New algorithms for the MAP (also known as the APP) decoding and the MAX-LogMAP decoding of linear block codes are presented. The algorithms are devised based on the structural properties of linear block codes, and succeeds in reducing the decoding complexity without degrading the error performance. The proposed algorithms are suitable for the parallel and pipeline processing which improves the throughput of the decoder. To evaluate the decoding complexity of the proposed algorithms, simulation results for some well-known codes are presented. The results show that the algorithms are especially efficient than the conventional BCJR-based algorithms for codes whose rate are relatively low.

With a view to virtual studio applications, we design an optimal grid pattern such that the observed image of a small portion of it can be matched to its corresponding position in the pattern easily. The grid shape is so determined that the cross ratio of adjacent intervals is different everywhere. The cross ratios are generated by an optimal Markov process that maximizes the accuracy of matching. We test our camera calibration system using the resulting grid pattern in a realistic setting and show that the performance is greatly improved by applying techniques derived from the designed properties of the pattern.

In this paper, we discuss on the realization of reduced peak power transmission for the multicarrier systems. Since the signals have large amplitude fluctuations in conventional multicarrier systems, signals amplified by a nonlinear amplifier are greatly distorted, resulting in severe performance degradation. In order to avoid this large amplitude fluctuation, we propose a scheme for reducing the nonlinear distortion by using the set of the signal point series which show low peak to mean envelope power ratio (PMEPR) value. In this system, one symbol is transmitted with multicarriers and the received signal is detected with maximum likelihood sequence detection.

An iterative decoder of turbo code over an inter-symbol interference channel is proposed. A component decoder realizes decoding and equalization simultaneously with the soft-output Viterbi algorithm (SOVA). A decoding algorithm and simulation results are shown.

A novel fabrication process and materials of LC layers have been developed for three layer LCDs. It is based on LC/resist composite that can be applied to patterning LC layers with high resolution by conventional photolithography processes. Using this process, we fabricated a 2" matrix panel of three GH-LC layers stacked on a substrate for the fist time.

Voltage holding property of liquid crystal (LC) cell for long period was investigated and the experimantal results were analyzed using a microscopic model considered the movement of ions in LC layer. The time dependent voltage decay curve observed in the experiment, which is not driven by the analysis with the conventional equivalent circuit comprised of the capacitance and the resistance, can be well explained by the microscopic model.

A new method is introduced for sequential estimation of TDOA (time delay of arrival) and FDOA (frequency delay of arrival) in a two sensor array. The proposed scheme is basically a two step algorithm utilizing 1-dimensional slice functions of the third order cumulants between two signal measurements, and is capable of suppressing the effect of correlated Gaussian measurement noises. It is demonstrated that the proposed algorithm outperforms existing TDOA/FDOA estimation algorithms from the viewpoint of computational burden and in the sense of mean squared error as well.

We analyze the performance of soft handoff used as intergroup handoff in the fiber-optic cellular system. Performance is evaluated in view of blocking and handoff refused probability. The numerical results show that the smaller the handoff region or the more the channel, the larger the system capacity.

The alignment of a nematic liquid crystal (LC) parallel to the polarization direction of the laser could be induced by three types of polyimide (PI) films, a PI based on aromatic dianhydride and two PIs on alicyclic dianhydride, exposed to polarized pulsed laser at 266 nm at high fluence in air. The UV-visible absorption spectra of the PI films showed that a remarkable chemical change occurred after exposure at the high fluence in air. In contrast, in argon atmosphere the PI based on aromatic dianhydride was radiation-resistant and the exposed PI film could induce alignment of the LC molecules parallel to laser polarization. We estimate that the mechanism of the parallel alignment observed in argon is not the photodegradation but the orientation of the PI molecules.

We successfully fabricated split alignment sleeves for single-mode operation with the injection-molding technique using both thermosetting epoxy resin and thermoplastic polyetherimide (PEI) resin. The relationship between the surface smoothness and the connection-loss characteristics of these injection-molded plastic sleeves was investigated. We made two-dimensional contour maps of the outer and inner surfaces of the plastic sleeves using the measured surface roughness. There were many contour lines on both the outer and inner surfaces of the PEI sleeve. In contrast, the epoxy sleeves had very smooth surface profiles. An offset Δr was estimated by using the inner-surface roughness data of the sleeve-ferrule contact regions. The connection loss of the sleeve increased as the Δr value increased. The measured losses agree fairly well with the theoretical losses estimated by using the Δr values. The PEI sleeves exhibited large Δr values, and one-third of them had large connection losses of > 0.5 dB. In contrast, the epoxy sleeves had very small Δr values of < 0.6 µm, and exhibited an average loss of < 0.1 dB.

This paper describes experimental results of the IP traffic condition based dynamic optical path allocation network system. In the system, optical paths are dynamically allocated between congested node pairs to cope with traffic fluctuations. It seems that this experiment is the first of its kind in the world.

In this paper, we propose path accommodation methods for unidirectional rings based on an optical compression time-division multiplexing (OCTDM) technology. We first derive a theoretical lower bound on the numbers of slots and frames, in order to allocate all paths among nodes. Three path accommodation algorithms for the all-optical access are next proposed to achieve the lower bound as closely as possible. Path splitting is next considered to improve the traffic accommodation. Finally, we analyze the packet delay time for given numbers of slots/frames, which are decided by our proposed algorithms. Numerical examples are also shown to examine the effectiveness of our proposed algorithms including path accommodation and path splitting methods.

The encoding procedure that allows one to represent integers by binary vectors (codewords) in such a way that addition is replaced with the OR operation applied to these vectors is described. The codeword of the sum is constructed using the decoding algorithm. As a result, many of the transformations can be realized using parallel processing, and the method can be considered as a competitor to existing computer arithmetic.

An AC coupling configuration for the active guard band filters is introduced for suppressing substrate coupling noise in analog and digital mixed-signal integrated circuits. With this method, a substrate-coupling-noise cancellation signal can be supplied to a ground-level substrate by using a single 3-V supply on-chip circuits. Noise was suppressed to a maximum of less than 0.05 from 100 Hz to 2 MHz in a 0.35-µm CMOS test chip. Both experiments and a simulation based on the substrate extraction model showed the similar dependence of the noise-suppression effect on the arrangement of the guard-bands and analog circuits. The simulation is thus effective for optimizing the arrangement to suppress noise effects when designing a chip.

We propose a variation of the Context Tree Weighting algorithm for tree source modified such that the growth of the context resembles Lempel-Ziv parsing. We analyze this algorithm, give a concise upper bound to the individual redundancy for any tree source, and prove the asymptotic optimality of the data compression rate for any stationary and ergodic source.

A "dual-ring" network configuration is proposed in wavelength-division multiplexing (WDM) metropolitan area network (MAN). In the proposed architecture, a "sub-ring" using two fibers is added to the existing metropolitan WDM ring for flexible and cost effective addition of new nodes.

The problem of self-timed implementation of Boolean functions is explained. The notions of combinational delay-insensitive code and delay-insensitive function are defined, giving precise conditions under which memoryless self-timed implementation of Boolean functions is feasible. Examples of combinational delay-insensitive code and delay-insensitive function are given. Generic design style, using standard CAD library, for constructing quasi delay-insensitive self-timed function blocks is suggested. Our design style is compared to other self-timed function block design styles.

This paper reviews the recent progress made by those working on optical filters and switches for photonic networks based on dense wavelength division multiplexing (WDM). While various kinds of optical devices have been developed for flexible and large-capacity networks, the key components for the WDM networks are narrow-band filters and switches. Three kinds of optical filter are described in this paper: thin-film interference filters, fiber grating filters and arrayed-waveguide-grating (AWG) filters. The optical switches reviewed here are mechanical fiber-type switches, thermo-optic switches made using planar-lightwave-circuit technologies, total-internal-reflection switches and micro-electromechanical-system switches. Each device has its own advantages, and has been or will be used in point-to-point WDM, optical add/drop mupliplexing systems and optical crossconnect systems. Further advances in optical components and technologies are expected to contribute greatly to the construction of future photonic networks.

The Next Generation Internet Initiative was launched in the U.S. to advance key networking technologies that will enable a new wave of applications on the Internet. Now, in its third year, the program has launched and fostered over one hundred new research projects in partnership with academic, industrial and government laboratories. One key research area that has been emphasized within the program is the next-generation optical networking. Given the ever increasing demand for network bandwidth, and the recent phenomenal advances in WDM technologies, the Next Generation Internet is expected to be an IP-based optical WDM network. As IP over WDM networking technologies mature, a number of important architectural, management and control issues have surfaced. These issues need to be addressed before a true Next Generation Optical Internet can emerge. This paper provides a brief introduction to the overall goals and activities of DARPA's NGI program and describes the key architectural, management, and control issues for the Optical Internet. We review the different IP/WDM networking architectural models and their tradeoffs. We outline and discuss several management and control issues and possible solutions related to the configuration, fault, and performance management of IP over dynamic WDM networks. We present an analysis and supporting simulation results demonstrating the potential benefits of dynamic IP over WDM networks. We then discuss the issues related to IP/WDM traffic engineering in more detail, and present the approach taken in the NGI SuperNet Network Control and Management Project funded by DARPA. In particular, we motivate and present an innovative integrated traffic-engineering framework for re-configurable IP/WDM networks. It builds on the strength of Multi-Protocol Label Switching (MPLS) for fine-grain IP load balancing, and on the strength of Re-configurable WDM networking for reducing the IP network's weighted-hop-distance, and for expanding the bottleneck bandwidth.

Loop optimization plays an important role in compiler optimization and program transformation. Many sophisticated techniques such as loop-invariance code motion, loop restructuring and loop fusion have been developed. This paper introduces a novel technique called loop quasi-invariance code motion. It is a generalization of standard loop-invariance code motion, but based on loop quasi-invariance analysis. Loop quasi-invariance is similar to standard loop-invariance but allows for a finite number of iterations before computations in a loop become invariant. In this paper we define the notion of loop quasi-invariance, present an algorithm for statically computing the optimal unfolding length in While-programs and give a transformation method. Our method can increase the accuracy of program analyses and improve the efficiency of programs by making loops smaller and faster. Our technique is well-suited as supporting transformation in compilers, partial evaluators, and other program transformers.