Certificateless cryptography eliminates the need of certificates in public key cryptosystems and solves the inherent key escrow problem in identity-based cryptosystems. In this paper we discuss the existence of short certificateless signature schemes provably secure in formal security models recently established, whose resulting signature consists of a single element of the underlying group by demonstrating key replacement attacks on Du-Wen's and Tso et al.'s short certificateless signature schemes.

Despite providing similar functionality, multiple network services may require the use of different interfaces to
access the functionality, and this problem will only get worse with the widespread deployment of ubiquitous
computing environments. One way around this problem is to use interface adapters that adapt one interface
into another. Chaining these adapters allows flexible interface adaptation with fewer adapters, but the loss
incurred due to imperfect interface adaptation must be considered. This paper outlines a matrix-based
mathematical basis for analyzing the chaining of lossy interface adapters. We also show that the problem of
finding an optimal interface adapter chain is NP-complete with a reduction from 3SAT.？

We study the formation of the (noncommutative) Schwarzschild black hole from collapsing shell of the
generalized matters containing polytropic and Chaplygin gas. We show that this collapsing shell depending on
various parameters forms either a black hole or a naked singular shell with the help of the pressure.
Furthermore, by considering the smeared gravitational sources, we investigate the noncommutative black holes
formation. Though this mild noncommutative correction of matters cannot ultimately resolve the emergence of
the naked singularity, we show that in some parameter region the collapsing shell evolves to a
noncommutative black hole before becoming a naked singular shell.

The stochastic quantization problem of Brownian particle motion that follows Kramers equation is
investigated in one-dimension using invariant related unitary transformation method. The explicit
Hamiltonians for Langevin equation are constructed separately for the systems that have several different
types of the external forces. In the case which does not have external forces, the spectrum of Schro?dinger
solution is continuous since the particles are unbound in a finite region. However, when a external force
is given by the (time-dependent) harmonic potential, the particles are bound inside the potential leading
the spectrum of quantum wave functions to be discrete. The bound?unbound transitions are important
since it is connected to metal?insulator transitions that can be achievable for certain compound
semiconductors by increasing the doping concentrations at low temperatures. Additionally, when the
Hamiltonian involves a higher order term of x as well as harmonic potential term, we have executed the
ordinary perturbation expansion in order to obtain the approximate quantum solutions.

The role of helicity in Lagrangian turbulence is investigated using direct numerical simulation of homogeneous
isotropic turbulence. Probability density functions and autocorrelations along a fluid particle trajectory
associated with geometric quantities such as curvature and torsion of the Lagrangian trajectory
are provided. The relationship between helicity and the ratio of torsion to curvature is investigated.
We found that probability density functions of torsion and torsion normalized by curvature clearly show
well-established slope in log?log plots. Finally, the relationship between helicity, acceleration and geometric
quantities are discussed.

The absorption cross section for the warped AdS3 black hole background shows that it is larger than the area
even if the s-wave limit is considered. It raises some question whether the deviation from the areal cross
section is due to the warped configuration of the geometry or the rotating co- ordinate system, where these
two effects are mixed up in the warped AdS3 black hole. So, we study the low-frequency scattering dynamics of
propagating scalar fields under the warped AdS3 background at the critical point which reduces to the BTZ black
hole in the rotating frame without the warped factor, which shows that the deformation effect at the critical
point does not appear.

Although many kinds of methods for tracking human gaze position in order as human-computer interface and virtual
reality have been developed and applied, there has no method of gaze tracking as human-TV interface of internet
protocol television (IPTV) at a distance. That is due to many limitations of camera optics and illumination since the
natural viewing distance is relatively far as almost 2m. To overcome such limitation, a new gaze tracking system and
method at a distance for controlling IPTV is proposed. Our method is novel in the following four ways compared to
previous work. First, this research is the first one of gaze tracking at a distance. Second, in order to solve the
limitation of camera optics at a distance, we use a zoom lens for acquiring enough eye image resolution. Third, in
order to directly estimate gaze position without complicate camera calibrations, we used only geometric information
about pupil and four cornea specular reflections from 2D eye image. Fourth, by using infrared illuminators and NIR
pass filter, the pupil region becomes distinctive in the input image irrespective of the change of environmental visible
light. Experimental results with an IPTV of 60 inch wide screen (16:9) showed that the proposed system could be
used as a new interface for controlling IPTV.

Applications based on eye-blink detection have increased, which requires eye-blink detection to be robust and non-
intrusive irrespective of the changes in the user’s facial pose. However, most previous studies of camera based blink
detection have the disadvantage that the performances were affected by the facial pose. They also focused on blink
detection using only frontal facial images. To overcome them, we propose a new method of blink detection robust to
the facial pose.
This research is novel in the following four ways compared to previous studies. First, the face and eye regions are
detected by using both AdaBoost face detector and Lucas-Kanade-Tomasi (LKT) based method in order to be robust
to facial pose. Second, the state of the eye being open or closed needed for blink detection is determined based on
two features, the ratio of the height to the width of the eye region in a still image, and the cumulative difference of the
number of black pixels of the eye region using an adaptive threshold in successive images. These two features are
robustly extracted irrespective of the illumination variations by using illumination normalization. Third, the accuracy of
determining eye state, open or close is increased by combining the above two features based on the support vector
machine (SVM). Finally, the SVM classifier for determining the eye state is adaptively selected according to the facial
rotation.
Experimental results with three databases showed that the blink detection by the proposed method was robust to
various facial poses.