4,469 research outputs found
Colour Change Measurements of Gravitational Microlensing Events by Using the Difference Image Analysis Method
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
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
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
Black Holes at the LHC: Progress since 2002
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
Distribution of Caustic-Crossing Intervals for Galactic Binary-Lens Microlensing Events
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, , 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
and peaks at 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 days, the fraction of events with resolvable
caustic crossing is . 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
.Comment: total 6 pages, including 5 Figures and no Table, submitted to MNRA
Inflation in the nonminimal theory with `K(phi)R' term
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
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
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