Ten Shows : Curated by Barb Choit

"Ten Shows is a catalog for ten exhibitions curated by Barb Choit and presented at the California Institute of the Arts Slide Library in 2002. The “shows” consisted of 35 mm slides that were culled from the CalArts library collection and placed in ten separate slide sheets on the slide library’s light table. After the exhibition, the book was acquisitioned by the library and now serves as a potential checklist for anyone interested in remounting the exhibitions." -- Publisher's website

O NÃO USO DO LABORATORIO DE FÍSICA NAS ESCOLAS DE ENSINO MÉDIO DA CIDADE DE DOURADOS.

A Física tem desempenhado papel relevante no desenvolvimento cientıfico e tecnológico, acreditamos que se torna importante desvelar como vem se processando atualmente o ensino desta disciplina. Em termos tecnológicos, a Física, juntamente com outras ciências, como a Química e a Biologia dentre outras, tem contribuído para o atual estagio de progresso cientıfico do mundo. Essa contribuição, no entanto, poderá ser vista e vivenciada de forma mais crıtica e mais humanizada na medida em que o professor de Física busque desenvolver em seus alunos a capacidade de compreender e de intervir criticamente na sociedade tecnológica. Nessa perspectiva, o uso de atividades experimentais como estrato gia de ensino de Física tem sido apontado por professores e alunos como uma das maneiras mais frutíferas de se minimizar as dificuldades de se aprender e de se ensinar Física de modo significativo e consistente. Embora seja praticamente consensual seu potencial para uma aprendizagem significativa, observa-se que a experimentação õ proposta e discutida na literatura de maneira bastante diversa quanto ao significado que essas atividades podem assumir em diferentes contextos e em diferentes aspectos. O problema a ser apresentado neste trabalho, õ que na cidade de Dourados, MS nenhuma das escolas de nível médio dispõem de laboratório didático para o ensino de Física.  Palavras-chave: Educação, Ensino de Física, Laboratório Didático

Outcomes of truncal vascular injuries in children.

BACKGROUND: Pediatric truncal vascular injuries occur infrequently and have a reported mortality rate of 30% to 50%. This report examines the demographics, mechanisms of injury, associated trauma, and outcome of patients presenting for the past 10 years at a single institution with truncal vascular injuries. METHODS: A retrospective review (1997-2006) of a pediatric trauma registry at a single institution was undertaken. RESULTS: Seventy-five truncal vascular injuries occurred in 57 patients (age, 12 +/- 3 years); the injury mechanisms were penetrating in 37%. Concomitant injuries occurred with 76%, 62%, and 43% of abdominal, thoracic, and neck vascular injuries, respectively. Nonvascular complications occurred more frequently in patients with abdominal vascular injuries who were hemodynamically unstable on presentation. All patients with thoracic vascular injuries presenting with hemodynamic instability died. In patients with neck vascular injuries, 1 of 2 patients who were hemodynamically unstable died, compared to 1 of 12 patients who died in those who presented hemodynamically stable. Overall survival was 75%. CONCLUSIONS: Survival and complications of pediatric truncal vascular injury are related to hemodynamic status at the time of presentation. Associated injuries are higher with trauma involving the abdomen

Light source selection for a solar simulator for thermal applications: A review

Solar simulators are used to test components and systems under controlled and repeatable conditions, often in locations with unsuitable insolation for outdoor testing. The growth in renewable energy generation has led to an increased need to develop, manufacture and test components and subsystems for solar thermal, photovoltaic (PV), and concentrating optics for both thermal and electrical solar applications. At the heart of any solar simulator is the light source itself. This paper reviews the light sources available for both low and high-flux solar simulators used for thermal applications. Criteria considered include a comparison of the lamp wavelength spectrum with the solar spectrum, lamp intensity, cost, stability, durability, and any hazards associated with use. Four main lamp types are discussed in detail, namely argon arc, the metal halide, tungsten halogen lamp, and xenon arc lamps. In addition to describing the characteristics of each lamp type, the popularity of usage of each type over time is also indicated. This is followed by guidelines for selecting a suitable lamp, depending on the requirements of the user and the criteria applied for selection. The appropriate international standards are also addressed and discussed. The review shows that metal halide and xenon arc lamps predominate, since both provide a good spectral match to the solar output. The xenon lamp provides a more intense and stable output, but has the disadvantages of being a high-pressure component, requiring infrared filtering, and the need of a more complex and expensive power supply. As a result, many new solar simulators prefer metal halide lamps

Optimized relative step size random search

A theoretical technique for the minimization of a function by a random search is presented. The search is a modification of the Optimum Step Size Random Search of Schumer and Steiglitz to include reversals. A theory for updating the step size is presented upon which an implementation of a search algorithm suitable for high-dimensional functions with no requirements for derivative evaluations is based.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat

THE INVERSES OF BLOCK HANKEL AND BLOCK TOEPLITZ MATRICES*

Abstract. A set ofnew formulae for the inverse of a block Hankel (or block Toeplitz) matrix is given. The formulae are expressed in terms of certain matrix Pad6 forms, which approximate a matrix power series associated with the block Hankel matrix. By using Frobenius-type identities between certain matrix Pad6 forms, the inversion formulae are shown to generalize the formulae of Gohberg-Heinig and, in the scalar case, the formulae of Gohberg-Semencul and Gohberg-Krupnik. The new formulae have the significant advantage of requiring only that the block Hankel matrix itself be nonsingular. The other formulae require, in addition, that certain submatrices be nonsingular. Since effective algorithms for computing the required matrix Pad6 forms are available, the formulae are practical. Indeed, some of the algorithms allow for the efficient calculation of the inverse not only of the given block Hankel matrix, but also of any nonsingular block principal minor