• Title/Summary/Keyword: variance to mean ratio

Search Result 155, Processing Time 0.024 seconds

Effect of Red Ginseng on cytochrome P450 and P-glycoprotein activities in healthy volunteers

  • Kim, Dal-Sik;Kim, Yunjeong;Jeon, Ji-Young;Kim, Min-Gul
    • Journal of Ginseng Research
    • /
    • v.40 no.4
    • /
    • pp.375-381
    • /
    • 2016
  • Background: We evaluated the drug interaction profile of Red Ginseng (RG) with respect to the activities of major cytochrome P450 (CYP) enzymes and the drug transporter P-glycoprotein (P-gp) in healthy Korean volunteers. Methods: This article describes an open-label, crossover study. CYP probe cocktail drugs, caffeine, losartan, dextromethorphan, omeprazole, midazolam, and fexofenadine were administered before and after RG supplementation for 2 wk. Plasma samples were collected, and tolerability was assessed. Pharmacokinetic parameters were calculated, and 90% confidence intervals (CIs) of the geometric mean ratios of the parameters were determined from logarithmically transformed data using analysis of variance after RG administration versus before RG administration. Results: Fourteen healthy male participants were evaluated, none of whom were genetically defined as poor CYP2C9, 2C19, and CYP2D6 metabolizers based on genotyping. Before and after RG administration, the geometric least-square mean metabolic ratio (90% CI) was 0.870 (0.805-0.940) for caffeine to paraxanthine (CYP1A2), 0.871 (0.800-0.947) for losartan (CYP2C9) to EXP3174, 1.027 (0.938-1.123) for omeprazole (CYP2C19) to 5-hydroxyomeprazole, 1.373 (0.864-2.180) for dextromethorphan to dextrorphan (CYP2D6), and 0.824 (0.658-1.032) for midazolam (CYP3A4) to 1-hydroxymidazolam. The geometric mean ratio of the area under the curve of the last sampling time ($AUC_{last}$) for fexofenadine (P-gp) was 0.963 (0.845-1.098). Administration of concentrated RG for 2 wk weakly inhibited CYP2C9 and CYP3A4 and weakly induced CYP2D6. However, no clinically significant drug interactions were observed between RG and CYP and P-gp probe substrates. Conclusion: RG has no relevant potential to cause CYP enzyme- or P-gp-related interactions.

Measurement of Shunt Amount Using Radionuclide Angiocardiography: Accuracy According to Level of Shunt and Associated Lesion (방사성 동위원소 심혈관 조영술을 이용한 단락량 측정법: 정확성에 영향을 미치는 인자)

  • Kim, Yang-Min
    • Nuclear Medicine and Molecular Imaging
    • /
    • v.40 no.4
    • /
    • pp.200-204
    • /
    • 2006
  • Purpose: Determination of pulmonary to systemic blood flow ratio (QP/QS) is important for the management of patients with left-to-right shunt. This study was performed to assess the agreement of Qp/Qs ratio using the radionuclide method and oxymetry, to investigate the factors influencing the agreement, and to know how interchangeable the results of each technique. Materials and Methods: We compared the Qp/Qs measured by single-pass radionuclide angiocardiography and oxymetry during catheterization in 207 patients who underwent both studies. In radionuclide method, Qp/Qs was calculated from the pulmonary time-activity curves using a gamma variate fit. The correlation and Bland-Altman analysis were performed according to the levels of shunt and associated lesions. Results: The mean Qp/Qs was $1.83{\pm}0.50$ by radionuclide, and $1.74{\pm}0.51$ by oxymetry. The overall correlation coefficient was 0.86(p<0.001), and Bland-Altman range of agreement encompassing 4SD was 1.05. For atrial septal defect, ventricular septal defect, patent ductus arteriosus, tricuspid and mitral insufficiency, the correlation coefficient was 0.78, 0.90, 0.84, 0.63 and 0.44, and Bland-Altman range was 1.51, 0.74, 0.96, 1.57, and 1.50, respectively. Conclusion: There is good agreement but wide variance between the Qp/Qs ratios by radionuclide method and oxymetry. Associated atrioventricular valvar insufficiency decreases the correlation coefficient and widens the variance. Wide overall variance suggests that Qp/Qs measurements by two techniques should not be used interchangeably.

BLUE-Based Channel Estimation Technique for Amplify and Forward Wireless Relay Networks

  • PremKumar, M.;SenthilKumaran, V.N.;Thiruvengadam, S.J.
    • ETRI Journal
    • /
    • v.34 no.4
    • /
    • pp.511-517
    • /
    • 2012
  • The best linear unbiased estimator (BLUE) is most suitable for practical application and can be determined with knowledge of only the first and second moments of the probability density function. Although the BLUE is an existing algorithm, it is still largely unexplored and has not yet been applied to channel estimation in amplify and forward (AF)-based wireless relay networks (WRNs). In this paper, a BLUE-based algorithm is proposed to estimate the overall channel impulse response between the source and destination of AF strategy-based WRNs. Theoretical mean square error (MSE) performance for the BLUE is derived to show the accuracy of the proposed channel estimation algorithm. In addition, the Cram$\acute{e}$r-Rao lower bound (CRLB) is derived to validate the MSE performance. The proposed BLUE channel estimation algorithm approaches the CRLB as the length of the training sequence and number of relays increases. Further, the BLUE performs better than the linear minimum MSE estimator due to the minimum variance characteristic exhibited by the BLUE, which happens to be a function of signal-to-noise ratio.

Natural frequency characteristics of composite plates with random properties

  • Salim, S.;Iyengar, N.G.R.;Yadav, D.
    • Structural Engineering and Mechanics
    • /
    • v.6 no.6
    • /
    • pp.659-671
    • /
    • 1998
  • Exercise of complete control on all aspects of any manufacturing / fabrication process is very difficult, leading to uncertainties in the material properties and geometric dimensions of structural components. This is especially true for laminated composites because of the large number of parameters associated with its fabrication. When the basic parameters like elastic modulus, density and Poisson's ratio are random, the derived response characteristics such as deflections, natural frequencies, buckling loads, stresses and strains are also random, being functions of the basic random system parameters. In this study the basic elastic properties of a composite lamina are assumed to be independent random variables. Perturbation formulation is used to model the random parameters assuming the dispersions small compared to the mean values. The system equations are analyzed to obtain the mean and the variance of the plate natural frequencies. Several application problems of free vibration analysis of composite plates, employing the proposed method are discussed. The analysis indicates that, at times it may be important to include the effect of randomness in material properties of composite laminates.

Predictors of Nursing Service Need for Nursing Homes Residents (장기요양시설 노인의 기능상태에 따른 간호서비스 필요도 예측)

  • Lee, Tae-Wha;Cho, Soon-Yung;Jang, Yoon-Kyung
    • Journal of Korean Academy of Nursing
    • /
    • v.39 no.1
    • /
    • pp.95-106
    • /
    • 2009
  • Purpose: The purposes of this study were to explore the functional status of elderly residents and to analyze time use, and finally identify factors to predict nursing care needs in relation to functional status and health related variables. Methods: In this study a descriptive-correlational design was used. Functional status of participants was obtained through interviews, and nursing care time was examined using a 1 min time-motion study with a standardized instrument developed by Korea Long-Term Care Planning Committee (2005). Results: The mean total functional score was 65 (range 28-125) and mean total nursing care time was 144.15 min per day. There were significant positive relationships between total nursing care time, marital status, back pain, dementia, and vision impairment. Multiple regression analyses showed that a liner combination of number of illnesses, types of primary disease, ADL, IADL, cognitive function, nursing demand, and rehabilitation demand explained 42.8% of variance of total nursing time. ADL (${\beta}$=-.533) was the most significant predictor of nursing service need. Conclusion: Identifying factors that result in variations of service need has implications for adequate nursing service, estimation of optimum nurse to patient ratio, quality of care and patient safety.

Comparative studies of different machine learning algorithms in predicting the compressive strength of geopolymer concrete

  • Sagar Paruthi;Ibadur Rahman;Asif Husain
    • Computers and Concrete
    • /
    • v.32 no.6
    • /
    • pp.607-613
    • /
    • 2023
  • The objective of this work is to determine the compressive strength of geopolymer concrete utilizing four distinct machine learning approaches. These techniques are known as gradient boosting machine (GBM), generalized linear model (GLM), extremely randomized trees (XRT), and deep learning (DL). Experimentation is performed to collect the data that is then utilized for training the models. Compressive strength is the response variable, whereas curing days, curing temperature, silica fume, and nanosilica concentration are the different input parameters that are taken into consideration. Several kinds of errors, including root mean square error (RMSE), coefficient of correlation (CC), variance account for (VAF), RMSE to observation's standard deviation ratio (RSR), and Nash-Sutcliffe effectiveness (NSE), were computed to determine the effectiveness of each algorithm. It was observed that, among all the models that were investigated, the GBM is the surrogate model that can predict the compressive strength of the geopolymer concrete with the highest degree of precision.

COMPARISONS OF LOSS FORMULAS FOR A CIRCUIT GROUP WITH OVERFLOW TRAFFIC

  • Park, Chul-Geun;Han, Dong-Hwan
    • Journal of applied mathematics & informatics
    • /
    • v.30 no.1_2
    • /
    • pp.135-145
    • /
    • 2012
  • Traditionally, ERM (Equivalent Random Method) is used to determine number of circuits in an overflow circuit group with rough traffic which has vmr(variance to mean ratio) greater than one. Recently, IPP(Interrupted Poisson Process) approximate method which represents the collective feature of the overflow has been introduced. The negative binomial loss formula can be applied to determine the required number of circuits in the overflow circuit group. In this paper, we deal with the negative binomial loss formula and determination method of number of circuits. We also analyze and compare these three loss formulas.

THE BOES CCD CAMERA II. CHARACTERISTICS OF THE CCD (BOES CCD 카메라 II. 카메라의 특성)

  • Park, B.G.;Seong, H.C.;Jang, J.G.;Jang, B.H.;Lee, B.C.;Park, Y.H.;Kim, K.M.;Han, I.
    • Publications of The Korean Astronomical Society
    • /
    • v.18 no.1
    • /
    • pp.75-79
    • /
    • 2003
  • The characteristics of the BOES (Bohyunsan Observatory Echelle Spectrograph) CCD camera is presented. In order to get optimum gain and readout noise of the CCD, we examine the variation of the gain and readout noise by changing the value of output drain voltage of the CCD and measuring the gain using transfer curve, which is defined as the plot of variance versus mean exposure level of a homogeneous light onto the CCD surface. The gain and readout noises are optimised to be 0.5e$^-$/ADU and 3e$^-$, which is good for highest signal-to-noise ratio and contrast for the low light level characteristics of the BOES. We also measure the dark count of the CCD by getting five dark images with 3600 seconds exposure time. The mean dark count from median stacked dark images is essentially zero. A table of positions of defected pixels is also presented.

Classification of adult male torso shapes using 3D body scan data (3D 스캔 데이터에 의한 성인 남성의 체간부 형태 유형화)

  • Hong, Eun-Hee
    • Journal of the Korea Fashion and Costume Design Association
    • /
    • v.21 no.4
    • /
    • pp.165-179
    • /
    • 2019
  • This study used 3D body scan data to classify body shapes according to the torso shape of adult males aged 20-75 years. This data will be provided so that the apparel industry can make apparel products corresponding to body characteristics by age. The study used 1,796 adult males between the ages of 20 and 75 and the 3D body shape data of the '5th Research on National Standard Anthropometry'. For data analysis, the program SPSSWIN Ver. 17.0 was used to calculate the mean and frequency allowing for a factor analysis, cluster analysis, analysis of variance, and Duncan test. To classify body shape according to the torso shape of adult males, this study considered nine factors: 'horizontal size of torso,' 'vertical size of body,' 'curve of torso and waist-abdomen flatness ratio,' 'length of torso,' 'shape of neck area,' 'degree of lateral curve,' 'difference between front and back interscye length,' 'shoulder armscye shape,' and 'chest flatness ratio.' Based on the results of the factor analysis, the torso shapes of adult males were classified into five types. Type 1 is "upright body with flat, curvy shape", Type 2 is "curve sway back body type", Type 3 is "flat, abdominally obese body", Type 4 is "obese, crooked body" and Type 5 is "thick sway front body type." named.

Interaction of Breed-by-chitosan Supplementation on Growth and Feed Efficiency at Different Supplementing Ages in Broiler Chickens

  • Suk, Y.O.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.17 no.12
    • /
    • pp.1705-1711
    • /
    • 2004
  • Three experiments were conducted to investigate the interaction of breed-by-chitosan supplementation on the major economic traits in broiler chickens. In experiment 1, one-day-old broiler chicks were fed ad libitum on a basal diet (CON-group) or basal diet containing chitosan at an inclusion level of 10.5 mg/bird/day (EXP-group). The EXP-group birds in experiments 2 and 3 were supplemented from 15 day-old by the same amount of chitosan used in experiment 1. In experiment 1, the mean body weight of the EXP-group chickens was significantly (p<0.05) heavier in comparison with those of CON-group birds from day 21 of the experiment. Especially in 35 day-old mean body weight, the EXP-group birds of Arbor Acres, Peterson, and Ross were significantly (p<0.05) heavier by 121.8 g, 118.5 g, and 242.8 g than the CON-group birds, respectively. However, the mean body weights in experiments 2 and 3 did not significantly differ between the CON-group birds and the EXP-group birds fed with chitosan supplementation from day 15 post birth. In the comparisons among breeds on the mean body weight at 35 day-old, the birds of Arbor Acres were significantly (p<0.05) heavier than ones of Peterson or Ross; however, there were no significant differences between Peterson and Ross or Cobb and Ross birds in overall in the experiments. The mean 15-35 d FCR of the EXP-group birds in experiment 1 were significantly (p<0.05) lower at least in two of the three breeds (Arbor Acres and Ross breeds) than that of the CON-group birds. None of the mean 15-35 d FCR in either experiment 2 or 3 showed significant differences between groups within a breed. In all three experiments, the differences amongst breeds in the mean 15-35 d FCR were not great either. Significant differences were not generally shown in the mean percentage of abdominal fat deposition between groups within a breed in overall experiments except in the Cobb breed in experiment 3. The mean percentages of abdominal fat deposition were significantly (p<0.05) lower in Ross birds than in Arbor Acres or Peterson birds and in Cobb birds than in Ross birds. By the results of the analysis of variance, the interaction of breed-by-diet (chitosan) supplementation on any of the major economic traits including mean percentage of abdominal fat deposition was not significant in overall experiments. Results of these experiments indicate that dietary supplementation with chitosan for the improvement of growth or feed conversion ratio in broilers has an efficacy when the supplementation begins from day-old.