In this paper, we introduce a biologically-motivated model to detect image saliency. The model employs an isophote based operator to detect potential structure and global saliency information related to each pixel, which are then combined with integral image to build up final saliency maps. We show that the proposed model outperforms seven state-of-the-art saliency detectors in experimental studies.

In this paper we propose a unified coprocessor architecture that, by using a Glitch PUF and a block cipher, efficiently unifies necessary functions for secure key storage and challenge-response authentication. Based on the fact that a Glitch PUF uses a random logic for the purpose of generating glitches, the proposed architecture is designed around a block cipher circuit such that its round functions can be shared with a Glitch PUF as a random logic. As a concrete example, a circuit structure using a Glitch PUF and an AES circuit is presented, and evaluation results for its implementation on FPGA are provided. In addition, a physical random number generator using the same circuit is proposed. Evaluation results by the two major test suites for randomness, NIST SP 800-22 and Diehard, are provided, proving that the physical random number generator passes the test suites.

How do global warming and agriculture influence each other? It is possible to answer the question by searching knowledge about the relationship between global warming and agriculture. As exemplified by this question, strong demands exist for searching relationships between objects. Mining knowledge about relationships on Wikipedia has been studied. However, it is desired to search more diverse knowledge about relationships on the Web. By utilizing the objects constituting relationships mined from Wikipedia, we propose a new method to search images with surrounding text that include knowledge about relationships on the Web. Experimental results show that our method is effective and applicable in searching knowledge about relationships. We also construct a relationship search system named “Enishi” based on the proposed new method. Enishi supplies a wealth of diverse knowledge including images with surrounding text to help users to understand relationships deeply, by complementarily utilizing knowledge from Wikipedia and the Web.

This paper presents an application of the constained interpolation profile basis set (CIP-BS) method to electromagnetic fields analyses. Electromagnetic fields can be expanded in terms of multi-dimensional CIP basis functions, and the Galerkin method can then be applied to obtain a system of linear equations. In the present study, we focus on a two-dimensional problem with TMz polarization. In order to examine the precision of the CIP-BS method, TE202 resonant mode in a rectangular cavity is analyzed. The numerical results show that CIP-BS method has better performance than the finite-difference time-domain (FDTD) method when the time step is small. Then an absorbing boundary condition based on the perfectly matched layer (PML) is formulated, and the absorption performance is demonstrated. Finally, the propagation in an inhomogeneous medium is computed by using the proposed method, and it is observed that in the CIP-BS method, smooth variation of material constants is effectively formulated without additional computational costs, and that accurate results are obtained in comparison with the FDTD method even if the permittivity is high.

In this paper, we propose a method for deciding the parameters to satisfy the experiment values, and also checked the effectiveness of this method based on Kramers-Kronig (K.K.) relation. In our proposed method, we are expressed as matrix the Sellmeier's formula, and are solved the simulatenaous equation until the satisfied the experiment value. Numerical results are given for the influence of pulse responses using the medium constants which can be found by proposed method. Also, numerical technique of pulse responses is employed the fast inversion of Laplace transform (FILT).

This paper shows a way to derive positive definite kernels from edit distances. It is well-known that, if a distance d is negative definite, e-λd is positive definite for any λ > 0. This property provides us the opportunity to apply useful techniques of kernel multivariate analysis to the features of data captured by means of the distance. However, the known instances of edit distance are not always negative definite. Even worse, it is usually not easy to examine whether a given instance of edit distance is negative definite. This paper introduces alignment kernels to present an alternative means to derive kernels from edit distance. The most important advantage of the alignment kernel consists in its easy-to-check sufficient condition for the positive definiteness. In fact, when we surveyed edit distances for strings, trees and graphs, all but one are instantly verified to meet the condition and therefore proven to be positive definite.

Recently, fuzzy set theory has been widely employed in building portfolio selection models where uncertainty plays a role. In these models, future security returns are generally taken for fuzzy variables and mathematical models are then built to maximize the investment profit according to a given risk level or to minimize a risk level based on a fixed profit level. Based on existing works, this paper proposes a portfolio selection model based on fuzzy birandom variables. Two original contributions are provided by the study: First, the concept of technical analysis is combined with fuzzy set theory to use the security returns as fuzzy birandom variables. Second, the fuzzy birandom Value-at-Risk (VaR) is used to build our model, which is called the fuzzy birandom VaR-based portfolio selection model (FBVaR-PSM). The VaR can directly reflect the largest loss of a selected case at a given confidence level and it is more sensitive than other models and more acceptable for general investors than conventional risk measurements. To solve the FBVaR-PSM, in some special cases when the security returns are taken for trapezoidal, triangular or Gaussian fuzzy birandom variables, several crisp equivalent models of the FBVaR-PSM are derived, which can be handled by any linear programming solver. In general, the fuzzy birandom simulation-based particle swarm optimization algorithm (FBS-PSO) is designed to find the approximate optimal solution. To illustrate the proposed model and the behavior of the FBS-PSO, two numerical examples are introduced based on investors' different risk attitudes. Finally, we analyze the experimental results and provide a discussion of some existing approaches.

Checkpoint-rollback recovery, which is a universal method for restoring distributed systems after faults, requires a sophisticated snapshot algorithm especially if the systems are large-scale, since repeatedly taking global snapshots of the whole system requires unacceptable communication cost. As a sophisticated snapshot algorithm, a partial snapshot algorithm has been introduced that takes a snapshot of a subsystem consisting only of the nodes that are communication-related to the initiator instead of a global snapshot of the whole system. In this paper, we modify the previous partial snapshot algorithm to create a new one that can take a partial snapshot more efficiently, especially when multiple nodes concurrently initiate the algorithm. Experiments show that the proposed algorithm greatly reduces the amount of communication needed for taking partial snapshots.

In analysis of general-purpose problems which involves many factors from different viewpoints, an important challenge is to acquire different opinions and distributed modeling templates from multiple remote experts, and to aggregate these templates. In order to deal with this problem, we developed the Distributed Cooperative Modeling System (DCMS) by integrating our achievements [1]-[5]. The paper introduces how to analyze a complex problem using DCMS, with distributed templates from multiple experts, historical templates based on statistical data, and trend templates deduced from historical data, with the example of analyzing “diversification of Macao industries”

Multiple access (MA) technology is of most importance for beyond long term evolution (LTE) system. Non-orthogonal multiple access (NOMA) utilizing power domain and advanced receiver has been considered as a candidate MA technology recently. In this paper, power assignment method, which plays a key role in performance of NOMA, is investigated. The power assignment on the basis of maximizing geometric mean user throughput requires exhaustive search and thus has an unacceptable computational complexity for practical systems. To solve this problem, a novel power assignment method is proposed by exploiting tree search and characteristic of serial interference cancellation (SIC) receiver. The proposed method achieves the same performance as the exhaustive search while greatly reduces the computational complexity. On the basis of the proposed power assignment method, the performance of NOMA is investigated by link-level and system-level simulations in order to provide insight into suitability of using NOMA for future MA. Simulation results verify effectiveness of the proposed power assignment method and show NOMA is a very promising MA technology for beyond LTE system.

This paper presents an experimental study of on-body ultra-wideband (UWB) radio propagation channels within an enclosed space. To facilitate high-speed wireless body area networks, UWB is a promising technology because of its low power consumption and anti-multipath capabilities. The motivation of this study is to examine the effects of nearby humans on the UWB channels by varying the population within an elevator cabin from one (subject alone) to 20 (full capacity of the elevator). The first domain (0 < delay, t ≤ 4ns) in the measured delay profiles was either a direct (for line-of-sight) or diffracted (for non-line-of-sight) wave, which was found almost unrelated to the population; whereas the second domain (t > 4ns) highly depended on it. Total received power and delay spreads decreased with increasing the population. In addition, by varying human population, average power delay profiles were modeled based on measurements.

Verifiable random functions (VRF), proposed in 1999, and selectively convertible undeniable signature (SCUS) schemes, proposed in 1990, are apparently thought as independent primitives in the literature. In this paper, we show that they are tightly related in the following sense: VRF is exactly SCUS; and the reverse also holds true under a condition. This directly yields several deterministic SCUS schemes based on existing VRF constructions. In addition, we create a new probabilistic SCUS scheme, which is very compact. We build efficient confirmation and disavowal protocols for the proposed SCUS schemes, based on what we call zero-knowledge protocols for generalized DDH and non-DDH. These zero-knowledge protocols are built either sequential, concurrent, or universally composable.

The security of pairing-based cryptosystems is determined by the difficulty of solving the discrete logarithm problem (DLP) over certain types of finite fields. One of the most efficient algorithms for computing a pairing is the ηT pairing over supersingular curves on finite fields of characteristic 3. Indeed many high-speed implementations of this pairing have been reported, and it is an attractive candidate for practical deployment of pairing-based cryptosystems. Since the embedding degree of the ηT pairing is 6, we deal with the difficulty of solving a DLP over the finite field GF(36n), where the function field sieve (FFS) is known as the asymptotically fastest algorithm of solving it. Moreover, several efficient algorithms are employed for implementation of the FFS, such as the large prime variation. In this paper, we estimate the time complexity of solving the DLP for the extension degrees n=97, 163, 193, 239, 313, 353, and 509, when we use the improved FFS. To accomplish our aim, we present several new computable estimation formulas to compute the explicit number of special polynomials used in the improved FFS. Our estimation contributes to the evaluation for the key length of pairing-based cryptosystems using the ηT pairing.

As businesses are increasingly relying on the cloud to host their services, cloud providers are striving to offer guaranteed and highly-available resources. To achieve this goal, recent proposals have advocated to offer both computing and networking resources in the form of Virtual Data Centers (VDCs). Subsequently, several attempts have been made to improve the availability of VDCs through reliability-aware resource allocation schemes and redundancy provisioning techniques. However, the research to date has not considered the heterogeneity of the underlying physical components. Specifically, it does not consider recent findings showing that failure rates and availability of data center equipments can vary significantly depending on various parameters including their types and ages. To address this limitation, in this paper we propose a High-availability Virtual Infrastructure management framework (Hi-VI) that takes into account the heterogeneity of cloud data center equipments to dynamically provision backup resources in order to ensure required VDC availability. Specifically, we propose a technique to compute the availability of a VDC that considers both (1) the heterogeneity of data center networking and computing equipments in terms of failure rates and availability, and (2) the number of redundant virtual nodes and links provisioned as backups. We then leverage this technique to propose an allocation scheme that jointly provisions resources for VDCs and backups of virtual components with the goal of achieving the required VDC availability while minimizing energy costs. Through simulations, we demonstrate the effectiveness of our framework compared to heterogeneity-oblivious solutions.

We introduce a new nonlinear control method to globally asymptotically stabilize a class of uncertain nonlinear systems. First, we provide a system reconfiguration method which reconfigures the nonlinear systems with smooth positive functions. Then, we provide a nonlinear controller design method to globally asymptotically stabilize the reconfigured systems by utilizing Lyapunov equations. As a result, a class of uncertain nonlinear systems which have not been treated in the existing results can be globally asymptotically stabilized by our control method. Examples are given for easy following and illustration.

A point-to-point fixed wireless access (FWA) system with a maximum throughput of 1Gbps has been developed in the 39GHz band. A double-layer plate-laminated waveguide slot array antenna is successfully realized with specific considerations of practical application. The antenna is designed so as to hold the VSWR under 1.5. The antenna input as well as feeding network is configured to reduce the antenna profile as well as the antenna weight. In addition, integrating the antenna into a wireless terminal is taken into account. A shielding wall, whose effectiveness is experimentally demonstrated, is set in the middle of the wireless terminal to achieve the spatial isolation of more than 65dB between two antennas on the H-plane. 30 test antennas are fabricated by diffusion bonding of thin metal plates, to investigate the tolerance and mass-productivity of this process. An aluminum antenna, which has the advantages of light weight and anti-aging, is also fabricated and evaluated with an eye to the future.

This paper deals with carrier frequency offset (CFO) estimation based on the minimum variance distortionless response (MVDR) criterion without using specific training sequences for interleaved orthogonal frequency division multiple access (OFDMA) uplink systems. In the presence of large CFOs, the estimator is proposed to find a new CFO vector based on the first-order Taylor series expansion of the one initially given. The problem of finding the new CFO vector is formulated as the closed form of a generalized eigenvalue problem, which allows one to readily solve it. Since raising the accuracy of residual CFO estimation can provide more accurate residual CFO compensation, this paper also present a decision-directed MVDR approach to improve the CFO estimation performance. However, the proposed estimator can estimate CFOs with less computation load. Several computer simulation results are provided for illustrating the effectiveness of the proposed blind estimate approach.

This letter proposes a fast intra prediction method to reduce encoding time for the high-efficiency video coding (HEVC) standard, which involves an increase in the number of intra-modes. The proposed intra-mode coding method uses correlation between intra-modes and adjacent pixels. The proposed method skips half of the intra-modes in certain blocks, specifically those that satisfy predetermined conditions. Using the half of intra-modes reduces number of bits for intra-mode coding and offsets a decline of coding performance caused by mode skipping. The experimental results show that the proposed method achieved 5.87% reduction in encoding time compared to the HEVC test model 7.1 encoder with almost no loss in coding performance.

This paper investigates the average block error rate (BLER) performance of star 16QAM schemes considering the effective peak-to-average power ratio (PAPR) criterion called a cubic metric (CM) for uplink discrete Fourier transform (DFT)-precoded orthogonal frequency division multiple access (OFDMA). We clarify the best ring amplitude ratio for the (4, 12) and (8, 8) star 16QAM schemes from the viewpoint of the required average signal-to-noise power ratio (SNR) that satisfy the target average BLER based on link-level simulations. We also validate the agreement of the best ring amplitude ratios with those maximizing the mutual information based throughput. Then, employing the best ring amplitude ratios for the respective coding rates of the turbo code, we show that (8, 8) star 16QAM achieves better average BLER performance compared to that for (4, 12) star 16QAM. Moreover, we show the effectiveness of the (8, 8) star 16QAM scheme compared to square 16QAM in terms of the required average received SNR considering the CM when the coding rate is low such as 1/3 for uplink DFT-precoded OFDMA.

With the increasing demand for geographic information and position information, the geographic information system (GIS) has come to be widely used in city planning, utilities management, natural resource environments, land surveying, etc. While most GIS maps use vector data to represent geographic information more easily and in greater detail, a GIS vector map can be easily copied, edited, and illegally distributed, like most digital data. This paper presents an invisible, blind, secure, and robust watermarking method that provides copyright protection of GIS vector digital maps by means of arc length distribution. In our method, we calculate the arc lengths of all the polylines/polygons in a map and cluster these arc lengths into a number of groups. We then embed a watermark bit by changing the arc length distribution of a suitable group. For greater security and robustness, we use a pseudo-random number sequence for processing the watermark and embed the watermark multiple times in all maps. Experimental results verify that our method has good invisibility, security, and robustness against various geometric attacks and that the original map is not needed in the watermark extraction process.