4,036 research outputs found

    Colour Change Measurements of Gravitational Microlensing Events by Using the Difference Image Analysis Method

    Full text link
    Detecting colour changes of a gravitational microlensing event induced by the limb-darkened extended source effect is important to obtain useful information both about the lens and source star. However, precise measurements of the colour changes are hampered by blending, which also causes colour changes of the event. In this paper, we show that although the colour change measured from the subtracted image by using the recently developed photometric method of the ``difference image analysis'' (DIA) differs from the colour change measured by using the conventional method based on the extraction of the individual source stars' point spread functions, the curve of the colour changes (colour curve) constructed by using the DIA method enables one to obtain the same information about the lens and source star, but with significantly reduced uncertainties due to the absence of blending. We investigate the patterns of the DIA colour curves for both single lens and binary lens events by constructing colour change maps.Comment: total 8 pages, including 4 figures and no table, MNRAS, in pres

    Real-Time Scheduling Method for Middleware of Industrial Automation Devices

    Get PDF
    In this study, a real-time scheduling algorithm, which supports periodic and sporadic executions with event handling, is proposed for the middleware of industrial automation devices or controllers, such as industrial robots and programmable logic controllers. When sensors and embedded controllers are included in control loops having different control periods, they should transmit their data periodically to the controllers and actuators; otherwise, fatal failure of the system including the devices could occur. The proposed scheduling algorithm manages modules, namely, the thread type (or .so type) and process type (or .exe type), for periodic execution, sporadic execution, and non-real-time execution. The program structures for the thread-type and process-type modules that can make the proposed algorithm manage the modules efficiently are suggested; then, they are applied in periodic and sporadic executions. For sporadic executions, the occurrences of events are first examined to invoke the execution modules corresponding to the events. The proposed scheduling algorithm is implemented using the Xenomai real-time operating system (OS) and Linux, and it is validated through several examples

    Chromaticity of Gravitational Microlensing Events

    Get PDF
    In this paper, we investigate the color changes of gravitational microlensing events caused by the two different mechanisms of differential amplification for a limb-darkened extended source and blending. From this investigation, we find that the color changes of limb-darkened extended source events (color curves) have dramatically different characteristics depending on whether the lens transits the source star or not. We show that for a source transit event, the lens proper motion can be determined by simply measuring the turning time of the color curve instead of fitting the overall color or light curves. We also find that even for a very small fraction of blended light, the color changes induced by the blending effect is equivalent to those caused by the limb-darkening effect, causing serious distortion in the observed color curve. Therefore, to obtain useful information about the lens and source star from the color curve of a limb-darkened extended source event, it will be essential to eliminate or correct for the blending effect. We discuss about the methods for the efficient correction of the blending effect.Comment: total 18 pages, including 5 figures and no table, MNRAS, submitte

    Distribution of Caustic-Crossing Intervals for Galactic Binary-Lens Microlensing Events

    Get PDF
    Detection of caustic crossings of binary-lens gravitational microlensing events is important because by detecting them one can obtain useful information both about the lens and source star. In this paper, we compute the distribution of the intervals between two successive caustic crossings, f(tcc)f(t_{\rm cc}), for Galactic bulge binary-lens events to investigate the observational strategy for the optimal detection and resolution of caustic crossings. From this computation, we find that the distribution is highly skewed toward short tcct_{\rm cc} and peaks at tcc∼1.5t_{\rm cc}\sim 1.5 days. For the maximal detection of caustic crossings, therefore, prompt initiation of followup observations for intensive monitoring of events will be important. We estimate that under the strategy of the current followup observations with a second caustic-crossing preparation time of ∼2\sim 2 days, the fraction of events with resolvable caustic crossing is ∼80\sim 80%. We find that if the followup observations can be initiated within 1 day after the first caustic crossing by adopting more aggressive observational strategies, the detection rate can be improved into ∼90\sim 90%.Comment: total 6 pages, including 5 Figures and no Table, submitted to MNRA

    Black Holes at the LHC: Progress since 2002

    Full text link
    We review the recent noticeable progresses in black hole physics focusing on the up-coming super-collider, the LHC. We discuss the classical formation of black holes by particle collision, the greybody factors for higher dimensional rotating black holes, the deep implications of black hole physics to the `energy-distance' relation, the security issues of the LHC associated with black hole formation and the newly developed Monte-Carlo generators for black hole events.Comment: 6 pages, 10 figures, Plenary talk given at the 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08), Seoul, Korea (June 16-21, 2008). To be published in the Conference Proceeding

    Inflation in the nonminimal theory with `K(phi)R' term

    Get PDF
    A class of inflationary models with the nonminimal coupling term `K(phi)R' is considered. We show that the successful inflation can take place if the ratio between the square of the nonminimal coupling term and the potential for the scalar goes asymptotically constant.Comment: 3 pages, 1 figure, Talk given at 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08), Seoul, Korea, 16-21 Jun 200

    How to Keep the Binary Compatibility of C++ Based Objects

    Get PDF
    This chapter proposes the binary compatibility object model for C++ (BiCOMC) to provide the binary compatibility of software components in order to share objects among C++ based executable files such as .exe, .dll, and .so. In addition, the proposed model provides the method overriding and overloading, multiple inheritance, and exception handling. This chapter illustrates how to use the proposed model via a simple example in the Windows and Linux environment. The proposed method is validated by application examples and comparisons with known object models such as C++, COM, and CCC in terms of the call time of a method during execution and the binary compatibility such as reusability due to interface version and the types of compilers. Also this chapter shows that BiCOMC-based components compiled with Microsoft Visual C++ and GCC can call each other and the interface version problems are resolved
    • …
    corecore