SDRC

About: SDRC is a based out in . It is known for research contribution in the topics: Modal testing & Modal analysis. The organization has 87 authors who have published 80 publications receiving 695 citations.

Optimum approximation for residual stiffness in linear system identification

Abstract: A new method of system identification uti 1 i zes projector m atrix theory and the MoorePenrose generalized inverse to derive an analytical stiffness matrix which, when combined with the analytical mass matrix, will more closely p redict modal test results. Weighting matrices a re used to enforce connectivity and make weighted corrections to the original analytical stiffness matrix. A simple and straightforward mathematical formulation is obtained. The method is compared and contrasted with other methods found in the literature, and a simple numerical example is presented.

Development and implementation of a shuttle modal inspection system

Abstract: One of the major tasks between Space Shuttle flights is inspection of the orbiter subsystems such as control surfaces, vertical tail, and wings. To date, inspection techniques have consisted primarily of visual and X-ray methods, which are not only time consuming but not as comprehensive as desired. Previous shuttle component and orbiter ground modal testing revealed that orbiter component damage could be identified using standard modal test methods. As a result, NASA has procured a dedicated shuttle modal inspection system (SMIS) that will be used for subsystem inspection. This paper presents a background on the use of modal testing to detect shuttle component damage, details on this new implementation, and an early use of the SMIS capability to investigate a potential orbiter vibration problem.

Young Sex-Workers in Ho Chi Minh City Telling Their Life Stories:

Abstract: In this study the life stories of 22 sex-workers (age 15-18 years) in Vietnam are organized into three thematic narratives depicting how the girls presented their lives. Poverty, lack of job altern...

Application of an enhanced Coordinate Modal Assurance Criterion

Abstract: This paper presents an extension of the Coordinate Modal Assurance Criterion (COMAC) for spatial comparison of mode shapes. As is the case for the original COMAC, this enhanced COMAC helps identify degrees of freedom differences between test and analysis modes, but also overcomes some of the limitations of the original COMAC. The original COMAC cannot identify errors caused by scaling or polarity mistakes in the test data. Such mistakes are easily made during modal tests and not always easily detected since they do not affect the subjective quality of a frequency response function.

Male sexuality in Vietnam: the case of male-to-male sex

Abstract: Background: To implement effective behaviour change interventions for men who have sex with men, qualitative information was collected about the contexts and meanings of sex and relationships between men in Ho Chi Minh City. Methods: Individual interviews and focus groups were conducted with 74 men aged 18 years or older who had had sex with another man in the previous 12 months. Results: Findings reveal that sex between men exists and is associated with two common descriptors in Vietnam: bong lo for those who are feminised in public and bong kin for those who are not, and are often married. In sexual relationships, for both groups of men, there is a trade off between sexual pleasure and risk. Condoms may not be used, particularly when having sex with a partner who was considered to be good looking or perceived as ‘clean’. Conclusions: The study highlights the need for HIV prevention programs which address issues of sexual meaning in male-to-male sexual relationships.