• 제목/요약/키워드: statistical confidence

Search Result 1,002, Processing Time 0.032 seconds

A Comparison of Sample Size Requirements for Intraclass Correlation Coefficient(ICC) (신뢰도 연구에서 급내상관계수와 관련한 표본수 결정 방법 비교)

  • Han, Soo-Yeon;Nam, Jung-Mo;Myoung, Sung-Min;Song, Ki-Jun
    • The Korean Journal of Applied Statistics
    • /
    • v.23 no.3
    • /
    • pp.497-510
    • /
    • 2010
  • In medical practice and research, the problem of assessing reliability between two or more quantitative measures is quite common. Intraclass correlation coefficient(ICC) is commonly used to scale of reliability. Some methods were developed to calculate the required number of subjects, raters or replicates in one-way or two-way random ANOVA models. This paper, studies and compares the performance of four methods such as Walter et al. (1998), Giraudeau and Mary (2001), Saito et al. (2006) and Bonett (2002). In order to compare the efficiency of methods we compare the number of subjects, replicates and the width of confidence interval of ICC needed for some specific ICC values. In the case of subject size, Giraudeau's method is the best. In case of the number of replicates, Saito's method was superior to others. The width of confidence interval of ICC was narrower for Giraudeau's method than any others.

REAL-TIME QUALITY EVALUATION OF FRICTION WELDING OF MACHINE COMPONENTS BY ACOUSTIC EMISSION (음향방출법(AE)에 의한 기계요소재의 마찰용접 품질 실시간 평가)

  • SAE-KYOO OH
    • Proceedings of the KWS Conference
    • /
    • 1995.10a
    • /
    • pp.3-20
    • /
    • 1995
  • Development of Real-Time Quality Evaluation of Friction Welding by Acousitc Emission : Report 1 ABSTRACT : According as the friction welding has been increasingly applied in manufacturing various machine components because of its significant economic and technical advantages, one of the important concerns is the reliable quality monitoring method for a good weld quality with both joint strength and toughness in the process of its production. However no reliable nondestructive test method is available at present to determine the weld quality particularly in process of production. So this paper presents an experimental examination and quantitative analysis for the real-time evaluation of friction weld quality by acoustic emission, as a new approach which attempts finally to develop an on-line quality monitoring system design for friction welds using AE techniques. As one of the important results, it was confirmed, through this study, that AE techniques can be reliably applied to evaluating the friction weld qualify with 100% joint strength, as the cumulative AE counts occurring during welding period were quantitatively correlated with reliability at 95% confidence level to the joint strength of welds. Real-Time Evaluation of Automatic Production Quality Control for Friction Welding Machine : Report 2 Abstract : Both in-process quality control and high reliability of the weld is one of the major concerns in applying friction welding to the economical and qualified mass-production. No reliable nondestructive monitoring method is available at present to determine the real-time evaluation of automatic production quality control for friction welding machine. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the initial cumulative counts of acoustic emission(AE) occurring during plastic deformation period of the welding and the tensile strength of the welded joints as well as the various welding variables, as a new approach which attempts finally to develop an on-line (or real-time) quality monitoring system and a program for the process of real-time friction welding quality evaluation by initial AE cumulative counts. As one of the important results, it was well confirmed that the initial AE cumulative counts were quantitatively and cubically correlated with reliability of 95% confidence level to the joint strength of the welds, bar-to-bar (SCM4 to SUM31, SCM4 to SUM24L) and that an AE technique using initial AE counts can be reliably applied to real-time strength evaluation of the welded joints, and that such a program of the system was well developed resulting in practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro-structural defects.

  • PDF

A Study on The Dental field of Present Health Insurance for custom-made Prosthetic implant by Dental technicians (건강보험 급여화 관련 치과임플란트보철물 제작실태 연구)

  • Lee, Heekyung;Cho, Mihyang
    • Journal of Technologic Dentistry
    • /
    • v.38 no.1
    • /
    • pp.9-22
    • /
    • 2016
  • Purpose: The Purpose of this study are to describe the Dental field of present health insurance for custom-made prosthetic implant by dental technicians' work. Results: A total of 300 dental technicians working at dental laboratories in Korea were randomly selected and surveyed, 206(68.7%) of them were used for the statistical analysis. Conclusion: Average daily working time was 10 hours 66%. The average cumulative credit of the clinic for dental prosthesis fabrication rates was Less than 10 million won(21.8%), 10~80 million won(11.7%), more than one hundred million won(1.5%). Remake dental prosthesis was one more than the monthly average of 98.5%. Causes of remake dental prosthesis was dentist impression 83% but did not pay 62.5%. Dental technicians Implant production period was 7 days(48.5%), 10 days(35%) was commissioned by dentists production time is 5 days(46.1%), 7 days(36.5%). President of dental laboratories 3.86 points and dental technicians 3.06 points knew differently about starting of implant health insurance coverage(p<.001). They alike were in favor of insurance coverage for the implant. Dental technicians were lower by 2.36 points for work do you know whether your health insurance application of dental prostheses. Dental technicians are 2.16 points on whether confidence in the pores payment of insurance coverage dental prosthesis, dental laboratory president was lower by 1.85 points. They are very low with 1.97 points on whether confidence in the rate payment of health insurance coverage dental prosthesis(p<.01). The implant prosthesis abutment selected, the abutments designed, design of the implant upper prosthetic, the upper prosthetic fitting dental technicians participate of dental laboratory president showed higher score (p <.05). Conclusion: Hours of dental technicians were making this short period of remake dental prosthesis-related dental prosthesis. Dental clinic and a detailed representation of the dental prosthodontic fabrication request is required for communication between the laboratory in order to reduce the remake of a dental prosthesis, dental insurance coverage written dental prosthodontic fabrication request should be legislated. Implant classification standard medical practice 1-3 Step conduct a thorough costing a total of no. 73 of the correct classification standard medical practice in addition to eight times defined by the act of dental technicians should be defined.

An Analysis of the Productivity Changes of Korean Pharmaceutical Industry Using Bootstrapped Malmquist Index (Bootstrapped Malmquist 지수를 이용한 국내 의약품산업의 생산성 변화 요인 분석에 관한 연구)

  • So, Soon-Hu
    • Management & Information Systems Review
    • /
    • v.35 no.4
    • /
    • pp.141-153
    • /
    • 2016
  • This study estimates the productivity change of pharmaceutical industry and decompose the change into technical efficiency change and technological change to explore ways to improve the productive efficiency. Unlike most previous studies, this study employs the non-radial and non-oriented slacks-based Malmquist productivity index which can deals directly with the input excesses and output shortfalls. In addition a smoothed bootstrap method is applied to estimate statistical confidence intervals for the Malmquist Index and its components. For the empirical analysis a balanced panel data set is constructed covering ten years over the period from 2005 to 2014. The input variables used in this study are number of workers, tangible assets and major production cost. The gross production is selected as a main output variable. The empirical results suggest that the productivity of pharmaceutical industry has decreased due mainly to decline in the technological progress rather than improvements in technical efficiency. An analysis result shows that the scale efficiency outweighs the pure efficiency in determining the technical efficiency of pharmaceutical industry. Therefore, in order to enhance the competitiveness of domestic pharmaceutical industry, it is important to continue supporting policies to promote the technology innovation capability through efficient R&D investment and industry reform strategy.

  • PDF

Bioequivalence of Alpit Tablet to Algiron Tablet (Cimetropium Bromide 50 mg) (알기론 정(브롬화 시메트로피움 50 mg)에 대한 알피트 정의 생물학적 동등성)

  • Cho, Hea-Young;Moon, Jai-Dong;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
    • /
    • v.32 no.1
    • /
    • pp.47-54
    • /
    • 2002
  • Cimetropium bromide, a quaternary ammonium compound which is chemically related to scopolamine, exhibits its antispasmodic activity by competing with acetylcholine for the muscarinic receptors of the smooth muscle of gastrointestinal tract. The drug has been used for the treatment of various disorders involving spasms of the musculature of the gastrointestinal, biliary and genitourinary tracts. The purpose of the present study was to evaluate the bioequivalence of two cimetropium bromide tablets, $Algiron^{TM}$ (Boehringer Ingelheim Korea Ltd.) and $Alpit^{TM}$ (Hana Pharmaceutical Co., Ltd.), according to the prior and revised guidelines of Korea Food and Drug Administration (KFDA). The cimetropium bromide release from the two cimetropium bromide tablets in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty normal male volunteers, $25.25{\pm}2.10$ years in age and $65.76{\pm}6.39$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After three tablets containing 50 mg of cimetropium bromide per tablet were orally administered, blood was taken at predetermined time intervals and the concentrations of cimetropium bromide in serum were determined using HPLC method with UV detector. The dissolution profiles of two cimetropium bromide tablets were very similar at all dissolution media. Besides, the 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 non-transformed and logarithmically transformed $AUC_t\;and\;C_{max}$. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two tablets based on the $Algiron^{TM}$ were 2.19%, -5.97% and 3.49%, respectively. Minimum detectable differences $({\Delta})\;at \;{\alpha}=0.05\;and\;1-{\beta}=0.8$ were less than 20% (e.g., 13.71 %, 19.05% and 15.11% for $AUC_t,\;C_{max}\;and\;T_{max}$, respectively). The powers $(1-{\beta})\;at\;{\alpha}=0.05,\;{\Delta}=0.2\;for\;AUC_t$, $C_{max}\;and\;T_{max}$ were 97.79%, 83.22% and 95.60%, respectively. The 90% confidence intervals were within ${\pm}20%$ (e.g., $-5.84{\sim}10.21,\;-17.11{\sim}5.18\;and\;-5.35{\sim}12.33\;for\;AUC_t,\;C_{max}\;and\;T_{max}$, respectively). There were no sequence effect between two tablets in logarithmically transformed $AUC_t\;and\;C_{max}$. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., $0.94{\sim}1.10\;and\;0.85{\sim}1.05\;for\;AUC_t\;and\;C_{max}$, respectively). Two parameters met the criteria of prior and revised KFDA guideline for bioequivalence, indicating that $Alpit^{TM}$ tablet is bioequivalent to $Algiron^{TM}$ tablet.

Reliability Study for Upgrade of Diagnosis System of Oriental Medicine DSOM(r) S.1.1 (한방진단설문지 DSOM (r) S.1.1의 Upgrade를 위한 신뢰도 연구)

  • Lee, In-Seon;Kim, Jong-Won;Chi, Gyoo-Yong;Lee, Yong-Tae;Kim, Kyu-Kon
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.26 no.1
    • /
    • pp.88-97
    • /
    • 2012
  • DSOM(Diagnosis System of Oriental Medicine), questionnaire for oriental medical(medicine) diagnosis is an online survey system containing 152 questions for female, 149 questions for male that asking the basic symtoms of 16 pathogenic factors(病機). The result of DSOM denotes reliability according to the level of major symptoms of each pathogenic factor. Standard level of reliability is equal to all 16 pathogenic factor basically except phlegm(痰). In case of phlegm(痰) we give different weight depending on whether the factor includes gray color under the orbit(痰飮氣) or not. To examine reliability of DSOM, statistical analysis has been done to the data of felmale 10101, male 1564 except for bad responses and stored between 1st April 2000 to 3rd June 2011. Based on the study, the conclusions were as follows. Reliability of DSOM. For female, all pathogenic factors showed over 85% confidence level except for phlegm 82.6%. For male, all pathogenic factors showed more than 90% confidence level except two factors, phlegm(痰) indicates 87.% and damp(濕) indicates 89.8%. HH rates among pathogenic factors were more than 50 points. For female, HH rates of other 14 pathogenic factors were all over 80% except for heat(熱) 78.2% and insufficiency of Yang(陽虛) 75.3%. For male HH rates of all pathogenic factors were more than 80% except HH rates of heat 78.2% and damp 77.8%. Research based on a degree of satisfaction of reliability derived from pathogenic factors with scores of HH results in for all 16 pathogenic factors showed over 85% of relatively high level of satisfaction for both sexes whose reliability standard come under 5~4 points. Comparing appearance frequency of pathogenic factors for both sexes. Male only displays higer than female in heat(熱). Whereas female were higher than male for other 15 pathogenic factors and the difference was biggest in heart(心) and least in insufficiency of Yin(陰虛). Comparing appearance frequency order of pathogenic factors for both sexes. Female outdistanced male in blood stasis(血瘀) coldness(寒) blood-deficiency(血虛) phlegm(痰), while male outdistance female in heat(熱) insufficiency of Yin(陰虛) deficiency of qi(氣虛). Male had lower average of each pathogenic factors than female except heat(熱) as well as deficiency of qi(氣虛).

Spatio-temporal Evaluation of Air Temperature-Water Quality Elasticity in Tributary Streams According To Climate Change (기후변화에 따른 지류 하천의 시공간적 기온-수질 탄성도 영향 평가)

  • Park, Jaebeom;Kal, Byungseok;Kim, Seongmin
    • Journal of Wetlands Research
    • /
    • v.23 no.4
    • /
    • pp.296-306
    • /
    • 2021
  • Elasticity is a statistical technique that interprets the changing pattern of another variable according to a change in one variable as a quantitative numerical value and provides more information than correlation analysis and is widely used in climate change research. In this study the elasticity was calculated and sensitivity analysis was performed using air temperature and water quality data of the major tributaries of the Nakdong River. In addition the confidence interval for the elasticity was calculated using the T-Test and the validity of the elasticity was examined. The strength of elasticity shows high strength in the order of summer>fall>spring>winter and the direction shows regional characteristics with both negative and positive elasticity. After performing hierarchical cluster analysis on monthly observation data they were classified into 5 clusters and the characteristics of each cluster were visually analyzed using a parallel coordinate graph. The direction and intensity of the air temperature elasticity show regional characteristics due to the relatively high population density and complex influencing factors such as sewage treatment plants, small-scale livestock houses and agricultural activities. In the case of TP it shows great regional variability according to the circulation of nutrients in the ecosystem caused by algae growth and death according to temperature changes. Since the air temperature elasticity of the major tributaries of the Nakdong River is over weak and is valid at the significance level of 5%, it was analyzed that there is a change in water quality according to the air temperature change.

A Study on the Estimation of the Minimum Buoyancy for the Respiration of a Drowning Person (익수자의 호흡이 가능한 최소 부력 추정에 관한 연구)

  • Yim, Jeong-Bin;Park, Deuk-Jin;Kang, Yu Mi
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.23 no.7
    • /
    • pp.820-828
    • /
    • 2017
  • Tools and equipment that can provide buoyancy for a drowning person are important for saving lives. The purpose of this study was to estimate the minimum amount of gas needed and the buoyancy value in newton units required to generate the minimum buoyancy determined to be sufficient for keeping the head of a drowning person above the water's surface to allow for respiration for at least 1 minute. A buoyancy experiment was carried out with a long rubber balloon injected with carbon dioxide gas, and a buoyancy measurement experiment was performed on six college students. The degree of buoyancy was measured using a 5-point scale, and the statistical value of the measured data was analyzed to estimate minimum buoyancy. As a result, 8 grams of carbon dioxide were determined to satisfy minimum buoyancy conditions with a confidence level of 72%, and buoyancy was calculated to be 44.66 newtons. 12 grams of carbon dioxide met the minimum buoyancy conditions with a confidence level of 100%, and buoyancy was calculated to be 66.99 newtons. This study is expected to contribute to the development of low cost, easy-to-carry minimum buoyancy aids.

An Experimental Study on Assessing Precision and Accuracy of Low-cost UAV-based Photogrammetry (저가형 UAV 사진측량의 정밀도 및 정확도 분석 실험에 관한 연구)

  • Yun, Seonghyeon;Lee, Hungkyu;Choi, Woonggyu;Jeong, Woochul;Jo, Eonjeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.40 no.3
    • /
    • pp.207-215
    • /
    • 2022
  • This research has been focused on accessing precision and accuracy of UAV (Unmanned Aerial Vehicle)-derived 3-D surveying coordinates. To this end, a highly precise and accurate testing control network had been established by GNSS (Global Navigation Satellite Systems) campaign and its network adjustment. The coordinates of the ground control points and the check points were estimated within 1cm accuracy for 95% of the confidence level. FC330 camera mounted on DJI Phantom 4 repeatedly took aerial photos of an experimental area seven times, and then processed them by two widely used software packages. To evaluate the precision and accuracy of the aerial surveys, 3-D coordinates of the ten check points which automatically extracted by software were compared with GNSS solutions. For the 95% confidence level, the standard deviation of two software's result is within 1cm, 2cm, and 4cm for the north-south, east-west, and height direction, and RMSE (Root Mean Square Error) is within 9cm and 8cm for the horizontal, vertical component, respectively. The interest is that the standard deviation is much smaller than RMSE. The F-ratio test was performed to confirm the statistical difference between the two software processing results. For the standard deviation and RMSE of most positional components, exception of RMSE of the height, the null hypothesis of the one-tailed tests was rejected. It indicates that the result of UAV photogrammetry can be different statistically based on the processing software.

Optimal Estimation of the Peak Wave Period using Smoothing Method (평활화 기법을 이용한 파랑 첨두주기 최적 추정)

  • Uk-Jae, Lee;Byeong Wook, Lee;Dong-Hui, Ko;Hong-Yeon, Cho
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.34 no.6
    • /
    • pp.266-274
    • /
    • 2022
  • In this study, a smoothing method was applied to improve the accuracy of peak wave period estimation using the water surface elevation observed from the Oceanographic and Meteorological Observation Tower located on the west coast of the Korean Peninsula. Validation of the application of the smoothing method was per- formed using variance of the surface elevation and total amount wave energy, and then the effect on the application of smoothing was analyzed. As a result of the analysis, the correlation coefficient between variance of the surface elevation and total amount wave energy was 0.9994, confirming that there was no problem in applying the method. Thereafter, as a result of reviewing the effect of smoothing, it was found to be reduced by about 4 times compared to the confidence interval of the existing estimated spectrum, confirming that the accuracy of the estimated peak wave period was improved. It was found that there was a statistically significant difference in proba- bility density between 4 and 6 seconds due to the smoothing application. In addition, for optimal smoothing, the appropriate number of smoothings according to the significant wave height range was calculated using a statistical technique, and the number of smoothings was found to increase due to the unstable spectral shape as the significant wave height decreased.