In this paper, we propose a method capable of shortening the distance from a noise detection microphone to a loudspeaker in active noise control system with non-minimum phase secondary path. The distance can be basically shortened by forming the noise control filter, which produces the secondary noise provided by the loudspeaker, with the cascade connection of a non-recursive filter and a recursive filter. The output of the recursive filter, however, diverges even when the secondary path includes only a minimum phase component. In this paper, we prevent the divergence by utilizing MINT (multi-input/output inverse theorem) method increasing the number of secondary paths than that of primary paths. MINT method, however, requires a large scale inverse matrix operation, which increases the processing cost. We hence propose a method reducing the processing cost. Actually, MINT method has only to be applied to the non-minimum phase components of the secondary paths. We hence extract the non-minimum phase components and then apply MINT method only to those. The order of the inverse matrix thereby decreases and the processing cost can be reduced. We finally show a simulation result demonstrating that the proposed method successfully works.

In this study, we show that the motion blur is caused by exposure time of video camera as well as the characteristics of LCD system. Also, we suggest that evaluation method of motion picture quality according to the frequency response of video camera and LCD systems of hold and scanning backlight type.

In this paper, a new swept-frequency method for the measurement of the complex permittivity and permeability of materials is proposed. The method is based on the S-parameters measurement of a cylindrical material placed inside a rectangular waveguide, where the axis of the cylinder is perpendicular to the narrow waveguide walls. The usage of cylinders in measurement is beneficial because they are easy to fabricate and handle. A novel exact solution of the field scattered by the cylinder is developed. The solution is based on expanding the field in a sum of orthogonal modes in cylindrical coordinates. Excitation coefficients relating the cylindrical scattered field to the waveguide modes are derived, and are used to rigorously formulates the S-parameters. Measurement are performed in the S-band with two dielectric materials (PTFE, nylon), and in the X-band with one magnetic material (ferrite epoxy). The measurement results agree with those from the literature.

In this paper, we present a supervised learning method to seek out answers to the most frequently asked descriptive questions: reason, method, and definition questions. Most of the previous systems for question answering focus on factoids, lists or definitional questions. However, descriptive questions such as reason questions and method questions are also frequently asked by users. We propose a system for these types of questions. The system conducts an answer search as follows. First, we analyze the user's question and extract search keywords and the expected answer type. Second, information retrieval results are obtained from an existing search engine such as Yahoo or Google . Finally, we rank the results to find snippets containing answers to the questions based on a ranking SVM algorithm. We also propose features to identify snippets containing answers for descriptive questions. The features are adaptable and thus are not dependent on answer type. Experimental results show that the proposed method and features are clearly effective for the task.

We propose a generic conversion from a key encapsulation mechanism (KEM) to an identification (ID) scheme. The conversion derives the security for ID schemes against concurrent man-in-the-middle (cMiM) attacks from the security for KEMs against adaptive chosen ciphertext attacks on one-wayness (one-way-CCA2). Then, regarding the derivation as a design principle of ID schemes, we develop a series of concrete one-way-CCA2 secure KEMs. We start with El Gamal KEM and prove it secure against non-adaptive chosen ciphertext attacks on one-wayness (one-way-CCA1) in the standard model. Then, we apply a tag framework with the algebraic trick of Boneh and Boyen to make it one-way-CCA2 secure based on the Gap-CDH assumption. Next, we apply the CHK transformation or a target collision resistant hash function to exit the tag framework. And finally, as it is better to rely on the CDH assumption rather than the Gap-CDH assumption, we apply the Twin DH technique of Cash, Kiltz and Shoup. The application is not “black box” and we do it by making the Twin DH technique compatible with the algebraic trick. The ID schemes obtained from our KEMs show the highest performance in both computational amount and message length compared with previously known ID schemes secure against concurrent man-in-the-middle attacks.

In this paper, we propose an effective mutation operators for Cooperative Genetic Algorithm (CGA) to be applied to a practical Nurse Scheduling Problem (NSP). The nurse scheduling is a very difficult task, because NSP is a complex combinatorial optimizing problem for which many requirements must be considered. In real hospitals, the schedule changes frequently. The changes of the shift schedule yields various problems, for example, a fall in the nursing level. We describe a technique of the reoptimization of the nurse schedule in response to a change. The conventional CGA is superior in ability for local search by means of its crossover operator, but often stagnates at the unfavorable situation because it is inferior to ability for global search. When the optimization stagnates for long generation cycle, a searching point, population in this case, would be caught in a wide local minimum area. To escape such local minimum area, small change in a population should be required. Based on such consideration, we propose a mutation operator activated depending on the optimization speed. When the optimization stagnates, in other words, when the optimization speed decreases, the mutation yields small changes in the population. Then the population is able to escape from a local minimum area by means of the mutation. However, this mutation operator requires two well-defined parameters. This means that user have to consider the value of these parameters carefully. To solve this problem, we propose a periodic mutation operator which has only one parameter to define itself. This simplified mutation operator is effective over a wide range of the parameter value.

This paper shows a new pulse swallow programmable frequency divider with the division step size of 0.5. To realize the division step size of 0.5 by a conventional pulse swallow method, we propose a parallel dual modulus prescaler with the division ratio of P and P + 0.5. It consists of simple circuit elements and has an advantage over the conventional dual modulus prescaler with the division step size of 0.5 in high frequency operation. The proposed parallel dual modulus prescaler with the division ratio 8 and 8.5 is implemented in the 0.13-µm CMOS technology. The proposed architecture achieves 7 times higher frequency operation than the conventional one theoretically. It is verified the functions over 5 GHz.

In this paper, the research advances in silicon based millimeter wave and THz ICs in the State Key Laboratory of Millimeter Waves is reviewed, which consists of millimeter wave amplifiers, mixers, oscillators at Q, V and W and D band based on CMOS technology, and several research approaches of THz passive ICs including cavity and filter structures using SIW-like (Substrate Integrated Waveguide-like) guided wave structures based on CMOS and MEMs process. The design and performance of these components and devices are presented.

The design and measured results of a 120-GHz transmitter and receiver chipset are described in this paper. A simple on-off keying (OOK) modulation is adopted for low power consumption. The proposed transmitter and receiver are fabricated using 65-nm CMOS technology. The current consumption of the transmitter and receiver are 19.2 mA and 48.2 mA respectively. A 9-Gbps PRBS is successfully transferred from the transmitter to the receiver with the bit error rate less than 10-9.

The Direct Sampling Mixer (DSM) with a complex coefficient transfer function is demonstrated. The operation theory and the detail design methodology are discussed for the high order complex DSM, which can achieve large image rejection ratio by introducing the attenuation pole at the image frequency band. The proposed architecture was fabricated in a 65 nm CMOS process. The measured results agree well with the theoretical calculation, which proves the validity of the proposed architecture and the design methodology. By using the proposed design method, it will be possible for circuit designers to design the DSM with large image rejection ratio without repeated lengthy simulations.

Ultra-wideband (UWB) technology is an excellent candidate for supporting wireless personal area networks (WPANs) because of its wide bandwidth, low transmission power, low complexity and multipath immunity. We study density-aware exclusive region (ER)-based scheduling for a nonuniform UWB-WPAN. Using a generalized radius for the ER based on statistical topology, we propose a scheduling scheme that uses a radius for the ER that varies according to the density information around the destination in the nonuniform network. Computer simulations show that (i) our approach to the radius of the generalized ER provides better scheduling performance than the radius solution of the conventional work [3] and (ii) scheduling that is based on an adaptive ER radius can always outperform both the fixed ER-based scheme and the TDMA scheme with respect to network throughput.

The scattering from a phase change disk that is illuminated by an optical near field through a ridged-square nano-aperture was analyzed. A finite-difference time-domain (FDTD) method installed with motion equations of free electrons was used in the analysis and a three dimensional disk structure was taken into consideration. The far-field scattering patterns from the phase change disk were analyzed and the sum-signal output through a condenser lens was calculated. The crosstalk between plural marks and the readout characteristics of mark trains were investigated.

We formulate the resource allocation problem to maximize the sum rate, subject to constraints on total power, bit error rate, and rate proportionality among the users for proportional resource allocation in orthogonal frequency division multiple access (OFDMA) systems. For this we propose a novel scheduling scheme based on weighted normalized user's channel state information (CSI). We then adopt the linear power distribution method and waterfilling technique to allocate power among the users and across the subcarriers respectively.

A direct inter-mode selection algorithm for P-frames in fast homogeneous H.264/AVC bit-rate reduction transcoding is proposed in this paper. To achieve the direct inter-mode selection, we firstly develop a low-complexity distortion estimation method for fast transcoding, in which the distortion is directly calculated from the decoded residual together with the reference frames. We also present a linear estimation method to approximate the coding rate. With the estimated distortion and rate, the rate-distortion cost can be easily computed in the transcoder. In our algorithm, a method based on the normalized rate difference of P-frames (RP) is used to detect the high motion scene. To achieve fast transcoding, only for the P-frames with RP larger than a threshold, the rate-distortion optimized (RDO) mode decision is performed; meanwhile, the average cost of each inter-mode (ACM) is calculated. Then for the subsequent frames transcoding, the optimal coding mode can be directly selected using the estimated cost and the ACM threshold. Experiments show that the proposed method can significantly simplify the complex RDO mode decision, and achieve transcoding time reductions of up to 62% with small loss of rate-distortion performance.

Most large-scale Peer-to-Peer (P2P) live streaming systems are constructed as a mesh structure, which can provide robustness in the dynamic P2P environment. The pull scheduling algorithm is widely used in this mesh structure, which degrades the performance of the entire system. Recently, network coding was introduced in mesh P2P streaming systems to improve the performance, which makes the push strategy feasible. One of the most famous scheduling algorithms based on network coding is R2, with a random push strategy. Although R2 has achieved some success, the push scheduling strategy still lacks a theoretical model and optimal solution. In this paper, we propose a novel optimal pull-push scheduling algorithm based on network coding, which consists of two stages: the initial pull stage and the push stage. The main contributions of this paper are: 1) we put forward a theoretical analysis model that considers the scarcity and timeliness of segments; 2) we formulate the push scheduling problem to be a global optimization problem and decompose it into local optimization problems on individual peers; 3) we introduce some rules to transform the local optimization problem into a classical min-cost optimization problem for solving it; 4) We combine the pull strategy with the push strategy and systematically realize our scheduling algorithm. Simulation results demonstrate that decode delay, decode ratio and redundant fraction of the P2P streaming system with our algorithm can be significantly improved, without losing throughput and increasing overhead.

The operating speed scalability is demonstrated by using the forward body biasing method for a 1-V 0.18-µm CMOS true single-phase clocking (TSPC) dual-modulus prescaler. With the forward body bias voltage varying between 0 and 0.4 V, the maximum operating speed changes by about 40–50% and the maximum input sensitivity frequency changes by about 400%. This speed scalability is achieved with less than 0.5-dB phase noise degradation. This demonstration indicates that the forward body biasing method is instrumental to build a cost-saving power-efficient 1-V 0.18-µm CMOS radio for low-power WBAN and WSN applications.

As the Internet represents a key social infrastructure, its reliability is essential if we are to survive failures. Physical connectivity of networks is also essential as it characterizes reliability. There are collaboration structures, which are topological structures where two or more nodes are connected to a node, and collaboration structures are observed in transcriptional regulatory networks and the router-level topologies of ISPs. These collaboration structures are related to the reliability of networks. The main objective of this research is to find whether an increase in collaboration structures would improve reliability or not. We first categorize the topology into a three-level hierarchy for this purpose, i.e., top-level, middle-level, and bottom-level layers. We then calculate the reliability of networks. The results indicate that the reliability of most transcriptional regulatory networks is higher than that of one of router-level topologies. We then investigate the number of collaboration structures. It is apparent that there are much fewer collaboration structures between top-level nodes and middle-level nodes in router-level topologies. Finally, we confirm that the reliability of router-level topologies can be improved by rewiring to increase the collaboration structures between top-level and middle-level nodes.

This paper employs the nature-inspired approach to investigate the ideal architecture of communication networks as large-scale and complex systems. Conventional architectures are hierarchical with respect to the functions of network operations due entirely to implementation concerns and not to any fundamental conceptual benefit. In contrast, the large-scale systems found in nature are hierarchical and demonstrate orderly behavior due to their space/time scale dependencies. In this paper, by examining the fundamental requirements inherent in controlling network operations, we clarify the hierarchical structure of network operations with respect to time scale. We also describe an attempt to build a new network architecture based on the structure. In addition, as an example of the hierarchical structure, we apply the quasi-static approach to describe user-system interaction, and we describe a hierarchy model developed on the renormalization group approach.

In parallel computing systems using the master/worker model for distributed grid computing, as the size of handling data grows, the increase in the data transmission time degrades the performance. For divisible workload applications, therefore, multiple-round scheduling algorithms have been being developed to mitigate the adverse effect of longer data transmission time by dividing the data into chunks to be sent out in multiple rounds, thus overlapping the times required for computation and transmission. However, a standard multiple-round scheduling algorithm, Uniform Multi-Round (UMR), adopts a sequential transmission model where the master communicates with one worker at a time, thus the transmission capacity of the link attached to the master cannot be fully utilized due to the limits of worker-side capacity. In the present study, a Parallel Transferable Uniform Multi-Round algorithm (PTUMR) is proposed. It efficiently utilizes the data transmission capacity of network links by allowing chunks to be transmitted in parallel to workers. This algorithm divides workers into groups in a way that fully uses the link bandwidth of the master under some constraints and considers each group of workers as one virtual worker. In particular, introducing a Grouping Threshold effectively deals with very heterogeneous workers in both data transmission and computation capacities. Then, the master schedules sequential data transmissions to the virtual workers in an optimal way like in UMR. The performance evaluations show that the proposed algorithm achieves significantly shorter turnaround times (i.e., makespan) compared with UMR regardless of heterogeneity of workers, which are close to the theoretical lower limits.

This letter proposes an automatic IQ imbalance compensation technique for quadrature modulators by means of spectrum measurement of RF signal using a spectrum analyzer. The analyzer feeds back only magnitude information of the frequency spectrum of the signal. To realize IQ imbalance compensation, the conventional method of steepest descent is modified; the descent direction is empirically determined and a variable step-size is introduced for accelerating convergence. The experimental results for a four-channel transmitter operating at 11 GHz are presented for verification.