A method is presented for selecting items asked for new users to input their preference rates on those items in recommendation systems based on the collaborative filtering. Optimal item selection is formulated by an integer programming problem and we solve it by using a kind of the Hopfield-network-like scheme for interior point methods.

In this paper, we propose a new technique to generate virtual views of three-dimensional (3D) models. The technique is implemented into our facial pose transformation system, which takes only one frontal image and transforms it into virtual views. In our system, to overcome the complex of 3D geometric model, Image Based Rendering based algorithm and mesh-based methods are applied. We also introduce our new Invertible Meshwarp Algorithm, which is developed based on Two-pass Meshwarp Algorithm. Firstly, in the system, for any given person, we take a frontal face image to compose a frontal mesh for it. The standard mesh set of a specific person is created for several face sides; front, half left, half right, left and right side. The other meshes are then automatically generated based on the standard mesh set and the frontal mesh. Continually, we use Invertible Meshwarp Algorithm, which improvably solves the overlap or inversion of neighbor vertices of those created meshes. This step will finalize the generation of different views or the virtual looks of the frontal face image. We then evaluate our transformation system performance by comparing the normalized distance between several feature points in the real and transformed face images. The system is built based on C/C++ language and our result shows that the average error in the feature location is about 7% of the distance from the center of both eyes to the center of a mouth between the actual and transformed face images.

This paper offers an initial analysis of economic and market issues in the development and deployment of mobile remote physiological monitoring services for medical patients through wireless wearable sensors and actuators. Examining the characteristics of the service technologies and related industries, this study focuses on the structure, participants and roles of standardisation of the layers within the emerging mobile remote physiological monitoring industry. The study concludes that the structure of the emerging mobile remote physiological monitoring industry will be oriented about service provision, be integrated with other personal / patient data storage services and be heavily influenced by the interplay of technological developments, the health market structure, existing players and regulation. Additionally, the keys players are likely to be the system integrators and service providers concentrating on large institutional customers. A focus of the paper is analysing both the causes and implications of a modular, horizontally layered industry structure likely to result from the mix of technologies, suppliers and customers as this market develops. The paper discusses why, although horizontal specialisation is the most likely outcome, there is little risk of key layers becoming commoditised. The paper also discusses the appropriate types and levels of standardisation and equipment certification activities that should be encouraged, along with from which groups and industries the pressure for these will come.

Internet traffic engineering is much important for Internet Service Providers (ISPs) today, since it can be used to fully utilize already deployed network resources. For ISPs, the requirements for traffic engineering should be simple, easy to configure, cost-effective and efficient. Based on these considerations, we propose an algorithm called Web First Adaptive Traffic Engineering (WFATE). Since World Wide Web (WWW) services dominate most of the total Internet traffic and WWW flows are not long-lived, we only apply load balancing to WWW traffic in the algorithm. It can be shown that the number of coexistent WWW flows at an ingress node is almost certainly below a bound, and thus a forward-per-flow mechanism without keeping track of the state of each flow is feasible. This mechanism can balance traffic load at fine granularity and therefore get better performance. Through simulations and performance comparison, it is shown that WFATE is quite efficient, which can improve the network throughput averagely by 26% under the "dense source" traffic pattern and 9% under the "sparse source" traffic pattern.

We present a new method in multiresolution rendering of a complex object. Our method uses viewer-centered features including the silhouette in generating multiresolution model. Because the silhouette of an object depends on the position of the viewer, the silhouette has difficulties in real-time generation. We propose the AGSphere for real-time management of the silhouette. The AGSphere easily identifies silhouette parts and manages it in multiresolution manner. The primary applicable feature of the AGSphere is the silhouette from the viewer, but we can also use the AGSphere for other directional features like light silhouette. In this paper, we show experimental results for the silhouette either from the viewer or the light. The efficiency of the proposed method is compared with other methods. We also propose new texture map generation method to use with the multiresolution geometry. Generated texture map has valid mapping function for the multiresolution geometry minimizing texture distortions.

Recently, the small-world network model has been popular to describe a wide range of networks such as human social relations and networks formed by biological entities. The network model achieves a small diameter with relatively few links as measured by the ratio of clustering coefficient and the number of links. It is quite natural to consider email communication similar to social network patterns. Quite surprisingly, we find from our empirical study that local email networks follow a different type of network model that falls into the category of scale-free network. We propose new network models to describe such communication structure.

In this paper, we propose a method of linear time-varying filtering of discrete time signals. The objective of this method is to derive a component, of an input signal, whose alias-free generalized discrete time-frequency distribution [Jeong & Williams 1992] concentrates on a specific region of a time-frequency plane. The method is essentially realized by computing an orthogonal projection of an input onto a subspace that is spanned by orthonormal signals, whose distributions concentrate on the region. We show that such orthonormal signals can be derived as eigenvectors of a matrix whose components are explicitly expressed by using the kernel of the distribution and the regions. This result shows that we can design such a filter prior to processing of the input if the specific region is given as a priori. This result is a generalization of [Hlawatsch & Kozek 1994], that is originally derived for the continuous Wigner distributions, to the discrete distributions.

In their paper, G. Gong and S.Q. Jiang construct a new pseudo-random sequence generator by using two ternary linear feedback shift registers (LFSR). The new generator is called an editing generator which a combined model of the clock-controlled generator and the shrinking generator. For a special case (Both the base sequence and the control sequence are mm-sequence of degree n), the period, linear complexity, symbol distribution and security analysis are discussed in the same article. In this paper, we expand the randomness results of the edited sequence for general cases, we do not restrict the base sequence and the control sequence has the same length. For four special cases of this generator, the randomness of the edited sequence is discussed in detail. It is shown that for all four cases the editing generator has good properties, such as large periods, high linear complexities, large ratio of linear complexity per symbol, and small un-bias of occurrences of symbol. All these properties make it necessary to resist to the attack from the application of Berlekamp-Massey algorithm.

Many diverse methods have been developed in the field of biometric identification as a greater emphasis is placed on human-friendliness in the area of intelligent systems. One emerging method is the use of human footprint. However, in the previous research, there were some limitations resulting from the spatial resolution of sensors. One possible method to overcome this limitation is through the use additional information such as dynamic walking information in dynamic footprint. In this study, we suggest a new person recognition scheme based on overlapped foot shape and COP (Center Of Pressure) trajectory during one-step walking. And, we show the usefulness of the suggested method, obtaining a 98.6% recognition rate in our experiment with eleven people.

Combinatorial designs are normally used to construct visual cryptographic schemes. For such schemes two parameters are very important viz. pixel expansion and contrast. Optimizing both is a very hard problem. The schemes having optimal contrast tend to use a high pixel expansion. The focus of the paper is to construct schemes for which pixel expansion is modest and the contrast is close to optimality. Here the tool is latin squares that haven't been used earlier for this purpose.

To examine the computational complexity of cryptographic primitives such as the discrete logarithm problem, the factoring problem and the Diffie-Hellman problem, we define a new problem called square-root exponent, which is a problem to compute a value whose discrete logarithm is a square root of the discrete logarithm of a given value. We analyze reduction between the discrete logarithm problem modulo a prime and the factoring problem through the square-root exponent. We also examine reductions among the computational version and the decisional version of the square-root exponent and the Diffie-Hellman problem and show that the gap between the computational square-root exponent and the decisional square-root exponent partially overlaps with the gap between the computational Diffie-Hellman and the decisional Diffie-Hellman under some condition.

Environment measurement is an important issue for various applications including household robots. Pulse radars are promising candidates in a near future. Estimating target shapes using waveform data, which we obtain by scanning an omni-directional antenna, is known as one of ill-posed inverse problems. Parametric methods such as Model-fitting method have problems concerning calculation time and stability. We propose a non-parametric algorithm for high-resolution estimation of target shapes in order to solve the problems of parametric algorithms.

We propose a method for reducing the size of a share in visual secret sharing schemes. The proposed method does not cause the leakage and the loss of the original image. The quality of the recovered image is almost same as that of previous schemes.

This paper addresses the problem of arranging fewest possible probes to detect a hidden object in a specified region and presents a reasonable scheme for the purpose. Of special interest is the case where an object is a double-sided conic cylinder which represents the shape of the energy distribution of laser light used in the optical network. The performance of our scheme is evaluated by comparing the number of probes to that of an existing scheme, and our scheme shows a potential for reducing the number of probes. In other words, the time for detection is significantly reduced from a realistic point of view.

The efficient squaring algorithm is an important role in large integer arithmetic. All multiplication algorithms can be used for squaring large integers, but their performance can be greatly improved by using the standard squaring algorithm. The standard squaring algorithm is quite well-known, but unfortunately there is an improper carry handling bug in it. Recently, Guajardo and Paar proposed a modified squaring algorithm to fix the bug in the standard squaring algorithm. In this paper, we first point out that there is still an error-indexing bug in the Guajardo-Paar squaring algorithm. Then, we propose a new efficient squaring algorithm that not only avoids the bugs in both the standard squaring algorithm and the Guajardo-Paar squaring algorithm but also improves the performance in squaring computation. Our analyses and our simulations indicate that the proposed squaring algorithm is about 2.5 times faster in comparison with the standard multiplication algorithm in Pentium Series CPU. The performance of 1024-bit RSA cryptosystem can be saved 34.3% by using the proposed squaring algorithm to replace the standard multiplication.

H-coloring problem is a coloring problem with restrictions such that some pairs of colors cannot be used for adjacent vertices, where H is a graph representing the restrictions of colors. We deal with the case that H is the complement graph of a cycle of odd order 2p + 1. This paper presents the following results: (1) chordal graphs and internally maximal planar graphs are -colorable if and only if they are p-colorable (p 2), (2) -coloring problem on planar graphs is NP-complete, and (3) there exists a class that includes infinitely many -colorable but non-3-colorable planar graphs.

Recently, the mulitihop wireless network system attracts the interest of many people as a communication network system of the next generation. The multihop wireless network has unique features in which neither base stations nor wired backbone networks are required and a terminal can communicate with the other terminal beyond the transmission range by multihopping. In this network, a communication link between two terminals which can communicate directly is required a channel. Since cochannel interference may occur, we need to assign channels to communication links carefully. In this paper, we describe a channel assignment strategy which takes the degree of cochannel interference into consideration, and we evaluate an effectiveness of this strategy by computer simulations. We show that this strategy is more effective than a strategy which does not take the degree of cochannel interference into consideration. And we also consider a few channel assignment algorithms briefly.

Efficient representations of a 3-D object shape and its texture data have attracted wide attention for the transmission of computer graphics data and for the development of multi-view real image rendering systems on computer networks. Polygonal mesh data, which consist of connectivity information, geometry data, and texture data, are often used for representing 3-D objects in many applications. This paper presents a wavelet coding technique for coding the geometry data structured on a triangular lattice plane obtained by structuring the connectivity of the polygonal mesh data. Since the structured geometry data have an arbitrarily-shaped support on the triangular lattice plane, a shape-adaptive wavelet transform was used to obtain the wavelet coefficients, whose number is identical to the number of original data, while preserving the self-similarity of the wavelet coefficients across subbands. In addition, the wavelet coding technique includes extensions of the zerotree entropy (ZTE) coding for taking into account the rate-distortion properties of the structured geometry data. The parent-children dependencies are defined as the set of wavelet coefficients from different bands that represent the same spatial region in the triangular lattice plane, and the wavelet coefficients in the spatial tree are optimally pruned based on the rate-distortion properties of the geometry data. Experiments in which proposed wavelet coding was applied to some sets of polygonal mesh data showed that the proposed wavelet coding achieved better coding efficiency than the Topologically Assisted Geometry Compression scheme adopted in the MPEG-4 standard.

The artifacts of low-bit rate quantization in images cannot be removed satisfactorily by known methods. We propose decomposition of images as HSI and LSI (higher- and lower- significance images), followed by subsampling and reconstruction methods for LSI. Experiments show significant improvement in image quality, as compared to other methods.

This paper provides methods for construction of pairing-based cryptosystems based on non-supersingular elliptic curves.