Dynamic forces in multiport mechanics: Direct and Lagrangian formulations     

Dean Karnopp 《Journal of The Franklin Institute》1982,314(5):265-270

Holonomic systems can be represented by a bond graph in which inertial variables are related to generalized variables using a multiport displacement-modulated transformer structure. It is shown that the part of the generalized forces due to inertial elements can be found either by direct calculation or by the operations of Lagrange's equations. Although no gyrators are needed for the representation, gyrational coupling may exist. Alternative representations may involve gyrators explicitly and it is possible to construct kinetic co-energy functions for these gyrators for use in Lagrange's equations.  相似文献   

The treatment of uncertainty in the sciences     

Dennis H. Rouvray B.Sc.  ARCS  Ph.D.  DIC 《Endeavour》1997,21(4):154-158

For some 300 years the modelling of uncertainty in the sciences has been totally dominated by probabilistic methods. Now, following major criticism of the theoretical foundations of probability theory, other approaches to dealing with uncertainty are being explored.  相似文献   

From learning to labour to learning for marginality: school segregation and marginalization in Swedish suburbs     

Dennis Beach  Ove Sernhede 《British Journal of Sociology of Education》2011,32(2):257-274

In this article, using data from ethnographic research, we try to present some glimpses of the way education is described as an experience and possibility ‘from below’, by pupils who grow up and study in schools in the most segregated and territorially stigmatized suburbs on the outskirts of our major cities. What we feel they describe is an experience of schooling for surviving the social and economic consequences of curtailed citizenship in a post‐industrial society rather than one of schooling that offers possibilities of integration and full citizenship or social transformation. Our findings have significant policy implications in this respect. Sweden has historically pursued projects aimed at educational inclusion but has recently taken a significant turn toward neo‐liberalism and educational consumerism, since which time various disadvantaged groups have become increasingly concentrated compared with others in under‐achieving schools in an economically threatened public sector. The article discusses some aspects and possible consequences of this development.  相似文献   

Whole-body vibration effects on the muscle activity of upper and lower body muscles during the baseball swing in recreational baseball hitters     

Reyes GF  Dickin DC  Crusat NJ  Dolny DG 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):280-293

The purpose of this study was to evaluate the effects of whole-body vibration (WBV) on the muscle recruitment of selected upper and lower body muscles during the baseball swing. Participants were recreationally trained males (n = 16, 22 +/- 2 years, 181.4 +/- 7.4 cm, 84.7 +/- 9.0 kg), with previous baseball experience. Subjects participated in three randomized sessions on separate days, consisting of three sets of five swings offa hitting tee. Exercises (upper and lower body dynamic and static movements) with or without WBVexposure were performed between swing sets. During each swing, the gastrocnemius, biceps femoris, gluteus maximus, pectoralis major, latissimus dorsi, and triceps brachii were evaluated for electromyographic (EMG) activity. EMG values were normalized to EMG measured during maximal voluntary isometric contraction. Statistical analysis revealed no significant differences in EMG activity across the three treatments. In addition, the results displayed a specific muscle recruitment order during the swing, starting with the lower body followed by the upper body muscles. This study was the first to report the recruitment order during the baseball swing. Although acute exposure to WBV did not significantly alter the muscle recruitment, these results may prove useful for practitioners looking to enhance baseball swing performance.  相似文献   

Perspective Paper: Assessing Air Quality as Part of a Physical Therapy Plan of Care     

Dennis C. Sobush  Monika Burrescia 《Cardiopulmonary Physical Therapy Journal》2011,22(1):20-24

Purpose: The purposes of this clinical perspective paper are (1) to expand physical therapists’ awareness to the topic of air quality as a health priority when providing professional services; and (2) to provide templates for screening the indoor clinical environments and patient profiles to avert respiratory exacerbations, especially in persons with asthma. Summary of Key Points: The location where a physical therapist practices determines the air quality indices to which a person is exposed. Poor indoor air quality can expose a person to even greater compromise of respiration (ie, Sick Building Syndrome) than outdoor air quality secondary to an array of factors like building materials, the ventilation exchange rate of an enclosed space, chemicals used in cleaning, and humidity. Statement of Conclusions: Extrinsic (ie, environmental) and intrinsic (eg, pre-disposition to airway hypersensitivity) factors must be accounted for by physical therapists to safeguard their patients and themselves from experiencing respiratory compromise and/or distress as a result of a treatment session or their place of employment. Recommendations: Efforts to screen indoor environments for potential triggers and patient risk profiles for abnormal airway reactivity should routinely be undertaken. Individualized Action Plans should be prospectively prepared and readied for implementation when warranted.Key Words: asthma, Sick Building Syndrome, indoor air quality, respiratory impairment  相似文献   

"A man's game": cricket, war and masculinity, South Africa, 1899-1902     

Allen D 《国际体育史杂志》2011,28(1):63-80

As practitioners of the imperial sport of the Victorian age, cricketers rallied whenever war descended upon England and its colonies. The South African War of 1899-1902 was no different. Adding to existing work on cricket's imperial development within South Africa, this study marks a significant contribution to research on the link between masculinity, war and sport during the Victorian era. A concept emerging from the English public schools of the mid- to late nineteenth century, the masculine ethos of sport and military honour had reached colonial South Africa by the outbreak of war in 1899. In its analysis of cricket and masculinity, this essay examines the events surrounding the war in South Africa and provides an example of the distinct relationship that existed between the military and the masculinity of sport and its organisation during this era.  相似文献   

Assessing and Addressing Student Barriers: Implications for Today's College Classroom          下载免费PDF全文

Dorothy A. Osterholt  Sophie Lampard Dennis 《About Campus》2014,18(6):18-24

The increasingly diverse set of learners in colleges and universities poses considerable challenges for educators. Dorothy A. Osterholt and Sophie Lampard Dennis explain the four domains of learning they have identified and suggest ways to apply them to help students overcome a variety of obstacles to learning.  相似文献   

Structural and conceptual interweaving of mathematics methods coursework and field practica     

Damon L. Bahr  Eula Ewing Monroe  Dennis Eggett 《Journal of Mathematics Teacher Education》2014,17(3):271-297

This paper describes a study of observed relationships between the design of a preservice elementary mathematics methods course with accompanying field practicum and changes in the extent to which participating prospective teachers identified themselves with the mathematics reform movement after becoming practicing teachers. The curriculum of the course with its embedded field practicum experiences was designed to support prospective teachers in interweaving methods coursework and pedagogical instruction with classroom practice. University and elementary school structures were interwoven by conducting weekly mathematics methods course sessions at a school site followed immediately by related practicum experiences in classrooms in the school. The interweaving of conceptualizations about mathematics teaching and learning was facilitated as the methods instructor provided professional development for classroom teachers simultaneously with the methods course, encouraging the teachers to create “reform-friendly” classroom environments. Survey data from 68 prospective teachers involved in the project were analyzed to identify and describe relationships between course/practicum experiences and the degree to which they as practicing teachers, 1–3 years following the course/practicum, identified with a reform mathematics perspective, as well as to examine factors influencing those relationships.  相似文献   

Adult Role Models: Feasibility,Acceptability, and Initial Outcomes for Sex Education     

Lisa Colarossi  Ellen Johnson Silver  Randa Dean  Amanda Perez  Angelic Rivera 《American journal of sexuality education》2014,9(2):155-175

The authors present the feasibility and acceptability of a parent sexuality education program led by peer educators in community settings. They also report the results of an outcome evaluation with 71 parents who were randomized to the intervention or a control group and surveyed one month prior to and six months after the four-week intervention. The program was highly feasible and acceptable to participants, and the curriculum was implemented with a high level of fidelity and facilitator quality. Pilot data show promising outcomes for increasing parental knowledge, communication, and monitoring of their adolescent children.  相似文献   

Digitising the modern archive     

Katrina Dean 《档案与原稿》2014,42(2):171-174

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