• 대한수학회지
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• 제56권6호
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• pp.1475-1488
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• 2019

In this paper, we firstly define the Ricci mean value along the gradient vector field of the Ricci potential function and show that it is non-negative on a compact Ricci soliton. Furthermore a Ricci soliton is Einstein if and only if its Ricci mean value is vanishing. Finally, we obtain a compact Ricci soliton $(M^n,g)(n{\geq}3)$ is Einstein if its Weyl curvature tensor and the Kulkarni-Nomizu product of Ricci curvature are orthogonal.

• Journal of Preventive Medicine and Public Health
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• 제19권2호
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• pp.167-176
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• 1986

For the purpose of determinating the normal values of some parameters relevant to lead exposure, a study was carried out from April 1 to June 30, 1986 on 258 healthy Korean adults who have had no apparant lead exposure. The lead indices subjected to this study were as follows; blood lead (PbB), hemoglobin (Hb), zinc protoporphyrin in blood (ZPP), delta-aminolevulinic acid dehydratase (ALAD) activity in blood, coproporphyrin in urine (CPU), delta-aminolevulinic acid in urine (ALAU). 1) The mean value of PbB was $17.17{\pm}7.87{\mu}g/100ml$, and there was no statistically significant difference by age & sex. The distribution of PbB fitted to the log-normal distribution ($x^2=7.38$, p>0.1). 2) The mean value of Hb in male ($15.17{\pm}1.56g/100ml$) was higher than in female ($13.22{\pm}1.51g/100ml$)(p<0.01). The distribution of Hb fitted to the normal distribution ($x^2=9.40$, p>0.1). 3) The mean value of ZPP was $32.61{\pm}8.78{\mu}g/100ml$, and there was no statistically significant difference by age & sex. The distribution of ZPP fitted to the normal distribution ($x^2=13.93$, p>0.05). The correlation of ZPP & ALAD (r=-0.229), CPU (r=0.183) was statistically significant respectively. 4) The mean value of ALAD was $30.20{\pm}10.96{\mu}mol$ ALA/min/L of R.B.C., and there was no statistically significant difference by age & sex. The distribution of ALAD activity did not fit to the normal distribution. The correlation between ALAD & PbB (r=-0.219) was statistically significant 5) The mean value of CPU was $36.10{\pm}24.54{\mu}g/L$, and there was no statistically significant difference by age & sex. The distribution of CPU did not fit to the normal distribution. The correlation between CPU & PbB (r=0.185), ZPP (r=0.183) was statistically signinificant respectively. 6) The mean value of ALAU was $1.94{\pm}0.96mg/L$, and there was no statistically significant difference by age & sex. The distribution of ALAU fitted to the normal distribution ($x^2=9.76$, p>0.1).

• 대한치과교정학회지
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• 제22권1호
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• pp.253-271
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• 1992

The purpose of this study was to investigate the difference of EMG activity of the Orbicularis oris and Mentalis muscle between normal occlusion and class III malocclusion group during various lip position and to find out whether any correlations exist between the muscular activity and craniofacial morphology. In this study, 50 subjects with a mean age of 22.9 Years (range 20.0-26.0) were investigated (25 subjects were normal occlusion, and 25 subjects were class III malocclusion). EMG data were recorded from the Orbicularis oris and Mentalis muscle during rest lip posture, lip position at maximum biting, lip position at maximum sealing effort, lip position at chewing, swallowing and phonation with the Medelec MS-25 electromyographic machine. Lateral cephalometric radiographs was taken with the mandible in intercuspal position on all subjects. All data were recorded and statistically processed. The findings of this study can be summerized as follows: 1. In normal occlusion, the maximal mean amplitude of upper lip during the lip position at chewing was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 2. In Class III malocclusion, the maximal mean amplitude of upper lip during the lip position at chewing, swallowing and phonation was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 3. Compare to normal occlusion, the Class III malocclusion was showed low maximal mean amplitude of upper lip during rest lip posture and the lip position at swallowing of saliva, and showed great maximal mean amplitude of lower lip and meantalis muscle during the lip position at chewing and phonation. 4. In normal occlusion, the maximal mean amplitude of upper lip during various lip position was not correlated with the length and thickness of upper lip, but the maximal mean amplitude of lower lip during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip. 5. In Class III malocclusion, the maximal mean amplitude of upper lip during rest lip posture was negatively correlated with the thickness of upper lip, and the maximal mean amplitude of lower lip and mentalis muscle during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not correlated with the cephalometric measurements of soft tissue. 6. The correlation between the maximal mean amplitude of orbicularis oris and mentalis muscle and cephalometric measurements of incisors was not nearly present. 7. In normal occlusion, the maximal mean amplitude of lower lip and mentalis muscle during the lip position at maximum biting was negatively correlated with the angle between palatal plane and mandibular plane. In Class III malocclusion, the maximal mean amplitude of upper lip, lower lip and mentalis muscle during function was negatively correlated with the length of maxilla, the maximal mean amplitude of upper lip and lower lip during function was negatively correlated with the SNA and SNPo, and the maximal mean amplitude of lower lip during the lip position at chewing was negatively correlated with the ANB.

• Journal of the Korean Statistical Society
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• 제24권2호
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• pp.563-568
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• 1995

It is well-known that the sample mean and the sample variance are jointly sufficient under normality assumption. In this paper a proof of the joint sufficiency is given without using the factorization criterion. It is related to a finite Sanov-type conditional theorem, i.e., the conditional probability density of $Y_1$ given sample mean $\mu$ and sample variance $\sigma^2$, where $Y_1, Y_2, \cdots, Y_n$ are independently and identically distributed (i.i.d.) normal random variables with mean m and variance $\delta^2$, equals that of $Y_1$ given sample mean $\mu$ and sample variance $\sigma^2$, where $Y_1, Y_2, \cdots, Y_n$ are i.i.d. normal random variables with mean $\mu$ and variance $\sigma^2$.

• 대한후두음성언어의학회지
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• 제9권2호
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• pp.109-114
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• 1998

Background and Objectives : Aerodynamic investigation is valuable information about the efficiency of the larynx in translating air pressure to acoustic signal. The normal data of the Korean has been reported, but there is no basic data of professional western classical singers who have learned how to control the flow of expiratory air for singing. The purpose of this study was to investigate the normal aerodynamic data of korean professional western classical singers and compare this with that of the Korean Materials and Methods : 50 Korean western classical singers were studied. Expiratory lung pressure combined with measurements of the mean air flow rate, voice frequency and intensity were measured with the aerodynamic test using airway interruption method. These data were compared with normal data of untrained normal adults. Results and Conclusions : The voice frequency and the voice intensity were increased in the western classic singers, but the mean air flow rate and the expiratory air pressure of the classical singers were within the same range of the untrained normal adults. This result means that western classical singers can change the loudness and pitch with a little increased or decreasing the mean air flow and the expiratory air pressure.

• 동의신경정신과학회지
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• 제13권1호
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• pp.19-37
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• 2002

Objectives : This study sought to define autonomic functional difference on heart rate variability between headache patients and normal subjects Methods : We determined, heart rate variability of 52 headache patients and 30 normal subjects by means of three time domain measures: Mean PR(mean pulse rate), SDNN(standard deviation of all normal R-R intervals), RMSSD(the square root of the mean of sum of the squares of differences between adjacent normal R-R intervals), and five frequency domain measures: TP(total power), VLF(very low frequency), LF(low frequency), HF(high frequency). Results : 1) RMSSD, TP, HF, HF Norm of HRV decreased with aging and LF Norm, LF/HF increased with aging in headache patients. 2) There was no significant differences between migraine and tention headache in any standard index of HRV, whereas, HRV of total headache patients were smaller than those of normal subjects. 3) In the gender comparison, SDNN, RMSSD, HF of tention headache patients were the smallest and then migraine patients, normal subjects in order with man, whereas, LF Norm, LF/HF of normal subjects were the smallest with man. RMSSD of migraine patients were the smallest and then tention headache patients, normal subjects in order with women. 4) In the term of history of headache patients, SDNN, RMSSD were getting lower as long term. 5) There was no significant differences of HRV in physical symptom of headache patients. Conclusions : All of these results show that standard index of HRV of headache patients were significantly different with normal subjects.

• 대한지역사회영양학회지
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• 제3권2호
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• pp.167-173
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• 1998

This study was performed to assess the lead and cadmium status of children residing in urban factory area and to see if there is a difference of lead and cadmium status between the group with normal iron status. The mean lead concentration of male hair was 9.55ppm which is significantly higher than 6.61 ppm that of female. The mean lead concentration of male urine sample was 0.04ppm, 10.3ppm and $48.14\mu{g/L}$, which is higher than 0.08ppm, 6.08ppm and $20.69\mu{g/L}$ of normal group, respectively. In a suboptimal group the proportion of children whose urinary lead is higher than normal$(35\mu{g/L)$was 87.3%, whereas 2.5% for a normal group. The mean cadmium concentration of male hair was 2.58ppm, which is higher than 2.48ppm that of a female. The mean cadmium concentration of erythrocyte, hair and urine was 0.25ppm, 2.65ppm and $38.83\mu{g/L}$, which is higher than 0.20ppm, 2.40ppm and $19.78\mu{g/L}$ of the normal group, respectively. The proportion of children whose urinary cadmium level is higher than the low limit of risk of cadmium intoxication$(40\mu{g/L)}$ was 21.4%, whereas 0% for a mormal group. Urinary lead and cadmium level showed significantly negative correlation with the RBC count, hematocrit, hemoglobin and serum ferritin, whereas they had significantly positive correlation with FEP/Hb(p<0.01). There was no correlation between the IQ and the level of lead and cadmium.

• 대한한방소아과학회지
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• 제21권2호
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• pp.1-12
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• 2007

Objectives : Allergic children have known to have multiple behavior problems. Among them, attentional ability disorder is one of the most common problems. This study is to examine relationship between learning ability and allergic rhinitis by analyzing EEG status of children. Methods : We analyzed cognitive functions of two different children groups; 21 children with allergic rhinitis and 19 normal children with CANS 3000(Central & Autonomic Nervous System, LAXTHA Inc., Korea), cognitive functions assessment program by EEG. Results : 1. According to mean active EEG rhythm of Theta, Alpha, SMR, M-beta, there were no significant difference between allergic rhinitis and the normal group. 2. According to mean active EEG rhythm of right H-beta, Gamma wave allergic rhinitis group's value was significantly higher than that of the normal group. 3. According to mean cognitive strength, response, concentration, left / right brain activity and learning ability score, there were no significant difference between allergic rhinitis and the normal group. 4. According to mean workload score, allergic rhinitis group's value was significantly higher than that of the normal group. Conclusions : It is likely that allergic rhinitis group, which showed relatively high frequency EEG rhythm, is more fragile to stress and less active on mental processing. Along side with physical examination, psychological assessment should also be conjugated on treating children with allergic rhinitis.

• 대한물리치료과학회지
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• 제10권1호
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• pp.109-121
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• 2003

The purpose of this study was to test the difference of sitting balance control between a normal group and a group of patients with low back pain when their eyes were opened or closed. The 30 subjects of the control group had been chosen from healthy individuals who fit into the pre-designed criteria, and the 30 subjects of the experimental group were composed of the patients with LBP who had their treatment from S hospital from september 1, 2002, to October 30, 2002, and the subjects were measured by static balance test by using a balance performance monitor(BPM). Static balance test was done twice for each subject with his or her eyes opened and closed. Collected data were statistically analyzed by SPSS/PC using unpaired T-Test, Pained T-Test and multiple regression. The results were as follows: 1. In static balance test, normal group did not show statistical significance in sway angle(Anterior, Posterior, left and Right), sway path, sway area and maximal sway velocity, but showed statistical significance in mean balance with eyes opened and eyes dosed(P<.05) 2. In static balance test, LBP group did not show statistical significance in sway angle(Anterior, Posterior, left and Right), mean balance, sway path, sway area and maximal sway velocity with eyes opened and eyes dosed 3. With eyes opened, the comparison between the normal group and the LBP group showed statistical significance in sway angle(Anterior, Posterior, left and Right), mean valance, sway path, sway area and maximal sway velocity(p<.05). With eyes closed, normal group and LBP group did not show statistical significance in sway angle(Anterior and Right), sway area, but showed statistical significance in sway angle(Posterior and Left), mean balance, sway path, sway area and maximal sway velocity(p<.05) In conclusion, there was a significant difference in static sitting balance between normal group and LBP patients group. For future studies, I strongly suggest that researches be done on the treatment with LBP by predicting changes of postures and manipulating them.

• Journal of applied mathematics & informatics
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• 제33권5_6호
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• pp.723-738
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• 2015

In this paper, the prescribed mean curvature Rayleigh p-Laplacian equation with a deviating argument