Research on Reliability Design and Verification of CT Based on Clinical Application Data / 中国医疗器械杂志

Based on the clinical application data of medical X-ray computed tomography (CT) in the Shanghai Sixth People's Hospital, this study transformed it into the product reliability index requirements, and took the mechanical representative component-examination table (hereinafter referred to as "patient table") and the electronic representative component-DCB (data control board) as examples. Based on the relationship between failure characteristics and clinical application data, a complete set of closed-loop implementation methods from reliability index requirements to reliability design and verification are discussed.

Trinta e dois anos do programa de melhoramento do feijoeiro comum em Minas Gerais / Thirty two years of common bean breeding in Minas Gerais state

Conduziu-se este trabalho, com o objetivo de proceder à análise crítica do Programa de melhoramento genético do feijoeiro comum em Minas Gerais nos últimos 32 anos com ênfase nas implicações da interação linhagens x ambientes, além de avaliar se houve progresso genético. Para isso, foram utilizados dados de 169 experimentos conduzidos no período de 1974 a 2004 e que envolveram 16 locais e três safras. A média da cultivar Carioca, comum em todos os experimentos, foi utilizada como estimador do efeito ambiental e a média das cinco melhores linhagens sob avaliação de cada biênio, como efeito fenotípico. A diferença entre essas duas médias forneceu o desvio genético. O coeficiente de regressão linear entre desvio genético Y (variável dependente) e o biênio X (variável independente) forneceu a estimativa do progresso genético. As interações linhagens x safras e linhagens x anos foram, na maioria dos casos, significativas, contudo, suas contribuições para a variação total foram inferiores a de linhagens x locais. Desse modo, fica clara a necessidade de que os experimentos sejam conduzidos em um maior número de locais. O programa de melhoramento genético do feijoeiro da UFLA tem sido eficiente e tem obtido linhagens com menor risco de adoção.

The objective of the present work was to make critical analysis of the dry bean genetic breeding program in Minas Gerais in the last 32 years by lines x environments interactions and genetic progress evaluations. Data from 169 experiments conducted from 1974 to 2004 in 16 locations and three seasons per year were used. The average of the cultivar Carioca, test in all experiments, was used as indicator of environmental variation; and the average of the five best lines, under evaluation in each biennium, was used as indicator of phenotypic variation. The difference between these two averages was used as genetic deviation. Genetic progress was estimated by linear regression coefficient between genetic deviation Y (dependent variable) and biennium X (independent variable). The interactions among lines x seasons and lines x years were significant in most cases, however, their contributions to the total variation were inferior to the lines x locations. Thus, it was necessary to conduct experiments in a larger number of locations. The common bean breeding program at UFLA has been efficient and has selected lines with less risk for adoption for farmers.

Correlation among Item Characteristics of Examinations in College of Medicine / 한국의학교육

After item analysis of examinations in College of Medicine, the correlation among characteristics were examined for the better understanding of their meaning. The 78 subjected examinations in College of Medicine, Hallym University, Korea from March 1999 to October 2000 were analyzed. Discrimination indexes (D) by the method of extreme group were positively correlated with item-total correlation(ITC) with mean correlation coefficient r=0.8506 ranged between 0.6430 and 0.9520. Number of items of each examination was positively correlated with Cronbach coefficient alpha reliability index(r=0.7920) whereas negatively correlated with standard deviation(r=-0.5691), odd-even split reliability index(r=-0.8767) and mean ITC(r=-0.4079). Thereafter, the standard deviation was positively correlated with odd-even split reliability index (r=0.5072) and mean ITC(r=0.6166). There was negative correlation between Cronbach coefficient alpha reliability index and odd-even split reliability index(r=-0.7385). Above results suggested that the number of items in each examination was most powerful factor affecting to other item analysis characteristics. The appropriate number of items should be considered for better result of item analysis characteristics. Odd-even split reliability index is not appropriate for the estimation of the reliability among item, since it decreased according to the increase of number of items. Positive and high correlation between D and ITC means that both methods are appropriate to interpretate the discriminating power of the items.