• Membrane Journal
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• v.19 no.1
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• pp.63-71
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• 2009

In this study, polysulfone which has excellent mechanical and thermal stability with low cost was used for preparing a non-conducting polymer matrix as a reinforced composite membrane for fuel cell application. The membranes were prepared by phase separation method. Polymer concentration and retention time were controlled to investigate the effects on the membrane morphology. The resaltant membranes showed all sponge-like structure independent of polymer concentration. The mechanical and thermal stability were improved with increasing polymer concentration in contrast to the membrane porosity. As a result, the membranes prepared with the retention time for 2 mins using 20 wt% of polymer solution was suitable for a fuel cell compositite membrane providing optimum properties such as approximately 80% of high porosity, 1.3 MPa of tensile strength, and less than 1% of thermal shrinkage both machine and transverse direction.

• Journal of Hydrogen and New Energy
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• v.19 no.6
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• pp.505-513
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• 2008

The two-step thermochemical cycle was examined on the $CeO_2$, YSZ, and $ZrO_2$-supported $NiFe_2O_4$ to investigate the effects of support material addition. The supported $NiFe_2O_4$ was prepared by the aerial oxidation method. Thermal reduction was conducted at 1573K and 1523K while water-splitting was carried out at 1073K. Supporting $NiFe_2O_4$ on $CeO_2$, YSZ and $ZrO_2$ alleviated the high-temperature sintering of iron-oxide. As a result, the supported $NiFe_2O_4$ exhibited greater reactivity and repeatability in the water-splitting cycle as compared to the unsupported $NiFe_2O_4$. Especially, $ZrO_2$-supported $NiFe_2O_4$ showed better sintering inhibition effect than other supporting materials, but hydrogen production amount was decreased as cycle repeated. In case of $CeO_2$-supported $NiFe_2O_4$, improvement of hydrogen production was found when the thermal reduction was conducted at 1573K. It was deduced that redox reaction of $CeO_2$ activated above 1573K.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.171-180
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• 2018

This study is to find the convergence effect of a spouse's support on postpartum depression and self-efficacy in primipara. The subjects were 37 primipara who gave birth to normal full term babies and their spouses. Each spouse supported their mother and baby from the period of postpartum 1st to 6th week after finishing three sessions of postpartum mother and baby care using teaching material. The data was collected in the 1st and 6th week postpartum and analyzed using SPSS 20.0. The prevalence of postpartum depression in the 1st and 6th week were 24.3% and 0% each. The spouses' support lowered mothers' postpartum depression and increased self-efficacy(p<.001). And, the factors affecting to mothers' postpartum depression were additional personnel for postpartum management, income and antepartum depression, and to their self-efficacy was hospital treatment during pregnancy(p<.05). The results could be used in developing intervention programs on lowering primiparas' postpartum depression and increasing their self-efficacy after further studies with wider range of subjects and setting control group.

• Journal of Korea Spatial Information System Society
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• v.8 no.2 s.17
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• pp.39-52
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• 2006

With the recent the use of spatio-temporal data mining which can extract various knowledge such as movement patterns of moving objects in history data of moving object gets increasing. However, the existing movement pattern extraction methods create lots of candidate movement patterns when the minimum support is low. Therefore, in this paper, we suggest the STMPE(Spatio-Temporal Movement Pattern Extraction) algorithm in order to efficiently extract movement patterns of moving objects from the large capacity of spatio-temporal data. The STMPE algorithm generalizes spatio-temporal and minimizes the use of memory. Because it produces and keeps short-term movement patterns, the frequency of database scan can be minimized. The STMPE algorithm shows more excellent performance than other movement pattern extraction algorithms with time information when the minimum support decreases, the number of moving objects increases, and the number of time division increases.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.422-430
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• 2021

It is very difficult to achieve denture support, stability and retention in single-maxillary complete denture patients with flabby tissue. A 57-year-old male patient was uncomfortable with the existing denture and wanted treatment. The reduction of flabby tissue was confirmed using the treatment denture. Non-pressure impression was obtained using an intraoral scanner during the definitive denture process. This is reported because the resulting denture improved when observing the retention, support and stability of the denture during occlusion.

• International Area Studies Review
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• v.14 no.1
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• pp.185-202
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• 2010

While it is often assumed that a country's trade balance will improve in the long-run if its currency is allowed to depreciate, this is not necessarily the case for specific industry. This paper is to examine the long-run relationships between trade balance and real exchange rate using bilateral data of SITC 10 Industry Classification for Korea vis-${\grave{a}}$-vis her trading partners Indonesia, India, China, Japan on a quarterly basis over the period of 1999Q1 to 2008Q4. I applied the recent panel cointegration technique to reduce the small sample problems and improving power performance of the relevant estimation and inference procedures. The results reveal evidence of the Marshall-Lerner Condition in Indonesia 2 industries, India 5 industries, Japanese 4 industries, Chinese 6 industries. Whole group's cointegration statistic of India, China, Japan was supported Marshall-Lerner Condition but Indonesia was rejected.

• Women's Health Nursing
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• v.2 no.1
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• pp.5-24
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• 1996

The Delivery Process can be viewed as one of the developmental crisis that forces the majority of women. During the labor and delivery process the women may face a variety of problems and pain with all its subjectivity. This developmental crisis may lead a pregnant women to have a negative experience in delivery. For nurses, to help to pregnant women check with the crisis and perceived support and to positive experience. This study intended to analyze the pregnant women's delivery experience according to supporter during labor. The subjects for this study were 45 pregnant women who had normal delivery without complications, within 37 to 42 weeks of pregnancy. Data Collection was done from April 24th to May 20th 1995 by two instruments, a support measurement scale and a delivery experience measurement scale which were consisted it 18-items scale developed by researcher. The data was analyzed by SPPS program using descriptive statistic Kruskal-Wallis one way analysis and Spearman Correlation Coefficient. The result of this study are as follows. 1. Support distribution by support contents is shown is order of holding the hands (97.8%), help to urination(86.7%), bed arrangement(57.8%), massaging the arms and legs(55.6%), changes in posture(44.4%), teaching how to produce power(44.4%), while emotional support is disclosed in order of sympathy(97.8%), encouragement(82.2%), hearing the needs(60.0%), However, information support was as low as less than 33.3%. 2. The extent of delivery experience a Pregnant woman perceives is revealed in order of a sense of comfortableness(44%), satisfaction(43.2%), reduction of fear(43.2%), familiarity (42.8%), self-confidence (42.5%), decrease of laborpain(39.9%). 3. The extent of delivery support a pregnant woman perceives reveals that physical support($x^2$=22.4452, P=.000) and information support($x^2$=7.5187, P=.0233) Show a significant difference among the mothers group, the mothers-in-law group, the husbands group, but to significant difference was found in emotional support among them. 4. The extent of delivery experience a pregnant woman perceives represents a significant difference in order of the mothers group, the mothers in-law group, and the husbands group($x^2$=13.4255, P=.0012). 5. A positive correlation was manifested between the extent of support and delivery experience a pregnant woman perceives(r=.8643, P=.000). This information can be utilized as data to further the understanding delivery experience according to supporter. In Consequence, it is recommended that the range of family support limited to husband should be expended including mother and mother-in-law.

• Membrane Journal
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• v.19 no.4
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• pp.310-316
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• 2009

The degradation characteristics of cross-linked lactide/hyaluronic acid (LA/HA) membranes were investigated for purpose of applying to tissue engineering. The lactide/hyaluronic acid cross-linked with 1,3-butadiene diepoxide (BD) and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) was degradated in deionized water in water bath at $37^{\circ}C$. As the LA/HA mole ratio or crosslinking agent concentration decreased, the degradation rate of the crosslinked membranes increased. In order to investigate the structure change of the membrane in the degradation process, the control sample and 3, 6, 9 days-degradated samples were analysed by the nuclear magnetic resonance spectroscopy. In case of the membranes crosslinked with EDC, the HA-EDC bonding structure was degradated slowly whereas the HA-LA bonding structure was degradated quickly and dissappeared completely after 6 days. In case of the membranes crosslinked with BD, all the crosslinked bonding structure degradated slowly. The HA-BD bonding structure maintained its original state about 89, 83% in case of 3, 6 days-degardated samples respectively whereas the HA-LA bonding structure maintained its original state about 83, 65%. The scanning electron microscopy of the degradated membranes showed that the pore density in the surface, and the structure in the surface and cross section, of the before and after-degradation membranes did not change greatly, so the membranes was shown to be applied to materials for tissue engineering.

• Analyses & Alternatives
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• v.7 no.3
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• pp.181-230
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• 2023

Evaluating the empirical validity of Modern Monetary Theory, this study implements panel cointegration analysis on annual panel data (2000-2022) of OECD countries. Specifically, the sample countries are divided into groups based on the presence of their own sovereign currencies, and for each group, the long-run equilibrium relation (cointegration) between the ratio of public debt or fiscal deficit and government bond rates is tested and estimated. Main findings are as follows: applying the pooled mean-group estimation for panel cointegration, it is found that both the ratios of public debt and fiscal deficit have significantly positive long-run correlation with government bond rates in countries without sovereign currency such as the Euro-zone or fixed exchange rate regime countries. However, in countries with sovereign currency such as non-Euro-zone or floating exchange rate regime countries, the long-run correlation is either negative or not statistically significant. Particularly, in countries without sovereign currency, the ratio of public debt has significantly positive correlation with the real government bond rates in the short run as well as the long run. These results are consistent with the prediction of Modern Monetary Theory, thus providing a supporting evidence for the empirical validity of the theory.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.1-8
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• 2005

An experimental investigation of a microthruster that uses hydrogen peroxide as a monopropellant is described. The study comprises of preparation method of silver as a catalyst and performance evaluation of a mesoscale reactor. Reduction of silver in $H_2\;at\;500^{\circ}C$ resulted in the best reactivity of all the treatment method tested. A mesoscale reactor was built to find the optimum configuration for full decomposition of propellant. The catalyst bed was made of a glass wafer substrate sputtered with silver and had a length of 20 mm. We measured the conversion rate with varying feed rate of $H_2O_2$ and preheating temperature. With the feed rate of $H_2O_2$, the space time within the reactor varies as well. For the bed length of 20 mm, space time more than 480 s was required for full conversion.