• Composites Research
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• v.30 no.2
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• pp.84-93
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• 2017

This study investigates thermal and mechanical characterization of environmental barrier coating on the $SiC_f-SiC$ composites. The spherical environmental barrier coating (EBC) powders are prepared using a spray drying process for flowing easily during coating process. The powders consisting of mullite and 12 wt% of Ytterbium silicate are air plasma sprayed on the Si bondcoat on the LSI SiC fiber reinforced SiC composite substrate for protecting the composites from oxidation and water vapor reaction. We vary the process parameter of spray distance during air plasma spray of powders, 100, 120 and 140 mm. After that, we performed the thermal durability tests by thermal annealing test at $1100^{\circ}C$ for 100hr and thermal shock test from $1200^{\circ}C$ for 3000 cycles. As a result, the interface delamination of EBC never occur during thermal durability tests while stable cracks are prominent on the coating layer. The crack density and crack length depend on the spray distance during coating. The post indentation test indicates thermal tests influence on the indentation load-displacement mechanical behavior.

• Journal of Families and Better Life
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• v.32 no.6
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• pp.125-138
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• 2014

The purpose of this study is to examine the effects a music group therapy program has on cognitive function and life satisfaction. We targeted the elderly who are receiving service at a daycare center. This study monitored seventeen elderly subjects who were available for language communication, walking, and defecation function even if the subject had a slight mind-body function disorder based on using the service of the daycare facilities. The subjects visited each of the welfare centers one week prior to the Korean classical music group therapy program. We conducted a pre-test of MMSE-K(Mini-Mental State Examination, Korean version) modified by Park and Gwon(1989). We also supplemented the MMSE developed by Folstein(1975) and LSI-A(Life Satisfaction Index) for the elderly developed by Neugarten, Havighurst and Tobin(1961). We conducted the Korean classical music group therapy program for 15 sessions at 50 minutes each for 1~2 times a week from July 9 to September 13, 2013 at the daycare center for OO senior welfare center. The welfare center belongs to the experimental group, excluding the OO general welfare center, which is the control group. Finally, we carried out the post-test of the MMSE-K and LSI-A in the same manner as the pre-test. We carried out the post-test on July 17, 2013, 4 days after concluding the Korean classical music group therapy program. A t-test was used in order to analyze the differences in cognitive function and life satisfaction according to each group. We used SPSS/WIN 18.0 program. This study has significance by proving that the use of Korean classical music is conducive in the improvement of cognitive function and life satisfaction of the elderly at the daycare facilities. Also, we presented the actual contents of the study to the clinical field.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.61-64
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• 2008

A 24-year-old female with primary amenorrhea was referred for a chromosome study. The karyotype of the patient was 46,X,der(X) under initial GTG-banding analysis. Fluorescence in situ hybridization (FISH) analysis with an LSI Kallmann (KAL) region probe [probes for Xp22.3(KAL) and CEP(X) for control] was carried out. The abnormal chromosome was KAL- and CEP(X)${\times}2$. In addition, interphase FISH analysis revealed the patient to be mosaic for two different cell lines: 90% of cells had three signals and 10% of the cells had only one signal for CEP(X). Based on these results, the karyotype of the patient was 45,X/46,X,psu idic(X)(p22.1), which is partial trisomy for Xqter${\rightarrow}$Xp22.1 and partial monosomy for Xpter${\rightarrow}$Xp22.1. This karyotype was considered a variant of Turner syndrome. In summary, Idic(X) and low-level mosaicism was successfully characterized by FISH analysis with a CEP(X) probe.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.927-933
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• 2016

In a solid propulsion system, the rocket nozzle is exposed to high temperature combustion gas. Hence, choosing an appropriate material that could demonstrate adequate performance at high temperature is important. As advanced materials, carbon/silicon carbide composites (C/SiC) have been studied with the aim of using them for the rocket nozzle throat. However, when compared with typical structural materials, C/SiC composites are relatively weak in terms of both strength and toughness, owing to their quasi-brittle behavior and oxidation at high temperatures. Therefore, it is important to evaluate the thermal and mechanical properties of this material before using it in this application. This study presents an experimental method to investigate the fracture behavior of C/SiC composite material manufactured using liquid silicon infiltration (LSI) method at elevated temperatures. In particular, the effects of major parameters, such as temperature, loading, oxidation conditions, and fiber direction on strength and fracture characteristics were investigated. Fractography analysis of the fractured specimens was performed using an SEM.

• 재활복지
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• v.21 no.4
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• pp.101-118
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• 2017

This study was conducted to investigate the effect of virtual reality game on old stroke patient's depression, relationship and life satisfaction. The subjects of this study were 40 stroke patients of over 65 years old and each 20 patients were randomly assigned in two groups. The study was conducted for 12 weeks. Nintendo Wii Sports Resort program was applied to the virtual reality game for the experimental group. In order to investigate psychological social factor (depression, relationship) and life satisfaction of the objects, BDI, RCS, LSI-Z were checked three times. The results are as followings. First, the psychological social change (depression, relationship) after the training program showed that depression is significantly decreased (p<.001) along with the intervention period in both 2 groups. Second, change of life satisfaction after the training program showed that significant statistical improvement were found both in control group(p<.05), and experimental group(p<.001). Third, depression, relationship showed the significant statistically correlation with life satisfaction(p<.05). We can conclude from the above that virtual reality games which were played by 2 persons had the significant effect on old stroke patient's psychological social factor(depression, relationship) and life satisfaction.

• Transactions on Electrical and Electronic Materials
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• v.2 no.1
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• pp.1-6
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• 2001

$C_{x}F_{y}$ polymer film was deposited in rf and dc Fluorinert vapor ($C_{7}F_{16}$) plasmas. In the plasma phase, the spatial distribution of optical emission spectra and the temporal concentration of decomposed species were monitored, and kinetics of the $C_{7}F_{16}$ decomposition process was discussed. Deposition of $C_{x}F_{y}$ film has been tried on substrates of stainless steel, glass, molybdenum and silicon wafers at room temperature in the vapor pressures of 40 and 100 Pa. The films deposited in the rf plasma showed excellent electrical properties as an insulator for multi-layered interconnection of deep-submicron LSI, i.e. the low dielectric constant ∼2.0, the dielectric strength ∼2 MV/cm and the high deposition rate ∼100nm/min at 100W input power.

• Korean Journal of Adult Nursing
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• v.28 no.3
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• pp.334-342
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• 2016

Purpose: This study was conducted to identify factors that influence on self-determination for withdrawal of life-sustaining treatment in the community dwelling elderly. Methods: This study used a descriptive correlational design. A convenience sample of 201 elderly were recruited from a welfare center located in Seoul, Korea. Data collection was done from September 1 to September 18, 2015. Four survey questionnaires were used: Multidimensional Scale of Perceived Social Support (MSPSS), Life Satisfaction Index-Z (LSI-Z), Attitude on Do Not Resuscitate (DNR), and Self-determination for Withdrawing Life-sustaining Treatment. Data analysis was done by t-test, ANOVA, Pearson's correlation, and hierrarchical multiple regression. Results: Hierarchial multiple regression showed that the factors predicting the level of self-determination for withdrawing life-sustaining treatment were educational level, DNR experience in family, life satisfaction, and DNR attitude. These factors explained 44% of the self-determination for withdrawing life-sustaining treatment in community dwelling elderly. Conclusion: The results of this study suggest developing educational programs aiming at changing elderly's DNR attitude positive ways so that they can enhance self-determination for withdrawing life-sustaining treatment. Further study is needed with more elderly population in extended areas.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.1
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• pp.6-10
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• 2009

Ring chromosome occurs when both telomeres of a chromosome are lost and the remaining portion of the chromosome circularizes to re-establish chromosome stability. This abnormal structure shows mitotic instability unlike the normal chromosomes, causing problems during mitosis. Here, we report one case of "chromosome 4 ring syndrome" on a 6-month-old male patient with growth retardation. Ring chromosome, monosomy, dicentric chromosome were shown by conventional chromosome analysis using peripheral blood. Peripheral blood was used and incubated for 72 hours for chromosome analysis. 3 probes (LSI WHS SpectrumOrange/CEP 4 SpectrumGreen, 4p subtelomere probe, 4q subtelomere probe) were used to detect the origin and breakpoint of ring chromosome 4 by FISH (fluorescense in situ hybridization) technique.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.9
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• pp.1357-1363
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• 1997

Currently it is increasing to use th bonded dissimilar materials in the various field of advanced engineering such as the highly rigid and lighter vehicle, plastic molding LSI package and metal/ceramic bonded joint. In spite of such a wide application of the bonded dissimilar materials, the evaluation method of the bonding strength has not been established yet. Therefore in this paper we analyze the interface crack problem by introducing fracture mechanics parameters as the basic research about estimating of the strength of adhesive joints. The variation of stress intensity factor according to the elastic modulus of adherend and thickness of bonded layer are investigated. Numerical results are based on the results of boundary element analysis of four different type butt joints subjected to uniaxial tension loading.

• Tribology and Lubricants
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• v.24 no.4
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• pp.163-169
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• 2008

Tribological properties of ceramic brake discs were investigated using a commercial friction material. The discs were manufactured by liquid silicon infiltration (LSI) into a C-C preform. The disc surface was modified by two different methods, producing sliding surfaces with chopped carbon fibers and carbon felt. In addition, the composition of the surface was also changed. Friction characteristics of the discs were examined using a 1/5 scale dynamometer. Results showed that the type and composition of the disc surface significantly affected the level of braking effectiveness and high temperature brake performance. The discs with felt surfaces showed higher friction levels than those with chopped fiber surfaces and SiC tended to increase the friction level while C lowered the friction coefficient. The ceramic disc was more sensitive to the deceleration rate than gray iron, showing high speed sensitivity.