632 research outputs found
Diffusion at constant speed in a model phase space
We reconsider the problem of diffusion of particles at constant speed and
present a generalization of the Telegrapher process to higher dimensional
stochastic media (), where the particle can move along directions.
We derive the equations for the probability density function using the
``formulae of differentiation'' of Shapiro and Loginov. The model is an
advancement over similiar models of photon migration in multiply scattering
media in that it results in a true diffusion at constant speed in the limit of
large dimensions.Comment: Final corrected version RevTeX, 6 pages, 1 figur
The conditional tunneling time for reflection using the WKB wave-function
We derive an expression for the conditional time for the reflection of a wave
from an arbitrary potential barrier using the WKB wavefunction in the barrier
region. Our result indicates that the conditional times for transmission and
reflection are equal for a symmetric barrier within the validity of the WKB
approach.Comment: 4 pages RevTeX, 1 eps figure include
DEVELOPMENT OF AN ADVANCED HIGH PRESSURE RATIO TRANSONIC FAN STAGE. PART-I: DESIGN AND ANALYSIS
A high performance fan stage of pressure ratio 2.0 is being designed and developed under a joint programme between Chinese Aeronautical Establishment (CAE) China and National Aerospace Laboratories (NAL), Bangalore, India.. Special features of the aerodynamic design are i) forward blade sweep and lean to increase the ability to bear intake distortion ii) reverse camber fan tip to reduce losses via pre compression iii) low aspect ratio of the blades to maximize stall margin. The blade will be fabricated using laminates of Carbon/Epoxy composites with tip shroud so as to limit the blade stress and deformation. Stress analysis was carried out using MSC/NASTRAN Finite Element Package. The fan stage has undergone a series of design improvements. Comparison of typical results obtained at NAL and BUAA is shown for the final version of the fan stage TTT98-29
Controlling Metamaterial Resonances with Light
We investigate the use of coherent optical fields as a means of dynamically
controlling the resonant behaviour of a variety of composite metamaterials,
wherein the metamaterial structures are embedded in a dispersive dielectric
medium. Control and switching is implemented by coherently driving the resonant
permittivity of the embedding medium by applied optical radiation. The effect
of embedding Split ring resonators (SRR) in a frequency- dispersive medium with
Lorentz-like dispersion or with dispersion engineered by electromagnetic
induced transparency (EIT), is manifested in the splitting of the negative
permeability band, the modified (frequency-dependent) filling fractions and
dissipation factors. The modified material parameters are strongly linked to
the resonant frequencies of the medium, while for an embedding medium
exhibiting EIT, also to the strength and detuning of the control field. The
robustness of control against the deleterious influence of dissipation
associated with the metallic structures as well as the inhomogeneous broadening
due to structural imperfections is demonstrated. Studies on plasmonic
metamaterials that consist of metallic nanorods arranged in loops and exhibit a
collective magnetic response at optical frequencies are presented. Control and
switching in this class of plasmonic nanorod metamaterials is shown to be
possible, for example, by embedding these arrays in a Raman active liquid like
CS and utilizing the Inverse Raman Effect.Comment: 9 pages, 9 figure
Imaging the Near Field
In an earlier paper we introduced the concept of the perfect lens which
focuses both near and far electromagnetic fields, hence attaining perfect
resolution. Here we consider refinements of the original prescription designed
to overcome the limitations of imperfect materials. In particular we show that
a multi-layer stack of positive and negative refractive media is less sensitive
to imperfections. It has the novel property of behaving like a fibre-optic
bundle but one that acts on the near field, not just the radiative component.
The effects of retardation are included and minimized by making the slabs
thinner. Absorption then dominates image resolution in the near-field. The
deleterious effects of absorption in the metal are reduced for thinner layers.Comment: RevTeX, (9 pages, 8 figures
Role of Elasticity on Forces and Deflections of a Submerged Elastic Plate in Waves
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Etiology, triggers and neurochemical circuits associated with unexpected, expected, and laboratory-induced panic attacks
Panic disorder (PD) is a severe anxiety disorder that is characterized by recurrent panic attacks (PA), which can be unexpected (uPA, i.e., no clear identifiable trigger) or expected (ePA). Panic typically involves an abrupt feeling of catastrophic fear or distress accompanied by physiological symptoms such as palpitations, racing heart, thermal sensations, and sweating. Recurrent uPA and ePA can also lead to agoraphobia, where subjects with PD avoid situations that were associated with PA. Here we will review recent developments in our understanding of PD, which includes discussions on: symptoms and signs associated with uPA and ePAs; Diagnosis of PD and the new DSM-V; biological etiology such as heritability and gene×environment and gene×hormonal development interactions; comparisons between laboratory and naturally occurring uPAs and ePAs; neurochemical systems that are associated with clinical PAs (e.g. gene associations; targets for triggering or treating PAs), adaptive fear and panic response concepts in the context of new NIH RDoc approach; and finally strengths and weaknesses of translational animal models of adaptive and pathological panic states
Pengaruh Beberapa Pola Latihan Otot Bisep terhadap Kemampuan Tolak Peluru Sisiwa Putra SD Gugus Kelusa Tahun Pelajaran 2014/2015
Penelitian ini bertujuan untuk meningkatkan kemampuan tolak peluru untuk siswa putra pada mata pelajaran olahraga kelas VI Gugus Kelusa Tahun pelajaran 2014/2015 melalui pengaruh pola pelatihan otot bisep. Populasi penelitian ini adalah semua siswa putra kelas VI Gugus Kelusa. Data kemampuan tolak peluru di kumpulkan melalui lembar observasi, dan di analisis menggunakan analisis varians (ANAVA satu jalur) dan t-Scheffe. Hasil penelitian menunjukan (1) terdapat pengaruh implementasi beberapa metode latihan (Angkat Beban 2 Kg, 8 Repetisi, 4 Set, Angkat Beban 2 Kg, 7 Repetisi, 3 Set, dan Angkat Beban 2 Kg, 6 Repetisi, 2 Set) terhadap kemampuan tolak peluru. (2) tidak terdapat perbedaan kemampuan tolak peluru antara siswa yang mengikuti metode latihan Angkat Beban 2 Kg, 8 Repetisi, 4 Set dan metode latihan Angkat Beban 2 Kg, 7 Repetisi, 3 Set. (3) terdapat perbedaan kemampuan tolak peluru antara siswa yang mengikuti metode latihan Angkat Beban 2 Kg, 8 Repetisi, 4 Set dan metode latihan Angkat Beban 2 Kg, 6 Repetisi, 2 Set. (4) terdapat perbedaan kemampuan tolak peluru antara siswa yang mengikuti metode latihan Angkat Beban 2 Kg, 7 Repetisi, 3 Set dan metode latihan Angkat Beban 2 Kg, 6 Repetisi, 2 Set.Kata Kunci : Kemampuan tolak peluru, dan pola pelatihan otot bisep This research was aimed to improve the shot put students\u27 ability to men student at sports lesson Group Kelusa Primary Schools students grade VI in academic year 2014/2015 through the influence of the training pattern of the biceps. The population of this research was the whole Group Kelusa Primary Schools men students grade VI. To collect the data of shot put ability students\u27 this research was using observation sheet, and the data were analyzed with statistical analysis of varians (one way ANAVA) and t-Scheffe. This research showed that (1) there are several methods of implementation effect of exercise (weight 2 kg, 8 reps, 4 sets , weight 2 kg, 7 reps, 3 sets, and weight 2 kg, 6 reps, 2 sets) toward shot put ability. (2) there was not significant different in shot put ability between the students\u27 using weight 2 kg, 8 reps, 4 sets method and weight 2 kg, 7 reps, 3 sets method. (3) there was a significant difference in shot put ability between the students\u27 using weight 2 kg, 8 reps, 4 sets method and weight 2 kg, 6 reps, 2 sets method. (4) there was a significant difference in shot put ability between the students\u27 using weight 2 kg, 7 reps, 3 sets method and weight 2 kg, 6 reps, 2 sets method
A Dorsal Hand Vein Recognition-based on Local Gabor Phase Quantization with Whitening Transformation
The hand vein pattern is a biometric feature in which the actual pattern is the shape of the vein network and its characteristics are the vein features. This paper investigates a new approach for dorsal hand vein pattern identification from grey level dorsal hand vein information. In this study Gabor filter quadrature pair is employed to compute locally in a window for every pixel position to extract the phase information. The phases of six frequency coefficients are quantized and it is used to form a descriptor code for the local region. These local descriptors are decorrelated using whitening transformation and a histogram is generated for every pixel which describes the local pattern. Experiments are evaluated on North China University of Technology dorsal hand vein image dataset with minimum distance classifier and the results are analyzed for recognition rate, run time and equal error rate. The proposed method gives 100 per cent recognition rate and 1 per cent EER for fusion of both left and right hands.Defence Science Journal, 2014, 64(2), pp. 159-167. DOI: http://dx.doi.org/10.14429/dsj.64.465
Cost and Coding Efficient Motion Estimation Design Considerations for High Efficiency Video Coding (HEVC) Standard
This paper focuses on motion estimation engine design in future high-efficiency video coding (HEVC) encoders. First, a methodology is explained to analyze hardware implementation cost in terms of hardware area, memory size and memory bandwidth for various possible motion estimation engine designs. For 11 different configurations, hardware cost as well as the coding efficiency are quantified and are compared through a graphical analysis to make design decisions. It has been shown that using smaller block sizes (e.g. 4 × 4) imposes significantly larger hardware requirements at the expense of modest improvements in coding efficiency. Secondly, based on the analysis on various configurations, one configuration is chosen and algorithm improvements are presented to further reduce hardware implementation cost of the selected configuration. Overall, the proposed changes provide 56 × on-chip bandwidth, 151 × off-chip bandwidth, 4.3 × core area and 4.5 × on-chip memory area savings when compared to the hardware implementation of the HM-3.0 design.Texas Instruments Incorporate
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