Operations Research, Systems Engineering and Industrial Engineering Commons^™

Tracking Of Bone Mass And Density During Childhood And Adolescence, Heidi J. Kalkwarf, Vicente Gilsanz, Joan M. Lappe, Sharon Oberfield, John A. Shepherd, Thomas N. Hangartner, Xangke Huang, Margaret M. Frederick, Karen K. Winer, Babette S. Zemel

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Context: Whether a child with low bone mineral density (BMD) at one point in time will continue to have low BMD, despite continued growth and maturation, is important clinically. The stability of a characteristic during growth is referred to as “tracking.”

Objective: We examined the degree of tracking in bone mineral content (BMC) and BMD during childhood and adolescence and investigated whether tracking varied according to age, sexual maturation, and changes in growth status.

Design: We conducted a longitudinal study with measurements at baseline and annually for 3 yr.

Setting: The Bone Mineral Density in Childhood Study was conducted at …

Height Adjustment In Assessing Dual Energy X-Ray Absorptiometry Measurements Of Bone Mass And Density In Children, Babette S. Zemel, Mary B. Leonard, Andrea Kelly, Joan M. Lappe, Vicente Gilsanz, Sharon Oberfield, Soroosh Mahboubi, John A. Shepherd, Thomas N. Hangartner, Margaret M. Frederick, Karen K. Winer, Heidi J. Kalkwarf

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Context: In children, bone mineral content (BMC) and bone mineral density (BMD) measurements by dual-energy x-ray absorptiometry (DXA) are affected by height status. No consensus exists on how to adjust BMC or BMD (BMC/BMD) measurements for short or tall stature.

Objective: The aim of this study was to compare various methods to adjust BMC/BMD for height in healthy children.

Design: Data from the Bone Mineral Density in Childhood Study (BMDCS) were used to develop adjustment methods that were validated using an independent cross-sectional sample of healthy children from the Reference Data Project (RDP).

Setting: We conducted the study in five …

An Improved Genetic Algorithm For Knapsack Problems, Taskiran, Gamze Kilincli

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In this study, an improved genetic algorithm (GA) is presented to solve the multidimensional 0-1 knapsack problem (MKP). The MKP is a well-known combinatorial optimization problem and has received wide attention from the operations research community for decades. Although recent advances in computing and optimization technologies have made the solution of small and medium size instances possible, this NP-hard problem, in general, still remains one of the challenging problems yet to be solved.

Of the various algorithms developed to solve the MKP, GA seems to be one of the best methods pointed out in the literature. A GA is an …

Impact Of Culture And Age On The Use Of Social Networking Websites, Ramya Reddy Ponnavolu

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Social networking websites have become very popular amongst people of all ages in recent times. These websites have brought into existence a new form of data - 'User generated content'. Companies everywhere have begun to identify the potential of these sites and have commenced efforts to take advantage of the profitable opportunities available. In spite of all this, it is reasonable to say that the latent possibilities in social networking sites are yet to be fully explored. This is due to the fact that the technology is still young and research on its potential is still ongoing. The current research …

Use Of Web-Based Lessons Of Statistical Concepts With Graphics And Animation To Enhance The Effectiveness Of Learning, Lavanya Pillala

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Statistics is of critical importance to engineers. However, many engineering students struggle to grasp the meaning of statistical concepts and the idiosyncrasies of statistical methodologies. Because of this problem, instructors of statistics are constantly searching for better ways to help students understand statistical concepts. The goal of this project is to design and develop web-based lessons that use graphics and animations to enhance the effectiveness of students' learning of statistical concepts.

Lessons of three important statistical concepts have been developed for this thesis - normal distribution, central limit theorem and confidence & tolerance intervals - following well-recognized instructional design development …

Domain-Specific Core Self-Evaluations And Stressors As Predictors Of Strains, Michael Raymond Hoepf

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The current study examines the use of a frame-of-reference (FOR) in the evaluation of core self-evaluations, stressors and strains. The study investigates the prediction that using a FOR that matches predictors and outcomes will result in a stronger relationship between the constructs being measured, specifically CSE, stressors, and strains. In addition, the study examines the extent to which following this procedure will add incremental validity after non-contextualized predictors are controlled. The hypotheses in this study were generally supported, although the hypotheses related to the school domain were not supported as strongly as those related to general and work domain. The …