• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3565-3583
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• 2022

The task scheduling problem has received a lot of attention in recent years as a crucial area for research in the cloud environment. However, due to the difference in objectives considered by service providers and users, it has become a major challenge to resolve the conflicting interests of service providers and users while both can still take into account their respective objectives. Therefore, the task scheduling problem as a bi-objective game problem is formulated first, and then a task scheduling model based on the bi-objective game (TSBOG) is constructed. In this model, energy consumption and resource utilization, which are of concern to the service provider, and cost and task completion rate, which are of concern to the user, are calculated simultaneously. Furthermore, a many-objective evolutionary algorithm based on a partitioned collaborative selection strategy (MaOEA-PCS) has been developed to solve the TSBOG. The MaOEA-PCS can find a balance between population convergence and diversity by partitioning the objective space and selecting the best converging individuals from each region into the next generation. To balance the players' multiple objectives, a crossover and mutation operator based on dynamic games is proposed and applied to MaPEA-PCS as a player's strategy update mechanism. Finally, through a series of experiments, not only the effectiveness of the model compared to a normal many-objective model is demonstrated, but also the performance of MaOEA-PCS and the validity of DGame.

• Korean Journal of Exercise Nutrition
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• v.13 no.1
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• pp.75-81
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• 2009

This study aims to find out the effect of ingestion of 3 mg·kg^-1 caffeine on fluid-electrolyte balance and Tty change during exercise under heat environment of 30~32℃ (40-50% humidity). Five trained males who routinely trained for approximately 60 min·d^-1, 3-6 d·wk^-1 (age; 28.20±3.56yrs, height; 174.56±5.46 cm, body mass; 76.13±9.02 kg, body fat(%); 14.24±3.99, VO₂max; 54.00±4.30 mL·kg^-1·min^-1, exercise career; 4.20±1.95yrs) performed 40min of treadmill running in heat chamber. The study was a double-blind, randomized, crossover design. Body mass change following exercise was higher for the PLAC (Placebo) and CAFF (Caffeine) in comparison to the CON (Control), there was no significant difference between the CAFF, PLAC, CON (p= .997). The U_sg not significant differences (p= .731) and Osm_urine not significant differences between the CAFF, PLAC, CON (p= .901). There also were not significant between the CAFF, PLAC, CON for [Na⁺]_urine and [K⁺]_urine (p= .928, p= .469). In the case of Tty, although the increase rate of Tty was the highest for the CAFF on exercise early, exercise the second half in comparison to the CON and PLAC, there was not significant interaction effect between the CAFF, PLAC, and CON of Tty (p= .067), In conclusion, it was confirmed that the 3 mg·kg^-1 caffeine ingestion prior to exercising in heat environment does not impart negative effect on body fluid, electrolyte balance and changes in Tty.

• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.121-139
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• 2014

Predicting corporate failure has been an important topic in accounting and finance. The costs associated with bankruptcy are high, so the accuracy of bankruptcy prediction is greatly important for financial institutions. Lots of researchers have dealt with the topic associated with bankruptcy prediction in the past three decades. The current research attempts to use ensemble models for improving the performance of bankruptcy prediction. Ensemble classification is to combine individually trained classifiers in order to gain more accurate prediction than individual models. Ensemble techniques are shown to be very useful for improving the generalization ability of the classifier. Bagging is the most commonly used methods for constructing ensemble classifiers. In bagging, the different training data subsets are randomly drawn with replacement from the original training dataset. Base classifiers are trained on the different bootstrap samples. Instance selection is to select critical instances while deleting and removing irrelevant and harmful instances from the original set. Instance selection and bagging are quite well known in data mining. However, few studies have dealt with the integration of instance selection and bagging. This study proposes an improved bagging ensemble based on instance selection using genetic algorithms (GA) for improving the performance of SVM. GA is an efficient optimization procedure based on the theory of natural selection and evolution. GA uses the idea of survival of the fittest by progressively accepting better solutions to the problems. GA searches by maintaining a population of solutions from which better solutions are created rather than making incremental changes to a single solution to the problem. The initial solution population is generated randomly and evolves into the next generation by genetic operators such as selection, crossover and mutation. The solutions coded by strings are evaluated by the fitness function. The proposed model consists of two phases: GA based Instance Selection and Instance based Bagging. In the first phase, GA is used to select optimal instance subset that is used as input data of bagging model. In this study, the chromosome is encoded as a form of binary string for the instance subset. In this phase, the population size was set to 100 while maximum number of generations was set to 150. We set the crossover rate and mutation rate to 0.7 and 0.1 respectively. We used the prediction accuracy of model as the fitness function of GA. SVM model is trained on training data set using the selected instance subset. The prediction accuracy of SVM model over test data set is used as fitness value in order to avoid overfitting. In the second phase, we used the optimal instance subset selected in the first phase as input data of bagging model. We used SVM model as base classifier for bagging ensemble. The majority voting scheme was used as a combining method in this study. This study applies the proposed model to the bankruptcy prediction problem using a real data set from Korean companies. The research data used in this study contains 1832 externally non-audited firms which filed for bankruptcy (916 cases) and non-bankruptcy (916 cases). Financial ratios categorized as stability, profitability, growth, activity and cash flow were investigated through literature review and basic statistical methods and we selected 8 financial ratios as the final input variables. We separated the whole data into three subsets as training, test and validation data set. In this study, we compared the proposed model with several comparative models including the simple individual SVM model, the simple bagging model and the instance selection based SVM model. The McNemar tests were used to examine whether the proposed model significantly outperforms the other models. The experimental results show that the proposed model outperforms the other models.

• Journal of Life Science
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• v.28 no.5
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• pp.587-596
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• 2018

This study aims to observe changes in heart-rate variability (HRV) indices induced by e-cigarette and conventional-cigarette smoking and to compare the differences in acute cardiac autonomic regulation. All participants (n=41) were exposed to both e-cigarette smoke (ES) and conventional cigarette smoke (CS) in a randomized crossover trial. HRV analysis was performed during each smoking session based on a recorded r-r interval 10 minutes before smoking and at specified recovery periods (REC1, 0-5 min; REC2, 5-10 min; REC3, 10-15 min; REC4, 15-20 min; REC5, 20-25 min; and REC6, 25-30 min). ES led to a significantly increased cardiac sympathetic index (LF/HF ratio) compared with the baseline, and it shifted the sympathovagal balance toward sympathetic predominance, including reduction in the complexity of the interbeat interval (SampEn). In REC1 after ES, only decreases of parasympathetic indices such as rMSSD, pNN50, HF, and SD1 were indicated. CS sessions produced not only an increased LF/HF ratio during smoking and recovery periods (REC1 and REC4) but also enhanced sympathetic predominance on autonomic balance during smoking and recovery periods (REC1, REC2, and REC4). In the CS trials, parasympathetic indices of time and non-linear analysis (rMSSD, pNN50, and SD1) were decreased during smoking and in REC1 to REC5. SampEn was also reduced during smoking and REC1 to REC4. Acute sympathoexcitatory effects induced by e-cigarette use produced statistically significant results. Parasympathetic withdrawal after smoking suggests that e-cigarettes may cause increased cardiovascular risk.

• Korean Journal of Clinical Pharmacy
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• v.8 no.2
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• pp.95-100
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• 1998

Piroxicam-$\beta$-cyclodextrin은 piroxicam을 $\beta$-cyclodextrin으로 포접시킨 비스테로이드성 항염증약물이다. 이러한 포접형 약물은 위장관에서의 흡수속도가 증가하는 것으로 외국자료에서 보고되고 있으며 이는 이 약물의 위장관 내성에 보다 나은 영향을 끼칠 수 있음을 시사하고 있다. 본 연구는 정상성인 한국인을 대상으로 randomized, crossover design에 의해 piroxicam-$\beta-cyclodextrin(Brexin^{(R)})$과 piroxicam 확산정$(Feldene^{(R)})$ 흡수속도를 비교하고자 하였다. 건강한 성인 8명의 피험자를 2군으로 나누어 시험약 또는 대조약을 각각 20 mg씩 20일의 휴약 기간을 두고 이중 맹검으로 교차 투여하였다. 시험약 또는 대조약의 투여 후 24시간 동안 일정 간격으로 채혈하여 HPLC 방법으로 혈장 내 piroxicam 농도를 측정하였다. $AUC_{0-24}\;({\mu}g/mL)$는 piroxicam-$\beta$-cyclodextrin군에서 $56.1\pm4.9$, piroxicam군에서 $57.3\pm5.6$으로 통계적인 유의성이 없었으나, 투여 후 0.5시간에서의 혈중농도는 piroxicam-$\beta$-cyclodextrin군 $2.9\pm0.4\;{\mu}g/mL$, piroxicam군 $1.6\pm0.3\;{\mu}g/mL$으로 통계적인 유의성을 보였다(p<0.05). 또한 최고혈중농도는 piroxicam-$\beta$-cyclodextrin$(4.3\pm0.5\;{\mu} g/mL)\;piroxicam(3.5\pm0.3\l{\mu}g/mL)$,으로 유의성이 있었으며(p<0.05), 흡수 속도상수는 piroxicam-$\beta$-cyclodextrin$(3.00\pm0.49\;h^{-1}), \;piroxicam(1.80\pm0.21\;h^{-1})$이었다(p<0.1). 이상의 결과에서, piroxicam-$\beta$-cyclodextrin정은 piroxicam 확산정과 비교하여 흡수되는 정도는 서로 비슷하지만 흡수 초기의 혈장농도 및 흡수속도상수에서 보다 빠른 약동학적 특성을 나타내었다.

• Journal of Acupuncture Research
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• v.30 no.3
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• pp.39-49
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• 2013

Objectives : The purpose of this study is to assess the effect of Taegeuk acupuncture on reducing mental stress by analyzing heart rate variability in Soeumin. Methods : Six Soeumin-diagnosed men participated in this study. They were randomly divided into group A and group B. Each participant went through 4 sessions every week with 1 week of washout period in between each session. HRV was measured three times at every session; at baseline, after administering mentally stressful circumstances and after applying Soeumin Taegeuk acupuncture or Soyangin Taegeuk acupuncture. This study was designed as a crossover clinical trial. Group A participants were treated with two sets of Soeumin Taegeuk and Soyangin Taegeuk acupuncture treatment in respective order (i.e. Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk acupuncture treatment). Group B participants were treated with reverse-ordered acupuncture treatment (i.e. Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk acupuncture treatment ). Bayesian analysis was performed by using WinBUGS(Ver. 1.4.3) for comparison between Soeumin Taegeuk acupuncture and Soyangin Taegeuk acupuncture. Results : Overall, Soeumin Taegeuk acupuncture tends to reduce LF/HF ratio, LF, HF, LF(Norm) and increase HF(Norm) more than Soyangin Taegeuk acupuncture, but the difference was not statistically significant. In one participant, however, Soeumin Taegeuk acupuncture reduced LF/HF ratio, LF(Norm) and increased HF(Norm) more than Soyangin Taegeuk acupuncture, and the difference was stastatistically significant. Conclusions : This study suggests that Soeumin Taegeuk acupuncture might be an effective means of stabilizing mental stress-induced imbalance of autonomic nervous system for Soeumin.

• Journal of Life Science
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• v.34 no.5
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• pp.320-332
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• 2024

The aims of this study were to compare the differences in hemodynamics between cigarette smoking and using heated tobacco products (HTPs) and to determine the acute effects of using HTPs on cardiac autonomic regulation. Another goal was to examine the acute cardiac autonomic responses when using different tobacco sticks in HTPs. Sixteen healthy male smokers completed an open-label, randomized, crossover trial consisting of non-smoking (NS), cigarette smoking, and the use of two different HTPs (IQOS with HEETS; lil SOLID with Fiit). Sub-trials, which included NS, lil SOLID with Fiit, and lil SOLID with HEET, were performed on eight smokers among the total subjects. Hemodynamic variables, such as systolic blood pressure (SBP) and diastolic blood pressure (DBP), and heart rate variability were measured before, during, and 30 minutes after using each tobacco product. Using HTPs resulted in a significant increase in both SBP and DBP, comparable to smoking cigarettes. Cardiac sympathetic activity significantly increased, and cardiac vagal tone (CVT) significantly decreased after acute exposure to HTP aerosol, similar to the effects of cigarette smoke exposure. Furthermore, differences in the withdrawal of CVT were observed when using different tobacco sticks in the same HTPs. The findings of this study indicate that acute exposure to HTP aerosol increases the hemodynamic burden and disrupts cardiac autonomic balance, similar to exposure to cigarette smoke. Moreover, depending on the type of tobacco stick inserted into the HTP device, acute withdrawal of CVT may have been enhanced.

• The Journal of Korean Medicine
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• v.44 no.4
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• pp.87-103
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• 2023

Backgrounds and objectives: Cardiotonic Pills^® (CP) are used for vascular diseases such as coronary diseases, atherosclerosis, and cerebral infarction. This study aimed to determine the transient effects of CP on cerebrovascular CO₂ reactivity (CVR) and erythrocyte deformability in normal subjects. Methods: This study had a crossover design and included 10 participants who were randomly allocated to 2 groups. The experimental group was given CP with water, while the control group was given only water. CVR was measured by hyperventilation-induced CVR of the middle cerebral artery (MCA) using transcranial Doppler (TCD). Erythrocyte deformability was measured using a Rheoscan-D microfluidic ektacytometer. All measurements were performed prior to and 1, 2, and 3 hours after CP or water administration. Blood pressure and heart rate were also measured before and after administration. Results: CP significantly improved CVR 3 hours after administration in the experimental group compared to the control group (p = 0.042). The corrected blood flow velocity at partial pressure of end-tidal carbon dioxide (PETCO₂) = 40mmHg (CV40) was also significantly improved 2 and 3 hours after administration in the CP group compared to the control group (p = 0.036 and p = 0.021, respectively). CP significantly improved erythrocyte deformability 3 hours after administration in the experimental group compared to the control group (p = 0.027). Mean heart rate and mean blood pressure showed no change. Conclusions: This study demonstrated that CP increases CVR and erythrocyte deformability. These results suggested that CP improves cerebral microcirculation which provide evidence for the future use of CP for prevention of ischemic stroke and neurodegenerative diseases.

• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.674-684
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• 2023

The purpose of this study was to investigate the effect of acute listening to music on the cardiovascular reactivity to sympathoexcitation. In this crossover design study, 15 healthy adults(23.1±1.94(yrs) were randomized to either (1)acute listen to the subject's preferred music for 30 minutes and (2)sat as a time control by an experiment coordinator. After completing each trial, the cold pressor test(CPT) was conducted. Heart rate(HR) and blood pressure(BP) were measured for 4 times at baseline, during and after the CPT. Heart rate variability(HRV) were measured for 3 times at baseline, prior and after the CPT. HR and BP increased during the CPT in both trial and returned to baseline after CPT(time effect, p < .001). After CPT, brachial systolic BP reactivity to the CPT was attenuated in listening to music trial compared to control trial(p = . 008). As a result of heart rate variability(HRV), the difference values between the baseline and prior to the CPT showed a significant increase in standard deviation of the NN intervals(SDNN), total power(TP) and high frequency(HF) only in the music trial (p = .001, p = .002, p = .011). The difference value between prior to and after the CPT did not show significance. But compared with the control trial, the music trial was confirmed that SDNN, TP and HF were more activated. Therefore, listening to music alleviated anxiety and tension before the CPT, and it is estimated that it had a favorable effect on stability after the CPT. This findings showed that listening to music may have a positive effect on brachial systolic BP and HRV to sympathoexcitation.

• Journal of Pharmaceutical Investigation
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• v.38 no.4
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• pp.269-275
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• 2008

The purpose of the present study was to evaluate the bioequivalence of two levofloxacin tablets, Jeil $Cravit^{TM}$ tablet (Jeil Pharm. Co., Ltd., Korea, reference drug) and $Lesacin^{TM}$ tablet (Ilhwa. Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four healthy male Korean volunteers received two tablets containing levofloxacin 200 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of levofloxacin were monitored for over a period of 24 hr after administration by using a high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The area under the plasma concentration-time curve from time zero to 24 hr ($AUC_t$), maximum plasma drug concentration ($C_{max}$) and time to reach $C_{max}\;(T_{max})$ were complied from the plasma concentration-time data. Analysis of variance (ANOVA) test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Lesacin^{TM}$/Jeil $Cravit^{TM}$ were $\log\;0.9527{\sim}\log\;0.9981$ and $\log\;0.8712{\sim}\log\;1.0556$, respectively. These values were within the acceptable bioequivalence intervals of $\log\;0.80{\sim}\log\;1.25$, recommended by KFDA. In all of these results, we concluded that $Lesacin^{TM}$ tablet was bioequivalent to Jeil $Cravit^{TM}$ tablet, in terms of rate and extent of absorption.