• Title/Summary/Keyword: Variance Ratio Test

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Effects of Nasal Continuous Positive Airway Pressure Application on Sympathetic Activation : Power Spectrum Analysis of Electrocardiogram in Obstructive Sleep Apnea Syndrome (폐쇄성 수면무호흡증에서 지속적 상기도 양압술 시행이 교감신경계 활성도에 끼치는 영향 : 심전도 스펙트럼 분석)

  • Youn, Tak;Park, Hae-Jeong;Kim, Eui-Joong;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
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    • v.7 no.1
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    • pp.43-50
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    • 2000
  • Objectives: Obstructive sleep apnea syndrome(OSAS) is known to be associated with the changes of autonomic nervous system (ANS). Nasal continuous positive airway pressure(nCPAP) treatment was found to correct abnormal ANS changes in OSAS but it remains to be further clarified. We aimed to assess the effects of nCPAP on ANS manifested on electrocardiogram, using spectrum analysis in the subjects with OSAS. Methods: Digital polysomnography was performed in 18 patients with OSAS(mean age $43.7{\pm}16.6$ years ; 17 males, 1 female ; mean respiratory disturbance index (RDI) $48.6{\pm}20.9$) for one baseline and another CPAP nights. From each night, 300 continuous beats of ECGs without artifact were chosen from both stage 2 sleep and REM sleep and they were used for power spectrum analysis. We compared between baseline and CPAP nights the heart rate variability including VLF(very low frequency power), LF (low frequency power), HF(high frequency power), R-R means, R-R variance, and LF/HF ratio, using Wilcoxon signed ranks test. Results: In all patients, nCPAP proved to be effective in relieving apneas and snoring. During nCPAP night compared with baseline night, decreases in VLF(p<0.05), LF(p<0.01), and R-R variance(p<0.05) were found in stage 2 sleep, and decreased LF(p<0.05) was found in REM sleep. No significant differences in each sleep stage were found in other variables between the two nights. Conclusion: Our findings suggest that OSAS increases the activity of sympathetic nervous system and nCPAP application effectively decreases the activity. And nCPAP does not appear to influence the parasympathetic nervous activity in OSAS.

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Pharmacokinetic Properties and Bioequivalence of Cefcapene Pivoxil Hydrochloride 75 mg in Korean Healthy Volunteers (건강한 한국인 피험자에서 Cefcapene Pivoxil Hydrochloride 75 mg 제제의 생물학적동등성시험)

  • Jeon, Ji-Young;Im, Yong-Jin;Hwang, Min-Ho;Kim, Yun-Jeong;Han, Su-Mi;Jo, Myeong-Jin;Kim, Hee-Sun;Kim, Sun-Young;Chae, Soo-Wan;Kim, Kang-Seog;Kim, Min-Gul
    • Korean Journal of Clinical Pharmacy
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    • v.22 no.1
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    • pp.9-12
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    • 2012
  • Background: Cefcapene pivoxil hydrochloride, is an ester-type oral cephem antibiotic. This study was performed to compare the pharmacokinetics and evaluate the bioequivalence of two cefcapene pivoxil hydrochloride 75 mg formulations. Method: In a randomized $2{\times}2$ crossover study, sixty healthy male volunteers were randomly assigned into two groups. After a single dose of 75 mg cefcapene pivoxil hydrochloride oral administration, blood samples were collected at specific time intervals from 0-12 hours. The plasma concentrations of cefcapene pivoxil hydrochloride were determined by LC-MS/MS. The pharmacokinetic parameters were determined from the plasma concentration-time profiles of both formulations. The pharmacokinetic parameters such as $AUC_{last}$, $AUC_{inf}$ and $C_{max}$, were calculated and the 90% confidence intervals for test/reference ratio for pharmacokinetic parameters were obtained by analysis of variance on logarithmically transformed data. Results: The mean value for $AUC_{last}$ in test and reference drug was $4053.1{\pm}876.5\;ng{\cdot}hr/mL$ and $3595.7{\pm}1029.1\;ng{\cdot}h/mL$, respectively. The mean value for $C_{max}$ in test and reference drug was $1324.9{\pm}321.4$ ng/mL and $1159.1{\pm}335.9$ ng/mL, respectively. The 90% confidence intervals of the $AUC_{last}$ and $C_{max}$ ratio for test drug and reference drug were log 1.09-log1.22 and log 1.09-log1.24, respectively. No adverse events were reported by subjects or found on analysis of vital signs or laboratory tests. Conclusion: This single dose study found that the test and reference products met the regulatory criteria for bioequivalence in these health volunteers. Both formulations were safe and well tolerated in 75 mg of cefcapene pivoxil hydrochloride.

Optimization of Methane Yield in Anaerobic Digestion of Sewage Sludge with Microwave Pretreatment (극초단파 전처리를 적용한 하수슬러지 혐기성소화에서 메탄수율 최적화)

  • Park, WoonJi;Lee, GwanJae;Lee, DongJun;Lee, SeoRo;Choi, YuJin;Hong, JiYeong;Yang, DongSeok;Lim, KyoungJae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.2
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    • pp.17-29
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    • 2020
  • The objective of this study was to find an optimum methane yield condition in anaerobic digestion of sewage sludge with microwave pretreatment. The pretreatment process was carried out using a lab scale industrial microwave unit (2,450 MHz frequency). The digestion efficiency of pretreated sludge was evaluated by biochemical methane potential (BMP) test. Box-Behnken design and Response Surface Analysis (RSA) were applied to determine the optimal combination of sludge mixing ratio (0 to 100%), power (400 to 1600 W), holding time (0 to 10 min) and pretreatment temperature (60 to 100℃). BMP test results showed that Volatile Solid (VS) removal efficiency was up to 48% at a condition of 0% for mixing ratio, 1600 W for power, 5 min for holding time, and 80℃ for pretreatment temperature. Methane production was up to 832.3 mL/g VSremoved at a condition of 50% for mixing ratio, 1000 W for power, 5 min for holding time, and 80℃ for pretreatment temperature. The results of the variance analysis (ANOVA) showed that the p-value of the power and pretreatment temperature among the independent variables were significant (p<0.05), and in particular, the pretreatment temperature significantly affected on the solubilization and methane production. The optimum condition for the maximum methane yield (847 mL/g VSremoved) was consist of 38.4% of mixing ratio, 909.1 W of power, 4.1 min of holding time, and 80℃ of temperature within the design boundaries.

The Understanding and Application of Noise Reduction Software in Static Images (정적 영상에서 Noise Reduction Software의 이해와 적용)

  • Lee, Hyung-Jin;Song, Ho-Jun;Seung, Jong-Min;Choi, Jin-Wook;Kim, Jin-Eui;Kim, Hyun-Joo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.54-60
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    • 2010
  • Purpose: Nuclear medicine manufacturers provide various softwares which shorten imaging time using their own image processing techniques such as UlatraSPECT, ASTONISH, Flash3D, Evolution, and nSPEED. Seoul National University Hospital has introduced softwares from Siemens and Philips, but it was still hard to understand algorithm difference between those two softwares. Thus, the purpose of this study was to figure out the difference of two softwares in planar images and research the possibility of application to images produced with high energy isotopes. Materials and Methods: First, a phantom study was performed to understand the difference of softwares in static studies. Various amounts of count were acquired and the images were analyzed quantitatively after application of PIXON, Siemens and ASTONISH, Philips, respectively. Then, we applied them to some applicable static studies and searched for merits and demerits. And also, they have been applied to images produced with high energy isotopes. Finally, A blind test was conducted by nuclear medicine doctors except phantom images. Results: There was nearly no difference between pre and post processing image with PIXON for FWHM test using capillary source whereas ASTONISH was improved. But, both of standard deviation(SD) and variance were decreased for PIXON while ASTONISH was highly increased. And in background variability comparison test using IEC phantom, PIXON has been decreased over all while ASTONISH has shown to be somewhat increased. Contrast ratio in each spheres has also been increased for both methods. For image scale, window width has been increased for 4~5 times after processing with PIXON while ASTONISH showed nearly no difference. After phantom test analysis, ASTONISH seemed to be applicable for some studies which needs quantitative analysis or high contrast, and PIXON seemed to be applicable for insufficient counts studies or long time studies. Conclusion: Quantitative values used for usual analysis were generally improved after application of the two softwares, however it seems that it's hard to maintain the consistency for all of nuclear medicine studies because result images can not be the same due to the difference of algorithm characteristic rather than the difference of gamma cameras. And also, it's hard to expect high image quality with the time shortening method such as whole body scan. But it will be possible to apply to static studies considering the algorithm characteristic or we can expect a change of image quality through application to high energy isotope images.

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Development of an Instrument based on the Protection Motivation Theory to Measure Factors Influencing Women's Intention to First Pap Test Practice

  • Hassani, Laleh;Dehdari, Tahereh;Hajizadeh, Ebrahim;Shojaeizadeh, Davoud;Abedini, Mehrandokht;Nedjat, Saharnaz
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1227-1232
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    • 2014
  • Background: Given that there are many Iranian women who have never had a Pap smear, this study was designed to develop and validate a measurement tool based on the Protection Motivation Theory to assess factors influencing the Iranian women's intention to perform first Pap testing. Materials and Methods: In this psychometric research, to determine the Content Validity Index (CVI) and the Content Validity Ratio (CVR), a panel of experts (n=10) reviewed scale items. Reliability was estimated through the Intraclass Correlation Coefficient (n=30) and internal consistency (n=240). Also, factor analysis (exploratory and conformity) was performed on the data of the sample women who had never had a Pap smear test (n=240). Results: A 26-item questionnaire was developed. The CVI and CVR scores of the scale were 0.89 and 0.90, respectively. Exploratory factor analysis loaded a 26-item with seven factors questionnaire (perceived vulnerability and severity, fear, response costs, response efficacy, self-efficacy, and protection motivation (or intention)) that jointly accounted for 72.76% of the observed variance. Confirmatory factor analysis indicated a good fit for the data. Internal consistency (range 0.70-0.93) and test-retest reliability (range 0.72-0.96) of sub-scales were acceptable. Conclusions: This study showed that the designed instrument was a valid and reliable tool for measuring the factors influencing the women's intention to perform their first Pap testing.

Influence of inorganic composition and filler particle morphology on the mechanical properties of self-adhesive resin cements

  • Marina Rodrigues Santi ;Rodrigo Barros Esteves Lins;Beatriz Ometto Sahadi;Giovanna Correa Denucci;Gabriela Soffner ;Luis Roberto Marcondes Martins
    • Restorative Dentistry and Endodontics
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    • v.47 no.3
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    • pp.32.1-32.11
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    • 2022
  • Objectives: This study aimed to evaluate the influence of inorganic composition and filler particle morphology on the mechanical properties of different self-adhesive resin cements (SARCs). Materials and Methods: Three SARCs including RelyX Unicem-2 (RUN), Maxcem Elite (MAX), and Calibra Universal (CAL) were tested. Rectangular bar-shaped specimens were prepared for flexural strength (FS) and flexural modulus (FM) and determined by a 3-point bending test. The Knoop microhardness (KHN) and top/bottom microhardness ratio (%KHN) were conducted on the top and bottom faces of disc-shaped samples. Sorption (Wsp) and solubility (Wsl) were evaluated after 24 hours of water immersion. Filler morphology was analyzed by scanning electron microscopy and X-ray energy dispersive spectroscopy (EDS). FS, FM, %KHN, Wsp, Wsl, and EDS results were submitted to 1-way analysis of variance and Tukey's post-hoc test, and KHN also to paired t-test (α = 0.05). Results: SARC-CAL presented the highest FS value, and SARC-RUN presented the highest FM. SARC-MAX and RUN showed the lowest Wsp and Wsl values. KHN values decreased from top to bottom and the SARCs did not differ statistically. Also, all resin cements presented carbon, aluminum, and silica in their composition. SARC-MAX and RUN showed irregular and splintered particles while CAL presented small and regular size particles. Conclusions: A higher mechanical strength can be achieved by a reduced spread in grit size and the filler morphology can influence the KHN, as well as photoinitiators in the composition. Wsp and Wsl can be correlated with ions diffusion of inorganic particles.

Study on the welding characteristic of aluminum laser weld using filler wire (용가 와이어를 이용한 알루미늄 레이저 용접부의 용접 특성에 관한 연구)

  • Park, Young-Whan;Park, Hyunsung;Rhee, Sehun
    • Laser Solutions
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    • v.8 no.3
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    • pp.11-19
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    • 2005
  • In automotive industry, light weight vehicle is one of issues because of the air pollution and the protection of environment. Therefore, automotive manufacturers have tried to adopt light materials such as aluminum alloy to production line. Aluminum welding using laser has some advantages high energy density and high productivity. It is very important to understand weld characteristic according to welding condition in order to determine the possibility of application to car body. In this study, Nd:YAG laser welding of 5182 aluminum alloy with filler wire AA5356 was carried out through experimental design according to wire feed rate, laser power and welding speed. Weld bead shape in terms of cross section photo, bead with, height of reinforcement and penetration depth and mechanical property in terms of tensile strength and formability was investigated. Analysis of variation (ANOVA) was performed to know the effect of weld parameter for weldability, laser power was statistically most significance factor of three variables.

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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.

Optimization of L-shaped Corner Dowel Joint in Modified Poplar using Finite Element Analysis with Taguchi Method

  • Ke, Qing;Zhang, Fan;Zhang, Yachi
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.2
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    • pp.204-217
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    • 2016
  • Modified poplar has emerged as a potential raw material for furniture production. Lack of specific modified poplar strength information; however, restricts applications in the furniture industry especially as related to strength in corner-joints. Optimization of strength in L-shaped corner dowel modified poplar joints under compression loads utilizing finite element analysis (FEA) by Taguchi method with the focus of this study. Four experiment factors (i.e., Structure Style, Tenon Length, Tenon Diameter, and Tenon Gap), each at three levels, were conducted by adopting a $L_9-3^4$ Taguchi orthodoxy array (OA) to determine the optimal combination of factors and levels for the von Mises stress utilizing ANSYS software. Results of Signal-to-Noise ratio (S/N) analysis and the analysis of variance (ANOVA) revealed the optimal L-shaped corner dowel joint in modified poplar is $45^{\circ}$ Bevel Butt in structure style, 24 mm in tenon length, 6 mm in tenon diameter, and 20 mm in tenon gap. Tenon length and tenon gap are determined to be significant design factors for affecting von Mises Stress. Confirmation tests with optimal levels and experimental test indicated the predicted optimal condition is comparable to the actual experimental optimal condition.

The effect of coloring liquids on the translucency of zirconia framework

  • Tuncel, Ilkin;Eroglu, Erdal;Sari, Tugrul;Usumez, Aslihan
    • The Journal of Advanced Prosthodontics
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    • v.5 no.4
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    • pp.448-451
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    • 2013
  • PURPOSE. Translucency of all-ceramic restorations is an important factor which affects the final appearance and esthetic outcome of the restoration. The aim of this study was to evaluate the effect of the shade of coloring liquid on the translucency of zirconia framework. MATERIALS AND METHODS. Thirty zirconium oxide core plate ($15{\times}12{\times}0.5$ mm) were divided into 6 groups of 5 plates each. Each group was classified according to the shade of coloring liquid based on Vita Classic Scale (A2, A3, B1, C2, and D2), and each sample was immersed in coloring liquid for 3 seconds as recommended by the manufacturer, except for the control group. Contrast ratio, as a translucency parameter, was calculated using a spectrophotometer and the data were analyzed with oneway analysis of variance (ANOVA) and Tukey's honestly significant differences (HSD) tests (${\alpha}$=.05). RESULTS. Significant differences in translucency among the control and test groups, and the B1 shaded group and other shades was observed. There were no significant differences among A2, A3, C2, and D2 shaded groups. CONCLUSION. The translucency of the zirconium oxide cores was affected by the coloring procedure and significant differences in the translucency measurements were identified between specific shades.