Linearity of a transconductor with a theoretical linear characteristic is deteriorated by mobility degradation, in practice. In this paper, a technique to improve the linearity by combining a source-coupled pair with the transconductor is proposed. The proposed transconductor is the circuit that the deteriorated linearity of the conventional part is compensated by the transconductance characteristic of the source-coupled pair. In order to confirm the validity of the proposed technique, SPICE simulation is carried out. The transconductance change ratio of the proposed technique is about 1% and is 1/10 or less of the conventional circuit.

An adaptive service framework is expected to support real-time multimedia services in wirless/mobile cellular networks with various classes of traffic and diverse bandwidth requirements. Quality of service (QoS) provisioning in an adaptive framework is another challenging consideration, such as quantifying the level of bandwidth degradation of an ongoing calls and guaranteeing stable QoS levels. Considering both the period and the depth of degradation, the degradation area ratio (DAR) represents the average ratio of a call's degradation and is one of the meaningful measures for adaptive service in call level analysis. In this paper, analytical models for estimating the DAR and finding the optimal control parameters are presented in multi-class traffic call management situations. In complete partitioning capacity based threshold-type call admission control (CAC), a one-dimensional Markov chain with an absorbing state is proposed for estimating the DAR in each traffic class. We formulate a two-leveled optimization problem minimizing the total blocking probabilities subject to QoS requirements and present the procedures required in finding the optimal capacities and threshold values by using modified dynamic programming. In complete sharing capacity based threshold-type CAC, the multidimensional Markov model is approximately reduced to a one-dimensional model in order to reduce complexity and hence calculation time. The reduced model is compared with multidimensional Markov model in numerical examples. The optimization problem is formulated minimizing the total blocking probabilities subject to QoS requirements and the optimal threshold parameters are found by using a genetic algorithm. Performance of two adopted admission policies in adaptive framework situations is illustrated by numerical results.

The relative window method provides quantitative crosstalk delay degradation for the post-layout timing analysis in deep sub-micron VLSI design. However, to the best of our knowledge, the relative window method has not been applied to the crosstalk minimization in gridded channel routing problem. Most conventional crosstalk optimizers only use the coupling length to estimate the crosstalk. In this paper, we present a post-layout timing driven crosstalk optimizer based on the relative window method. According to the relative signal arrival time and the coupling length, we define a delay degradation graph to describe the crosstalks between nets in a routing solution. Our optimization goal is to maximize the time slack by iteratively improving the delay degradation graph without increasing the channel height. Benchmark data consistently show that our post-layout timing driven crosstalk optimizer can further improve the routing solution obtained by a conventional crosstalk optimizer.

We investigated the accuracy of nickel-cadmium (Ni/Cd) battery degradation estimation by measuring the capacity of over 400 used cordless-telephone batteries using a discharge-current-pulse technique. The capacity is calculated from the change in battery voltage after the current pulse is applied, using an equation that we developed. Battery degradation is represented by a percentage of the capacity based on the nominal one. To estimate the accuracy of the degradation estimation, we compare capacity Qe estimated from the current pulse with the capacity Qa measured by discharging the batteries. The Qe estimated from the current pulse was within a range of 20% of error indicated by (Qe-Qa) for 47% of the tested batteries. The Qe of 51% of the batteries, however, was underestimated and exceeded lower limit (-20%) of the error. One reason for the discrepancy could be that the equation is inadequate for estimating the capacity from the current pulse. On the other hand, the capacity Qe of 1% of the batteries was overestimated and exceeded upper limit (+20%) of the error. An internal short is probably the main reason for this.

In this letter, a concise formula for the SNR degradation of OFDM caused by carrier frequency offset is derived by approximations over a shadowed two-path channel, which explicitly shows the sensitivity of SNR degradation to various parameters including the frequency offset. It is shown that, for small frequency offset, the SNR degradation is proportional to the square of the frequency offset and the square of the number of subcarriers. It is also shown that, if Es/N0 is reasonably large, the SNR degradation becomes insensitive to Es/N0, which is contrary to the case of the AWGN channel.

We investigated the intercalation of water into BaMgAl10O17:Eu2+ (BAM), a blue phosphor that is used in plasma display panels. The adsorption and desorption characteristics of water with BAM have hysteresis; showing that water is intercalated into BAM. Using thermal analysis techniques, we suggested that water hydrated to barium ions caused oxidation. We found that the water intercalated into BAM played an important role in the oxidation of Eu2+ between 450 and 600, and contributed to a 10% degradation of luminance. In contrast, oxidation due to oxygen is a principal factor in degradation above 600 through baking process in air.

In this paper, we propose a TCAD driven hot carrier reduction methodology of 3.3 V I/O pMOSFETs design. The hot carrier reliability of surface channel I/O pMOSFET having drain structure in common with core devices has a critical issue. It is substantially important for the high-reliability devices to reduce both drain avalanche and channel hot hole components. The drain structures are successfully optimized in short time by applications of TCAD local models. Considering tradeoffs between hot carrier injection (HCI) and drive current (ION), SDE/HALO of both core and I/O transistors can be totally optimized for reduction of process-steps and/or photo-masks.

In this paper, three algorithms are proposed for rate maximization (RM) of transmitted data in multichannel (MC) communications, subject to joint constraints on available energy budget and tolerable degradation of service (DOS). Altogether referred to as the RM algorithms, they consist of the EADRM, the DADRM, and the fDADRM algorithms. Based on the rate-distortion optimization theory, closed-form expressions for optimally distributing the energy (for EADRM) or DOS (for DADRM and fDADRM ) among the subchannels (SC's) are derived, when the bit allocation is pre-specified. The specification of bit allocations is achieved by the use of the so-called eligible bit allocation matrix (EBAM), which is a function of the total data rate and the number of SC's. A greedy approach is adopted, where the total data rate is kept on raising until the relevant constraints can no longer be satisfied. While all three RM algorithms essentially generate identical maximum data rates, the fDADRM algorithm is much faster than the other two in computation. As compared to the result achievable by a single-channel communication scheme, the RM algorithms produce a much higher data rate for spectrally shaped channels.

A blue-light-emitting Eu2+ doped CaMgSi2O6 phosphor with a long lifetime for a plasma display panel (PDP) was developed. The CaMgSi2O6:Eu2+(CMS:Eu2+) phosphors synthesized using SiO2-rich source materials show no luminance degradation during the baking process for binder burn-off, and the photoluminescence peak intensity of the Eu2+ emission band is higher than that of conventional blue phosphor BaMgAl10O17:Eu2+ (BAM) after the baking process. The test PDP using synthesized CMS:Eu2+ phosphor shows a comparable emission peak intensity to that of BAM, while the luminance of the CMS:Eu2+ panel is approximately 55% that of the BAM panel due to the narrower spectral bandwidth and shorter peak wavelength. The CMS:Eu2+ panel shows less luminance degradation than BAM under the aging test, and the CMS:Eu2+ panel retains 85% of its luminance after 300 hours driving. It is found that CMS:Eu2+ appears to be a promising blue phosphor material for PDP.

We obtained a relation between the characteristics of optical life and panel structural factors which is one of the important factors for panel design of Plasma Display Panel (PDP). We introduced the equation under the consideration that dominant factor determining the characteristics of optical life is luminance degradation of phosphors and that ion bombardment causes luminance degradation of phosphors. This equation contains the following four panel structural factors such as gap between electrodes, gas pressure, gas kinds, and voltage. Furthermore, we compared the equation with experimental values as a verification.

We have recently developed a programmable composite noise generator (P-CNG) which can easily control noise parameters such as average power, time-based amplitude probability distribution (APD), crossing rate distribution, occurrence frequency distribution and burst duration. Two applications of the P-CNG are demonstrated to show its usefulness. For the first application, Middleton's Class A noise is simulated. A method of setting parameters for Class A noise is demonstrated. The APD of P-CNG output is in good agreement with that of true Class A noise. In the second application, the P-CNG is used for subjective evaluation test (opinion test) of TV picture degradation. Five simple composite noise models with two kinds of APD are used. Other parameters such as average power are kept constant. Experimental results show that the envelope and APD of composite noises do not greatly influence the subjective evaluation. Finally the capabilities of the P-CNG are shown.

Photoirradiation effects on the polymer light-emitting devices (PLEDs) with a semitransparent-Al cathode have been studied. A light-emitting polymers, a poly (p-phenylene vinylene) derivative MDOPPV has been used in this study. Upon photoirradiation, the emission intensity at a constant voltage was rapidly decreased. However, the quantum efficiency of electroluminescence remained constant, indicating the spatial separation between recombination zone and photooxidized defects. On the other hand, the quantum efficiency of photoluminescence rapidly dropped upon similar photoirradation. These can be understood by taking the difference in the spatial distribution and the origin of excitons between electro- and photo-luminescence processes. It was also found that the photooxidation rate of the polymer film whose thickness is ca. 100 nm does not have thickness dependence, suggesting that the photooxidation of the polymer proceeds uniformly throughout the device.

We developed a novel model for degradation of remanent polarization resulting from repeated polarization reversal cycling. The characteristics of ferroelectric capacitors have been simulated with the double saturation function model that required only five parameters; Ec, Qrmax, Qdmax, Kr and Kd. This novel model combines an equivalent gap capacitor with the double saturation function model. The model predicts hysteresis loops under endurance conditions. The simulated results are well in agreement with the results obtained in the experiment. The model is utilized to quantify the degradation effect of remanent polarization on ferroelectric memory applications.

In this paper an analytical parametric formulation of total degradation in Orthogonal Frequency Division Multiplexing (OFDM) systems including High Power Amplifiers (HPA) is presented. Two classes of non-linear devices are considered: Traveling Wave Tube Amplifiers (TWTA) and Solid State Power Amplifiers (SSPA). In the results the accuracy of the proposed method is checked and the impact of coding to mitigate non-linear distortion is easily assessed.

For vacuum-UV (VUV) phosphor application such as plasma display panels (PDPs) and mercury free lamps, CaAl2O4:Eu2+ (CA:Eu2+) showing 440 nm blue emission was examined. A single phase CA:Eu2+ was obtained by two step firing technique. The photoluminescence (PL) spectrum shows blue shift compared to that of blue-emitting BaMgAl10O17:Eu2+ (BAM:Eu2+) phosphors. CA:Eu2+ phosphors with β-tridymite crystal structure show less luminance degradation on baking in comparison to the commercial BAM:Eu2+ phosphors under VUV excitation. The initial PL intensity of CA:Eu2+ (Eu: 2 mol%) powder phosphor excited by 147 nm light was found to be about 60% of the commercial BAM:Eu2+ and the luminance of test panel with CA:Eu2+ (Eu: 1 mol%) was 37.4 cd/m2. The low test panel luminance with CA:Eu2+ phosphor is partly caused by the poor spread characteristics of the phosphor slurry due to the large particle size distribution. With improvement of luminance efficiency and the powder characteristics, there is a possibility that CA:Eu2+ phosphors can be applied for PDPs.

With the continuing growth of the World Wide Web (WWW) services over the Internet, the demands for rapid image transmission over a network link of limited bandwidth and economical image storage of a large image database are increasing rapidly. In this paper, a classified binary-tree-structured Self-Organizing Feature Map neural network is proposed to design image vector codebooks for quantizing images. Simulations show that the algorithm not only produces codebooks with lower distortion than the well-known CVQ algorithm but also can minimize the edge degradation. Because the adjacent codewords in the proposed algorithm are updated concurrently, the codewords in the obtained codebooks tend to be ordered according to their mutual similarity which means more compression can be achieved with this algorithm. It should also be noticed that the obtained codebook is particularly well suited for progressive image transmission because it always forms a binary tree in the input space.

Optically patternable light-emitting devices based on conducting polymers were fabricated and were characterized. The cathode of the devices is made with a semitransparent-Al film, which enables to photoinduced degradation of the polymers in air. The optically patternable devices were successfully made with poly (2-methoxy-5-dodecyloxy-p-phenylene vinylene) (MDOPPV), as well as with poly (3-dodecylthiophene) (PAT12). However, optical absorption study indicated that the patterning mechanism of the MDOPPV device is considerably different from that of the PAT12 device.

A new motion analysis method and an image restoration process for removing motion blur are proposed. Motion analysis includes the motion estimation and motion-based segmentation. Based on the analysis, we can obtain an image divided into multiple segments with different point spread functions. For removing motion blur, we propose an image degradation model for the motion with an arbitrary direction and a regularized iterative restoration method. By using the proposed degradation model and the restoration method, we can efficiently remove the space-variant motion blur.

Wavelength Division Multiplex (WDM) photonic networks are expected as key for global communication infrastructure. The accurate measurement methods for AWG-MUX/DMUX are desirable for WDM network design. We measured a transfer function matrix of an AWG-MUX to find that polarization mode dispersion (PMD) and polarization dependent loss (PDL) shows the bandpass characteristics, which may limit the maximum size and the bit rate of the system. These bandpass characteristics of PMD and PDL are reproduced by a simple AWG-MUX model: The phase constant difference of 0.5% between orthogonal modes in arrayed waveguides is sufficient to obtain the measured passband characteristics of PMD and PDL. We find phase distribution difference between two orthogonal modes in the arrayed waveguide grating gives arise to complex PMD.

Wavelength Division Multiplex (WDM) photonic networks are expected as key for global communication infrastructure. The accurate measurement methods for AWG-MUX/DMUX are desirable for WDM network design. We measured a transfer function matrix of an AWG-MUX to find that polarization mode dispersion (PMD) and polarization dependent loss (PDL) shows the bandpass characteristics, which may limit the maximum size and the bit rate of the system. These bandpass characteristics of PMD and PDL are reproduced by a simple AWG-MUX model: The phase constant difference of 0.5% between orthogonal modes in arrayed waveguides is sufficient to obtain the measured passband characteristics of PMD and PDL. We find phase distribution difference between two orthogonal modes in the arrayed waveguide grating gives arise to complex PMD.