To give comprehensive and consecutive understanding about load line regulation in the previous companion paper [1], more generalized expansion and theoretical derivation will be proposed in this paper. The paper provides an alternative current control approach to control the bias voltage compensation for full-color LED display based on the load-line approach. Modeling and formulation of the driver circuit system will be discussed in detail. Bias voltage compensation based on three load-lines regulation will keep the operating point fixed for the three color cells. Many properties can be observed based on the proposed model. Parasite effect such as the stray resistor and the stray capacitor will be considered in this paper. The associated standard RGB color testing for color cells and white color testing will be illustrated to verify the proposed compensation for the display driver circuit. The objectives of the luminance uniformity and the gray scale control can be achieved by using circuit approach. It is believed that this paper will be helpful to the driver circuit technology for the full-color LED display.

In this letter, we propose an efficient user selection algorithm aiming to select users with less spatially correlation and meet the user number limit of zero-forcing beamforming in downlink multiuser MIMO systems. This algorithm yields a considerable complexity reduction with only a small loss in performance and it only needs partial users' CSI feedback. Coupled with the algorithm, a null space updating method in O(K2) time and a modified proportional fair scheduling algorithm are also proposed.

A deep null algorithm for adaptive narrowband beamforming in the presence of array gain errors is proposed. This new algorithm not only preserves the desired signal, but also yields superior performance. Simulations confirm this new approach.

Electromagnetic crystals formed by vertical full posts stacked in a rectangular waveguide are analyzed using the image theory and the lattice sums technique. It is shown that the frequency response of the crystals consisting of circular posts can be obtained by a simpler matrix calculus based on the one-dimensional lattice sums, the T-matrix of a circular cylinder in free space, and the generalized reflection and transmission matrices.

This letter proposes a compensation method that can alleviate the problem of I/Q mismatch generated in the direct-conversion receiver of OFDM systems. In the proposed method, the amount of I/Q mismatch is estimated using null-carriers in transmitted signals, and it is subtracted from received symbols to suppress I/Q mismatch effects. Simulations show experiments that the proposed method can effectively eliminate the I/Q mismatch effects.

The most of conventional information services are based on the implicit premise that the users has already defined their desired information. This study proposes a mobile information service that allows the users who have not yet defined their desired information or whose desired information varies according to the situation to get appropriate information. When the user can specify their desired information to the system explicitly, the authors develop a "Pull" service. Conversely, when the user cannot verbally specify their desired information to the system, this study provides "Push" service and "Don't disturb" option for the user who does not welcome this service. This study considers the characteristics of the environment of mobile terminal to focus on "Time", "Place" and user's "Preference": long term and short term preference. This study also creates rules, algorithms and filtering to the service. Furthermore, the results of experiments have been discussed to verify the idea that different of user desired requires different information services.

In this paper, the voice signal processing module has been designed using the micro processor for the use of fully implantable middle ear devices (F-IMEHD). The voice signal processing module for F-IMEHD should be designed to compensate for the hearing loss of hearing impaired person and have the flexibility for compensating various hearing threshold level. So, the voice signal processing module has been designed and implemented to present the various frequency characteristics using the low-power micro processor, MSP430F169. The different voice signal path to the inner ear entrance was considered so that two voice signal would be combined in-phase using an all pass filter with a constant time-delay to improve the vibration of the ossicles.

In this paper, for the fully-implantable middle ear hearing devices (F-IMEHD), a transcutaneous recharging system that has the function of the bi-directional signal transmission with the implant module in a body as well as recharging battery has been designed and implemented. The electromagnetic coupling method using two coils has been adopted for the transfer of electrical power to recharge internal battery of the implant module. To increase the efficiency of power transfer, the switching frequency of recharging system is determined by the consideration of the resonance of LC tank circuits. The bidirectional signal transmission between the recharging system and the implant module has been designed through the on-off keying modulation of switching signal in the recharging system and the impedance variation of LC tank circuit in the implant module. Through the demonstration of the implemented system, it has been verified that the proposed system has the performance of bidirectional signal transmission with the implant module of F-IMEHDs as well as the battery recharging.

This paper proposes a low power scan test scheme and formulates a problem based on this scheme. In this scheme the flip-flops are grouped into N scan chains. At any time, only one scan chain is active during scan test. Therefore, both average power and peak power are reduced compared with conventional full scan test methodology. This paper also proposes a tabu search-based approach to minimize test application time. In this approach we handle the information during deterministic test efficiently. Experimental results demonstrate that this approach drastically reduces both average power and peak power dissipation at a little longer test application time on various benchmark circuits.

In this paper, we describe a new interface for a barge-in free spoken dialogue system combining multichannel sound field control and beamforming, in which the response sound from the system can be canceled out at the microphone points. The conventional method inhibits a user from moving because the system forces the user to stay at a fixed position where the response sound is reproduced. However, since the proposed method does not set control points for the reproduction of the response sound to the user, the user is allowed to move. Furthermore, the relaxation of strict reproduction for the response sound enables us to design a stable system with fewer loudspeakers than those used in the conventional method. The proposed method shows a higher performance in speech recognition experiments.

XML query processing is one of the most active areas of database research. Although the main focus of past research has been the processing of structural XML queries, there are growing demands for a full-text search for XML documents. In this paper, we propose XICS (XML Indices for Content and Structural search), which aims at high-speed processing of both full-text and structural queries in XML documents. An important design principle of our indices is the use of a B+-tree. To represent the structural information of XML trees, each node in the XML tree is labeled with an identifier. The identifier contains an integer number representing the path information from the root node. XICS consist of two types of indices, the COB-tree (COntent B+-tree) and the STB-tree (STructure B+-tree). The search keys of the COB-tree are a pair of text fragments in the XML document and the identifiers of the leaf nodes that contain the text, whereas the search keys of the STB-tree are the node identifiers. By using a node identifier in the search keys, we can retrieve only the entries that match the path information in the query. The STB-tree can filter nodes using structural conditions in queries, while the COB-tree can filter nodes using text conditions. We have implemented a COB-tree and an STB-tree using GiST and examined index size and query processing time. Our experimental results show the efficiency of XICS in query processing.

A systematic method is introduced to the computational synthesis of CMOS voltage followers (VFs). The method is divided in three steps: generation of the small-signal circuitry by selection of nullators to model the behavior of a VF, and addition of norators to form nullator-norator joined-pairs; generation of the bias circuitry by addition of ideal biases according to the properties of nullators and norators; and synthesis of the joined-pairs by MOSFETs, and of the current-biases by CMOS current mirrors. It is shown that the proposed synthesis method has the capability to generate already known and new CMOS VF topologies.

Fixed polarity Reed-Muller expressions (FPRMs) exhibit several useful properties that make them suitable for many practical applications. This paper presents an exact minimization algorithm for FPRMs for incompletely specified functions. For an n-variable function with α unspecified minterms there are 2n+α distinct FPRMs, and a minimum FPRM is one with the fewest product terms. To find a minimum FPRM the algorithm requires to determine an assignment of the incompletely specified minterms. This is accomplished by using the concept of integer-valued functions in conjunction with an extended truth vector and a weight vector. The vectors help formulate the problem as an assignment of the variables of integer-valued functions, which are then efficiently manipulated by using multi-terminal binary decision diagrams for finding an assignment of the unspecified minterms. The effectiveness of the algorithm is demonstrated through experimental results for code converters, adders, and randomly generated functions.

In this letter, a novel general design method of quasi-orthogonal space-time block codes for four antennae is presented. Comparison with the design method proposed by Jafarkhani, this method enlarges the number of quasi-orthogonal space-time block codes. The performance of these codes is also analyzed and the simulation results show that it is similar to even better than that of the codes proposed by Jafarkhani.

We propose a new class of binary nonlinear codes of constant weights derived from a permutation representation of a group that is given by a combinatorial definition such as Cayley graphs of a group. These codes are constructed by the following direct interpretation method from a group: (1) take one discrete group whose elements are defined by generators and their relations, such as those in the form of Cayley graphs; and (2) embedding the group into a binary space using some of their permutation representations by providing the generators with realization of permutations of some terms. The proposed codes are endowed with some good characteristics as follows: (a) we can easily learn information about the distances of the obtained codes, and moreover, (b) we can establish a decoding method for them that can correct random errors whose distances from code words are less than half of the minimum distances achieved using only parity checking procedures.

Under dynamic and heterogenous environment, the need for adaptability and rapid response time to information service systems has become increasingly important. To cope with the continuously changing conditions of service provision and utilization, Faded Information Field (FIF) has been proposed, which is an agent-based distributed information service system architecture. In the case of a mono-service request, the system is designed to improve users' access time and preserve load balancing through the information structure. However, with interdependent requests of multi-service increasing, adaptability, reliability and timeliness have to be assured by the system. In this paper, the relationship between the timeliness and the reliability of correlated services allocation and access is clarified. Based on these factors, the autonomous network-based heterogeneous information services integration technology to provide one-stop service for users' multi-service requests is proposed. We proved the effectiveness of the proposed technology through the simulation and the results show that the integrated service can reduce the total users access time compared with the conventional systems.

This paper proposes an efficient two-phase optimization approach for a compact W-band double-plane stepped rectangular waveguide filter design, which combines genetic algorithms (GAs) with the simplified transmission-line model and full-wave analysis. Being more efficient and robust than the gradient-based method, the approach can lead to a compact waveguide filter design. Numerical results show that the resultant waveguide filter design with 4 sections (total length 19.6 mm) is sufficient to meet the design goal and provides comparable performance to that with 8 sections (total length 35.6 mm) by the Chebyshev synthesis approach. Based on the present approach, nineteen compact high-pass waveguide filters have been implemented and measured at the W-band with satisfactory performance.

Visibility culling techniques have been studied extensively in computer graphics for interactive walkthrough applications in recent years. In this paper, a visibility culling approach by exploiting hardware-accelerated occlusion query is proposed. Organizing the regular grid representation of input scene as an octree-like hierarchy, a 2-tier view frustum culling algorithm is to efficiently cull away nodes invisible from a given viewpoint. Employing the eye-siding number of nodes, we can quickly enumerate an occlusion front-to-back order and effectively maximize the number of parallelizable occlusion queries for nodes while traversing the hierarchy. As experimental results show, our approach improves the overall performance in the test walkthrough.

We have proposed a novel spatial filtering technique named "VIrtual Subcarrier Assignment (VISA)" for orthogonal frequency division multiplexing (OFDM) signals, which enables the transceiver equipped with an adaptive array antenna (AAA) to selectively receive or reject OFDM signals through coloring them with different virtual subcarrier positions in their frequency spectra. In this paper, we develop the VISA to use multiple virtual subcarrier assignment, which assigns a different combination of multiple virtual subcarrier positions in the frequency spectrum to each OFDM signal. Furthermore, we present two kinds of recursive least square (RLS)-based array weight control methods to support the VISA with multiple subcarrier puncturing in an IEEE802.11a-based system and evaluate the link-level performance in typical indoor wireless environments by computer simulations.

MBF (Microwave Beam Forming) antennas are beam forming antennas that perform pattern control in RF, for a low-cost design suitable for mobile terminals. An MBF antenna has only a single output port, since this antenna consists of an array antenna, microwave phase shifters, and a power combiner. Because of this simple configuration, MBF antennas cannot adopt conventional beam forming algorithms that require both phase and amplitude control, and signal observation of each antenna element. In this paper, mutual coupling matrix estimation and null forming methods are presented for MBF antennas. It is shown that the mutual coupling matrix can be estimated by changing the antenna weight instead of signal observation of each antenna element. It is also shown that phase-only null forming, including mutual coupling effect, can be done by the optimum phase perturbations. Numerical and experimental results show the performance of these algorithms.