energy
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• v.23 no.5
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• pp.559-571
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• 2012

Dimethyl ether (DME) is a new clean fuel as an environmentally-benign energy resource. DME can be manufactured from various energy sources including natural gas, coal, and biomass. In addition to its environmentally friendly properties, DME has similar characteristics to those of LPG. The aim of this article is to represent the development of new DME process with KOGAS's own technologies. KOGAS has investigated and developed new innovative DME synthesis process from synthesis gas in gaseous phase fixed bed reactor. DME has been traditionally produced by the dehydration of methanol which is produced from syngas, a product of natural gas reforming. This traditional process is thus called the two-step method of preparing DME. However, DME can also be manufactured directly from syngas (single-step). The single-step method needs only one reactor for the synthesis of DME, instead of two for the two-step process. It can also alleviate the thermodynamic limitations associated with the synthesis of methanol, by converting the produced methanol into DME, thereby potentially enhancing the overall conversion of syngas into DME. KOGAS had launched the 10 ton/day DME demonstration plant project in 2004 at Incheon KOGAS LNG terminal. In the mid of 2008, KOGAS had finished the construction of this plant and has successively finished the demonstration plant operation. And since 2008, we have established the basic design of commercial plant which can produce 3,000 ton/day DME.

• Magazine of the Korea Concrete Institute
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• v.8 no.2
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• pp.129-138
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• 1996

Localization of concrete is a phenomenon such that the deformation of concrete is localized in finite region with softening behavior and it governs ultimate load of concrete. In this Paper, concrete under strain localization was modeled with localization region and non-localization region and lc~calization behavior was formulated based on averaging concept of heterogeneous material. By using the formulation, the localization phenomena of concrete under uniaxial loadings were well predicted. The analytical results show that size of localization region of concrete under uniaxial compression is three times of maximum aggregate size and the size effect of concrete is well predicted. The use of tension-softening curve obtained from direct tension test is suitable for well prediction of localization of concrete under uniaxial tension.

• Human Ecology Research
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• v.56 no.5
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• pp.447-460
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• 2018

This study determines whether certain cognitive biases (i.e., time preference, goal attainment expectation, unrealistic optimism, and overconfidence) and a specific negative mood-state (i.e., anxiety) influence credit misuse among college students. Data were collected from fourth-year college students (N=1,146), all of whom attended the same university in the southwest United States. Hierarchical multiple regression analyses and moderator analyses were employed to test the research hypotheses. Results showed that specific cognitive biases and anxiety were directly associated with credit misuse. We found that the longer goal attainment was delayed, the greater the students' unrealistic optimism concerning future income; in addition, the more overconfident they became with respect to financial knowledge, the more frequently they engaged in credit misuse. The study also showed that the higher a student's level of anxiety, the more often that students engaged in credit misuse. We also found that cognitive bias factors and anxiety interact to influence credit misuse. Anxiety interacted with time preference and unrealistic optimism such that present-oriented time preference was negatively related to credit misuse while optimism toward future income was positively related to credit misuse, but only for students with high anxiety levels. The findings of this study are discussed in the context of understanding and preventing irresponsible financial behavior among young adults.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.475-488
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• 1996

The opaque porcelain layer of porcelain-fused-to-metal(PFM) restoration is critical for the success of PFM restoration because it is the first layer placed over the treated alloy. But, the methods of opaquing technique have not been confirmed. Usually, the one layer method and two layer method have been used for the application of opaque porcelain. In the past, alloys with porcelain veneers which have been used successfully have contained various precious metals. Recent increase in the cost of precious metals stimulates considerable interest in nonprecious alloys. Although nickel-chromium alloys and nickel-chromium-beryllium alloys have been widely used, the use of cobalt-chromium alloys would be gradually increased with elimination of any potential risk of nickel-related allergic responses and/or beryllium-related toxic responses. This investigation examined one- and two-layer opaque porcelain applications to determine the effect on the bond strength of titanium added cobalt-chromium metal ceramic alloy. Bond strength of Ceramco II porcelain to titanium added cobalt-chromium alloy(2Dentitan) and gold-platinum-palladium alloy(Degudent H) were evaluated by direct shear bond strength test with Instron universal testing machine. The results were as follows; 1. When the mean shear bond strength of each experimental group were compared in $0.25cm^2$ unit area, the titanium added cobalt-chromium alloy/two layer method exhibited the greatest strength(79.7kg), followed by titanium added cobalt-chromium alloy/one layer method(76.2kg), gold-platinum-palladium alloy/two layer method(71.4kg), gold-platinum-palladium alloy/one layer method(64.2kg). 2. No significant differences in bond strength were recorded between the two opaquing techniques for gold-platinum-palladium alloy and titanium added cobalt-chromium alloy. 3. No significant differences in bond strength were recorded between the gold-platinum-palladium alloy and the titanium added cobalt-chromium alloy.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1682-1691
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• 2018

Natural ester is a suitable substitute for mineral oil and has been widely used in AC transformer in many countries. In order to further application of natural ester in direct current (DC) equipment, it is needed to investigate its long term insulation property under DC condition. In this paper, a thermal ageing experiment was conducted for both mineral oil-paper and natural ester-paper insulation. The DC breakdown and space charge characteristics of insulation paper impregnated with natural ester and mineral oil was compared. Results show that the resistivity of the paper immersed in natural ester and mineral oil both increase as the ageing goes on. While insulation paper impregnated with natural ester has higher resistivity and DC breakdown voltage than the paper impregnated with mineral oil. The DC breakdown voltage for the oil impregnated insulation paper being DC pre-stressing is higher than that without pre-stressing. The average DC breakdown field strength difference between the test with pre-stressing and without pre-stressing clearly shows that there is an apparent enhancement effect for the homo-charge injection on the DC breakdown.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.9
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• pp.189-196
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• 2020

Recently, GPU cloud computing technology applying GPU(Graphics Processing Unit) devices to virtual machines is widely used in the cloud environment. In a cloud environment, GPU devices assigned to virtual machines can perform operations faster than CPUs through massively parallel processing, which can provide many benefits when operating high-performance computing services in a variety of fields in a cloud environment. In a cloud environment, a GPU device can help improve the performance of a virtual machine, but the virtual machine scheduler, which is based on the CPU usage time of a virtual machine, does not take into account GPU device usage time, affecting the performance of other virtual machines. In this paper, we test and analyze the performance degradation of other virtual machines due to the virtual machine that performs GPGPU(General-Purpose computing on Graphics Processing Units) task in the direct path based GPU virtualization environment, which is often used when assigning GPUs to virtual machines in cloud environments. Then to solve this problem, we propose a GPGPU task management method for a virtual machine.

• Journal of Korean society of Dental Hygiene
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• v.15 no.2
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• pp.295-301
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• 2015

Objectives: The objective of this study was to investigate the effect of gender role identity on major choice, and preference and choice of job for applicants of dental hygiene department. Methods: The subjects were 202 high school girl students visiting K university in October, 2014 and in January, 2015 for the interview of early and regular admission to the university. The questionnaire consisted of 3 questions of general characteristics of the subjects, 40 questions of gender role identity, and 6 questions of career choice factors. Gender role identity included 15 questions of masculinity, 15 questions of feminity, and 10 questions of neutral gender using instrument of Kim by Likert scale. Cronbach's alpha of masculinity, feminity, and neutral gender was 0.810, 0.762, and 0.801 respectively. The data were analyzed using ${\chi}^2$-test with SPSS Win 12.0. Results: The effects of gender role identity on major choice and professionalism were as follows. In major choice motivation, psychological type, feminity type and masculinity types selected aptitude, professional sustainability and recommendation by acquaintance in order, but undifferentiated type selected aptitude, recommendation by acquaintance and professional sustainability in order. There was a statistically significant difference(p<0.05). In major choice information, psychological, feminity and undifferentiated types prefer indirect experience but masculinity type prefers direct experience. There was a statistically significant difference(p<0.05) In job selection, psychological, feminity and undifferentiated types want to do assistant works rather than oral health prevention and education. Masculinity type want to do oral health prevention and education rather than assistant work. There was a statistically significant difference(p<0.001). Conclusions: The gender role identity affected the factors related to choice of major and job in dental hygiene major applicants. It is necessary to provide the career choice program for the high school students by personality types and gender role identity types.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.115-123
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• 2018

In a long-span bridge, the cables are important elements that support the load of the bridge. Accordingly, the cable tension is a very important variable in evaluating the health and safety of the bridge. The most popular methods of estimating the cable tensions are the direct method, which directly measures the cable stresses using load cells, hydraulic jacking devices, etc., and the vibration method, which inverses the tensions using the cable shapes and the measured dynamic characteristics. Studies on the use of the electromagnetic (EM) sensor, which detects the magnetic field variations caused by the change in the stress of the steel in the cable, are increasing. In this study, the lift-off test, the EM sensor, and the vibration method (Vision-based System and Accelerometer) were used to measure cable tension, and their results were compared and analyzed.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.200-205
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• 2017

Objectives: The aim of this in vivo study was to assess the accuracy of 2 third-generation electronic apex locators (EALs), Propex II (Dentsply Maillefer) and Root ZX II (J. Morita), and radiographic technique for locating the major foramen (MF). Materials and Methods: Thirty-two premolars with single canals that required extraction were included. Following anesthesia, access, and initial canal preparation with size 10 and 15 K-flex files and SX and S1 rotary ProTaper files, the canals were irrigated with 2.5% sodium hypochlorite. The length of the root canal was verified 3 times for each tooth using the 2 apex locators and once using the radiographic technique. Teeth were extracted and the actual WL was determined using size 15 K-files under a ${\times}25$ magnification. The Biostat 4.0 program (AnalystSoft Inc.) was used for comparing the direct measurements with those obtained using radiographic technique and the apex locators. Pearson's correlation analysis and analysis of variance (ANOVA) were used for statistical analyses. Results: The measurements obtained using the visual method exhibited the strongest correlation with Root ZX II (r = 0.94), followed by Propex II (r = 0.90) and Ingle's technique (r = 0.81; p < 0.001). Descriptive statistics using ANOVA (Tukey's post hoc test) revealed significant differences between the radiographic measurements and both EALs measurements (p < 0.05). Conclusions: Both EALs presented similar accuracy that was higher than that of the radiographic measurements obtained with Ingle's technique. Our results suggest that the use of these EALs for MF location is more accurate than the use of radiographic measurements.