We previously developed a shape recognition methodology that uses “branch length similarity” (BLS) entropy, which is defined as a simple branching network consisting of a single node and branches. The simple network is referred to as a “unit branching network” (UBN). Our approach involves obtaining BLS entropy profiles from UBNs created by joining each pixel in the outline of a shape with every other pixel in the shape's border. The profiles successfully characterize the shapes by comparing their BLS entropy profiles. Presently, we modified this approach to facilitate its application to butterfly species identification by partitioning and weighting the entropy profile. As a test, we identified the butterfly species Colias erate, Parnassius bremeri, Eurema hecabe, Gonepteryx rhamni, and Papilio maackii. Each species group consisted of 10 specimens. We used wing shape to identify a species. We extracted evenly spaced x–y coordinates of boundary pixels for the wing shapes in a counter counterclockwise direction. The number of the pixels was 749. We then sequentially partitioned 749 x–y pairs into 15 groups, calculated entropy profiles for the groups, and weighted the profiles. The profiles were combined in order, resulting in a single weighted BLS entropy profile for a wing's shape. Subsequently, we statistically compared the correlation coefficient among the weighted BLS profiles. Our experimental results showed that this method was statistically successful for butterfly species identification. The advantage of the partitioning and weighting process in shape recognition is also discussed.

Image matting may be defined as the extraction and composition of foreground pixels from a given image using colour or opacity estimation. A novel alpha matting methodology is proposed using compressive sensing. The experimental results show that the proposed matting method can provide good mattes from either scribbles or large parts of unknown regions in a trimap.

3D object retrieval is an important research issue in the area of computer graphics for applications such as computer-aided design, simulation, and visualisation. The performance of 3D object retrieval systems is dependent on the development of efficient and effective deors and similarity measures. Presented is an effective approach for supporting 3D object retrieval based on optimising the gradient deor which has recently been shown to perform among the state of the art. The approach relies on sparse coding and the effectiveness of the method is demonstrated by experimental evaluation.

In this paper, we propose a round-optimal identity-based authenticated key agreement protocol for a three-party setting in which three parties can actually transmit messages simultaneously. We then give its security proof in the random oracle model under the Bilinear Diffie–Hellman assumption.

In this paper, we propose a conditional privacy-preserving authentication scheme, called CPAS , using pseudo-identity-based signatures for secure vehicle-to-infrastructure communications in vehicular ad hoc networks. The scheme achieves conditional privacy preservation, in which each message launched by a vehicle is mapped to a distinct pseudo-identity, and a trust authority can always retrieve the real identity of a vehicle from any pseudo-identity. In the scheme, a roadside unit (RSU) can simultaneously verify multiple received signatures, thus considerably reducing the total verification time; an RSU can simultaneously verify 2540 signed-messages/s. The time for simultaneously verifying 800 signatures in our scheme can be reduced by 18%, compared with the previous scheme.

The identity-based infrastructure introduced by Shamir allows a user's public key to be easily derivable from her known identity information such as an email address or a cellular phone number. Such cryptosystems alleviate the certificate overhead and solve the problems of PKI technology. In this letter, we show that two identity-based authenticated key agreement protocols proposed by Holbl and Welzer are completely broken.

Many motile bacteria display wiggling trajectories, which correspond to helical swimming paths. Wiggling trajectories result from flagella pushing off-axis relative to the cell body and making the cell wobble. The spatial extent of wiggling trajectories is controlled by the swimming velocity and flagellar torque, which leads to rotation of the cell body. We employ the method of regularized stokeslets to investigate the wiggling trajectories produced by flagellar bundles, which can form at many locations and orientations relative to the cell body for peritrichously flagellated bacteria. Modelling the bundle as a rigid helix with fixed position and orientation relative to the cell body, we show that the wiggling trajectory depends on the position and orientation of the flagellar bundle relative to the cell body. We observe and quantify the helical wiggling trajectories of Bacillus subtilis, which show a wide range of trajectory pitches and radii, many with pitch larger than 4 . For this bacterium, we show that flagellar bundles with fixed orientation relative to the cell body are unlikely to produce wiggling trajectories with pitch larger than 4 . An estimate based on torque balance shows that this constraint on pitch is a result of the large torque exerted by the flagellar bundle. On the other hand, multiple rigid bundles with fixed orientation, similar to those recently observed experimentally, are able to produce wiggling trajectories with large pitches.

We introduce a mathematical model, which describes the charge inversion phenomena in systems with a charged wall or boundary. This model may prove helpful in understanding semiconductor devices, ion channels, and electrochemical systems like batteries that depend on complex distributions of charge for their function. The mathematical model is derived using the energy variational approach that takes into account ion difusion, electrostatics, finite size effects, and specific boundary behavior. In ion dynamic theory, a wellknown system of equations is the Poisson-Nernst-Planck (PNP) equation that includes entropic and electrostatic energy. The PNP type of equation can also be derived by the energy variational approach. However, the PNP equations have not produced the charge inversion/layering in charged wall situations presumably because the conventional PNP does not include the finite size of ions and other physical features needed to create the charge inversion. In this paper, we investigate the key features needed to produce the charge inversion phenomena using a mathematical model, the energy variational approach. One of the key features is a finite size (finite volume) effect, which is an unavoidable property of ions important for their dynamics on small scales. The other is an interfacial constraint to capture the spatial variation of electroneutrality in systems with charged walls. The interfacial constraint is established by the difusive interface approach that approximately describes the boundary effect produced by the charged wall. The energy variational approach gives us a mathematically self-consistent way to introduce the interfacial constraint. We mainly discuss those two key features in this paper. Employing the energy variational approach, we derive a non-local partial diferential equation with a total energy consisting of the entropic energy, electrostatic energy, repulsion energy representing the excluded volume effect, and the contribution of an interfacial constraint related to overall electroneutrality between bulk/bath and wall. The resulting mathematical model produces the charge inversion phenomena near charged walls. We compare the computational results of the mathematical model to those of Monte-Carlo computations.