35,650 research outputs found

    Analysis of a spherical shell with a non-axisymmetric boundary

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    Spherical shell problem formulated in terms of stress functions, and applied to nonaxisymmetric boundar

    Supersymmetric reduced models with a symmetry based on Filippov algebra

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    Generalizations of the reduced model of super Yang-Mills theory obtained by replacing the Lie algebra structure to Filippov nn-algebra structures are studied. Conditions for the reduced model actions to be supersymmetric are examined. These models are related with what we call \{cal N}_{min}=2 super pp-brane actions.Comment: v3: In the previous versions we overlooked that Eq.(3.9) holds more generally, and missed some supersymmetric actions. Those are now included and modifications including a slight change in the title were made accordingly. 1+18 page

    Stress-Induced Delamination Of Through Silicon Via Structures

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    Continuous scaling of on-chip wiring structures has brought significant challenges for materials and processes beyond the 32 nm technology node in microelectronics. Recently three-dimensional (3-D) integration with through-silicon-vias (TSVs) has emerged as an effective solution to meet the future interconnect requirement. Thermo-mechanical reliability is a key concern for the development of TSV structures used in die stacking as 3-D interconnects. This paper examines the effect of thermal stresses on interfacial reliability of TSV structures. First, the three-dimensional distribution of the thermal stress near the TSV and the wafer surface is analyzed. Using a linear superposition method, a semi-analytic solution is developed for a simplified structure consisting of a single TSV embedded in a silicon (Si) wafer. The solution is verified for relatively thick wafers by comparing to numerical results obtained by finite element analysis (FEA). Results from the stress analysis suggest interfacial delamination as a potential failure mechanism for the TSV structure. Analytical solutions for various TSV designs are then obtained for the steady-state energy release rate as an upper bound for the interfacial fracture driving force, while the effect of crack length is evaluated numerically by FEA. Based on these results, the effects of TSV designs and via material properties on the interfacial reliability are elucidated. Finally, potential failure mechanisms for TSV pop-up due to interfacial fracture are discussed.Aerospace Engineerin

    Two--Electron Atoms in Short Intense Laser Pulses

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    We discuss a method of solving the time dependent Schrodinger equation for atoms with two active electrons in a strong laser field, which we used in a previous paper [A. Scrinzi and B. Piraux, Phys. Rev. A 56, R13 (1997)] to calculate ionization, double excitation and harmonic generation in Helium by short laser pulses. The method employs complex scaling and an expansion in an explicitly correlated basis. Convergence of the calculations is documented and error estimates are provided. The results for Helium at peak intensities up to 10^15 W/cm^2 and wave length 248 nm are accurate to at least 10 %. Similarly accurate calculations are presented for electron detachment and double excitation of the negative hydrogen ion.Comment: 14 pages, including figure

    Analisa Pengaruh Service Quality Terhadap Customer Loyalty Dengan Customer Satisfaction Sebagai Variabel Intervening Celebrity Fitness Center Surabaya

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    The development of fitness centers in the city of Surabaya is growing rapidly, strategic locations such as in the center of the famous city in the city of Surabaya, of course this is directly proportional to the changing lifestyle of people in the city of Surabaya is more advanced and the view of an increasingly healthy lifestyle. With so many fitness centers in Surabaya, this is also affecting the fitness industry competition in terms of quality of service that becomes one factor that impacts on customer satisfaction, which in the end faced with the advantage of improving both the quality and the quantity of output produced. This research aims to analyze the influence of Service Quality (Tangible, Emphaty, Responsiveness, Realibility, Assurance) to Customer Loyalty (Say positive thing, Recommend to friend, Continue purchasing) by considering the factor of Customer Satisfaction (Satisfaction as Fulfillment, Satisfaction as Pleasure, Satisfaction as Ambivalance) This research was conducted by distributing questionnaires to 100 respondents of Celebrity Fitness Centre customers. Analyze technique used is quantitative analysis technique with path analysis method

    Thermalisation of Local Observables in Small Hubbard Lattices

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    We present a study of thermalisation of a small isolated Hubbard lattice cluster prepared in a pure state with a well-defined energy. We examine how a two-site subsystem of the lattice thermalises with the rest of the system as its environment. We explore numerically the existence of thermalisation over a range of system parameters, such as the interaction strength, system size and the strength of the coupling between the subsystem and the rest of the lattice. We find thermalisation over a wide range of parameters and that interactions are crucial for efficient thermalisation of small systems. We relate this thermalisation behaviour to the eigenstate thermalisation hypothesis and quantify numerically the extent to which eigenstate thermalisation holds. We also verify our numerical results theoretically with the help of previously established results from random matrix theory for the local density of states, particularly the finite-size scaling for the onset of thermalisation.Comment: 22 pages, 23 figure

    A new observational and numerical study of tidal interactions in M81-M82-NGC3077 system

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    A nearby system of interacting galaxies M81-M82-NGC3077 triplet (D = 3.3 Mpc; Freeman & Madore 1988) has been studied using multi-wavelength observations and numerical simulations to obtain a comprehensive understanding on the dynamics and the consequences of tidal interactions in a group environment. The VLA 12-field Mosaic H I observations of 2 x 1.5 deg. region have revealed a vast array of H I filaments which suggests that the severity and extent of tidal disruptions far exceed the previous estimates. A tidal remnant of the former H I disk of M82 extending up to 30 kpc (in projection) is identified for the first time, and the pervasive effects of the tidal disruption are traced into the inner disk by optical and CO observations, including a kinematic trace of a large scale bar potential (Yun, Ho, & Lo 1992). The H I disk of M81 is traced out to 40 kpc in radius, and a large scale (l approx. 20 kpc) velocity anomaly ('High Velocity Trough'), which may be a remnant of a gaseous collision, is found within the disk of M81. The large H I bridge between M81 and NGC 3077 (van der Hulst 1979) is also found to extend approx. greater than 50 kpc further, bending around NGC 3077, toward M82. The total H I detected in this experiment, 5.6 x 10(exp 9) solar mass, represents the majority of the single-dish flux (Appleton, Davies, & Stephenson 1981) and suggests that the bulk of H I found in the region belongs to the three galaxies and the tidal filaments. The impact and details of the tidal interactions have been further examined through the use of numerical techniques. The 'restricted 3-body' approach was used to simulate the observed distribution of tidal H I streamers connecting the three galaxies, and the success of the simulation is further strengthened by the accurate predictions on the gas kinematics

    Representations of linear dual rate system via single SISO LTI filter, conventional sampler and block sampler

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    In this brief, it is proved that a linear dual-rate system can be represented via a series cascade of: 1) a conventional expander, a single-input single-output (SISO) linear time-invariant (LTI) filter and a block decimator, or 2) a block expander, an SISO LTI filter and a conventional decimator. Hence, incompatible nonuniform filter banks could achieve perfect reconstruction via LTI filters, conventional samplers and block samplers without expanding the input-output dimension of a subsystem of linear dual-rate systems or converting the nonuniform filter banks to uniform filter banks. The main advantage of the proposed representations is to avoid complicated design of the circuit layout caused by connecting subsystems with large input-output dimension or a lot of subsystems togethe
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