In this paper, the substitutability of the indifferentiability framework with non-sequential scheduling is examined by reformulating the framework through applying the Task-PIOA framework, which provides non-sequential activation with oblivious task sequences. First, the indifferentiability framework with non-sequential scheduling is shown to be able to retain the substitutability. Thus, the substitutability can be applied in another situation that processes of the systems may behave non-sequentially. Next, this framework is shown to be closely related to reducibility of systems. Reducibility is useful to discuss about the construction of a system from a weaker system. Finally, two modelings with respectively sequential scheduling and non-sequential scheduling are shown to be mutually independent. We find examples of systems which are indifferentiable under one model but differentiable under the other. Thus, the importance of scheduling in the indifferentiability framework is clarified.

This paper proposes the countermeasures against an improved fault sensitivity analysis. Our countermeasure is proposed based on the WDDL technique due to its built-in resistance against both the power-based attack and differential fault analysis. At CHES 2010, Li et al. proposed the FSA attack on WDDL-AES. The vulnerability of WDDL-AES in their attack mainly comes from the implementation deficiency rather than the WDDL technique itself. This paper first proposes an improved fault sensitive analysis that can threat a well-implemented WDDL-AES based on the input-data dependency for the critical path delay of WDDL S-box. Then we discuss the possibility of efficient countermeasures by modifying the WDDL circuit with a limited overhead. The countermeasures are discussed based on either modifying the dual-rail to single-rail converter or the introduction of the enable signal.

Handoff plays an important role in vehicular networks due to high movement of vehicles. To provide seamless connectivity under Access Points (AP), this paper proposes an adaptive handoff triggering method to minimize communication time for a vehicle with an AP switch (i.e., whether and when to trigger a handoff process). In the proposed method, combined with an improved data transmission rate based trigger, handoff triggering decision is executed based on three different communication methods (called C-Dire, C-Relay and C-ALLRelay) to minimize the transmission delay when a vehicle moves from an AP to another. Transmission delay is derived through considering vehicle mobility and transmission rate diversity. The simulation results show that the proposed method is proven to be adaptive to vehicular networks.

In this paper, we present a maximum a posteriori probability (MAP) approach to the problem of blind estimation of single-input, multiple-output (SIMO), finite impulse response (FIR) channels. A number of methods have been developed to date for this blind estimation problem. Some of those utilize prior knowledge on input signal statistics. However, there are very few that utilize channel statistics too. In this paper, the unknown channel to be estimated is assumed as the frequency-selective Rayleigh fading channel, and we incorporate the channel prior distributions (and hyperprior distributions) into our model in two different ways. Then for each case an iterative MAP estimator is derived approximately. Performance comparisons over existing methods are conducted via numerical simulation on randomly generated channel coefficients according to the Rayleigh fading channel model. It is shown that improved estimation performance can be achieved through the MAP approaches, especially for such channel realizations that have resulted in large estimation error with existing methods.

Let T be a text of length n and P be a pattern of length m, both strings over a fixed finite alphabet. The Pattern Matching with Swaps problem is to find all occurrences of P in T if adjacent pattern characters can be swapped. In the Approximate Pattern Matching problem with Swaps, one seeks for every text location with a swapped match of P, the number of swaps necessary to obtain a match at the location. In this paper we provide the first off-line solution for the swap matching problem and the approximate pattern matching problem with swaps. We present a new data-structure called a Swap-transforming Tree. And we give a precise upper-bond of the number of the swapped versions of a pattern. By using the swap-transforming tree, we can solve both problems in time O(λmlog2 n) on an O(nHk) bits indexing data structure. Here λ is a constant. Our solution is more effective when the pattern is short.

An efficient method is proposed for reconstructing speakerphone-mode cellular phone sound. The overall transfer function from digital PCM signals stored in a cellular phone to dummy head-recorded signals is modeled as a combination of a cellular phone transfer function (CPTF) and a cellular phone-to-listener transfer function (CPLTF). The CPTF represents the linear and nonlinear characteristics of a cellular phone and is modeled by the Volterra model. The CPLTF represents the effect of the path from a cellular phone to a dummy head and is measured. Listening tests show the effectiveness of the proposed method. An application scenario of the proposed method is also addressed for sound quality assessment of cellular phones in speakerphone mode.

As the fundamental component of dynamic spectrum access, implementing spectrum sensing is one of the most important goals in cognitive radio networks due to its key functions of protecting licensed primary users from harmful interference and identifying spectrum holes for the improvement of spectrum utilization. However, its performance is generally compromised by the interference from adjacent primary channels. To cope with such interference and improve detection performance, this paper proposes a non-coherent power decomposition-based energy detection method for cooperative spectrum sensing. Due to its use of power decomposition, interference cancellation can be applied in energy detection. The proposed power decomposition does not require any prior knowledge of the primary signals. The power detection with its interference cancellation can be implemented indirectly by solving a non-homogeneous linear equation set with a coefficient matrix that involves only the distances between primary transmitters and cognitive secondary users (SUs). The optimal number of SUs for sensing a single channel and the number of channels that can be sensed simultaneously are also derived. The simulation results show that the proposed method is able to cope with the expected interference variation and achieve higher probability of detection and lower probability of false alarm than the conventional method in both hard combining and soft combining scenarios.

This paper presents the iterative progressive numerical methods (IPNMs) based on the induced dimension reduction (IDR) theorem. The IDR theorem is mainly utilized for the development of new nonstationary linear iterative solvers. On the other hand, the use of the IDR theorem enables to revise the classical linear iterative solvers like the Jacobi, the Gauss-Seidel (GS), the relaxed Jacobi, the successive overrelaxation (SOR), and the symmetric SOR (SSOR) methods. The new IPNMs are based on the revised solvers because the original one is similar to the Jacobi method. In the new IPNMs, namely the IDR-based IPNMs, we repeatedly solve linear systems of equations by using a nonstationary linear iterative solver. An initial guess and a stopping criterion are discussed in order to realize a fast computation. We treat electromagnetic wave scattering from 27 perfectly electric conducting spheres and reports comparatively the performance of the IDR-based IPNMs. However, the IDR-based SOR- and the IDR-based SSOR-type IPNMs are not subject to the above numerical test in this paper because of the problem with an optimal relaxation parameter. The performance evaluation reveals that the IDR-based IPNMs are better than the conventional ones in terms of the net computation time and the application range for the distance between objects. The IDR-based GS-type IPNM is the best among the conventional and the IDR-based IPNMs and converges 5 times faster than a standard computation by way of the boundary element method.

Error analysis of the multilevel fast multipole algorithm is studied for electromagnetic scattering problems. We propose novel error prediction and control methods and verify that the computational error for scattering problems with over one million unknowns can be precisely controlled under desired digits of accuracy. Optimum selection of truncation numbers to minimize computational error also will be discussed.

This paper proposes a method for detecting determiner errors, which are highly frequent in learner English. To augment conventional methods, the proposed method exploits a strong tendency displayed by learners in determiner usage, i.e., mistakenly omitting determiners most of the time. Its basic idea is simple and applicable to almost any conventional method. This paper also proposes combining the method with countability prediction, which results in further improvement. Experiments show that the proposed method achieves an F-measure of 0.684 and significantly outperforms conventional methods.

Asymptotic expansions of the amplitudes of the direct and scattered waves in a waveguide system with an imperfection core are derived for large core number and the partial cancellation of the direct wave by the scattered wave is shown in detail. The total power of light in the cross section of a waveguide system is analytically derived and it is shown that the total power of the sum of the direct and scattered waves decreases from that of the direct wave because of the cancellation, the difference of the total power transfers to the localized wave and the total power of light is conserved.

An adaptive and iterative intertrack-interference (ITI) cancelling scheme is described for multi-track signal detection in inter-track asynchronous shingled write magnetic recording. There is write-clock frequency drift in asynchronous recording systems. Read-back signals obtained with a wide read head scanning narrow tracks thus suffer from not only intersymbol interference (ISI) but also time-variant ITI. To efficiently cope with static ISI and time-variant ITI, multi-track soft interference cancellers and two-dimensional partial-response filters are incorporated based on per-survivor processing into each trellis state defined in a one-dimensional/two-dimensional trellis-switching max-log-MAP detector. In addition, the computational complexity can be reduced based on channel interpolation and intermittent TDPR-filter control by allowing small degradation in signal detection. Computer simulation results in media-noise-dominant environments demonstrate that the proposed adaptive and iterative ITI canceller achieves bit error rates close to those obtained in a non-ITI case when the read-head off-track ratio is up to 50% in write-clock frequency difference of 0.02%.

This paper discusses the task of human action detection. It requires not only classifying what type the action of interest is, but also finding actions' spatial-temporal locations in a video. The novelty of this paper lies on two significant aspects. One is to introduce a new graph based representation for the search space in a video. The other is to propose a novel sub-volume search method by Minimum Cycle detection. The proposed method has a low computation complexity while maintaining a high action detection accuracy. It is evaluated on two challenging datasets which are captured in cluttered backgrounds. The proposed approach outperforms other state-of-the-art methods in most situations in terms of both Precision-Recall values and running speeds.

The Kobayashi potential in electromagnetic theory is reviewed. As an illustration we consider two problems, diffraction of plane wave by disk and rectangular plate of perfect conductor. Some numerical results are compared with approximated and experimental results when they are available to verify the validity of the present method. We think the present method can be used as reference solutions of the related problems.

CLEFIA is a 128-bit block cipher proposed by Shirai et al. in 2007. On its saturation attack, Tsunoo et al. reported peculiar saturation characteristics in 2010. They formulated some hypotheses on the existence of the characteristics with no proof. In this paper we have theoretically proved their hypotheses. In their attack scenario, we show that the mod-2 distribution is a code word of Extended Hamming code, and then proof is given by using the property of Hadamard transform.

This paper presents a folded surface detection and tracking method for augmented maps. First, we model a folded surface as two connected planes. Therefore, in order to detect a folded surface, the plane detection method is iteratively applied to the 2D correspondences between an input image and a reference plane. In order to compute the exact folding line from the detected planes for visualization purpose, the intersection line of the planes is computed from their positional relationship. After the detection is done, each plane is individually tracked by the frame-by-frame descriptor update method. We overlay virtual geographic data on each detected plane. As scenario of use, some interactions on the folded surface are introduced. Experimental results show the accuracy and performance of folded surface detection for evaluating the effectiveness of our approach.

The range-dependence of clutter spectrum for forward-looking airborne radar strongly affects the accuracy of the estimation of clutter covariance matrix at the range under test, which results in poor clutter suppression performance if the conventional space-time adaptive processing (STAP) algorithms were applied, especially in the short range cells. Therefore, a new STAP algorithm with clutter spectrum compensation by utilizing knowledge-aided subspace projection is proposed to suppress clutter for forward-looking airborne radar in this paper. In the proposed method, the clutter covariance matrix of the range under test is firstly constructed based on the prior knowledge of antenna array configuration, and then by decomposing the corresponding space-time covariance matrix to calculate the clutter subspace projection matrix which is applied to transform the secondary range samples so that the compensation of clutter spectrum for forward-looking airborne radar is accomplished. After that the conventional STAP algorithm can be applied to suppress clutter in the range under test. The proposed method is compared with the sample matrix inversion (SMI) and the Doppler Warping (DW) methods. The simulation results show that the proposed STAP method can effectively compensate the clutter spectrum and mitigate the range-dependence significantly.

We propose a novel metamaterial antenna that is based on loading a single complementary split ring resonator (CSRR) onto a substrate integrated waveguide (SIW) structure. Negative order and zeroth-order resonance can be observed in the proposed structure. These resonance modes are used to reduce the antenna size. In addition, a high quality (Q) factor of the CSRR-loaded SIW structure can minimize the radiation loss. The -1st, 0th, and 1st resonances are experimentally observed at 6.63, 13.68, and 20.31 GHz with maximum gains of 1.59, 3.97, 6.83 dBi, respectively. The electrical size of the antenna at the -1st resonance is only 42% of the resonance of a square microstrip patch antenna.

We address a problem of sampling and reconstructing periodic piecewise polynomials based on the theory for signals with a finite rate of innovation (FRI signals) from samples acquired by a sinc kernel. This problem was discussed in a previous paper. There was, however, an error in a condition about the sinc kernel. Further, even though the signal is represented by parameters, these explicit values are not obtained. Hence, in this paper, we provide a correct condition for the sinc kernel and show the procedure. The point is that, though a periodic piecewise polynomial of degree R is defined as a signal mapped to a periodic stream of differentiated Diracs by R + 1 time differentiation, the mapping is not one-to-one. Therefore, to recover the stream is not sufficient to reconstruct the original signal. To solve this problem, we use the average of the target signal, which is available because of the sinc sampling. Simulation results show the correctness of our reconstruction procedure. We also show a sampling theorem for FRI signals with derivatives of a generic known function.

This paper proposes a combinatorial auction-based marketplace mechanism for cloud computing services, which allows users to reserve arbitrary combination of services at requested timeslots, prices and quality of service. The proposed mechanism helps enterprise users build workflow applications in a cloud computing environment, specifically on the platform-as-a-service, where the users need to compose multiple types of services at different timeslots. The proposed marketplace mechanism consists of a forward market for an advance reservation and a spot market for immediate allocation of services. Each market employs mixed integer programming to enforce a Pareto optimum allocation with maximized social economic welfare, as well as double-sided auction design to encourage both users and providers to compete for buying and selling the services. The evaluation results show that (1) the proposed forward/combinatorial mechanism outperforms other non-combinatorial and/or non-reservation (spot) mechanisms in both user-centric rationality and global efficiency, and (2) running both a forward market and a spot market improves utilization without disturbing advance reservations depending on the provider's policy.