Embedded minimal and constant mean curvature annulus touching spheres

We show that a compact embedded minimal or constant mean curvature annulus with non-vanishing Gaussian curvature which is tangent to two spheres of same radius or tangent to a sphere and meeting a plane in constant contact angle is rotational.Comment: 10 page

Does Capitalism Need a Government to Be Nice: Robert Axelrod and His Iterated Prisoner’s Dilemma Computer Tournament

In the past few decades, the progressive political ideal of strong central governments or collective morality being necessary to enforce cooperative behavior has become widely-accepted. However, many philosophers throughout history, especially that from the classical liberalism tradition, have espoused free market, open society ideals arguing not only that governments are the source of much of the immorality and conflict many are afraid of, but also that man left in a free environment can and will cooperate and develop naturally moral systems that allow for economic and societal development. Robert Axelrod, more recently, studied this debate using the famous Prisoner’s Dilemma (PD) game from traditional game theory and applied computer science to find that, indeed, cooperation can arise naturally even between selfish prisoners. This paper develops the study further by examining more realistic situations of PD games involving multiple players, using computer simulations, i.e. agent-based modeling, and finds that Axelrod’s original conclusions hold true

Rendering non-pictorial (Scientific) high dynamic range images

In recent years, the graphics community is seeing an increasing demand for the capture and usage of high-dynamic-range (HDR) images. Since the production of HDR imagery is not solely the domain of the visualization of real life or computer generated scenes, novel techniques are also required for imagery captured from non-visual sources such as remote sensing, medical imaging, astronomical imaging, etc. This research proposes to integrate the techniques used for the display of high-dynamic-range pictorial imagery for the practical visualization of non-pictorial (scientific) imagery for data mining and interpretation. Nine algorithms were utilized to overcome the problem associated with rendering the high-dynamic-range image data to low-dynamic-range display devices, and the results were evaluated using a psychophysical experiment. Two paired-comparison experiments and a target detection experiment were performed. Paired-comparison results indicate that the Zone System performs the best on average and the Local Color Correction method performs the worst. The results show that the performance of different encoding schemes depend on the type of data being visualized. The correlation between the preference and scientific usefulness judgments (R2 = 0.31) demonstrates that observers tend to use different criteria when judging the scientific usefulness versus image preference. The experiment was conducted using observers with expertise (Radiologists) for the Medical image to further elucidate the success of HDR rendering on these data. The results indicated that both Radiologists and Non-radiologists tend to use similar criteria regardless of their experience and expertise when judging the usefulness of rendered images. A target detection experiment was conducted to measure the detectability of an embedded noise target in the Medical image to demonstrate the effect of the tone mapping operators on target detection. The result of the target detection experiment illustrated that the detectability of targets the image is greatly influenced by the rendering algorithm due to the inherent differences in tone mapping among the algorithms

Simulation of random packing of hard spheres using Monte Carlo method

A computer based method of generating a random packing of hard spheres is described. Using a Monte Carlo method as employed in the field of Computational Statistical Physics, packing of hard spheres are generated and analyzed. The mean packing fractions for the present assemblies of 1000 spheres are 0.555±0.015 after pouring and 0.582±0.018 after 10 cycles of shaking. These values are approximately 5 to 6 per cent lower than the experimental results of G.D. Scott[30], but similar with the result of Visscher & Bolsterli [17]. The mean coordination numbers are 5.97 and 6.33 for the pouring and shaking case, respectively. The radial distribution function was calculated and compared with other published data. The simulated results are similar with those of G.D. Scott. The pouring simulations with 5 different system sizes verified that the resulting low packing density is independent of the number of particles In the system. In an attempt to determine the reasons for the 5 to 6 per cent difference between existing experimental data of G.D. Scott and the simulation results, two computations were done. The first case study measured the total void volume formed by the gaps of the neighboring spheres. It was found that the void volume occupied approximately 0.0017 per cent of the total volume. Therefore the use of the corrected diameter cannot be a factor. The second series of computations studied the effects of allowing the system to rapidly cool to an equilibrated state as opposed to incrementally reducing T* from a value of 15.8 to 0.00211, whereby the system Is allowed to equlibrium at each incremental step. The result shows that the packing density increased from 0.565 to 0.617. This can account for the 5 to 6 per cent difference between the experimental result of G.D. Scott and the result of current simulation

RPC Gap Production and Performance for CMS RE4 Upgrade

CMS experiment constructed the fourth Resistive Plate Chamber (RPC) trigger station composed of 144 RPCs to enhance the high momentum muon trigger efficiency at both endcap regions. All new CMS endcap RPC gaps are produced in accordance with QA and QC at the Korea Detector Laboratory (KODEL) in Korea. All qualified gaps have been delivered to three assembly sites: CERN in Switzerland, BARC in India, and Ghent University in Belgium for the RPC detector assembly. In this paper, we present the detailed procedures used in the production of RPC gaps adopted for the CMS upgrade.Comment: RPC2014 conference contribution, 7 pages, 8 figure

Electrical Investigation of the Oblique Hanle Effect in Ferromagnet/Oxide/Semiconductor Contacts

We have investigated the electrical Hanle effect with magnetic fields applied at an oblique angle ({\theta}) to the spin direction (the oblique Hanle effect, OHE) in CoFe/MgO/semiconductor (SC) contacts by employing a three-terminal measurement scheme. The electrical oblique Hanle signals obtained in CoFe/MgO/Si and CoFe/MgO/Ge contacts show clearly different line shapes depending on the spin lifetime of the host SC. Notably, at moderate magnetic fields, the asymptotic values of the oblique Hanle signals (in both contacts) are consistently reduced by a factor of cos^2({\theta}) irrespective of the bias current and temperature. These results are in good agreement with predictions of the spin precession and relaxation model for the electrical oblique Hanle effect. At high magnetic fields where the magnetization of CoFe is significantly tilted from the film plane to the magnetic field direction, we find that the observed angular dependence of voltage signals in the CoFe/MgO/Si and CoFe/MgO/Ge contacts are well explained by the OHE, considering the misalignment angle between the external magnetic field and the magnetization of CoFe.Comment: 19 pages, 8 figure