5,264 research outputs found

    The GPRIME approach to finite element modeling

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    GPRIME, an interactive modeling system, runs on the CDC 6000 computers and the DEC VAX 11/780 minicomputer. This system includes three components: (1) GPRIME, a user friendly geometric language and a processor to translate that language into geometric entities, (2) GGEN, an interactive data generator for 2-D models; and (3) SOLIDGEN, a 3-D solid modeling program. Each component has a computer user interface of an extensive command set. All of these programs make use of a comprehensive B-spline mathematics subroutine library, which can be used for a wide variety of interpolation problems and other geometric calculations. Many other user aids, such as automatic saving of the geometric and finite element data bases and hidden line removal, are available. This interactive finite element modeling capability can produce a complete finite element model, producing an output file of grid and element data

    Final Calibration of the Berkeley Extreme and Far-Ultraviolet Spectrometer on the ORFEUS-SPAS I and II Missions

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    The Berkeley Extreme and Far-Ultraviolet Spectrometer (BEFS) flew as part of the ORFEUS telescope on the ORFEUS-SPAS I and II space-shuttle missions in 1993 and 1996, respectively. The data obtained by this instrument have now entered the public domain. To facilitate their use by the astronomical community, we have re-extracted and re-calibrated both data sets, converted them into a standard (FITS) format, and placed them in the Multimission Archive at Space Telescope (MAST). Our final calibration yields improved wavelength scales and effective-area curves for both data sets.Comment: To appear in the January 2002 issue of the PASP. 17 pages with 9 embedded postscript figures; uses emulateapj5.st

    Lawyering for Justice and the Inevitability of International Human Rights Clinics

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    As globalization forces a deeper understanding of social and legal pluralism, law schools must respond by redesigning their curricula to meet the challenges of a transnational public order and legal practice. International human rights law, in particular, now must constitute a part of any legal training that is truly relevant to the contemporary world-especially in view of the new and multifarious human rights problems associated with globalization, many of which affect and concern each member of the global community no matter where the actual human rights violation occurs. Legal education institutions thus face a challenge of determining how such an ethic of global responsibility can most effectively be taught. This Article posits that, given the highly practical and fundamentally values-driven nature of human rights law, human rights education is greatly enhanced through an applied-that is, clinical-component. In this respect, human rights lawyering draws important parallels to the work of the traditional poverty law clinics of the 1970s and 1980s-and indeed can be considered a modern manifestation of the original social justice mission of those clinics. After a brief overview of the contours of human rights practice, this Article explores how human rights clinics are both part of this tradition of clinical legal education and, at the same time, different from conventional clinics. In making the case for increased reliance on the clinical model, it also examines how lecture and seminar courses are limited in their capacity to properly teach international human rights. It then proceeds to consider the structure and pedagogical goals of international human rights clinics and to discuss aspects of projects that are most meaningful for teaching human rights advocacy. Finally, the Article discusses some of the tensions and challenges inherent to human rights clinics that ultimately give them their pedagogical dynamism

    Piping network response.

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    Work on steam bubble collapse, water hammer and piping network response was carried out in two closely related but distinct sections. Volume I of ,,is report details the experiments and analyses carried out in conjunction with the steam bubble collapse and water hammer project. Volume II details the work which was performed in the analysis of piping network response to steam generated water hammer

    Joint attention revisited: Finding strengths among children with autism

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    Differences in joint attention (JA) are prominent for some children with autism and are often used as an indicator of the disorder. This study examined the JA competencies of young children with autism who demonstrated JA ability and compared them to children with developmental delays. Method: Forty children with autism and developmental delays were matched pairwise based on mental and chronological age. Videos of children engaging in play were coded for the frequency and forms (eye contact, gestures, affect, etc.) of JA. Additionally, concurrent language was compared among children with autism (N=32) by their JA ability. Results: Children with ASD entered into JA significantly less often than children with DD but once engaged, used the forms of JA similarly. For the matched pairs there were no differences in language but the children with autism who used JA had significantly better language than children with autism who did not (even after controlling for mental age). Conclusions: There is a group of young children with autism who can use JA but do so at lower frequencies than children with DD. Possible reasons include difficulty disengaging attention and limited intrinsic social motivation to share. Adult persistence is recommended to encourage JA

    Lag synchronization and scaling of chaotic attractor in coupled system

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    We report a design of delay coupling for lag synchronization in two unidirectionally coupled chaotic oscillators. A delay term is introduced in the definition of the coupling to target any desired lag between the driver and the response. The stability of the lag synchronization is ensured by using the Hurwitz matrix stability. We are able to scale up or down the size of a driver attractor at a response system in presence of a lag. This allows compensating the attenuation of the amplitude of a signal during transmission through a delay line. The delay coupling is illustrated with numerical examples of 3D systems, the Hindmarsh-Rose neuron model, the R\"ossler system and a Sprott system and, a 4D system. We implemented the coupling in electronic circuit to realize any desired lag synchronization in chaotic oscillators and scaling of attractors.Comment: 10 pages, 7 figure

    The symplectic origin of conformal and Minkowski superspaces

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    Supermanifolds provide a very natural ground to understand and handle supersymmetry from a geometric point of view; supersymmetry in d=3,4,6d=3,4,6 and 1010 dimensions is also deeply related to the normed division algebras. In this paper we want to show the link between the conformal group and certain types of symplectic transformations over division algebras. Inspired by this observation we then propose a new\,realization of the real form of the 4 dimensional conformal and Minkowski superspaces we obtain, respectively, as a Lagrangian supermanifold over the twistor superspace C4∣1\mathbb{C}^{4|1} and a big cell inside it. The beauty of this approach is that it naturally generalizes to the 6 dimensional case (and possibly also to the 10 dimensional one) thus providing an elegant and uniform characterization of the conformal superspaces.Comment: 15 pages, references added, minor change

    Tumor bed brachytherapy for locally advanced laryngeal cancer: a feasibility assessment of combination with ferromagnetic hyperthermia

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    Purpose. To assess the feasibility of adding hyperthermia to an original method of organ-preserving brachytherapy treatment for locally advanced head and neck tumors. Methods and materials. The method involves organ-preserving tumor resection and adjunctive high-dose-rate (HDR) brachytherapy delivered via afterloading catheters. These catheters are embedded in a polymeric implant prepared intraoperatively to fill the resection cavity, allowing precise computer planning of dose distribution in the surrounding at-risk tumor bed tissue. Theoretical and experimental analyzes address the feasibility of heating the tumor bed implant by coupling energy from a 100 kHz magnetic field applied externally into ferromagnetic particles, which are uniformly distributed within the implant. The goal is to combine adjuvant hyperthermia (40 °C–45 °C) to at-risk tissue within 5 mm of the resection cavity for thermal enhancement of radiation and chemotherapy response. Results. A five-year relapse free survival rate of 95.8% was obtained for a select group of 48 male patients with T3N0M0 larynx tumors, when combining organ-preserving surgery with HDR brachytherapy from a tumor bed implant. Anticipating the need for additional treatment in patients with more advanced disease, a theoretical analysis demonstrates the ability to heat at-risk tissue up to 10 mm from the surface of an implant filled with magnetically coupled ferromagnetic balls. Using a laboratory induction heating system, it takes just over 2 min to increase the target tissue temperature by 10 °C using a 19% volume fraction of ferromagnetic spheres in a 2 cm diameter silicone implant. Conclusion. The promising clinical results of a 48 patient pilot study demonstrate the feasibility of a new organ sparing treatment for laryngeal cancer. Anticipating the need for additional therapy, theoretical estimations of potential implant heating are confirmed with laboratory experiments, preparing the way for future implementation of a thermobrachytherapy implant approach for organ-sparing treatment of locally advanced laryngeal cancer
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