• Bulletin of the Korean Mathematical Society
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• v.52 no.2
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• pp.367-376
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• 2015

In this paper, we classified finite p-groups G such that $$C_G(x)/<x>$$ is cyclic for all non-central elements $x{\in}G$. This solved a problem proposed By Y. Berkovoch.

• Bulletin of the Korean Mathematical Society
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• v.42 no.2
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• pp.245-256
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• 2005

We consider the second-order nonlinear difference equation (1) $$\Delta(a_nh(x_{n+1}){\Delta}x_n)+p_{n+1}f(x_{n+1})=0,\;n{\geq}n_0$$ where ${a_n},\;{p_n}$ are sequences of integers with $a_n\;>\;0,\;\{P_n\}$ is a real sequence without any restriction on its sign. hand fare real-valued functions. We obtain some necessary conditions for (1) existing nonoscillatory solutions and sufficient conditions for (1) being oscillatory.

• Research in Community and Public Health Nursing
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• v.25 no.3
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• pp.198-206
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• 2014

Purpose: The purposes of this study were to identify the prevalence and influencing factors of fecal incontinence, and to analyze the association between fecal incontinence and depression. Methods: The subjects of this study were 233 women living in rural areas, and data were collected using questionnaires from February 24 to May 30, 2012. Fecal incontinence was measured with the Continence Grading Score, and depression with the Geriatric Depression Scale. Collected data were analyzed using SPSS through $x^2$-test, Fisher's exact test, t-test and ANOVA. Results: Of the subjects, 16.7% had fecal incontinence. The prevalence of fecal incontinence was higher in older women ($x^2=23.55$, p<.001), those with vaginal delivery ($x^2=4.81$, p=.049), those with parity of 4 or more ($x^2=13.47$, p=.003), and those with urinary incontinence ($x^2=26.36$, p<.001). The level of depression was significantly higher in older women (F=19.27, p<.001), those with low academic qualification (F=18.17, p<.001), those with urinary incontinence (F=4.15, p=.043), and those with fecal incontinence (F=14.90, p<.001). Conclusion: These results suggest that there should be supports by public health care for fecal incontinence prevention and care programs in order to promote the physical and emotional health of rural women.

• Journal of Korean Academy of Nursing
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• v.41 no.1
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• pp.92-100
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• 2011

Purpose: Mortality Provability Model (MPM) II is a model for predicting mortality probability of patients admitted to ICU. This study was done to test the validity of MPM II for critically ill neurological patients and to determine applicability of MPM II in predicting mortality of neurological ICU patients. Methods: Data were collected from medical records of 187 neurological patients over 18 yr of age who were admitted to the ICU of C University Hospital during the period from January 2008 to May 2009. Collected data were analyzed through $X^2$ test, t-test, Mann-Whiteny test, goodness of fit test, and ROC curve. Results: As to mortality according to patients' general and clinically related characteristics, mortality was statistically significantly different for ICU stay, hospital stay, APACHE III score, APACHE predicted death rate, GCS, endotracheal intubation, and central venous catheter. Results of Hosmer-Lemeshow goodness-of-fit test were MPM $II_0$ ($X^2$=0.02, p=.989), MPM $II_24$ ($X^2$=0.99 p=.805), MPM $II_48$ ($X^2$=0.91, p=.822), and MPM $II_72$ ($X^2$=1.57, p=.457), and results of the discrimination test using the ROC curve were MPM $II_0$, .726 (p<.001), MPM $II_24$, .764 (p<.001), MPM $II_48$, .762 (p<.001), and MPM $II_72$, .809 (p<.001). Conclusion: MPM II was found to be a valid mortality prediction model for neurological ICU patients.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.111-121
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• 2007

The experimental design and response surface methodologies haven been applied to the investigation of the chemical coagulation of livestock wastewater. The chemical coagulation reactions were mathematically described as a function of parameters raping mixing (rpm) of chemical coagulation ($X_1$), slow mixing (rpm) of chemical coagulation ($X_2$), $FeCl_3 $ concentration (mg/L) ($X_3$) and pH ($X_4$) being modeled by use of the central composite design. Empirical models were developed to describe relationship between the experimental variables and response. Statistical analysis indicates that three factors ($X_1$: raping mixing (rpm), $X_2$: slow mixing (rpm), $X_3$: $FeCl_3 $ concentration (mg/L) on the linear term (main effect), slow mixing (rpm) (${X_2}^2$) on the non-linear term (quadratic), and two factors ($X_1-X_3$, $X_2-X_3$) on the non-linear term (cross-product) had significant effects, respectively. The estimated ridge of maximum responses and optimal conditions for CODcr using canonical analysis was 87.44% ($X_1$: 229 rpm, $X_2$: 51 rpm, $X_3$: 877 mg/L, $X_4$: 4.3). To confirm this optimum condition, three additional experiments were performed and the mean CODcr removal (%) and concentration (mg/L) with a standard deviation of $87{\pm}1.2%$ ($576{\pm}34ppm$) were obtained.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.297-300
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• 2012

Lead-free (1-x)$(Na_{0.5}K_{0.5})NbO_3-xLiNbO_3$, i.e., NKN-LNx (x=0.0, 0.1, 0.2, 0.3, 0.4 mol) was prepared using the conventional solid state reaction method. The effects of LN mixing on the ferroelectric properties of NKN-LNx ceramics were studied using a dielectric constant and P-E (Polarization-electric field) measurements. Ferroelectricity was observed in the composition for x approximately varying between 0.0 and 0.4. Minimum remanent polarization $2P_r=5C/cm^2$ was achieved in the composition for x = 0.2. The ferroelectric phase transition temperature $T_C$ increased with increasing LN content. The ferroelectric phase transition of NKN-LNx ($x{\geq}0.1$) is a second-order phase transition, and that of NKN-LNx ($x{\leq}0.2$) is a first-order phase transition. These results indicate that the ferroelectric phase transition temperature of NKN-LNx change from that of second-order to weak first-order phase transition according to the LN content.

• Journal of Magnetics
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• v.8 no.4
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• pp.129-132
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• 2003

We investigated the crystallographic and magnetic properties of double perovskite $Sr_2Fe_{l-x}Cr_{x}MoO_{6}$ (x=0.0, 0.01, 0.03, 0.05, and 0.10). Mossbauer spectra of the $Sr_2Fe_{l-x}Cr_{x}MoO_{6}$ have been taken at various temperatures ranging from 15 to 415 K. As the temperature increased towards $T_{c}$(415 K), the Mossbauer spectra showed line broadening and 1, 6 and 3, 4 line-width differences because of anisotropic hyperfine field fluctuation. The Mossbauer spectra indicated that an anisotropic field fluctuation of +H ( $P_{+}$=0.85) was greater than that of -H ($P_{-}$=0.15). We also calculated the field fluctuation frequency factors and the temperature dependence of anisotropy energies from its relaxation rate. We interpreted the effect of Cr ($t^3$$_{2g}$) doping as a decrease in the anisotropy energy.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.197-204
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• 1992

This study was divided into experiment 1(191 g egg-albumen plus 150g sucrose) and experiment 2(222g egg-albumen plus 150g sucrose)which were subdivided into groups treated with 0, 8.71, 17.43 and 26.149 egg yolk. These experiments were incubated in a shaking water bath($50^{\circ}C$ ) with a speed of 92(turnaround) per minute (or a period of times. The pH and specific gravity were measured after 2, 4, 6, 8, 10 and 12 hours incubation. The results obtained were as follows ： 1. The pH and specific gravity were steadily increased by shaking time, but decreased by the amount of egg yolk. 2. In the groups treated with egg-albumen, egg yolk, and sucrose of experiments 1 and 2, PH was increased by shaking time and reached highest value at 10 hours shaking time. However, after 12 hours shaking time pH slightly decreased though not significantly. 3. In the experiment 1 and 2, specific gravity had a higher correlation with pH and the regression equation between specific gravity and pH (X) were Y＝0.1081x+0.272(r＝0.899n) and Y＝0.083X＋0.476(r＝0.825$^{* *}$), respectively.y.

• Communications of the Korean Mathematical Society
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• v.31 no.3
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• pp.625-635
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• 2016

In this paper, we study certain doubly-warped products which admit gradient Ricci solitons with harmonic Weyl curvature and non-constant soliton function. The metric is of the form $g=dx^2_1+p(x_1)^2dx^2_2+h(x_1)^2\;{\tilde{g}}$ on ${\mathbb{R}}^2{\times}N$, where $x_1$, $x_2$ are the local coordinates on ${\mathbb{R}}^2$ and ${\tilde{g}}$ is an Einstein metric on the manifold N. We obtained a full description of all the possible local gradient Ricci solitons.

• KSBB Journal
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• v.8 no.5
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• pp.417-423
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• 1993

The effect of moisture content of biocatalyst on the performance of a gas phase continuous bioreactor was investigated along with study on the mass transfer limitation. The biocatalysts whose moisture contents are 46.2% and 37.2%, respectively were prepared by immobilization of alcohol oxidase on Amberlite IRA-400, following by slow dehydration method, and packed into a column. Relative production rate (RPR), acetaldehyde composition ($X_p$) and conversion (X) of biocatalysts (37.2%) are better than those of biocatalysls (46.2%), and it was considered that these are attributed to the mass transfer enhancement in the gas phase compared with the aqueous phase.