• Korean Journal of Food Science and Technology
• /
• v.18 no.5
• /
• pp.364-371
• /
• 1986

High-ester pectin was demethylated by the treatments of HCl alone and a combination of HCl and $NH_4OH$. The low-ester pectin prepared were analyzed for chemical composition and the pectin gels were evaluated for firmness by sag values and strength by puncture stress. Gels made from HCl demethylated sample showed brittle, weak and poor elastic characteristics while the $HCl-NH_4OH$ treated samples generally resulted in a smooth and elastic gels except those samples having very low content of ester group or acid amide group. Statistical analysis showed that significant correlations were found between sag values and ester content or molecular weight, and puncture stress and ester content, acid amide groups or molecular weight. The equations derived for sag, puncture stress and sag/puncture stress from chemical data could be useful for prediction of some of the physical properties of low-ester pectin gel.

• Science of Emotion and Sensibility
• /
• v.17 no.4
• /
• pp.51-60
• /
• 2014

This double-blind study, as a human experiment of nonlocality, investigated the effects of senders' intention on the central nervous system of a distant human receiver and it explored the roles that motivation might have in modulating these effects. Whole brain activity was measured in the receiver whom was asked to relax in a distant room for 16 minutes; the sending person directed intention of oneness toward the receiver during repeated variable-second epochs separated by variable-second non-intention epochs. The total length of intention epochs and that of nonintention epochs were balanced. Eighteen sessions were conducted. In 9 of those sessions, the sender was the receiver's lover. In another 9 of those sessions, the sender was just acquainted with the receiver before the session. The receiver's whole brain activity recorded during the intention epochs were compared with the same measures recorded during the nonintention epochs used as controls. The statistical difference between the intentions versus controls across 18 sessions was examined by paired-t test. In addition, subgroup analysis for the 9 couple sessions and 9 non-couple sessions were additionally examined by the same test. The effect of distant intentionality decreased slow waves or increased EEG fast waves mainly in frontal regions, and increased EEG coherence during the intention epochs. The effects was not statistically significant after Bonferroni correction, but the couple sessions combined showed the largest effect followed by all sessions combined. Non-couple sessions combined showed the smallest effect. The changes in EEG power mean that receiver participants became more alert during the intention epochs and the change in EEG coherence might be evidence of coherent heart influence on EEG activity. Planned comparison with specific hypothesis testing for the suggested changes in this study have to be followed for an evidence of electroencephalographic changes in isolated subjects for the distant mental intention.

• The Journal of Korean Physical Therapy
• /
• v.27 no.6
• /
• pp.419-424
• /
• 2015

Purpose: This study aimed to evaluate the effects of lumbar stabilization exercise on the abdominal muscle-back muscle ratio in white-collar workers. Methods: Forty white-collar workers without any pain who worked at an information technology (IT) company located in the Gyeonggi province were included in this study. Of these, 20 subjects were randomly allocated to the lumbar stabilization exercise group, whereas the remaining 20 were randomly allocated to the control group. The lumbar stabilization exercise group performed a 40-minute-long exercise once a week for 8 weeks. The strength of the abdominal and back muscles was measured using the CENTAUR 3-D Spatial Rotation Device (BFMC, Germany). Data analysis was conducted using SPSS 18.0 for Windows. The Paired t-test was performed to compare the values measured before and after exercise within each group. The independent sample t-test was performed to analyze the differences between the 2 groups. The statistical significance for all the analyses was set at .05. Results: The strength of the abdominal muscles after the exercise significantly differed between the lumbar stabilization exercise group and the control group (p<0.05). However, the increase in the abdominal muscle-back muscle ratio was significant in only the lumbar stabilization exercise group (p<0.05), but not in the control group (p>0.05). Conclusion: The improvement of the abdominal muscle-back muscle ratio through lumbar stabilization exercise may have positive effects on lumbar stabilization. Moreover, lumbar stabilization exercise is considered beneficial for the prevention of back pain and musculoskeletal diseases.

• The Korean Journal of Applied Statistics
• /
• v.19 no.3
• /
• pp.481-504
• /
• 2006

VaR, a tail-related risk measure is now widely used as a tool for a measurement and a management of financial risks. For more accurate measurement of VaR, recently we are particularly concerned about the approach based on extreme value theory rather than the traditional method based on the assumption of normal distribution. However, many studies about the approaches using extreme value theory was done only for the univariate case. In this paper, we discuss portfolio risk measurements with modelling multivariate extreme value distributions by combining copulas and extreme value theory. We also discuss the estimation of ES together with VaR as portfolio risk measures. Finally, we investigate the relative superiority of EVT-copula approach than variance-covariance method through the back-testing of an empirical data.

• The Korean Journal of Applied Statistics
• /
• v.22 no.4
• /
• pp.735-744
• /
• 2009

In this paper, we introduce a fast approach for Bayesian detection of change points in long-memory processes. Since a heavy computation is needed to evaluate the likelihood function of long-memory processes, a method for simplifying the computational process is required to efficiently implement a Bayesian inference. Instead of estimating the parameter, we consider selecting a element from the set of possible parameters obtained by categorizing the parameter space. This approach simplifies the detection algorithm and reduces the computational time to detect change points. Since the parameter space is (0, 0.5), there is no big difference between the result of parameter estimation and selection under a proper fractionation of the parameter space. The analysis of Nile river data showed the validation of the proposed method.

• The Korean Journal of Applied Statistics
• /
• v.33 no.4
• /
• pp.409-420
• /
• 2020

In business survey, modified cut-off sampling is commonly used to greatly increase the accuracy of the estimation while reducing the number of samples. However, non-response rate of take-all stratum has increased significantly and the sample substitution is not possible because the non-response in the take-all stratum affects the accuracy of the estimation. It is important to adjust the bias appropriately if non-response is affected by the variable of interest. In this study, a bias adjusted estimation is proposed as an appropriate method to deal with a non-response in the take-all stratum. In particular, the estimator proposed by Chung and Shin (2020) was applied to the bias adjustment for the take-all stratum; therefore, we suggest a new method to adjust properly for the take-all stratum. The superiority of the proposed estimator was examined through simulation studies and confirmed through actual data analysis.

• Journal of Korean Society of Transportation
• /
• v.24 no.3 s.89
• /
• pp.95-102
• /
• 2006

This study develops a methodology on how to assess the traffic safety benefit of advanced vehicular technology for Protecting pedestrian in pedestrian-vehicle collision. Safety benefit is defined here as the reduction of Pedestrian fatality by employing advanced vehicular technology. As an application of the proposed methodology the safety benefit of active hood lift system (AHLS) is assessed. Both actual accident data analysis and simulation experiment are conducted to establish statistical models that are used for estimating the reduction of pedestrian fatality It is believed that the developed methodology and outcomes would be greatly useful in developing various advanced vehicular technologies and establishing more effective traffic safety policies.

• Journal of Trauma and Injury
• /
• v.33 no.1
• /
• pp.18-22
• /
• 2020

Purpose: Damage control laparotomy has contributed to improved survival rates for severe abdominal injuries. A large part of severe abdominal injury occurs with a concomitant pelvic bone fracture. The safety and effectiveness of internal fixation of pelvic bone fracture(s) has not been established. The aim of the present study was to evaluate infection risk in the pelvic surgical site in patients who underwent emergent abdominal surgery. Methods: This single-center retrospective observational study was based on data collected from a prospectively maintained registry between January 2015 and June 2019. Patients who underwent laparotomy and pelvic internal fixation were included. Individuals <18 and ≥80 years of age, those with no microbiological investigations, and those who underwent one-stage abdominal surgery were excluded. Comprehensive statistical comparative analysis was not performed due to the small number of enrolled patients. Results: A total of six patients met the inclusion criteria, and the most common injury mechanism was anterior-posterior compression (67%). The average duration of open abdomen was 98 hours (range, 44-98), and the time interval between abdominal closure and pelvic surgery was 98 hours. One patient (16.7%) died due to multi-organ dysfunction syndrome. Micro-organisms were identified in the abdominal surgical site in five patients (83%), with no micro-organisms in pelvic surgical sites. There was no unplanned implant removal. Conclusions: Internal fixation of pelvic bone fracture(s) could be performed in the state of open abdomen, and the advantages of early fixation may countervail the risks for cross contamination.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.2
• /
• pp.253-258
• /
• 2011

The purpose of this study was to compare metabolic energy expenditure with the computed kinetic energy for different speeds of walking and running over the treadmill and to find the relevance for individual and group equation by performing a statistical analysis, Bland-Altman plot. Seven male subjects participated, and they were required to walk and run on the treadmill with the gas analyzer and triaxial accelerometer. Walking speeds were 3.0, 4.0, 5.0 and 6.0 km/h and running speeds were 7.0, 8.0 and 9.0 km/h respectively. Kinetic energy was calculated by the integration of acceleration data and compared with the metabolic energy measured by a gas analyzer. Correlation coefficients showed relatively good between the measured metabolic energy and the calculated kinetic energy. In addition, a dramatic increase in kinetic energy was also observed at the transition speed of walking and running, and two standard deviations in Bland-Altman plot, derived from the difference between measured and predicted values, were 1.14, 2.53, 2.93, 1.80, 2.80, 0.60 and 2.48 respectively. It was showed that there is no difference for methods of how to predict the kinetic energy expenditure for individual and group even though people had each different physical characteristic.

• Journal of Pharmaceutical Investigation
• /
• v.33 no.3
• /
• pp.229-235
• /
• 2003

The purpose of the present study was to evaluate the bioequivalence of two enalapril maleate tablets, $Renitec^{TM}$ (MSD Korea Ltd.) and $Enalace^{TM}$ (Welfide Korea Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four normal male volunteers, $22.33{\pm}2.55$ year in age and $66.54{\pm}8.30$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After two tablets containing 10 mg of enalapril maleate per tablet were orally administered, blood was taken at predetermined time intervals and concentrations of enalapril in plasma were determined using LC-MS-MS. Pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t,\;and\;C_{max}$ untransformed $T_{max}$. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals for the log transformed data were acceptance range of log0.8 to log1.25$(e.g.,\;log1.02{\sim}log1.14\;and\;log1.03{\sim}log1.19\;for\;AUC_t\;and\;C_{max},\;respectively)$. The major parameters, $AUC_t,\;and\;C_{max}$, met the criteria of KDFA for bioequivalence indicating that $Enalace^{TM}$ tablet is bioequivalent to $Renitec^{TM}$ tablet.