This paper concerns a problem of on-line model parameter estimations for multiple time-delay systems. In order to estimate unknown model parameters from measured state variables, we propose two schemes using Lyapunov's direct method, called parallel and series-parallel model estimators. It is shown through a numerical example that the proposed parallel and series-parallel model estimators can be effective when sufficiently rich inputs are applied.

In this paper, a stochastic asymptotic stabilization method is proposed for deterministic input-affine control systems, which are randomized by including Gaussian white noises in control inputs. The sufficient condition is derived for the diffusion coefficients so that there exist stochastic control Lyapunov functions for the systems. To illustrate the usefulness of the sufficient condition, the authors propose the stochastic continuous feedback law, which makes the origin of the Brockett integrator become globally asymptotically stable in probability.

Managing the configurations of complex systems consisting of various components requires the combined efforts by multiple domain experts. These experts have extensive knowledge about different components in the system they need to manage but little understanding of the issues outside their individual areas of expertise. As a result, the configuration constraints, changes, and procedures specified by those involved in the management of a complex system are often interrelated with one another without being noticed, and their integration into a coherent procedure for configuration represents a major challenge. The method of synthesizing the configuration procedure introduced in this paper addresses this challenge using a combination of formal specification and model finding techniques. We express the knowledge on system management with this method, which is provided by domain experts as first-order logic formulas in the Alloy specification language, and combine it with system-configuration information and the resulting specification. We then employ the Alloy Analyzer to find a system model that satisfies all the formulas in this specification. The model obtained corresponds to a procedure for system configurations that satisfies all expert-specified constraints. In order to reduce the resources needed in the procedure synthesis, we reduce the length of procedures to be synthesized by defining and using intermediate goal states to divide operation procedures into shorter steps. Finally, we evaluate our method through a case study on a procedure to consolidate virtual machines.

Content addressable memory is widely used for fast lookup table data searching, but it often consumes considerable power. Moreover, designing the suitable content addressable memory architecture for a specific application also consumes lots of time, since the behavioral simulation is often done in the transistor level. SystemC is a system-level modeling language and simulation platform, providing high simulation efficiency for hardware software co-design. Unfortunately, SystemC does not provide the function for estimating power dissipation of a structure design. In this paper, a SystemC-based fast content addressable memory power estimation method is presented for estimating the power dissipation of the match-line circuit, the search-line circuit, and the storage cell array of content addressable memory in the early design stage. The mathematical equations and behavioral patterns are used as the inputs of power estimation model. The simulation results based on 10 Mibench benchmarks show that the simulation time of the proposed method is in average 1233 times faster than that of HSPICE simulator with only 3.51% error rate.

The 10-gigabit Ethernet passive optical network (10G-EPON) is a promising candidate for the next generation of fiber-to-the-home access systems. In the symmetric 10G-EPON system, the gigabit Ethernet passive optical network (GE-PON) and 10G-EPON will have to co-exist on the same optical network. For this purpose, an optical triplexer (10G-transmitter, 1G-transmitter, and 10G/1G-receiver) for optical line terminal (OLT) transceivers in 10G/1G co-existing EPON systems has been developed. Reducing the size and cost of the optical triplexer has been one of the largest issues in the effort to deploy 10G-EPON systems for practical use. In this paper, we describe a novel small and low-cost dual-rate optical triplexer for use in 10G-EPON applications. By reducing the optical path length by means of a light collection system with a low-magnification long-focus coupling lens, we have successfully miniaturized the optical triplexer for use in 10G-EPON OLT 10-gigabit small form factor pluggable (XFP) transceivers and decreased the number of lenses. A low-cost design of sub-assemblies also contributes to cost reduction. The triplexer's performance complies with IEEE 802.3av specifications.

This paper presents a novel adaptable 4-moduli set {2n + k, 2n+1, 2n-1, 22n+1}. It offers diverse dynamic ranges (DRs) from 25n-2n to 25n + k-2n + k that are used to conquer the over-range issue in RNS-application hardware designs. The proposed adaptable set possesses the coarse parameter n and fine parameter k. It not only has better parallelism and larger dynamic range (DR) than the existing adaptive 3-moduli sets, but also holds more sizable and flexible than the general 4-moduli sets with single parameter. For the adaptable R-to-B conversion, this paper first derives a fast reverse converting algorithm based on Chinese Remainder Theorem (CRT) and then presents the efficient converter architecture. From the experimental results, the proposed adaptable converter achieves better hardware performance in various DRs. Based on TSMC 0.18 µm CMOS technology, the proposed converter design is implemented and its results get at least 20.93% saving of Area-Delay-Power (ADP) products on average when comparing with the latest converter works.

This study investigated the relationship between human use of automation and their sensitivity to changes in automation and manual performance. In the real world, automation and manual performance change dynamically with changes in the environment. However, a few studies investigated whether changes in automation or manual performance have more effect on whether users choose to use automation. We used two types of experimental tracking tasks in which the participants had to select whether to use automation or conduct manual operation while monitoring the variable performance of automation and manual operation. As a result, we found that there is a mutual relationship between human use of automation and their sensitivity to automation and manual performance changes. Also, users do not react equally to both automation and manual performance changes although they use automation adequately.

We propose a sound field control system to control the sound over a wide area within a room by reducing the influence of the reproduction space using power envelope inverse filtering (PEIF). Envelopes of the impulse response within the room have approximately the same shape at all observation points. Therefore, the proposed sound field control system can control with a small number of loudspeakers a wider area by reducing reverberation in the room through envelope processing. We present experimental data demonstrating that the proposed PEIF system can provide better control than a system that uses minimum phase inverse filtering (MPIF), which is conventionally used for reducing reverberation. Improvement was observed across the frequency band, especially above 1 kHz. Additionally, our PEIF system is more effective over the high-frequency range.

This paper presents the stability analysis for continuous-time Takagi-Sugeno fuzzy systems using a fuzzy Lyapunov function. The proposed fuzzy Lyapunov function involves the time derivatives of states to include new free matrices in the LMI stability conditions. These free matrices extend the solution space for Linear Matrix Inequalities (LMIs) problems. Numerical examples illustrate the effectiveness of the proposed methods.

Scale Invariant Feature Transform (SIFT) algorithm is a very excellent approach for feature detection. It is characterized by data intensive computation. The current studies of accelerating SIFT algorithm are mainly reflected in three aspects: optimizing the parallel parts of the algorithm based on general-purpose multi-core processors, designing the customized multi-core processor dedicated for SIFT, and implementing it based on the FPGA platform. The real-time performance of SIFT has been highly improved. However, the factors such as the input image size, the number of octaves and scale factors in the SIFT algorithm are restricted for some solutions, the flexibility that ensures the high execution performance under variable factors should be improved. This paper proposes a reconfigurable solution to solve this problem. We fully exploit the algorithm and adopt several techniques, such as full parallel execution, block computation and CORDIC transformation, etc., to improve the execution efficiency on a REconfigurable MUltimedia System called REMUS. Experimental results show that the execution performance of the SIFT is improved by 33%, 50% and 8 times comparing with that executed in the multi-core platform, FPGA and ASIC separately. The scheme of dynamic reconfiguration in this work can configure the circuits to meet the computation requirements under different input image size, different number of octaves and scale factors in the process of computing.

We consider the problem of constructing public-key encryption (PKE) schemes that are resilient to a-posteriori chosen-ciphertext and key-leakage attacks (LR-CCA2). In CTYPTO'09, Naor and Segev proved that the Naor-Yung generic construction of PKE which is secure against chosen-ciphertext attack (CCA2) is also secure against key-leakage attacks. They also presented a variant of the Cramer-Shoup cryptosystem, and showed that this PKE scheme is LR-CCA2-secure under the decisional Diffie-Hellman assumption. In this paper, we apply the generic construction of “Universal Hash Proofs and a Paradigm for Adaptive Chosen Ciphertext Secure Public-Key Encryption” (EUROCRYPT'02) to generalize the above work of Naor-Segev. In comparing to the first construction of Naor-Segev, ours is more efficient because of not using simulation-sound NIZK. We also extend it to stateful PKE schemes. Concretely, we present the notion of LR-CCA2 attack in the case of stateful PKE, and a generic construction of stateful PKE that is secure against this attack.

This letter proposes an iterative learning control with advanced output data (ADILC) scheme using an estimation of the impulse response for non-minimum phase (NMP) systems, whose model is unknown, except for the relative degree and the number of NMP zeros. Although the ADILC has a simple learning structure that can be applied to both minimum phase and NMP systems, at least a partial model should be known in order to apply ADILC. Considering this fact, in this letter, we propose a new ADILC method based on the estimation of the impulse response for NMP systems whose model is unknown. An estimation method for the learning matrix and an ADILC scheme are presented for NMP systems.

In this paper, we present a novel class of long quasi-cyclic low-density parity-check (QC-LDPC) codes. Each of the codes in this class has a structure formed by concatenating single-parity-check codes and QC-LDPC codes of shorter lengths, which allows for efficient, high throughput encoder/decoder implementations. Using a code in this class, we design a forward error correction (FEC) scheme for optical transmission systems and present its high throughput encoder/decoder architecture. In order to demonstrate its feasibility, we implement the architecture on a field programmable gate array (FPGA) platform. We show by both FPGA-based simulations and measurements of an optical transmission system that the FEC scheme can achieve excellent error performance and that there is no significant performance degradation due to the constraint on its structure while getting an efficient, high throughput implementation is feasible.

We have developed a dedicated onboard “sensor” utilizing wireless communication devices for collision avoidance around road intersections. The “sensor” estimates the positions of transmitters on traffic participants by comparing the strengths of signals received by four ZigBee receivers installed at the four corners of a vehicle. On-board sensors involving cameras cannot detect objects in non line-of-sight (NLOS) area caused by buildings and other vehicles. Although infrastructure sensors for vehicle-to-infrastructure (V2I) cooperative systems can detect such hidden objects, they are substantially more expensive than on-board sensors. The on-board wireless “sensor” developed in this work would function as an alternative tool for collision avoidance around intersections. Herein, we extend our previous work by considering a road surface reflection model to improve the estimation accuracy. By using this model, we succeeded in reducing the error mismatches between the observed data and the calibration data of the estimation algorithm. The proposed system will be realized on the basis of these enhancements.

For a development of energy harvesting system, the fact of radio waves and ambient RF (Radio Frequency) sources, including passive devices along with novel circuits, are very closely related to mobile charging devices and energy storage system. The use of schottky diode and voltage multiplier circuits to express on the ambient RF sources surrounding the system is one way that has seen a sudden rise in use for energy harvesting. Practically speaking, the RF and ambient sources can be provided by active and passive devices such as inductors, capacitors, diode, etc. In this paper, we present a schottky based voltage multiplier circuits for mobile charging device which integrate the power generation module with radio wave generation module. We also discuss that multi-stage schematic, e.g., three-stage schottky diode based voltage multiplier circuits, for a continuing effort on energy harvesting system.

This paper studies stabilization of uncertain systems over finite data rate and lossy channels. Limitations on data rate and packet loss probability are derived, characterized by the product of the eigenvalues of the plant. It is worth noting that even if we assume the most conservative plant dynamics, existing limitations for nominal plants are looser than those given in this paper. This fact implies that plant uncertainties cause strictly higher requirements in communication. We consider linear discrete-time systems with parametric uncertainties and employ uniform quantizers, which have the simplest quantization structure. Under the setup, a necessary condition and a sufficient condition for stability are derived. In particular, for scalar plants case, the conditions are exact. They coincide with the existing results for nominal plants as a special case and hence generalize them to the uncertain case.

Self-triggered control is a control method that the control input and the sampling period are computed simultaneously in sampled-data control systems, and is studied in the field of networked control systems. In this paper, a new approach for self-triggered control is proposed based on the model predictive control (MPC) method. First, self-triggered MPC with delay compensation in which the delay-compensation input is introduced is newly formulated. Next, in order to efficiently solve this MPC problem, the optimal control problem with horizon one is formulated, and an approximate solution method is derived. Finally, the effectiveness of the proposed approach is shown by a numerical example.

This paper presents a novel color descriptor based on the proposed Color Barycenter Hexagon (CBH) model for automatic Road-Sign (RS) detection. In the visual Driver Assistance System (DAS), RS detection is one of the most important factors. The system provides drivers with important information on driving safety. Different color combinations of RS indicate different functionalities; hence a robust color detector should be designed to address color changes in natural surroundings. The CBH model is constructed with barycenter distribution in the created color triangle, which represents RS colors in a more compact way. For detecting RS, the CBH model is used to segment color information at the initial step. Furthermore, a judgment process is applied to verify each RS candidate through the size, aspect ratio, and color ratio. Experimental results show that the proposed method is able to detect RS with robust, accurate performance and is invariant to light and scale in more complex surroundings.

In this letter, a design of inverse discrete cosine transform for energy-efficient watermarking mechanism based on DS-CDMA with significant energy and area reduction is presented. Taking advantage of converged input data value set as a precomputation concept, the proposed one-dimensional IDCT is a multiplierless hardware which differs from Loeffler architecture and has benefits of low complexity and low power consumption. The experimental results show that our design can reduce 85.2% energy consumption and 58.6% area. Various spectrum and spatial attacks are also tested to corroborate the robustness.

This paper describes an overview of demands on wireless communications from the point of view of robotics, oceanics and aviation technologies. These technologies are mostly applied to extreme environments, where humans cannot easily approach and directly operate equipment. In such environments, reliable and robust wireless communications are highly required to perform missions perfectly. However, there are many issues for wireless technologies to meet those requirements due to poor propagation and large delay conditions. This paper discusses wireless communication technologies required in land-sea-and-air environments based on the recent development challenges of unmanned ground and marine robots and next-generation air-transportation systems. This paper will contribute future wireless communication techniques for unmanned robots and next-generation aviations.