2,280 research outputs found

    Disconnected Skeleton: Shape at its Absolute Scale

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    We present a new skeletal representation along with a matching framework to address the deformable shape recognition problem. The disconnectedness arises as a result of excessive regularization that we use to describe a shape at an attainably coarse scale. Our motivation is to rely on the stable properties of the shape instead of inaccurately measured secondary details. The new representation does not suffer from the common instability problems of traditional connected skeletons, and the matching process gives quite successful results on a diverse database of 2D shapes. An important difference of our approach from the conventional use of the skeleton is that we replace the local coordinate frame with a global Euclidean frame supported by additional mechanisms to handle articulations and local boundary deformations. As a result, we can produce descriptions that are sensitive to any combination of changes in scale, position, orientation and articulation, as well as invariant ones.Comment: The work excluding {\S}V and {\S}VI has first appeared in 2005 ICCV: Aslan, C., Tari, S.: An Axis-Based Representation for Recognition. In ICCV(2005) 1339- 1346.; Aslan, C., : Disconnected Skeletons for Shape Recognition. Masters thesis, Department of Computer Engineering, Middle East Technical University, May 200

    A quantum heat engine with coupled superconducting resonators

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    We propose a quantum heat engine composed of two superconducting transmission line resonators interacting with each other via an optomechanical-like coupling. One resonator is periodically excited by a thermal pump. The incoherently driven resonator induces coherent oscillations in the other one due to the coupling. A limit cycle, indicating finite power output, emerges in the thermodynamical phase space. The system implements an all-electrical analog of a photonic piston. Instead of mechanical motion, the power output is obtained as a coherent electrical charging in our case. We explore the differences between the quantum and classical descriptions of our system by solving the quantum master equation and classical Langevin equations. Specifically, we calculate the mean number of excitations, second-order coherence, as well as the entropy, temperature, power and mean energy to reveal the signatures of quantum behavior in the statistical and thermodynamic properties of the system. We find evidence of a quantum enhancement in the power output of the engine at low temperatures.Comment: 15 pages, 14 figures, new references adde

    Crocheting Mathematics Through COVID-19

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    As it is often said, something good often comes out of most bad situations. The time I spent during COVID-19, at home and isolated with my two children, brought out one secret passion in me: crocheting. Not only did it help me pass the time in a sane and productive way, but also it gave me a new goal in life. It connected my math side with my artistic side. It gave me a new perspective to look at math, and helped me help others see math in a positive way

    Non-parametric comparison of histogrammed two-dimensional data distributions using the Energy Test

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    When monitoring complex experiments, comparison is often made between regularly acquired histograms of data and reference histograms which represent the ideal state of the equipment. With the larger HEP experiments now ramping up, there is a need for automation of this task since the volume of comparisons could overwhelm human operators. However, the two-dimensional histogram comparison tools available in ROOT have been noted in the past to exhibit shortcomings. We discuss a newer comparison test for two-dimensional histograms, based on the Energy Test of Aslan and Zech, which provides more conclusive discrimination between histograms of data coming from different distributions than methods provided in a recent ROOT release.The Science and Technology Facilities Council, U

    A Research on the Association between Corporate Governance and Corporate Performance in Turkish Energy Sector

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    Today’s harsh market conditions prompt companiesto allocate the highest level of emphasis on corporateperformance. However, in some cases interests of managementand shareholders may clash. Subsequently providing investorswith timely, accurate and valid information in today’s everchanging economic environment is vital for transparency. Aim ofthis paper is to measure the association between corporategovernance and corporate performance within companies in theenergy sector listed at Borsa Istanbul (formerly known asIstanbul Stock Exchange)

    Laparoscopic artificial insemination in dairy sheep with chilled semen stored for up to 26 h

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    Adult East Freisan crossbred (n = 220) and Chios ewes (n = 105) were divided into four groups and inseminated with chilled semen, which had been stored for 7, 13, 20 or 26 h at 5°C. Unilateral intrauterine insemination (50 x 106 spermatozoa in 0.25 ml) was performed with the aid of a laparoscope. Inseminations were carried out 48 – 52 h after pessary removal (30 mg FGA) without detecting estrus. The lambing rates after intrauterine insemination with chilled semen were found to be similar in East Fresian crossbred (40%) and Chios ewes (30%). Intrauterine insemination with chilled semen stored up to 26 h resulted in similar lambing rates; whereas, fertility of Chios ewes tended to decline with increased holding time of chilled semen. From this study, it is concluded that decreasing the storage time of chilled semen at 5°C improves pregnancy in Chios ewes and that East Fresian crossbred ewe’s conception rates to intrauterine insemination with chilled semen was relatively higher than Chios ewes.Key words: Dairy sheep, chilled semen, time of insemination, lambing rate

    The Meaning of Memory Safety

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    We give a rigorous characterization of what it means for a programming language to be memory safe, capturing the intuition that memory safety supports local reasoning about state. We formalize this principle in two ways. First, we show how a small memory-safe language validates a noninterference property: a program can neither affect nor be affected by unreachable parts of the state. Second, we extend separation logic, a proof system for heap-manipulating programs, with a memory-safe variant of its frame rule. The new rule is stronger because it applies even when parts of the program are buggy or malicious, but also weaker because it demands a stricter form of separation between parts of the program state. We also consider a number of pragmatically motivated variations on memory safety and the reasoning principles they support. As an application of our characterization, we evaluate the security of a previously proposed dynamic monitor for memory safety of heap-allocated data.Comment: POST'18 final versio

    Annealed Silver-Island Films for Applications in Metal-Enhanced Fluorescence: Interpretation in Terms of Radiating Plasmons

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    The effects of thermally annealed silver island films have been studied with regard to their potential applicability in applications of metal-enhanced fluorescence, an emerging tool in nano-biotechnology. Silver island films were thermally annealed between 75 and 250°C for several hours. As a function of both time and annealing temperature, the surface plasmon band at ≈420 nm both diminished and was blue shifted. These changes in plasmon resonance have been characterized using both absorption measurements, as well as topographically using Atomic Force Microscopy. Subsequently, the net changes in plasmon absorption are interpreted as the silver island films becoming spherical and growing in height, as well as an increased spacing between the particles. Interestingly, when the annealed surfaces are coated with a fluorescein-labeled protein, significant enhancements in fluorescence are osbserved, scaling with annealing temperature and time. These observations strongly support our recent hypothesis that the extent of metal-enhanced fluorescence is due to the ability of surface plasmons to radiate coupled fluorophore fluorescence. Given that the extinction spectrum of the silvered films is comprised of both an absorption and scattering component, and that these components are proportional to the diameter cubed and to the sixth power, respectively, then larger structures are expected to have a greater scattering contribution to their extinction spectrum and, therefore, more efficiently radiate coupled fluorophore emission. Subsequently, we have been able to correlate our increases in fluorescence emission with an increased particle size, providing strong experiment evidence for our recently reported metal-enhanced fluorescence, facilitated by radiating plasmons hypothesis
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