Today’s wireless communication products become more complex and more integrated. The low cost prices paid by the consumer for wireless phones and the competitive market imposed a tremendous pressure to have low cost RF ICs. The test cost becomes almost the main factor determining profit margin. To economically test high volumes of integrated RF ICs at a fraction of the cost of the IC we have to...

To the Editors: Of course we agree with Kristal et al. (1) that validity is an issue of degree rather than a dichotomy and that multiple methods will usually be useful when evaluating validity because a perfect standard is rarely available. However, their examples based on face validity, construct validity, and predictive validity do not provide evidence that food frequency questionnaires shoul...

Researchers at the National Cancer Institute developed a new cognitively based food frequency questionnaire (FFQ), the Diet History Questionnaire (DHQ). The Eating at America's Table Study sought to validate and compare the DHQ with the Block and Willett FFQs. Of 1,640 men and women recruited to participate from a nationally representative sample in 1997, 1,301 completed four telephone 24-hour ...

In measuring food intake, three common methods are used: 24-hour recalls, food frequency questionnaires and food records. Food records or 24-hour recalls are often thought to be the most reliable, but they are difficult and expensive to obtain. The question of interest to us is to use the food records or 24-hour recalls to examine possible systematic biases in questionnaires as a measure of usu...

The food frequency questionnaires are widely used in epidemiological researches like dietary assessment method. Traditionally, they have been self-administered in paper but the use of information and communication technologies has led to develop Internet and computerized food frequency questionnaires. It is the objective of this article to offer a global perspective of the new technologies appl...

background: earlier forms of food frequency questionnaire (ffq) used in iran have extensive lists of foods, traditional categories and food-based design, mostly with the interviewer-administered approach. the aim of the current paper is to describe the development of a dish-based, machine-readable, semi-quantitative food frequency questionnaire (dfq). methods: within the framework of the study ...

patients and methods a total of 553 pregnant females, aged 18 - 40 years, during the third trimester of pregnancy, were included in the study. statistical analysis of pearson correlation coefficient, analysis of covariance for logistic regression and factor analysis were performed using spss software version 23. results in this study, pearson correlation coefficients between test and retest for...