http://hdl.handle.net/123456789/2202 Search the Channel search http://repository.ksu.edu.sa/jspui/simple-search http://hdl.handle.net/123456789/10624 Title: Optimal control of the rotational motion of a rigid body using moving masses<br/><br/>Authors: El-Gohary, AI; Tawfik, TS<br/><br/>Abstract: The non-linear equations of motion of a rigid body affected by white Gaussian noises are used to study the stabilization of the rotational motion with the help of internal moving masses. The control laws ensuring the tendency of the stochastic motion to the unperturbed motion and the programmed motion are determined as non-linear functions of the variables describe the stochastic and programmed motions. The programmed control law ensures the asymptotic stability with probability is obtained. An estimation of the angular velocity of the body tending to the programmed angular velocity is found. Thu, 01 Jan 2004 00:00:00 GMT http://hdl.handle.net/123456789/6580 Title: Health-enhancing physical activity among Saudi adults using the International Physical Activity Questionnaire (IPAQ)<br/><br/>Authors: Al-Hazzaa, Hazzaa M.<br/><br/>Abstract: Objectives To describe the physical activity profile of Saudi adults living in Riyadh, using the International Physical Activity Questionnaire (IPAQ) short-version telephone format.Methods Physical activity was assessed using the official Arabic short form of IPAQ, intended for use in telephone interview. The instrument asks for times spent in walking, moderate- and vigorous-intensity physical activity of at least 10 min duration. The sample consisted of 1616 Saudis, between 15 and 78 years of age, living in Riyadh. Participants were drawn from a list of names in the telephone book using a simple random method. Telephone interviews were administered during the spring of 2003 by trained male interviewers.Results The final sample size was 1064 Saudi males and females (response rate of 66%), with males comprising about 66% of the respondents. Over 43% of Saudis did not participate in any type of moderate-intensity physical activity lasting for at least 10 min. More than 72% of the sample did not engage in any type of vigorous-intensity physical activity lasting for at least 10 min. The proportion of Saudis who walked for 150 min or more per week was 33.3%. Females were engaged more in moderate physical activity than males, whereas males participated more in vigorous activity compared with females. Activity levels did not show significant relationships with education level or job hours per week. Based on the three activity categories established by IPAQ, 40.6% of Saudis were inactive, 34.3% were minimally active and 25.1% were physically active. Physical inactivity increased with advancing age.Conclusion The data suggest that the prevalence of physical inactivity among Saudis adults is relatively high. Efforts are needed to encourage Saudis to be more physically active, with the goal of increasing the proportion of Saudis engaging in health-enhancing physical activity.<br/><br/>Description: Exercise Physiology Laboratory, King Saud University, PO Box 9792, Riyadh 11423, Saudi ArabiaEmail: halhazzaa@hotmail.com Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/123456789/6447 Title: Prevalence of physical inactivity in Saudi Arabia: a brief review<br/><br/>Authors: Al-Hazzaa, H.M.<br/><br/>Abstract: Major lifestyle changes in recent years in Saudi Arabia may be leading to physical inactivity anda low level of physical fitness. This paper reviews the current literature about physical inactivity in the SaudiArabian population and discusses its implications for health. Available data from a small number of studiessuggests a high prevalence (43.3%–99.5%) of physical inactivity among Saudi children and adults alike.Furthermore, the proportion of Saudi children and adults who are at risk due to inactivity is much higher thanfor any other coronary heart disease risk factor. It is recommended that a national policy encouraging activityin daily life be established and more studies are carried out to address physical activity patterns withrepresentative samples of the Saudi Arabian population. Thu, 01 Jan 2004 00:00:00 GMT http://hdl.handle.net/123456789/4017 Title: Anthropometric measurements of Saudi boys aged 6-14 years<br/><br/>Authors: Al-Hazzaa, Hazzaa M<br/><br/>Abstract: Anthropometric measurements of 1169 Saudi school boys between the ages of 6 and 14 years are reported. The boys were randomly selected from primary schools in the city of Riyadh, Saudi Arabia. Measurements of height, weight, grip strength, chest, triceps andsubscapular skinfold thicknesses as well as biacromial, chest, bi-iliac, knee, and elbowbreadths were taken. Saudi boys have slightly lower values for body weight and height thanAmerican boys (NCHS standards)- Value« of skinfold measurements increased with age upto age II where they plateaued and took then a sharp increase by age 14. Means of triceps andsubscapular skinfolds of the Saudi boys are also lower than some standards from U.S.A.throughout age 13. At age 14, however, the Saudi boys have higher means than the U.S.A boys. Mon, 01 Jan 1990 00:00:00 GMT