The present letter deals with the blind equalization problem of a single-input single-output infinite impulse response (SISO-IIR) channel with additive Gaussian noise. To solve the problem, we propose a new criterion for maximizing constrainedly a fourth-order cumulant. The algorithms derived from the criterion have such a novel property that even if Gaussian noise is added to the output of the channel, an effective zero-forcing (ZF) equalizer can be obtained with as little influence of Gaussian noise as possible. To show the validity of the proposed criterion, some simulation results are presented.

The label placement problem is one of the most important problems in geographic information systems, cartography, graph drawing, and graphical interface design. In this paper, we considered the label size maximization problem for points with axes-parallel rectangular labels that correspond to character strings and have different widths based on the number of characters. We propose an algorithm for computing the optimum size for the label size maximization problem in the 2-position model and a polynomial time algorithm for the problem in the 4-position model. Our algorithm cannot obtain the maximum value in the 4-position model because the label size maximization problem in the 4-position model is NP-hard. However, our algorithm is efficient in practice, as shown by computational experiments. Further, computational results for JR trains, subways and major private railroads in Tokyo are presented.

A new video text localization approach is proposed. First, some pre-processing techniques, including color space conversion and histogram equalization, are applied to the input video frames to obtain the enhanced gray-scale images. Features are then extracted using wavelet transform to represent the texture property of text regions. Next, an unsupervised fuzzy c-means classifier is performed to discriminate candidate text pixels from background. Effective operations such as the morphological dilation operation and logical AND operation are applied for locating text blocks. A projection analysis technique is then employed to extract text lines. Finally, some geometric heuristics are used to remove noise regions and refine location of text lines. Experimental results indicate that the proposed approach is superior to other three representative approaches in term of total detection rate.

A cell search technique utilizing a known postfix for OFDM (orthogonal frequency division multiplexing) cellular systems is described. The known postfix is generated in the time domain by inserting pilots in the frequency domain and plays the role of the cyclic prefix in general OFDM systems. Since it demonstrates good correlation properties, it can be facilitated to synchronize each symbol with an identified postfix. In this paper, two different known postfixes are allocated to each cell. One is used for cell identification and symbol synchronization, which is designed to be different among neighboring cells. The other is used for frame synchronization and is the same for all cells. In the simulation, the cell search is accomplished with a probability greater than 10-3 at -27 dB in a vehicular channel. Even at -30 dB, the cell search probability is greater than 10-2 in a pedestrian channel as well as 10-3 in the AWGN (additive white gaussian noise) channel.

Two compact and low loss dual-mode filters are proposed by using degenerate modes of slotted triangular microstrip patch resonators. The geometrical size and radiation loss of the triangular patch are reduced simultaneously by loading both horizontal and vertical slots. The resonant frequencies of two degenerate modes can be easily controlled by varying the dimensions and positions of the slots. A two-pole dual-mode filter operating at 3.94 GHz with a fractional bandwidth of 4.3% is designed, fabricated, and measured. The measured results verify well the theoretical predictions.

We propose a likelihood detection scheme that utilizes ordering and decision of partial bits in MIMO spatial multiplexing systems. We compute BER performance of the proposed detection scheme under Rayleigh fading channels in a 33 MIMO spatial multiplexing system and compare it with BER performance using MLD only and detection utilizing ZF or MMSE only. In addition, the computational complexity of the proposed detection scheme is compared with that of MLD and detection utilizing ZF or MMSE. The results of our investigation show that the proposed detection is a scheme achieves both good BER performance and low computational complexity.

This paper studies the robustness of message masking communication over noisy channels using modified chaotic systems. First, the modified chaotic systems are introduced with a higher capability of transmitting messages than typical chaotic systems. Then, assuming an ideal channel, the chaotic message masking scheme is derived which achieves asymptotic convergence or dead-beat performance for recovering messages. Next, considering the case of noisy channels, an H∞ performance and an L2-gain optimal noise rejection are achieved by solving linear matrix inequality (LMI) problems. Furthermore, the ultimate bound of synchronization error and recovered message error can be adjusted by both design gains and the system parameter of the modified chaos. Using the proposed method, the bit-error-ratio and noise tolerance are improved. Finally, numerical simulations and DSP experiments are carried out to verify the theoretical derivations.

Recently, system level design languages (SLDL), which can describe both hardware and software aspects of the design, are receiving attention. Mixed-signal extensions of SLDL enable current discrete-oriented SLDLs to describe and simulate not only digital systems but also digital-analog mixed-signal systems. The synchronization between discrete and continuous behaviors is widely regarded as a critical part in the extensions. In this paper, we present an event-driven synchronization mechanism for both timed and untimed system level designs through which discrete and continuous behaviors are synchronized via AD events and DA events. We also demonstrate how the synchronization mechanism can be incorporated into the kernel of SLDL, such as SpecC. In the extended kernel, a new simulation cycle, the AMS cycle, is introduced. Three case studies show that the extended SpecC-based system level design environment using our synchronization mechanism works well with timed/untimed mixed-signal system level description.

In this paper a newly designed internally-coupled asymmetric stepped-impedance resonator (SIR) bandpass filter (BPF) is proposed. The asymmetric SIR structure not only can effectively reduce the circuit size but also can provide two flexibly tunable transmission zeros near the lower and upper passband edges. The first transmission zero is due to the series resonance of the quarter-wavelength open stepped-impedance stub, and the second one is produced by anti-parallel coupling between adjacent SIRs. The proposed BPF was fabricated and simulated using the commercial software HFSS, and agreement between the measured and simulated results was observed. A 0.9-dB insertion loss and a shape factor of 3.6 were achieved in the passband, thus indicating that the proposed filter structure is of practical value.

There is still much problem in sizing software despite the existence of well-known software sizing methods such as Function Point method. Many developers still continue to use ad-hoc methods or so called "expert" approaches. This is mainly due to the fact that the existing methods require much information that is difficult to identify or estimate in the early stage of a software project. The accuracy of ad-hoc and "expert" methods also has much problem. The entity-relationship (ER) model is widely used in conceptual modeling (requirements analysis) for data-intensive systems. The characteristic of a data-intensive system, and therefore the source code of its software, is actually well characterized by the ER diagram that models its data. This paper proposes a method for building software size model from extended ER diagram through the use of regression models. We have collected some real data from the industry to do a preliminary validation of the proposed method. The result of the validation is very encouraging.

A hybrid evolutionary neuro-fuzzy system (HENFS) is proposed in this paper, where the weighted Gaussian function (WGF) is used as the membership function for improved premise construction. With the WGF, different types of the membership functions (MFs) can be accommodated in the rule base of HENFS. A new hybrid algorithm of random optimization (RO) algorithm incorporated with the least square estimation (LSE) is presented. Based on the hybridization of RO-LSE, the proposed soft-computing approach overcomes the disadvantages of other widely used algorithms. The proposed HENFS is applied to chaos time series identification and industrial process modeling to verify its feasibility. Through the illustrations and comparisons the impressive performances for unknown system identification can be observed.

Hardware prototyping has been widely used for ASIC/SoC verification. This paper proposes a new hardware design verification method, Transition and Transaction Tracer (TTT), which probes and records the signals of interest for a long time, hours, days, or even weeks, without a break. It compresses the captured data in real time and stores it in a state transition format in memory. Since it records all the transitions, it is effective in finding and fixing errors, even ones that occur rarely or intermittently. It can also be programmed to generate a trigger for a logic analyzer when it detects certain transitions. This is useful for debugging situations where the engineer has trouble finding an appropriate trigger condition to pinpoint the source of errors. We have been using the method in hardware prototyping for ASIC/SoC development for two years and found it useful for system level tests, and in particular for long running tests.

The goal of this study was to design a practical fuzzy controller of the cycle-to-cycle control for multi-joint movements of swing phase of functional electrical stimulation (FES) induced gait. First, we designed three fuzzy controllers (a fixed fuzzy controller, a fuzzy controller with parameter adjustment based on the gradient descent method, and a fuzzy controller with parameter adjustment based on a fuzzy model) and two PID controllers (a fixed PID and an adaptive PID controllers) for controlling two-joint (knee and ankle) movements. Control capabilities of the designed controllers were tested in automatic generation of stimulation burst duration and in compensation of muscle fatigue through computer simulations using a musculo-skeletal model. The fuzzy controllers showed better responses than the PID controllers in the both control capabilities. The parameter adjustment based on the fuzzy model was shown to be effective when oscillating response was caused due to the inter-subject variability. Based on these results, we designed the fuzzy controller with the parameter adjustment realized using the fuzzy model for controlling three-joint (hip, knee, and ankle) movements. The controlled gait pattern obtained by computer simulation was not significantly different from the normal gait pattern and it could be qualitatively accepted in clinical FES gait control. The fuzzy controller designed for the cycle-to-cycle control for multi-joint movements during the swing phase of the FES gait was expected to be examined clinically.

Because of the data correlation in the motion estimation (ME) algorithm of H.264/AVC reference software, it is difficult to implement an efficient ME hardware architecture. In order to make parallel processing feasible, four modified hardware friendly ME workflows are proposed in this paper. Based on these workflows, a scalable full search ME architecture is presented, which has following characteristics: (1) The sum of absolute differences (SAD) results of 44 sub-blocks is accumulated and reused to calculate SADs of bigger sub-blocks. (2) The number of PE groups is configurable. For a search range of MN pixels, where M is width and N is height, up to M PE groups can be configured to work in parallel with a peak processing speed of N16 clock cycles to fulfill a full search variable block size ME (VBSME). (3) Only conventional single port SRAM is required, which makes this architecture suitable for standard-cell-based implementation. A design with 8 PE groups has been realized with TSMC 0.18 µm CMOS technology. The core area is 2.13 mm1.60 mm and clock frequency is 228 MHz in typical condition (1.8 V, 25).

Authority zones in the Domain Name System must be declared to have one or more authoritative name servers, usually consisting of one primary name server and several secondary name servers. These name servers are expected to synchronize zone data using DNS's zone transfer protocols, but the configuration of these synchronization relationships depends upon out of band information and manual processes. This paper describes a way to create name service federations such that a varying set of zones offered by a primary name server can be automatically configured for synchronization by secondary name servers. A sample implementation based on ISC BIND and Perl is described.

A novel variable-length code (VLC), called alternate VLC (AVLC), is proposed, which employs two types of VLC to encode source symbols alternately. Its advantage is that it can not only stop the symbol error propagation effect, but also correct symbol insertion errors and symbol deletion errors, which is very important in video communication.

This letter presents robustness bounds (RBs) for receding horizon controls (RHCs) of uncertain systems. The proposed RBs are obtained easily by solving convex problems represented by linear matrix inequalities (LMIs). We show, by numerical examples, that the RHCs can guarantee robust stabilization for a larger class of uncertain systems than conventional linear quadratic regulators (LQRs).

The generalized sorting problem is to find the first k largest elements among n input elements and to report them in a sorted order. In this paper, we propose a fast generalized sorting algorithm under the single hop wireless networks model with collision detection (WNCD). The algorithm is based on the maximum finding algorithm and the sorting algorithm. The key point of our algorithm is to use successful broadcasts to build broadcasting layers logically and then to distribute the data elements into those logic layers properly. Thus, the number of broadcast conflicts is reduced. We prove that the average time complexity required for our generalized sorting algorithm is Θ(k + log(n - k)). When k = 1, our generalized sorting algorithm does the work of finding maximum, and when k = n, it does the work of sorting. Thus, the analysis of our algorithm builds a connection between the two extremely special cases which are maximum finding and sorting.

A per-user AGC technique is proposed to combat the signal level variation of an individual user in a DS-CDMA receiver. A simple signal model for a Rake receiver is derived, and the potential cause of the signal variation in the Rake receiver output is discussed. The adaptive scheme is also compared with a conventional fixed quantization scheme in simulations.

We propose optical wireless multiple-input multiple-output (OMIMO) communications to achieve high speed transmission with a compact transmitter and receiver. In OMIMO, by using zero forcing (ZF), minimum mean square error (MMSE) or other detection techniques, we can eliminate the interference from the other optical transmit antennas. In this paper, we employ ZF as the detection technique. We analyze the signal-to-interference-plus-noise ratio (SINR) and the bit error rate (BER) of the proposed OMIMO with a linear array and a square array of optical transmit and receive antennas, where we employ subcarrier multiplexing (SCM) for each optical transmit antenna. Note that the proposed OMIMO is applicable to other arrangements of optical transmit and receive antennas. We show that the proposed OMIMO system can realize MIMO multiplexing and achieve high speed transmission by correctly aligning the optical transmit and receive antennas and the transmitter semiangle.