14,544 research outputs found

    Application Experiences of NASTRAN Thermal Analysis in Engineering

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    The application of the thermal analysis phase of NASTRAN in engineering is described. Some illustrative samples are presented to demonstrate the applicability and limitation of NASTRAN thermal analysis capability. The results of the evaluation of the relative efficiency, applicability and accuracy among NASTRAN, other finite element programs, and finite difference programs are also presented

    Implementation experiences of NASTRAN on CDC CYBER 74 SCOPE 3.4 operating system

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    The implementation of the NASTRAN system on the CDC CYBER 74 SCOPE 3.4 Operating System is described. The flexibility of the NASTRAN system made it possible to accomplish the change with no major problems. Various sizes of benchmark and test problems, ranging from two hours to less than one minute CP time were run on the CDC CYBER SCOPE 3.3, Univac EXEC-8, and CDC CYBER SCOPE 3.4. The NASTRAN installation deck is provided

    Multiplicative random walk Metropolis-Hastings on the real line

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    In this article we propose multiplication based random walk Metropolis Hastings (MH) algorithm on the real line. We call it the random dive MH (RDMH) algorithm. This algorithm, even if simple to apply, was not studied earlier in Markov chain Monte Carlo literature. The associated kernel is shown to have standard properties like irreducibility, aperiodicity and Harris recurrence under some mild assumptions. These ensure basic convergence (ergodicity) of the kernel. Further the kernel is shown to be geometric ergodic for a large class of target densities on R\mathbb{R}. This class even contains realistic target densities for which random walk or Langevin MH are not geometrically ergodic. Three simulation studies are given to demonstrate the mixing property and superiority of RDMH to standard MH algorithms on real line. A share-price return data is also analyzed and the results are compared with those available in the literature

    Effects of oligomer-to-monomer ratio on ink film properties of white UV-curable gravure ink for printing on biaxially oriented polypropylene (BOPP)

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    The high shear rate environment of gravure requires very low viscosity, fluid inks. The problems associated with low viscosity such as spilling, crawling, scumming and crazing, have hindered the development of UV-curable gravure inks. This led the researcher to study UV-curable gravure ink formulation. The effects of oligomer-to-monomer ratio and pigment dispersion loading on white ultraviolet (UV)-curable gravure ink film properties (surface cure efficiency, abrasion resistance, substrate adhesion, and ink film flexibility) were investigated. In this study, molecules normally used as monomers, in UV-curable systems, were selected as oligomers relative to the selected monomer, Glycerol Propoxylate Triacrylate (GPTA). The selected oligomers were, Trimethylolpropane Triacrylate (TMPTA), Trimethylolpropane Ethoxylate Triacrylate (ETMPTA), and a commercially available oligomer, Commerical Product A, used in flexographic ink applications. The outcome of this research created a starting point for white UV-curable gravure ink formulation, which will be used in the researcher\u27s family printing business. The results of the experiment showed that oligomer-to-monomer ratio did not have significant effects on surface cure efficiency, substrate adhesion, and ink film flexibility in the range from 70 to 90% oligomer concentration. Abrasion resistance was dependent on the type of oligomer. Using oligomer Commercial Product A, a soft oligomer, in combination with monomer Glycerol Propoxylate Triacrylate (GPTA), exhibited a decrease in abrasion resistance from 70:30 to 90:10 ratio. However, when using oligomers Trimethylolpropane Triacrylate (TMPTA) and Trimethylolpropane Ethoxylate Triacrylate (ETMPTA), oligomer-to-monomer ratio had no effect on abrasion resistance within the same range. Titanium dioxide pigment dispersion loading on 70:30 ratio (TMPTA:GPTA) did not have significant effects on substrate adhesion and ink film flexibility. Surface curing efficiency increased to 100% (from 99.5% with no pigment present) with pigment loadings equal to about 20%, but would begin to slightly decrease from complete curing at concentrations exceeding 40%. A significant decrease in abrasion resistance, caused by increased friction, was observed at 20 percent loading. There was, however, an increase in ink film strength from 30 to 50 percent pigment loading. Developments in UV ink components and persistent research will most likely solve the issues of UV-curable gravure inks. This research opened up a wide array of research opportunities in UV-curable gravure ink formulation and taken a step towards creating an effective white UV-curable gravure ink

    Seismic analysis of nuclear power plant structures

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    Primary structures for nuclear power plants are designed to resist expected earthquakes of the site. Two intensities are referred to as Operating Basis Earthquake and Design Basis Earthquake. These structures are required to accommodate these seismic loadings without loss of their functional integrity. Thus, no plastic yield is allowed. The application of NASTRAN in analyzing some of these seismic induced structural dynamic problems is described. NASTRAN, with some modifications, can be used to analyze most structures that are subjected to seismic loads. A brief review of the formulation of seismic-induced structural dynamics is also presented. Two typical structural problems were selected to illustrate the application of the various methods of seismic structural analysis by the NASTRAN system

    Catholic Educational Leadership as a Spiritual Practice

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    Being a leader is tough—the best ones I know consider it a burden more than an honor, a responsibility more than a promotion, a sacrifice more than a perk. Leaders of Catholic schools, in particular, find themselves today in situations of increasing complexity and vulnerability. More and more scholars and practitioners are thus linking leadership to spirituality precisely because of this, perhaps, a connection that was, quite frankly, unimaginable a few decades ago.This multi-disciplinary approach to leadership—one that includes not only the disciplines of psychology and sociology but also spirituality in particular—has led to deeper investigations into the motivation, values, and behaviors of both leader and follower. Based on my own practice and the experiences of those I have worked with, I have come to believe that spirituality serves as a valuable source for the courage and clear thinking so essential to the challenging task of leadership today

    Stimulating E-Learning in Europe: A Supply Chain Approach

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    In: A.J. Kallenberg and M.J.J.M. van de Ven (Eds), 2002, The New Educational Benefits of ICT in Higher Education: Proceedings. Rotterdam: Erasmus Plus BV, OECR ISBN 90-9016127-9This 'research in progress' paper examines a supply chain approach to stimulate e-learning in Europe. It builds on a recent study (van der Linden and van Baalen 1998), which found that it is possible to add a new dimension through distance learning to traditional pedagogical techniques. One of the unexpected side effects reported when using electronic mail was the disappearing of cultural boundaries. From a socio-cultural perspective within an increasingly international setting optimal e-learning requires a supply chain approach, in which face-to-face meetings play a critical complementary function to ensure that important clues such as body language and tone of voice are not filtered out (Lee 1994:143). A relevant issue for institutions of higher learning is whether or not it is desirable for ICT applications to complement or substitute traditional forms of management education (van der Linden and van Baalen 1998:15). There is an increasing need to interact in the complex international environment, which implies that students must obtain the skills to bridge five identified gaps in the polycontextual learning environment (Fenema, 2001). In the early 1990s the Rotterdam School of Management, Erasmus University internationalized its curriculum. It is currently responding to the challenge of applying digital learning techniques to deliver management education. The diffusion of knowledge plays an important role in innovation processes. (Hertog and Bilderbeek (2000:222). This paper concludes with a summary and research agenda for higher education in the global knowledge economy

    Quantum circuit for security proof of quantum key distribution without encryption of error syndrome and noisy processing

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    One of the simplest security proofs of quantum key distribution is based on the so-called complementarity scenario, which involves the complementarity control of an actual protocol and a virtual protocol [M. Koashi, e-print arXiv:0704.3661 (2007)]. The existing virtual protocol has a limitation in classical postprocessing, i.e., the syndrome for the error-correction step has to be encrypted. In this paper, we remove this limitation by constructing a quantum circuit for the virtual protocol. Moreover, our circuit with a shield system gives an intuitive proof of why adding noise to the sifted key increases the bit error rate threshold in the general case in which one of the parties does not possess a qubit. Thus, our circuit bridges the simple proof and the use of wider classes of classical postprocessing.Comment: 8 pages, 2 figures. Typo correcte
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