• 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).

• 대한물리치료과학회지
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• 제12권3호
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• pp.47-58
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• 2005

The purpose of this study is to estimate how much the motility of affected and unaffected lower limb respectively would have effects on their ambulation through comparing the difference between their affected and unaffected lower limb and studying the correlation between such difference and their ambulation. In addition, the study also intends to find out remedial measures suitable for improving their ambulation with relevant physical treatment. To do this, a quantitative electromyogram(QEMG) test was done to both quadriceps and hamstring of affected and unaffected lower limb so as to yield IP values. Based on such IP values, RMS(root mean square) values as the total sum of IP values were found with QEMG analysis system (made by Medelec Co.) and then the ambulation depending on the difference in muscular strength were analyzed by ink-foot print method as well as the corresponding statistics were processed by T-test through SPSS. The effect of differences in muscular strength of quadriceps in affected and unaffected limb of hemiplegic patients on their ambulation was also different in each element of ambulation. However, there was not any statistically significant difference (p>.05). The differences in muscular strength of hamstring in unaffected limbs of hemiplegic patients only affect stride length. It was statistically significant. The effect of difference in muscular strength of the hamstring in affected limb of hemiplegic patients on their ambulation was very different between strong and weak group in terms of walking velocity, step per minute, stride and step length, showing statistically significant difference(p<.05). Although there was a difference in the step length of the affected limb, it was not statistically significant(p>.05). For the unaffected hamstring, there were significant differences of stride length between in unaffected limb and in affected limb. For the affected hamstring, there were also significant differences in walking velocity, step per minute, stride and step length. Besides, it was found that the difference of the muscular strength between strong and weak group was at the highest. Thus, the effect of difference in muscular strength on ambulatory factors such as walking velocity, step per minute, stride and step length did not show any statistical significance but differences in affected and unaffected quadriceps. However, it was found that both the difference of stride in unaffected hamstring and the difference of all ambulatory factors except from step length with affected limb had effects on ambulation depending upon muscular strength.

• 대한간호학회지
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• 제30권3호
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• pp.741-749
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• 2000

This study was performed to investigate the relationship between reversed circadian blood pressure and risk factors of peripheral vascular disease in non-insulin-dependent diabetes mellitus (NIDDM) subjects. The subjects in this study were 18 NIDDM patients who were hospitalized in a medical unit of an university medical center located in Incheon, Korea, between November, 1998 and March, 1999. Blood pressure was measured with a mercury sphygmomanometer by 2 trained examiners every 2 hours during 24 hours. NIDDM subjects were divided into a dipper group and non-dipper group. Dippers are defined as those who show a mean nighttime blood pressure(BP) drop of more than 10% compared with daytime BP. Non-dippers are defined as those who show a mean nighttime BP drop of less than 10%, or an elevation in BP compared with daytime BP. Daytime BP included values obtained between 6 a.m. and 10 p.m. Night time BP included values obtained between 10 p.m. and 6 a.m. Data was analyzed by SPSS/PC package. Chi-square( $^2$) test was used for the comparison of sex between The dipper group and non-dipper group. Mann-Whitney test was used for comparisons of values of the risk factors of peripheral vascular disease and the frequency of complications of diabetes between the dipper group and non-dipper group. The results are as follows. There were no significant differences in daytime systolic, diastolic, and mean blood pressures between the dipper group and non-dipper group. However, night time systolic, diastolic, and mean blood pressures in the non-dipper group were significantly nigher than those in the dipper group (p=.021). There were no differences in sex, age, body, weight, duration of diabetes, serum lipid levels, BUN and HbA1c between the two groups. On the contrary, 87.5% of non-dipper group subjects showed having hypertension, 30% of dipper group subjects showed having hypertension and this difference was statistically significant (p=.018). All of the non-dipper group subjects (N=8) showed having at least one diabetic complication. However, 40% of the dipper group subjects (N=10) showed having no diabetic complication at all and this difference was also statistically significant (p=.049). There were no significant differences in frequency of nephropathy, neuropathy and retinopathy between the dipper group and non-dipper group.

• 한국도로학회논문집
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• 제18권5호
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• pp.117-125
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• 2016

PURPOSES : The density in uninterrupted traffic flow facilities plays an important role in representing the current status of traffic flow. For example, the density is used for the primary measures of effectiveness in the capacity analysis for freeway facilities. Therefore, the estimation of density has been a long and tough task for traffic engineers for a long time. This study was initiated to evaluate the performance of density values that were estimated using VDS data and two traditional methods, including a method using traffic flow theory and another method using occupancy by comparing the density values estimated using vehicular trajectory data generated from a radar detector. METHODS : In this study, a radar detector which can generate very accurate vehicular trajectory within the range of 250 m on the Joongbu expressway near to Dongseoul tollgate, where two VDS were already installed. The first task was to estimate densities using different data and methods. Thus, the density values were estimated using two traditional methods and the VDS data on the Joongbu expressway. The density values were compared with those estimated using the vehicular trajectory data in order to evaluate the quality of density estimation. Then, the relationship between the space mean speed and density were drawn using two sets of densities and speeds based on the VDS data and one set of those using the radar detector data. CONCLUSIONS : As a result, the three sets of density showed minor differences when the density values were under 20 vehicles per km per lane. However, as the density values become greater than 20 vehicles per km per lane, the three methods showed a significant difference among on another. The density using the vehicular trajectory data showed the lowest values in general. Based on the in-depth study, it was found out that the space mean speed plays a critical role in the calculation of density. The speed estimated from the VDS data was higher than that from the radar detector. In order to validate the difference in the speed data, the traffic flow models using the relationships between the space mean speed and the density were carefully examined in this study. Conclusively, the traffic flow models generated using the radar data seems to be more realistic.

• 한국임상보건과학회지
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• 제12권1호
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• pp.1654-1659
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• 2024

Purpose: The aim of this study was to determine Correlation analysis of central corneal thickness, anterior chamber volume, and anterior chamber depth in Koreans aged 20 to 24 years using the Pentacam tool. Methods: The subjects of this study were 53 Korean adults with healthy eyes. The central corneal thickness(CCT), anterior chamber volume(ACV), and anterior chamber depth(ACD) was measured with Pentacam device. Data was analyzed by means of the Pearson's correlation cofficient. P-values<0.001 were considered statistically significant. Results: Mean age of subjects was 22.0±2.01 years. The mean +/- central corneal thickness of the right eye and left eye were 546.66±32.221mmg and 545.70±32.759mm, respectively. Also The mean central cornea thickness was 546.19 um in the whole sample. The mean anterior chamber volume the right eye and left eye was 181.66±33.738 mm³ and 180.12±30.84 mm³, respectively. The mean anterior chamber depth was 3.158±0.257 mm and 3.122±0.233 mm in right eye and left eye, respectively. There was a statistically significant difference between anterior camber volume and anterior chamber depth(p<0.001, Pearson's correlation). However there was no statistically significant difference between central cornea thickness and anterior chamber volume. Also there was no statistically significant difference between central cornea thickness and anterior chamber depth. Conclusion: The results of this study could be used as a clinical reference data for diagnosis and treatment of cornea in Korean adolescents.

• 한국의학물리학회지:의학물리
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• 제27권4호
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• pp.203-212
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• 2016

Dose differences between three-dimensional (3D) and four-dimensional (4D) doses could be varied according to the geometrical relationship between a planning target volume (PTV) and an organ at risk (OAR). The purpose of this study is to evaluate the correlation between the overlap volume histogram (OVH), which quantitatively shows the geometrical relationship between the PTV and OAR, and the dose differences. 4D computed tomography (4DCT) images were acquired for 10 liver cancer patients. Internal target volume-based treatment planning was performed. A 3D dose was calculated on a reference phase (end-exhalation). A 4D dose was accumulated using deformation vector fields between the reference and other phase images of 4DCT from deformable image registration, and dose differences between the 3D and 4D doses were calculated. An OVH between the PTV and selected OAR (duodenum) was calculated and quantified on the basis of specific overlap volumes that corresponded to 10%, 20%, 30%, 40%, and 50% of the OAR volume overlapped with the expanded PTV. Statistical analysis was performed to verify the correlation with the OVH and dose difference for the OAR. The minimum mean dose difference was 0.50 Gy from case 3, and the maximum mean dose difference was 4.96 Gy from case 2. The calculated range of the correlation coefficients between the OVH and dose difference was from -0.720 to -0.712, and the R-square range for regression analysis was from 0.506 to 0.518 (p-value <0.05). However, when the 10% overlap volume was applied in the six cases that had OVH value ${\leq}2$, the average percent mean dose differences were $34.80{\pm}12.42%$. Cases with quantified OVH values of 2 or more had mean dose differences of $29.16{\pm}11.36%$. In conclusion, no significant statistical correlation was found between the OVH and dose differences. However, it was confirmed that a higher difference between the 3D and 4D doses could occur in cases that have smaller OVH value.

• 암석학회지
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• 제25권2호
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• pp.151-163
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• 2016

거창지역의 쥬라기 화강암에서 발달하는 결의 특성을 분석하였다. 3개 면, 3개 결에 대한 평가는 (1) 미세균열의 간격의 빈도수(N), (2) 총 간격(${\leq}1mm$), (3) 평균 간격($S_{mean}$), (4) 평균 간격과 중앙 간격($S_{median}$) 사이의 차이값($S_{mean}-S_{median}$), (5) 간격의 밀도(${\rho}$), (6) 도표의 전체구간에 대한 두 지수 사이의 차이값(${\lambda}_H-{\lambda}_L$), (7) 지수의 평균값(${\lambda}_M$), (8) 지수의 상수의 평균값($a_M$), (9) 최초 교차점 이하의 구간에 대한 두 지수 사이의 차이값(${\lambda}t_H-{\lambda}t_L$), (10) 지수의 평균값(${\lambda}t_M$) 및 (11) 지수의 상수의 평균값($at_M$)과 같은 파라미터를 이용하여 수행하였다. 3개 결 그리고 3개 면에 대한 파라미터의 값 사이의 상관성 분석의 결과는 다음과 같다. (I) 파라미터(1, 2, 7 및 8) 및 (II) 파라미터(3, 4 및 5)의 값은 (I) H(3번 결, (H1 + H2)/2) < G(2번 결, (G1 + G2)/2) < R(1번 결, (R1 + R2)/2) 및 (II) R < G < H의 순서이다. 반면에 3개 면에 대한 상기 두 그룹(I~II)의 파라미터의 값은 역순을 보여준다. 그 외에도, 3개 면에 대한 파라미터 $6({\lambda}_H-{\lambda}_L)$, 파라미터 $9({\lambda}t_H-{\lambda}t_L)$, 파라미터 $10({\lambda}t_M)$ 및 파라미터 $11(at_M)$의 값은 각각 R(1번 면, (G1 + H2)/2) < H(3번 면, (R2 + G2)/2) < G(2번 면, (R1 + H2)/2), H < G < R, H < R < G 및 R < H < G의 순이다. 3개 결에 대한 상기 네 파라미터의 값은 R < H < G, R < H < G, H < G < R 및 H < G < R의 다양한 순을 각각 보여준다. 한편, 두 방향의 도표 사이의 최초 접촉점 및 교차점에 해당되는 간격값을 도출하였다. 3개 결에 대한 상기 간격값은 1번 결(R1 및 R2) < 2번 결(G1 및 G2) < 3번 결(H1 및 H2)의 순이다. 3개 면에 대한 간격값은 1번 면(G1 및 H1) < 3번 면(R2 및 G2) < 2번 면(R1 및 H2)의 순이다. 특히 3개 결과 3개 면에 대한 교차각은 1번 결 및 1번 면 < 3번 결 및 3번 면 < 2번 결 및 2번 면의 순이다. 따라서, 1번 결(R1 및 R2) 및 1번 면(G1 및 H1)의 두 도표는 보다 높은 접촉점 또는 교차점의 빈도수를 보여준다. 이러한 변화 특성은 3개 면 및 3개 결의 종합도를 통하여 도출하였다. 마지막으로, 분포 형태와 함께 파라미터의 값을 통한 상관성 분석은 3개 채석면의 판별에 유용하다.

• 수산해양기술연구
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• 제28권1호
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• pp.10-20
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• 1992

The new course distances of a ship are considered to be the indices to indicate directly her abilities of course altercation. Generally, they have long been calculated by using the maneuvering indices obtained from her Z test. However, at sea actually the maneuvering indices can not sometimes be obtained according to ship's condition or circumstances and the new course distances can not be calculated. To find out other method to calculate the new course distances, in this paper the author analyzed them from a viewpoint of ship motion, and worked out a numerical formula to calculate them easily, using the data of ship's heading test. In order to check whether the presented method is applicable to actual ships or not, the experiment by them were also performed. The results obtained are summarized as follow: 1. The mean difference of the distance between two new course distances by the heading test and the maneuvering indices of the experimental ship was about 0.98% values of the ones by the maneuvering indices, when her heading were 10。, 20。 and 30。, using the rudder angle of 15。. These new course distances were therefore found to be almost same in values of the distance. 2. The mean difference of the distance between two new course distances by the heading test and the observation of experimental ship was about 1.16% values of the ones by the observation, when her headings were 10。, 20。 and 30。, using the rudder angle of 15。. These new course distances were therefore found to be almost same in values of the distance. 3. It is confirmed that the new course distances can be calculated easily by using the method of ship's simple heading test, without the observation or using the maneuvering indices. 4. It is considered to be helpful for the safety of shiphanding to draw curves of new course distances by ship's heading test and utilize them at sea.

• 대한치과교정학회지
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• 제12권2호
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• pp.145-154
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• 1982

Plaster models were constructed and orthopantomographs were taken for 86 male and 70 female primary school pupils, whose upper and lower permanent 4 incisors and 1st molars were completely erupted without crowding; whose deciduous canines and molars were found almost uniformly even without any visible tooth fractures, dental caries or restorations on proximal surfaces of the teeth. Certain reference points on the orthophantomograph were set up and measured and the values were compared with actual or predicted values from the models. The following results were obtained: 1. In regards to available space, the values from the orthopantomograph were greater than the values from the models by a mean of 3.24% on the upper and 10.06% on the lower for males; 3.05% on the upper and 10.01% on the lower for females. 2. In regards to total mesiodistal widths of permanent canine, 1st and 2nd premolars, the values from the orthopantomograph were greater than the presumed values based on the size of lower permanent 4 incisors from the models by a mean of 18.50% on the upper and 24.09% on the lower for males; 14.54 on the upper and 20.51% on the lower for females. 3. Comparing the magnified values of total mesiodistal widths of permanent canine, 1st and 2nd premolars with those of available space, the regression constants of regression equation (Y = a + bX) between them were a=3.2336, b=0.6533 on the upper and a=5.0138, b=0.3290 on the lower for males; a=2.5994, b=0.6521 on the upper and a=3.0113, b=0.6586 on the lower for females. 4. The correlation coefficients between the magnified values of available space and permanent canine, 1st and 2nd premolars were moderately positive as 0.6474 in the upper and 0.505 on the lower for males; 0.6493 on the upper and 0.6183 on the lower for females. 5. In regards to magnified values of the available space from the orthopantomographs there were no significant difference between sexes, (P>0.05) but of the total mesiodistal widths of permanent canine, 1st and 2nd premolars, a significant difference between sexes was found.(p<0.01).

• Communications for Statistical Applications and Methods
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• 제30권6호
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• pp.631-652
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• 2023

In the two-condition within-subject mediation design, pairs of variables such as mediator and outcome are observed under two treatment conditions. The main objective of the design is to investigate the indirect effects of the condition difference (sum) on the outcome difference (sum) through the mediator difference (sum) for comparison of two treatment conditions. The natural condition variables mean the original variables, while the rotated condition variables mean the difference and the sum of two natural variables. The outcome difference (sum) is expressed as a linear model regressed on two natural (rotated) mediators as a parallel two-mediator design in two condition approaches: the natural condition approach uses regressors as the natural condition variables, while the rotated condition approach uses regressors as the rotated condition variables. In each condition approach, the total indirect effect on the outcome difference (sum) can be expressed as the sum of two individual indirect effects: within- and cross-condition indirect effects. The total indirect effects on the outcome difference (sum) for both condition approaches are the same. The invariance of the total indirect effect makes it possible to analyze the nature of two pairs of individual indirect effects induced from the natural conditions and the rotated conditions. The two-condition within-subject design is extended to the addition of a between-subject moderator. Probing of the conditional indirect effects given the moderator values is implemented by plotting the bootstrap confidence intervals of indirect effects against the moderator values. The expected indirect effect with respect to the moderator is derived to provide the overall effect of moderator on the indirect effect. The model coefficients are estimated by the structural equation modeling approach and their statistical significance is tested using the bias-corrected bootstrap confidence intervals. All procedures are evaluated using function lavaan() of package {lavaan} in R.