• Title/Summary/Keyword: Reproducibility of the results

Search Result 869, Processing Time 0.022 seconds

A Study on the Effects of Immediate Side Shift to the Pantographic Reproducibility Index (Immediate Side Shift가 Pantographic Reproducibility Index에 끼치는 영향에 관한 연구)

  • Nam, Cheon Woo;Han, Kyung Soo
    • Journal of Oral Medicine and Pain
    • /
    • v.12 no.1
    • /
    • pp.75-83
    • /
    • 1987
  • This study was designed to investigate the effects of TMJ incoordination to condylar movements, especially, the ISS. The sounds are one of the symptoms in TMJ incoordinated disorder, and it may cause the changes of mandibular movement trajectory. 19 students with only TMJ sounds and 16 students with no TMJ problems participated in this study. The subject performed Rt. lateral, Lt. lateral and protrusive movements, and repeated 3 times on each movement. Pantronic was used to record the measures of condylar movement paths. The obtained results were as follows : 1. The mean values of RISS and LISS in control group were 0.29mm, 0.36mm respectively, and those in experimental group were 0.49mm, 0.41mm repectively. The mean values of RISS was higher in experimental group than that of RISS in control group. 2. Correlation coefficients between PRI and RISS, LISS were slightly higher in experimental group than those in control group, therefore, PRI was more likely to be affected by ISS in experimental group. 3. In control group PRI was correlated to RISS, LORB, RPRO and LPRO, but in experimental group PRI was not correlated to those items. From the study, the author knew that the condylar movements was stable in control group.

  • PDF

A Study of Gage R&R Analysis Considering the Variations of Between-Within Group and Within Part (군간-군내-부품내 변동을 고려한 Gage R&R 분석에 관한 연구)

  • Lee, Seung-Hoon;Lee, Chang-Woo
    • IE interfaces
    • /
    • v.18 no.4
    • /
    • pp.444-453
    • /
    • 2005
  • The purpose of the Gage R&R study is to determine whether a measurement system is adequate for monitoring a process. If the measurement system variation is small relative to the process variation, then the measurement system is deemed "adequate". The sources of variation associated with the measurement system are compared using an analysis of variance (ANOVA) model, in general. A typical ANOVA model used in a standard Gage R&R study is the two-factor random effect model. Then, the ANOVA partitions the total variation into three categories: repeatability, reproducibility, part variation. However, if the process variation possesses the between group variation, within group variation, and within part variation, these variations can cause the measurement system evaluation to provide misleading results. That is, in the standard Gage R&R study these variations affect the estimate of repeatability, reproducibility, or both. This paper presents a four-factor nested factorial ANOVA model which explicitly considers these variations for the Gage R&R study. The variance component estimators are derived by setting the EMS equations equal to the corresponding mean square from the ANOVA table and solving. And the proposed model is compared with the standard Gage R&R model.

Catalytic Biofilms on Structured Packing for the Production of Glycolic Acid

  • Li, Xuan Zhong;Hauer, Bernhard;Rosche, Bettina
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.2
    • /
    • pp.195-204
    • /
    • 2013
  • While structured packing modules are known to be efficient for surface wetting and gas-liquid exchange in abiotic surface catalysis, this model study explores structured packing as a growth surface for catalytic biofilms. Microbial biofilms have been proposed as selfimmobilized and self-regenerating catalysts for the production of chemicals. A concern is that the complex and dynamic nature of biofilms may cause fluctuations in their catalytic performance over time or may affect process reproducibility. An aerated continuous trickle-bed biofilm reactor system was designed with a 3 L structured packing, liquid recycling and pH control. Pseudomonas diminuta established a biofilm on the stainless steel structured packing with a specific surface area of 500 $m^2m^{-3}$ and catalyzed the oxidation of ethylene glycol to glycolic acid for over two months of continuous operation. A steady-state productivity of up to 1.6 $gl^{-1}h^{-1}$ was achieved at a dilution rate of 0.33 $h^{-1}$. Process reproducibility between three independent runs was excellent, despite process interruptions and activity variations in cultures grown from biofilm effluent cells. The results demonstrate the robustness of a catalytic biofilm on structured packing, despite its dynamic nature. Implementation is recommended for whole-cell processes that require efficient gas-liquid exchange, catalyst retention for continuous operation, or improved catalyst stability.

Development of Direct Measurement Device for Alveolar Breath Carbon Monoxide

  • Jo, Wan-Kuen;Oh, Jee-Won
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.18 no.E4
    • /
    • pp.181-190
    • /
    • 2002
  • A novel portable device for the direct measurement of alveolar breath carbon monoxide (CO) was developed. The major components of the device include a mouthpiece, non-rebreathing two-way valve, Teflon tube, and CO dosimeter. An alveolar CO measurement can be completed within 1.5 min when using the proposed device and measurement protocol. Measurements could be read to the nearest 0.1 ppm. Humidity did not influence the CO measurements taken by the CO dosimeter, plus there were no problems associated with the recovery and carryover of CO through the device. The criterion for significance in statistical analyses was p< 0.05. The average recovery was 103 and 99% for recovery and carryover experiments, respectively. Test results using the proposed alveolar CO measurement system reflected a good reproducibility. This reproducibility was also supported by the finding that the relative standard deviations (RSDs) of the data sets were less than 7% for the loss experiment and less than 8% for the carryover experiment. Consequently, it would appear that the proposed device can be effectively applied to measure CO levels found in breath, thereby overcoming several disadvantages associated with the conventional bag and adsorbent tube sampling methods.

A Study of Gage R&R Analysis Considering the Variations of Between-Within Group and Within Part (군간-군내-부품내 변동을 고려한 Gage R&R 분석에 관한 연구)

  • Lee, Seung-Hun;Lee, Chang-U
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 2005.05a
    • /
    • pp.975-982
    • /
    • 2005
  • The purpose of the Gage R&R study is to determine whether a measurement system is adequate for monitoring a process. If the measurement system variation is small relative to the process variation, then the measurement system is deemed 'adequate'. The sources of variation associated with the measurement system are compared using an analysis of variance (ANOVA) model, in general. A typical ANOVA model used in a standard Gage R&R study is the two-factor random effect model. Then, the ANOVA partitions the total variation into three categories: repeatability, reproducibility, part variation. However, if the process variation possesses the between group variation, within group variation, and within-part variation, these variations can cause the measurement system evaluation to provide misleading results. That is, in the standard Gage R&R study these variations affect the estimate of repeatability, reproducibility, or both. This paper presents a four-factor nested factorial ANOVA model which explicitly considers these variations for the Gage R&R study. The variance component estimates are derived by setting the EMS equations equal to the corresponding mean square from the ANOVA table and solving. And the proposed model is compared with the standard Gage R&R model.

  • PDF

Reproducibility of Measures of Lumbar Spine, Hip and Whole Body BMD according to Longitudinal Physical Activity in Older Athletes (노인 운동가에 있어 장기적인 운동에 따른 척추, 힙과 신체 총 골밀도 감소에 관한 재현성)

  • Jung, Youn-Soo
    • Journal of muscle and joint health
    • /
    • v.8 no.2
    • /
    • pp.278-286
    • /
    • 2001
  • With the aging of society a great deal of interest is being placed on the value of longitudinal data in evaluating physiological losses. We present data on test-one/test-two reliability and reproducibility for measures of training, bone density from a longitudinal study of master athletes. Fifty-two males (mean age at test $1=58.2{\pm}9.8\;years$) and thirty-two females ($54.4{\pm}8.8\;years$) were selected from the study population. Bone mineral density was determined using DEXA (Hologic 1500). The characteristics of the subjects are presented below as $means\;{\pm}\;S.D$. The data was imported into the Statistical Package for the Social Science (SPSS 9.0, Chicago, IL). Paired t-tests were performed between visit 1 and visit 2 in subjects. Pearson correlations were performed. The results of this study indicate the measures of training history, body mass and bone density are reasonably stable and reproducible. We conclude that body composition and bone density parameters are stable and reproducible over time in active older subjects. Physiologic measures in master athletes are fairly stable, and reproducible over time Longitudinal studies investigating age-related changes in master athletes need to be conducted on a time schedule of greater than two years.

  • PDF

Reproducibility and validity of semi-quantitative food frequency questionnaire measuring dietary trans-fatty acids intake among Korean adults

  • Joh, Hee-Kyung;Oh, Seung-Won;Lee, Eun
    • Nutrition Research and Practice
    • /
    • v.9 no.1
    • /
    • pp.99-105
    • /
    • 2015
  • BACKGROUND/OBJECTIVES: Compelling evidence indicates that consumption of trans-fatty acids (TFA) is associated with a wide range of diseases. However, few validated tools for TFA intake assessment are available in Korea. We aimed to validate a food frequency questionnaire (FFQ) estimating usual intake of TFA in Korean adults. MATERIALS/METHODS: Eighty-two healthy adults completed an FFQ with a 3-day diet record (3DDR), and 58 completed a second FFQ at a 1-month interval. To assess the reproducibility of the FFQ, we compared estimated TFA intakes from each FFQ. To assess the validity, we compared estimates from the FFQ with those from the 3DDR. RESULTS: The FFQ was reproducible (Spearman r = 0.71) and provided modest correlations with the 3DDR (Spearman r = 0.38). After adjustment for total energy intake, the correlations increased (r = 0.45). Measurement-error correction also de-attenuated the correlations (r = 0.57). When quintiles of the FFQ and 3DDR were joint-classified, 9% on average were misclassified into extreme quintiles. CONCLUSIONS: Our findings suggest that the developed FFQ is reproducible and reasonably valid in categorizing individuals according to TFA intakes among healthy young and middle aged adults in Korea.

Improvement of the repeatability and reproducibility of the meridian impedance measurement system MIR-2 (경락노선상 임피던스 측정기(MIR-2)의 측정신뢰도 개선방안 연구)

  • Yin, Chang-Shik;Lee, Hye-Jung;Kim, Jong-Yeol;Lee, Woo-Cheol
    • Korean Journal of Acupuncture
    • /
    • v.24 no.4
    • /
    • pp.55-67
    • /
    • 2007
  • Objectives : The repeatability and reproducibility of MIR-2, a newly developed impedance measurement device (four electrode method) on skin are of the meridian system, is evaluated and a method to improve the reliability is discussed. Methods : Multiple gage R&R studies were conducted for the impedance measurements over bilateral KI3 acupoint in ten participants by three assessors using MIR-2 device. Gage R&R studies were repeated after controlling the acupoint locating method or one value correction by replacing one assessor's outlying value with an average of the other assessors' values to explore any feasibility of improvement of measurement reliability. Results : Controlling acupoint locating method and replacing one value with an average of other assessors' value led to improved variation metrics in a gage R&R study. Conclusions : Measurement reliability can be improved by controlling measurement procedures or by using repeated measurement method, which will facilitate development of clinically applicable measurement device with reliability.

  • PDF

A numerical method for improving the reliability of knee translation measurement in skin marker-based motion analysis

  • Wang, Hongsheng;Zheng, Nigel
    • Advances in biomechanics and applications
    • /
    • v.1 no.4
    • /
    • pp.269-277
    • /
    • 2014
  • In skin-marker based motion analysis, knee translation measurement is highly dependent on a pre-selected reference point (functional center) on each segment determined by the location of anatomical landmarks. However, the placement of skin markers on palpable anatomical landmarks (i.e., femoral epicondyles) has limited reproducibility. Thus, it produces large variances in knee translation measurement among different subjects, as well as across studies. In order improve the repeatability of knee translation measurement, in this study an optimization method was introduced, by which the femoral functional center was numerically determined. At that point the knee anteroposterior translation during the stance phase of walking was minimized. This new method was tested on 30 healthy subjects during walking in gait lab with motion capture system. Using this new method, the impact of skin marker position (at anatomical landmarks) on the knee translation measurement has been minimized. In addition, the ranges of anteroposterior knee translations during stance phase were significantly (p<0.001) smaller than those measured by conventional method which relies on a pre-selected functional center ($11.1{\pm}3.5mm$ vs. $19.9{\pm}5.5mm$). The results of anteroposterior translation using this new method were very close to a previously reported knee translation (12.4 mm) from dual fluoroscopic imaging technique. Moreover, this new method increased the reproducibility of knee translation measurement by 50%.

Optimization of Wet Reduction Processing for Nanosized Cobalt Powder (나노코발트 분말합성을 위한 액상환원공정의 최적화)

  • Hong, Hyun-Seon;Jung, Hang-Chul;Kim, Geon-Hong;Kang, Lee-Seung;Suk, Han-Gil
    • Journal of Powder Materials
    • /
    • v.20 no.3
    • /
    • pp.191-196
    • /
    • 2013
  • Nano-sized cobalt powder was fabricated by wet chemical reduction method at room temperature. The effects of various experimental variables on the overall properties of fabricated nano-sized cobalt powders have been investigated in detail, and amount of NaOH and reducing agent and dropping speed of reducing agent have been properly selected as experimental variables in the present research. Minitab program which could find optimized conditions was adopted as a statistic analysis. 3D Scatter-Plot and DOE (Design of Experiments) conditions for synthesis of nano-sized cobalt powder were well developed using Box-Behnken DOE method. Based on the results of the DOE process, reproducibility test were performed for nano-sized cobalt powder. Spherical nano-sized cobalt powders with an average size of 70-100 nm were successfully developed and crystalline peaks for the HCP and FCC structure were observed without second phase such as $Co(OH)_2$.