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The isomerization of bicyclo[1.1.0]butane which comprises species with different multireference character is studied by means of the diffusion quantum Monte Carlo method (DMC). Accurate multireference DMC calculations are presented. It can be shown that at most three configuration state functions are required to achieve a balanced description of dynamical and nondynamical electron correlation. A general scheme is described that promotes efficient error cancellation in multireference DMC calculations.

This chapter contains sections titled: Introduction Adaptive Feedforward Error Cancellation Architectural Concepts Alternate Feedforward Path Block Design Considerations Experimental Design of an Adaptively Linearized UMTS Receiver Experimental Results of an Adaptively Linearized UMTS Receiver Conclusions References

Rewiring is known to be a new class of logic restructuring technique at least equally powerful in flexibility compared to other logic transformation techniques while being wiring-sensitive, a property particularly useful for interconnect based circuit synthesis processes. One of the most mature rewiring techniques is the ATPG-based Redundancy Addition and Removal (RAR) technique which adds a redundant alternative wire to make an originally irredundant target wire become redundant and thus removable. In this paper, we propose a new Error Cancellation based Rewiring scheme (ECR) which can also do non-RAR based rewiring operations with high efficiency. Based on the notion of error cancellation, we analyze and reformulate the rewiring problem and develop a generalized rewiring scheme being able to detect more rewiring cases which are not obtainable by existing schemes while still maintains low runtime complexity. Comparing with the most recent non-RAR rewiring tool IRRA, the total number of alternative wires found by our approach is about twice while CPU time is just slightly more (26%) upon benchmarks pre-optimized by rewriting of ABC.

This work presents a design procedure for Continuous Time (CT) Cascade Sigma Delta Modulators (SDMs) using the Sturdy approach for Discrete Time Modulators [1], where the usual Digital Cancellation Filters are removed. The error cancellation mechanism is affected by excess loop delay in the CT approach. Special design considerations are derived and a specific design methodology is proposed. A 10-MHz bandwidth and 80-dB peak SNR example is designed and simulated using a 2–1 topology.

In a recent paper (J. Phys. Cond. Matter vol.1, p.2199, 1989), M.C. Payne has analysed the method originally introduced by two of the authors to perform molecular dynamics simulations with interatomic forces derived directly from the electronic ground state (Phys. Rev. Lett. vol.55 p.2471, 1985). However the equations quoted in the paper by M.C. Payne do not correspond entirely to the original procedure. For this reason the authors have decided to write a joint comment in order to outline the differences and explain the consequences.

An attempt to upgrade the robustness of telecommunication systems in which some packets can be lost is presented. The specific properties of the combined signal in transmultiplexer systems make it be possible to provide almost undetectable small errors to many end-users, instead of a serious error to one end-user only. Some experimental data obtained for the 4-channel integer-to-integer transmultiplexer are presented.

Analytical studies of the hole pressure for non-Newtonian creeping flow past a transverse slot are pursued with particular interest in the formulation of Higashitani and Pritchard (HP). To correct the flaws in the treatment of HP's original work, a modified hole-pressure relation (MHPR) is employed. Some important mathematical properties of the MHPR are presented. By studying the MHPR in streamline coordinate formulation, we find a fortuitouserror cancellation phenomenon in the derivation of the HP formula: namely, the error caused by one key flaw is fortuitously cancelled out by the error introduced through another key flaw. For second-order fluids and Tanner's “viscometric model” (under certain assumptions) the cancellation of errors is proved to be exact. It is this cancellation of errors that provides a theoretical explanation for the paradox between an apparently flawed derivation and the fortunate success of the HP prediction.

A novel motion-insensitive method for scan rate conversion and removing cross errors from video signals is presented. It is based on the recently introduced vector median concept, which utilizes the correlation between different video signal components. In the developed system both scan rate conversion and cross error cancellation use common image memories and can be implemented by the same filtering circuit. By assigning different weights to input values of the proposed scheme, the interpolator and cross-error filter are able to adapt to different signal regions without any motion control. >

A set of optimum design objectives for the Six-Port technique is derived from an examination of the system equations. The optimization criterion is to minimize the sensitivity of the solution to calibration errors. The resulting set of design specifications gives significant improvement in error cancellation.

An architecture that improves the performance degradation caused by the DAC nonlinearity in a cascaded multibit sigma-delta modulator is presented. The proposed architecture, with an extra feedback path in each internal stage, can totally cancel out the errors caused by the DAC nonlinearity at the final stage and, in general, increases the shaping function of DAC errors by one order for the other internal stages as compared to the MASH structure. Behavioral simulation shows that the proposed fourth-order modulator has excellent immunity of DAC nonlinearity over the MASH structure when OSR is greater than 16. With maximum DAC integral nonlinearity (INL) of /spl plusmn/0.05 LSB and an OSR of 32, an improvement of 15 dB over the MASH structure has been observed.

An error cancellation technique is described for suppressing capacitor mismatch in a successive approximation A/D converter. At the cost of a 50% increase in the conversion time, the first order capacitor mismatch error is cancelled. Methods for achieving top-plate parasitic insensitive operation are described, and the use of a gain- and offset-compensated op amp is explained. SWIT-CAP simulation results show that the proposed 16-bit SAR ADC can achieve an SNDR of over 91 dB under nonideal conditions, including 1% 3/spl sigma/ nominal capacitor mismatch, 10-20% randomized parasitic capacitors, 66 dB op amp gain, and 30 mV op amp offset.

In this paper an incremental analog-to-digital converter (ADC) designed as part of the signal-conditioning circuitry of a pressure sensor interface is presented. For technological compatibility the switched-current (SI) technique has been used which does not need double polysilicon CMOS process. To overcome the lack of precision of this technique a conversion algorithm with digital correction has been chosen and circuit enhancements has been sought. Electrical simulations show the correct error cancellation performed by the proposed converter. Resolution of 10 bits is achieved for a 4 MHz master clock. A 1 /spl mu/m CMOS prototype is being tested and some experimental results are given.

We propose and demonstrate a phase stabilization method for transfer and downconvert radio frequency (RF) signal from remote antenna to center station via a radio-over-fiber (ROF) link. Different from previous phase-locking-loop-based schemes, we post-correct any phase fluctuation by mixing during the downconversion process at the center station. A rapid and endless operation is predicted. The ROF technique transfers the received RF signal directly, which will reduce the electronic complexity at the antenna end. The proposed scheme is experimentally demonstrated, with a phase fluctuation compression factor of about 200. The theory and performance are also discussed.

Extended basis set calculations have been performed for ClF and ClF3 using the CPF method, a size consistent modification of the Cl(SD), to clarify discrepancies between experiment and previous computations. Good agreement is found for ClF for the large 3d2flg polarization basis: re = 163 pm (exp: 162.8). De = 2.45 eV (2.67). μe = 0.85 D (0.89). ΔE for the reaction 1 2 F2 + 1 2 Cl2 ⇌ ClF is already accurate on the 2dlf level: ΔE = −53.7 kJ mol−1 (−56.0). Correlation effects involving the 2s orbital of F are shown to be non-negligible. Agreement is slightly poorer for ClF3, since only the 2dlf basis could be used: reeq = 160.7 pm (159.7), reax = 171 pm (169.8). ∠FClF = 87.1° (87.3°). The computation of ΔE (ClF3 ⇌ ClF+F2) turned out to be difficult: ΔE = 59.3 kJ mol−1 (113) on the 2dlf level. Various extensions of the basis lead to improvements of a few kJ mol−1 each, the estimate for the 3d2flg basis is ΔE ⋍ 80 kJ mol−1. The remaining discrepancy to experiment is attributed to incomplete error cancellation within CPF arising from the very different binding in ClF3 (three-centre-four-electron bonding) as compared to ClF and F2.

From a simplified version of the mathematical structure of the strong coupling limit of the exact exchange-correlation functional, we construct an approximation for the electronic repulsion energy at physical coupling strength, which is fully nonlocal. This functional is self-interaction free and yields energy densities within the definition of the electrostatic potential of the exchange-correlation hole that are locally accurate and have the correct asymptotic behavior. The model is able to capture strong correlation effects that arise from chemical bond dissociation, without relying on error cancellation. These features, which are usually missed by standard density functional theory (DFT) functionals, are captured by the highly nonlocal structure, which goes beyond the "Jacob's ladder" framework for functional construction, by using integrals of the density as the key ingredient. Possible routes for obtaining the full exchange-correlation functional by recovering the missing kinetic component of the correlation energy are also implemented and discussed.

An automatic error cancellation technique for higher accuracy successive-approximation analog/digital (A/D) converters is described. The technique uses a binary-weighted capacitor array as its own reference, and no other special elements are required for capacitor mismatch compensation. Experimental results indicate that more than 14-bit A/D conversion can be performed on a conventional MOS IC chip without trimming.

An adaptive equalizer using switched capacitor techniques, fabricated in NMOS technology, will be described. The chip (16mm2) performs tap weight adaption and offset error cancellation according to the least-mean-square algorithm.

To boost the accuracy of electronic structure calculations, the exchange-correlation energy may be constructed from the Kohn-Sham orbitals. A formally exact construction is the density-functional perturbation series, which appears to diverge for many real systems. We predict the radius of convergence and resum this series, using only exact exchange and second-order correlation plus explicit density functionals for the strong-interaction limit. Our new correlation functional, along with exact exchange, predicts atomization energies with competitive accuracy and without the usual error cancellation.

Transmultiplexation changes the parallel transmission into a serial transmission. The paper presents the suitable data preprocessing method of error reduction for images transmitted by transmultiplexer system. The solution is based on blocks of sizes adequate to separation filter orders, used in detransmultiplexation. The proposed method results directly from the detransmultiplexation algorithm. An example of a four-channel transmultiplexer system is presented and analyzed to illustrate the suggested method