• Korean Journal of Environment and Ecology
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• v.29 no.1
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• pp.29-45
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• 2015

Water chemistry and fish community, based on fish compositions and ecological characteristics(trophic/tolerance guilds and condition factor), were compared in Gucheon Reservoir($G_cR$) and Yeoncho Reservoir($Y_cR$). Chemical parameters of water quality such as BOD, COD, nutrient(N, P) and suspended solids indicated that water quality was better in the $Y_cR$ than $G_cR$, and the temporal variability in seasonal and interannual patterns were greater in the $Y_cR$. The greater variability was mainly attributed to intense dilutions of reservoir water by Asian monsoon rain during July-August. Fish guild analysis indicated that species diversity was higher in the $G_cR$ than the $Y_cR$, and that the proportion of tolerant and omnivore species were greater in the $Y_cR$. Regression analysis of body weight-total length showed that the regression coefficient(b value) was lower in the $G_cR$(2.15 ~ 2.40) than the $Y_cR$(2.59 ~ 3.14). Condition factor(K) of fish against the total length showed negative slope of Zacco temminckii, Carassius auratus, Pseudorasbora parva and Rhinogobius brunneus population in the $G_cR$, and a positive slope of Carassius auratus and Rhinogobius brunneus population in $Y_cR$. Overall, our data suggest that the growth of the fish populations, based on the length-weight relations and condition factor, reflected the trophic regime of nutrients and organic matter.

• The Korean Journal of Emergency Medical Services
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• v.12 no.2
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• pp.85-97
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• 2008

Purpose : This study was cross-sectional study to examine the influence of job stress in 119 briefing room workers and aimed to provide the important basic materials for improving working conditions of 119 briefing room workers and further studies. Methods : This study selected 271 workers of 119 briefing room at National Emergency Management Agency and fire stations, metropolitan cities and provinces to examine the influences of job stress of 119 briefing room workers on depression. and as a result of analysis, the following conclusions. Results : 1) The whole average of job stress measure was 3.30. The highest area was interpersonal relationship factor as 3.41, 'job characteristic factor' as 3.36 and communication factor' as 3.01. 2) Total score of whole items of depression was 11.88 and showed slight depression level. 3) There was static correlation between job stress and depression(r=44.7, p= .000). There were statistically significant static correlations between job stress factor and depression(r= .388, p= .000), interpersonal relationship factor and depression(r= .471, p= .000), and communication factor and depression(r= .386, p= .000). 4) There was statistically significant difference in the influence of job stress on depression(B=8.575, p< .001). Influence of job stress on depression was explained as $R^2=.200$. When job stress factors as independent variables were input, interpersonal relationship factor(B=5.062, p< .001) had the greatest influence on depression and there was no statistically significant difference in communication factor(B=2.490, p< .05). Conclusions : It is considered that development of the various programs including program for getting rid of job stress of 119 briefing room workers and counseling program will be needed. particularly, factors such as human relationships and communication in the area of job stress must be the first priority.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2551-2557
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• 2012

This study analyses the relative importance of R&D business model of the small and medium manufacturing firm. We also compare samples by classifying by its properties, technology and market circumstance. The most important factor of the R&D business model is marketing factor and infrastructure factor is relatively less important. Also the relative importance of the R&D business model is different according to firm's properties and technology. So when government establishes the R&D policy, he focuses on designing the R&D business model.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.977-982
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• 2011

This study was conducted to redetermine the rainfall erosion factor (R factor) in USLE for the estimation of soil loss at Korea. The redetermined R factor may be applied more precisely to interpret the changes of regional/yearly/seasonal patterns, including the amount of rainfall and the kinetic energy of rainfall, in Korea. This study calculated the R factors based on 60-minute precipitation data from 60 sites covering the whole country for 30 years from 1981 to 2010. As a result, the annual mean rainfall was $4,147MJ\;mm\;ha^{-1}\;yr^{-1}\;hr^{-1}$ in Korea. Coastal regions of Jeonnam and Gyeongnam, northwest regions of Gyeonggi, and Seoul had the greater values of R factor compared to other regions. The annual mean R factors for every decade were 3,988, 4,085, and $4,370MJ\;mm\;ha^{-1}\;yr^{-1}\;hr^{-1}$ in 1981~1990, 1991~2000, and 2001~2010, respectively. Generally, the R factors had an increasing tendency over and over pest decades. The ratios of summer R factor to total annual mean R factor were 69.8% (1981~1990), 73.7% (1991~2000), and 74.2% (2001~2010). We found that the absolute values and the relative ratios of summer rainfall are gradually increased.

• Korean Journal of Psychosomatic Medicine
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• v.11 no.2
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• pp.137-148
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• 2003

Introduction: This research was performed to contract the attitude of dietary restriction and the psychological problems such as depressive mood and perceived stress and to investigate the relationship of these and obesity in women who visited the obesity clinic. Methods: During May 2001, sociodemographic variables, physical characteristics, Three Factor Eating Questionnaire(TFEQ), Symptom Check List-90-R(SCL-90-R) and Perceived Stress Scale were assessed from 150 female who visited the obesity clinics which were located at downtown, Seoul and the Hospital of Ajou University, Medical College. Hamilton depression rating scale(HDRS) was estimated by author. And then 116 female cases who filled up the questionnaire faithfully were included. Results: Obese group more than Body Mass Index(BMI) $25.0kg/m^2$ was 50% of the total subjects. BMI was increased as the age goes up(p<0.001). The frequency of unmarried cases in the under normal weight group was high rate of 48.8% while it in the obese group was 13.8%(p<0.001). There was no significant difference in the rate of smoking and alcohol drinking among subjects by BMI. There was no significant difference of TFEQ among subjects by BMI and the percent of body fat. Factor 2(r=0.27, p<0.01) and Factor 3(r=0.24, p<0.01) were significantly correlated with Global Severity Index(GSI). Only the paranoia scale among each estimated mean value of T scores of SCL-90-R by BMI was the significant difference between the overweight group and the obese group(p<0.05). T scores of scales of SCL-90-R were less than 50, but T scores of the under normal weight group and the obese group were higher than overweight group. GSI was significantly correlated with HDRS(r=0.75, p<0.01) and Perceived Stress Scale(r=0.32, p<0.01). Depressive mood in the obese group was significantly higher than non-obese group that HDRS was compared to two groups by the percent of body fat(p<0.05). Perceived Stress Scale was no significant correlation with BMI and the percent of body fat. All of the subject were in trouble of high stress. Stress affected dietary restriction owing that perceived stress had a relation with Factor 2(r=0.29, p<0.01) and Factor 3(r=0.37, p<0.01). Also, it affected psychological characteristics owing that perceived stress had a relation with the depression scale, GSI and HDRS(r=0.33, r=0.32, r=0.34, p<0.01). Conclusion: Obese women have more psychological difficulties including depression and high perceived stress, which closely related with the attitude of dietary restriction. Psychiatric intervention and aggressive assessment of psychological problems will be needed to the people who visit the obesity clinic in the future.

• Structural Engineering and Mechanics
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• v.27 no.2
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• pp.117-134
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• 2007

The force (load) reduction factor, R, which is one of the most important parameters in earthquake load calculation, is independent of the dimensions of the structure but is defined on the basis of the load bearing system of the structure as defined in earthquake codes. Significant damages and failures were experienced on prefabricated reinforced concrete structures during the last three major earthquakes in Turkey (Adana 1998, Kocaeli 1999, Duzce 1999) and the experts are still discussing the main reasons of those failures. Most of them agreed that they resulted mainly from the earthquake force reduction factor, R that is incorrectly selected during design processes, in addition to all other detailing errors. Thus this wide spread damages caused by the earthquake to prefabricated structures aroused suspicion about the correctness of the R coefficient recommended in the current Turkish Earthquake Codes (TEC - 98). In this study, an attempt was made for an approximate determination of R coefficient for widely utilized prefabricated structure types (single-floor single-span) with variable dimensions. According to the selecting variable dimensions, 140 sample frames were computed using pushover analysis. The force reduction factor R was calculated by load-displacement curves obtained pushover analysis for each frame. Then, formulated artificial neural network method was trained by using 107 of the 140 sample frames. For the training various algorithms were used. The method was applied and used for the prediction of the R rest 33 frames with about 92% accuracy. The paper also aims at proposing the authorities to change the R coefficient values predicted in TEC - 98 for prefabricated concrete structures.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.8
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• pp.675-680
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• 2000

In this study the temperature coefficient of resonant frequency(TC $F_{r}$) dielectric and piezoelectric properties of Pb[(S $b_{1}$2//N $b_{1}$2/)$_{0.065}$)-(Z $r_{x}$, $Ti_{1-x}$ )$_{0.90}$] $O_3$ceramics were investigated with Zr/Ti ratio. The compositions near the morphotropic phase boundary (MPB) appeared when Zr/Ti ratio was 49.5/50.5 The dielectric constant and electromechanical coupling factor( $k_{p}$) also showed the highest values of 1,257, 0.653 respectively when the Zr/Ti ratio was 49.5/50.5 Moreover the mechanical quality factor( $Q_{m}$) showed th lowest value of 713 when the Zr/Ti ratio. The temperature coefficient of resonant frequency(TC $F_{r}$) abruptly change at the morphotropic phase boundary(MPB) which existed between the rhombohedral phase with highly negative TC $F_{r}$ of -106ppm/$^{\circ}C$ and the tetragonal phase with highly positive TC $F_{r}$ of +64pp $m^{\circ}C$ as Zr/Ti ratio varied from 50/50 to 49.5/50.5.50.5..50.5.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.391-395
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• 2000

In this study, the temperature coefficient of resonant frequency(TC $F_{r}$), dielectric and piezoelectric properties of Pb[(S $b_{1}$2/N $b_{1}$2/)$_{0.0035}$-(M $n_{1}$3/N $b_{2}$3/)$_{0.0065}$-(Z $r_{x}$ $Ti_{1-x}$ )$_{0.90}$] $O_3$ceramics is investigated with Zr/Ti ratio. The dielectric constant and electromechanical coupling factor( $k_{p}$) showed the highest values of 1257, 0.562 respectively when the Zr/Ti ratio is 49.5/50.5. The mechanical quality factor( $Q_{m}$) is the lowest value of 713 when the Zr/Ti ratio is 49.5/50.5, and increased with the decrease of the Zr/Ti ratio. The temperature coefficient of resonant frequency(TC $F_{r}$) change abruptly at the morphotropic phase boundary(MPB), which is between the rhombohedral phase with highly negative TC $F_{r}$ of -106ppm/$^{\circ}C$ and the tetragonal phase with highly positive TC $F_{r}$ of +64pp $m^{\circ}C$ as Zr/Ti ratio changes from 50/50 to 49.5/50.5.50.5..5.50.5.5.

• Bulletin of the Korean Mathematical Society
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• v.59 no.3
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• pp.529-545
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• 2022

This article concerns a ring property that arises from combining one-sided duo factor rings and centers. A ring R is called right CIFD if R/I is right duo by some proper ideal I of R such that I is contained in the center of R. We first see that this property is seated between right duo and right π-duo, and not left-right symmetric. We prove, for a right CIFD ring R, that W(R) coincides with the set of all nilpotent elements of R; that R/P is a right duo domain for every minimal prime ideal P of R; that R/W(R) is strongly right bounded; and that every prime ideal of R is maximal if and only if R/W(R) is strongly regular, where W(R) is the Wedderburn radical of R. It is also proved that a ring R is commutative if and only if D₃(R) is right CIFD, where D₃(R) is the ring of 3 by 3 upper triangular matrices over R whose diagonals are equal. Furthermore, we show that the right CIFD property does not pass to polynomial rings, and that the polynomial ring over a ring R is right CIFD if and only if R/I is commutative by a proper ideal I of R contained in the center of R.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.197-206
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• 2021

microRNA-361-3p (miR-361-3p) is involved in the carcinogenesis of oral cancer and pancreatic catheter adenocarcinoma, and has anti-carcinogenic effects on non-small cell lung cancer (NSCLC). However, its effect on multiple myeloma (MM) is less reported. Here, we found that upregulating the expression of miR-361-3p inhibited MM cell viability and promoted MM apoptosis. We measured expressions of tumor necrosis factor receptor-associated factor 6 (TRAF6) and miR-361-3p in MM cells and detected the viability, colony formation rate, and apoptosis of MM cells. In addition, we measured expressions of apoptosis-related genes Bcl-2, Bax, and Cleaved caspase-3 (C caspase-3). The binding site between miR-361-3p and TRAF6 was predicted by TargetScan. Our results showed that miR-361-3p was low expressed in the plasma of MM patients and cell lines, while its overexpression inhibited viability and colony formation of MM cells and increased the cell apoptosis. Furthermore, TRAF6, which was predicted to be a target gene of miR-361-3p, was high-expressed in the plasma of patients and cell lines with MM. Rescue experiments demonstrated that the effect of TRAF6 on MM cells was opposite to that of miR-361-3p. Upregulation of miR-361-3p induced apoptosis and inhibited the proliferation of MM cells through targeting TRAF6, suggesting that miR-361-3p might be a potential target for MM therapy.