• Journal of dental hygiene science
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• v.21 no.4
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• pp.219-226
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• 2021

Background: Proper detection and management of dental plaque are essential for individual oral health. We aimed to evaluate the maturation level of dental plaque using a two-tone disclosing agent and to compare it with the fluorescence of dental plaque on the quantitative light-induced fluorescence (QLF) image to obtain primary data for the development of a new dental plaque scoring system. Methods: Twenty-eight subjects who consented to participate after understanding the purpose of the study were screened. The images of the anterior teeth were obtained using the QLF device. Subsequently, dental plaque was stained with a two-tone disclosing solution and a photograph was obtained with a digital single-lens reflex (DSLR) camera. The staining scores were assigned as follows: 0 for no staining, 1 for pink staining, and 2 for blue staining. The marked points on the DSLR images were selected for RGB color analysis. The relationship between dental plaque maturation and the red/green (R/G) ratio was evaluated using Spearman's rank correlation. Additionally, different red fluorescence values according to dental plaque accumulation were assessed using one-way analysis of variance followed by Scheffe's post-hoc test to identify statistically significant differences between the groups. Results: A comparison of the intensity of red fluorescence according to the maturation of the two-tone stained dental plaque confirmed that R/G ratio was higher in the QLF images with dental plaque maturation (p<0.001). Correlation analysis between the stained dental plaque and the red fluorescence intensity in the QLF image confirmed an excellent positive correlation (p<0.001). Conclusion: A new plaque scoring system can be developed based on the results of the present study. In addition, these study results may also help in dental plaque management in the clinical setting.

• PNF and Movement
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• v.19 no.3
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• pp.435-440
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• 2021

Purpose: The purpose of this study is to investigate the effects of older adult's head-turn gait on gait parameters by comparing with head oriented forward gait and to provide criteria for their risk of falling compared to young adult. Methods: The subjects were 19 young adults in their 20s and 18 older adults in their 60s or above residing in Daegu or Gyeongsangbuk-do. To evaluate their gait parameters, spatiotemporal gait parameters were measured using a gait analysis tool (Legsys, BioSensics, USA) under two conditions: 1) walking while keeping one's eyes forward and 2) walking while turning the head. The measurement for each test was performed after one practice session, and the mean value of three measurements was analyzed. The collected data were statistically processed using a two-way analysis of variance (ANOVA) to compare any differences in gait parameters between the two groups under the two conditions. The statistical significance level was set at α=0.05. Results: According to the comparison of gait parameters in young adult and older adult between the head oriented forward gait and head-turn gait, statistically significant differences were observed in two parameters: stride length according to the height ratio and stride speed obtained by dividing the stride length according to the height ratio by time (p<0.05). Conclusion: The results of this study indicate that the head-turn gait causes greater differences in stride length and speed among older adult than in young adult and therefore can act as a cause of falling.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.27-39
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• 2012

This research is to propose the reinforcing method and design code for the lateral behaviors of the abutment displacement induced from the rainfall infiltration on high landfill slope. First, to make the proper numerical analysis, in-situ soil (weathered granite soil) was taken, and the variance of strength parameters according to water content variance was examined by undrained direct shear test, furthermore, other soil parameters were calculated from the standard penetration test such as elastic modulus and Poisson's ratio etc,. Those parameters were used to calculate the lateral behavior of abutment by finite element method and the member force of pile in high landfill slope according to rainfall infiltration . From the results, the shoe displacement on abutment was calculated as 8.98cm, which is 3 times bigger than the allowable displacement, 3cm. To reinforce it, several reinforcing methods were selected and analyzed such as reinforced retaining wall, soil surcharge, pile reinforcing (5m enlargement, 3-line arrangement, 5m enlargement and 3-line arrangement). In case of 5m enlarged and 3-line arrangement piles, the lateral behavior of shoe showed lower value(2.26 cm) than allowable displacement.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.258-263
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• 2013

The primary goal of this study was to compute sample sizes required to achieve the each aim of a variety of foot-and-mouth disease (FMD) surveillance programs, using a statistically valid technique that takes the following factors into account: sensitivity (Se) and specificity (Sp) of diagnostic test system, desired minimum detectable prevalence, precision, population size, and desired power of the survey. In addition, sample sizes to detect FMD if the disease is present and also as proof of freedom were computed. The current FMD active surveillance programs consist of clinical, virological, and serological surveillance. For the 2012 serological surveillance, annual sample sizes (n = 265,065) are planned at four separate levels: statistical (n = 60,884) and targeted (n = 115,232) at breeding pig farms and slaughter house, in together with the detection of structural proteins (SP) antibodies against FMD (n = 88,949). Overall, the sample size was not designed taking the specific aims of each surveillance stream into account. The sample sizes for statistical surveillance, assuming stratified two-stage sampling technique, was based to detect at least one FMD-infected case in the general population. The resulting sample size can be used to obtain evidence of freedom from FMD infection, not for detecting animals that have antibodies against FMD virus non-structural proteins (NSP). Additionally, sample sizes for targeted surveillance were not aimed for the population at risk, and also without consideration of statistical point of view. To at least the author's knowledge, sampling plan for targeted, breeding pig farms and slaughter house is not necessary and need to be included in the part of statistical surveillance. Assuming design prevalence of 10% in an infinite population, a total of 29 animals are required to detect at least one positive with probability of 95%, using perfect diagnostic test system (Se = Sp = 100%). A total of 57,211 animals needed to be sampled to give 95% confidence of estimating SP prevalence of 80% at the individual animal-level with a precision of ${\pm}5%$, assuming 800 herds with an average 200 heads per farm, within-farm variance of 0.2, between-farm variance of 0.05, cost ratio of 100:1 of farm against animals. Furthermore, 779,736 animals were required to demonstrate FMD freedom, and the sample size can further be reduced depending on the parameters assumed.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.153-161
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• 2000

This study was carried out to examine the drift of Gammarus sobaegensis by acid stress as pH depression in Oweol creek from April 1996 to October 1996. The behavioral drifting was revealed to the characteristics of G. sobaegensis that is tend to increase as acid stress. And, tolerance level of G. sobaegensis to pH depression was different among the size classes. Individuals belong to small to medium size classes were weak in lower pH. Pattern of response in G. sobaegensis has a lower tolerance to acid stress at below pH 4.0 than above pH 5.0 in the artificial channel and show the possibility as an effective aquatic ecotoxicity test organism. The result of analysis of variance, water temperature (F-ratio : 66.596, p< 0.0005) and the size classes (F-ratio : 71.386, p< 0.0005) except pH level (F-ratio : 353.415, p<0.0005) were showed to the major factor for drift behavior by acid depression. [Gammarus, pH, Drift, Acid stress, Ecotoxicity test].

• Journal of the Korean Dietetic Association
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• v.11 no.3
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• pp.365-374
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• 2005

This study was conducted to compare the validity of obese index among body mass index(BMI), waist to hip ratio(WHR), and waist circumference(WC) and to determine which is the best in relation to cardiovascular risk factors of middle aged Korean(40-64yr).Data from the 1998 Korean Health and Nutrition Survey were used(N=3380). Anthropometric indices and cardiovascular risk factors were measured. Chi-square test, analysis of variance following duncan's multiple range test, partial correlation analysis, and Receiver Operator characteristic(ROC) curves were used in the analysis. There was a significant increasing trend in WHR, systolic blood pressure(SBP), high density lipoprotein cholesterol(HDL), and fasting blood sugar(FBS) with age categories of male and in BMI, WC, WHR, diastolic blood pressure(DBP), SBP, total cholesterol(TC), low density lipoprotein cholesterol(LDL), triglycerol(TG), and FBS with those of female. Specially female had the characteristics of upper body fat and systolic blood pressure risk(p<0.05). Proportions of subjects with lifestyle factors related to cardiovascular risk in overweight or upper body fat group were higher than that of normal group. Higher proportions of subjects were practiced exercise in upper body fat group of male than in other groups. Among 7 cardiovascular risk factors in partial correlation analysis, BMI had the highest correlation coefficient in 6 risk factors in male, whereas WC in 4 risk factors in female. Mean of each obese index according to cardiovascular risk groups except smoker was higher than that of normal(p<0.05). These trends were shown in upper body fat group and female. In ROC analysis of 12 risk factors and health conditions, the largest area under curve among obese indices for risk factors were BMI in male and WHR in female. The optimal cutoff values of each index(BMI: WHR: WC) for one or more cardiovascular risk factors were 23.13: 0.89: 85.35 in male and 23.57: 0.84: 78.35 in female. The results showed that cardiovascular risk factors were prevalent in middle aged Koreans within normal limits of obese indices like another Asians. For the identification of cardiovascular risk factors of middle aged Koreans, BMI for men and WHR for women are appropriate indices. But it is recommended that BMI, WHR, and WC, all three indices should be considered, when using these indices.

• Journal of Nutrition and Health
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• v.38 no.6
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• pp.445-454
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• 2005

The purpose of this study was to compare the validity of obese index among body mass index (BMI), waist to hip ratio (WHR), and waist circumference (WC) and to determine which is the best in relation to cardiovascular disease (CVD) risk in Korean elderly more than 65 ages. Data from the 1998 Korean Health and Nutrition Survey were used (n=1017). Anthropometric indices and CVD risk factors were measured, and chi-square test, analysis of variance following duncan's multiple range test, partial correlation analysis, and Receiver Operator Characteristic (ROC) curves were used in the analysis. Anthropometric values were decreased in both male and female when ages were goes up. In female elderly, it specially showed the characteristics of upper body fat and systolic blood pressure risk (p<0.05). Among life style factors the current smokers were prevalent in obese male (p<0.05), but not prevalent in female having obese or upper body fat. Also, person with upper body obesity have more exercise than that of normal group (p<0.01). Mean BMI values of the current smoker was lower than that of normal group in both sexes (p<0.01). Mean BMI value of person with other risk factors were higher than that of normal groups (p<0.05). Among 7 CVD risk factors in partial correlation analysis, WC had the highest correlation coefficient in 5 in male, whereas BMI in 4 in female. In ROC analyses of 12 risk factors and health conditions, the largest area under curve of obese indices for risk factors were WC>WHR>BMI in male and BMI>WHR>WC in female. The optimal cutoff values of each index (BMI : WHR : WC) for one or more risk factors were 19.02 : 0.84 : 71.3 in male and 19.04 : 0.88 : 85.6 in female. In conclusion, Most Korean elderly showed non-obese and abdominal obesity likewise other Asians. Also CVD risk factors were prevalent in Korean elderly within normal limits of obese indices. Therefore the upper body fat indices reflected in the aged whose muscle mass is replaced by fat must be used as an indicator of CVD risk together with BMI. Although WHR was the worst index based on partial correlation analysis and so located between BMI and WC in ROC curve analysis in both sexes, it need to be use with WC to screen the cardiovascular risk group.

• Journal of the Korea Concrete Institute
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• v.21 no.1
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• pp.3-11
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• 2009

The increased demand and consumption of coal has intensified problems associated with disposal of solid waste generated in utilization of coal. Major utilization of coal by-products has been in construction-related applications. Since fly ash accounts for the part of the production of utility waste, the majority of scientific investigations have focused on its utilization in a multitude of use, while little attention has been directed to the use of bottom ash. As a consequence of this neglect, a large amount of bottom ash has been stockpiled. However, the need to obtain safe and economical solution for its proper utilization has been more urgent. The study presented herein is designed to ascertain the performance characteristics of bottom ash, as autoclaved lightweight foamed concrete product. The laboratory test results indicated that tobermorite was generated when bottom ash was used as materials for hydro-thermal reaction. According to the analysis of variance, at the fresh state, water ratio affects on flow and slurry density of autoclaved lightweight foamed concrete, but foam ratio influences on slurry density, while, at the hardened state, foam ratio affects on the density of dry and the compressive strength but doesn't affect on flexural and tensile strength. In the results of response surface analysis, to obtain target performance, the most suitable mix condition for lightweight foamed concrete using bottom ash was water ratio of 70$\sim$80% and foaming ratio of 90$\sim$100%.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.4
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• pp.545-560
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• 2019

During EPB TBM tunnelling, an appropriate application of additives such as foam and polymer is an essential factor to secure the stability of TBM as well as tunnelling performance. From the '90s, there have been many studies on the optimal injection of additives worldwidely contrary to the domestic situation. Therefore, in this paper, the foam, which is widely adopted for soil conditioning, was selected as an additive in order to investigate the effect of foam injection on TBM performance through a series of laboratory excavation tests. The excavation experiments were carried out on artificial sandy soil specimens with consideration of the variance of FIR (Foam Injection Ratio), FER (Foam Expansion Ratio) and $C_f$ (Surfactant Concentration), which indicate the amount and quality of the foam. During the tests, torque values were measured, and the workability of conditioned soil was evaluated by comparing the slump values of muck after each experiment. In addition, a weight loss of the replaceable aluminum cutter bits installed on the blade was measured to estimate the degree of abrasion. Finally, the foam injection ratio for the optimal TBM excavation for the typical soil specimen was determined by comparing the measured torque, slump value and abrasion. Note that the foam injection conditions satisfying the appropriate level of machine load, mechanical wear and workability are essential in the EPB TBM operational design.

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.325-333
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• 2001

The purpose of this study was to find out the effects of hallux valgus on the ankle plantarflexor and dorsiflexor peak torque, on the total work, on the average power, and on the Peak torque of plantarflexor to dorsiflexor ratio values. Isokinetic ankle plantarflexor and dorsiflexor strength was evaluated in 30 women(control: 15, hallux valgus: 15) by Cybex NORM System. Test data was gathered in the right ankle at a speed of 60/sec, 90/sec, 120/sec in the control group and the hallux valgus group. Statistical analysis was performed using SPSS 10.0 for windows software. Mean and standard deviations were measured and calculated for the General characterristic of subjects. A paired t-test was used to examine the differnces in the means for the ankle plantarflexor and dorsiflexor between two groups. Pearson coefficient correlation was used to examine the correlation of the hallux valgus and the peak torque. Analysis of variance indicated that isokinetic values of the control group were greater than the hallux valgus group(p<.05, p<.01).