• Title/Summary/Keyword: normal variance ratio

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Practical statistics in pain research

  • Kim, Tae Kyun
    • The Korean Journal of Pain
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    • v.30 no.4
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    • pp.243-249
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    • 2017
  • Pain is subjective, while statistics related to pain research are objective. This review was written to help researchers involved in pain research make statistical decisions. The main issues are related with the level of scales that are often used in pain research, the choice of statistical methods between parametric or nonparametric statistics, and problems which arise from repeated measurements. In the field of pain research, parametric statistics used to be applied in an erroneous way. This is closely related with the scales of data and repeated measurements. The level of scales includes nominal, ordinal, interval, and ratio scales. The level of scales affects the choice of statistics between parametric or non-parametric methods. In the field of pain research, the most frequently used pain assessment scale is the ordinal scale, which would include the visual analogue scale (VAS). There used to be another view, however, which considered the VAS to be an interval or ratio scale, so that the usage of parametric statistics would be accepted practically in some cases. Repeated measurements of the same subjects always complicates statistics. It means that measurements inevitably have correlations between each other, and would preclude the application of one-way ANOVA in which independence between the measurements is necessary. Repeated measures of ANOVA (RMANOVA), however, would permit the comparison between the correlated measurements as long as the condition of sphericity assumption is satisfied. Conclusively, parametric statistical methods should be used only when the assumptions of parametric statistics, such as normality and sphericity, are established.

Comparing Validity of Body Mass Index, Waist to Hip Ratio, and Waist Circumference to Cardiovascular Disease Risk Factors in Korean Elderly (한국노인에서 심장혈관계 질환 위험인자에 대한 비만지표인 체질량지수, 허리-엉덩이둘레비, 및 허리둘레의 타당도 비교)

  • Moon Hyun-Kyung;Kim Eu-Gene
    • 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.

Assessment of the Correlation for Geometry Transition using Bone Mineral Density in Proximal Femur (골밀도를 이용한 대퇴근위부 형태 변화의 상관관계 평가)

  • Kim, Da-Hye;Ko, Seong-Jin;Kang, Se-Sik;Kim, Jung-Hoon;Kim, Dong-Hyun;Ye, Soo-Young;Kim, Changsoo
    • The Journal of the Korea Contents Association
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    • v.12 no.12
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    • pp.335-344
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    • 2012
  • Osteoporosis is increasing in Korea as it becomes an aging society with the rapid economic growth and the development of medical technology. Osteoporosis also develops due to chemo and radiation therapy of cancer which also increases owing to Westernized diet. Osteoporosis is caused by reduced bone density, has close relationship with the change of geometry of proximal femur, which is a factor of hip fracture risk. The purpose of this study was the analysis of the correlations of osteoporosis and the change of geometry of proximal femur, which was observed according to T-score variance. The 350 male and female patients are chosen from D hospital in Busan, who were classified by age, sex and T-score values (normal, osteopenia, and osteo porosis). The results show that the age and gender have significant difference in the incidence of osteoporosis; the disease classification according to T-score value has significant difference in the geometry of the proximal femur such as Cortical ratio calcar, Cortical ratio shaft, Hip/shaft Angle, Strength index, Section modulus, CSMI, and CSA, and is highly correlated with the incidence of osteoporosis. Therefore, the findings of this research is that the change of the geometry of the proximal femur could be used as an indicator in the diagnosis of osteoporosis, could enhance the accuracy of the diagnosis in the future, and could be used as a clinical predictive factors through the analysis of the correlations of T-score variance and the geometry changes of the proximal femur.

Comparing validity of using Body Mass Index, Waist to Hip Ratio, and Waist Circumference to Cardiovascular Risk Factors of Middle Aged Koreans (한국중년층에서 체질량지수, 허리-엉덩이둘레비, 및 허리둘레의 심장혈관계질환 위험인자 타당도 비교)

  • Mun, Hyeon-Gyeong;Kim, Yu-Jin
    • 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.

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The Effect of a Combination of Scapular Protraction With Resistance and Forward Flexion of the Shoulder on Serratus Anterior Muscle Activity

  • Jung, Sung-hoon;Jeon, In-cheol;Hwang, Ui-jae;Kim, Jun-hee;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.23 no.4
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    • pp.55-62
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    • 2016
  • Background: The functioning of the serratus anterior (SA) muscle is essential to normal scapulohumeral rhythm during forward flexion (FF) of the shoulder. Also, SA weakness and overuse of the upper trapezius (UT) is observed in patients with shoulder dysfunction and trapezius myalgia. We designed a combination exercise involving FF and scapular protraction with resistance (CFFSP) to activate the SA muscle and to deactivate the UT muscle. Objects: The purpose of this study was to determine whether or not CFFSP would be more effective in activating the SA muscle than FF alone and FF with scapular protraction (FFP). Methods: Nineteen subjects (12 men and 7 women) participated in this study and performed FF, FFP, and CFFSP at $120^{\circ}$. Surface electromyography was applied to the SA, UT, and pectoralis major (PM) muscles, as was one-way analysis of variance (ANOVA) with repeated measures. Statistical significance was set at .05. Bonferroni adjustment was used to counteract the problem of multiple comparisons, with a statistical level of significance of .017 (.05/3). Results: A statistically significant difference was found in relation to the three positions for the SA muscle (p<.001) and the SA/UT ratio (p=.005) using ANOVA. Significantly different results, depending on the position, were also demonstrated using the Bonferroni post-hoc test for the SA muscle ($FF=28.27{\pm}16.20$, $FFP=45.66{\pm}15.81$, and $CFFSP=62.4{\pm}27.21$) and for the SA/UT ratio ($FF=3.04{\pm}2.14$, $FFP=3.61{\pm}2.38$, and $CFFSP=5.95{\pm}3.01$). Significant differences between the three positions was not found regarding the average amplitude of SA/PM muscle ratio (SA/PM: p=.060). Conclusion: We recommend the use of CFFSP to strengthen the SA muscle at $120^{\circ}$.

The Comparison of Clinical Assessment Tools for the Foot Posture

  • Lee, Jin-Yi;Choi, Jong-Duk
    • Physical Therapy Korea
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    • v.19 no.3
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    • pp.115-123
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    • 2012
  • It is important to assess foot posture when investigating the relationship between lower extremity dysfunctions and foot types. Although several measurements of static foot posture have been used, there is no consensus regarding clinical measurements for foot posture. The aim of this study is to explore the differences among navicular drift (NDt), foot posture index (FPI), arch index (AI), dorsal arch height ratio (DAHR), normal navicular height truncated (NNHt) and to discover the most effective measurement. After foot types were classified by navicular drop test (NDp), clinical measurements of NDt, FPI, AI, DAHR, and NNHt were performed on 64 subjects' feet. ANOVA analysis was used for the variance of the difference between the NDp and the five kinds of clinical measurements, and the level of significance was set at ${\alpha}$=.05. The results showed that all five clinical measurements demonstrated significant differences with navicular drop. In post-hoc, FPI and NNHt showed significant differences in all foot types. The five clinical measurements are suitable the classification of foot types through the NDp. Therefore, it could be possible to assess correct and objective foot posture by using FPI and NNHt.

A Study on Steady-State Criterion based on COV and a Fault Detection Method during GHP Operation (GHP 운전시 COV에 의한 정상상태 판별 및 이상검출 방법 연구)

  • Shin, Young-Gy;Oh, Se-Jae;Jeong, Jin-Hee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.11
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    • pp.705-710
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    • 2011
  • Fault detection has to be proceeded by steady state filtering to get rid of transient effect associated with thermal capacity. Coefficient of variance (COV), ratio of standard deviation devided by moving average, was employed as steady-state filter. Engine speed and refrigerant pressures were selected as parameters representing system dynamics. The filtered values were registered as members of steady-state DB. They were found to show good functional relationship with ambient temperature. The relationship was fitted with a second order polynomial and the distribution bounds of the data around the fitted curve were expressed by visual inspection because of varying average and random data interval. Fault data were compared with the steady-state data obtained during normal operation. The fault data were easily isolated from the fault-free one. To make such isolation reliable, tests to construct good DB should be designed in a systematic way.

Relationships between Inbound Tourism, Financial Development, and Economic Growth: An Empirical Study of Fujian Province, China

  • An Lin, LIU;Yong Cen, LIU
    • The Journal of Asian Finance, Economics and Business
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    • v.10 no.2
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    • pp.213-222
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    • 2023
  • This paper mainly studies the relationship between financial development, inbound tourism development, and economic growth rate in Fujian Province, China. This study uses the data of real GDP, foreign exchange income from international tourism, and financial interrelations ratio from 1994 to 2019. In the analysis process, the Johansen cointegration test is first used to analyze whether the three have a long-term equilibrium relationship. Then the vector error correction model is established to test the restrictive relationship among the three. Next, the Granger causality test assesses whether the three have a causal relationship. Finally, the contribution rate of the three is analyzed by variance decomposition. The above methods show the following conclusions: first, the three have a long-term equilibrium relationship. Secondly, in the short term, local economic growth is constrained by inbound tourism and financial development. Thirdly, there is a causal relationship between economic growth and inbound tourism in Fujian, while there is a unidirectional causal relationship between financial development and economic growth, financial development, and inbound tourism. Fourthly, the contribution rate of inbound tourism to economic growth fluctuations in Fujian is higher than that of financial development.

Speech Perception and Gap Detection Performance of Single-Sided Deafness under Noisy Conditions

  • Kwak, Chanbeom;Kim, Saea;Lee, Jihyeon;Seo, Youngjoon;Kong, Taehoon;Han, Woojae
    • Journal of Audiology & Otology
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    • v.23 no.4
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    • pp.197-203
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    • 2019
  • Background and Objectives: Many studies have reported no benefit of sound localization, but improved speech understanding in noise after treating patients with single-sided deafness (SSD). Furthermore, their performances provided a large individual difference. The present study aimed to measure the ability of speech perception and gap detection in noise for the SSD patients to better understand their hearing nature. Subjects and Methods: Nine SSD patients with different onset and period of hearing deprivation and 20 young adults with normal hearing and simulated conductive hearing loss as the control groups conducted speech perception in noise (SPIN) and Gap-In-Noise (GIN) tests. The SPIN test asked how many presented sentences were understood at the +5 and -5 dB signal-to-noise ratio. The GIN test was asked to find the shortest gap in white noise with different lengths in the gap. Results: Compared to the groups with normal hearing and simulated instant hearing loss, the SSD group showed much poor performance in both SPIN and GIN tests while supporting central auditory plasticity of the SSD patients. Rather than a longer period of deafness, the large individual variance indicated that the congenital SSD patients showed better performance than the acquired SSD patients in two measurements. Conclusions: The results suggested that comprehensive assessments should be implemented before any treatment of the SSD patient considering their onset time and etiology, although these findings need to be generalized with a large sample size.

Speech Perception and Gap Detection Performance of Single-Sided Deafness under Noisy Conditions

  • Kwak, Chanbeom;Kim, Saea;Lee, Jihyeon;Seo, Youngjoon;Kong, Taehoon;Han, Woojae
    • Korean Journal of Audiology
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    • v.23 no.4
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    • pp.197-203
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    • 2019
  • Background and Objectives: Many studies have reported no benefit of sound localization, but improved speech understanding in noise after treating patients with single-sided deafness (SSD). Furthermore, their performances provided a large individual difference. The present study aimed to measure the ability of speech perception and gap detection in noise for the SSD patients to better understand their hearing nature. Subjects and Methods: Nine SSD patients with different onset and period of hearing deprivation and 20 young adults with normal hearing and simulated conductive hearing loss as the control groups conducted speech perception in noise (SPIN) and Gap-In-Noise (GIN) tests. The SPIN test asked how many presented sentences were understood at the +5 and -5 dB signal-to-noise ratio. The GIN test was asked to find the shortest gap in white noise with different lengths in the gap. Results: Compared to the groups with normal hearing and simulated instant hearing loss, the SSD group showed much poor performance in both SPIN and GIN tests while supporting central auditory plasticity of the SSD patients. Rather than a longer period of deafness, the large individual variance indicated that the congenital SSD patients showed better performance than the acquired SSD patients in two measurements. Conclusions: The results suggested that comprehensive assessments should be implemented before any treatment of the SSD patient considering their onset time and etiology, although these findings need to be generalized with a large sample size.