Throughput improvement scheme in multi-code CDMA

In multi-code CDMA, there is no self-interference among the sub-codes of a single user. By taking advantage of this property, the authors propose a new scheduling scheme to improve throughput, and derive the system throughputs of two cases with the proposed scheme applied and not applied. Analysis results show that the proposed scheme considerably improves the system throughput     

Calculation and measurement of resonant-mode blueshifts inoxide-apertured VCSELs

As the aperture size of oxide-apertured vertical-cavity surface-emitting lasers (VCSELs) shrinks, the lasing wavelength blueshifts. We have calculated this effect using both a scalar effective index model and a full-vector weighted index model. Results were compared against experimental data for two different VCSEL designs emitting near 780 and 850 nm. We find that the full-vector weighted index calculation matches the data remarkably well, while the scalar effective index calculation underestimates the blueshift     

Noninvasive botryoid extension of Wilms'' tumor into the bladder

We present the previously unreported CT appearance of a Wilms' tumor which extended down the ureter and protruded into the bladder as a botryoid mass. The tumor apparently arose from an intralobar nephrogenic rest and demonstrated local invasion into renal sinus vessels and papillae. There was no tumor invasion into the wall of the ureter or bladder, and therefore, the extension into the ureter and bladder did not upstage the tumor. This report adds to the list of differential diagnoses of a botryoid bladder mass in a child and demonstrates yet another unusual manifestation of Wilms' tumor.     

Improved electrical and reliability Characteristics of HfN--HfO/sub 2/-gated nMOSFET with 0.95-nm EOT fabricated using a gate-first Process

By using a high-temperature gate-first process, HfN--HfO/sub 2/-gated nMOSFET with 0.95-nm equivalent oxide thickness (EOT) was fabricated. The excellent device characteristics such as the sub-1-nm EOT, high electron effective mobility (peak value /spl sim/232 cm/sup 2//V/spl middot/s) and robust electrical stability under a positive constant voltage stress were achieved. These improved device performances achieved in the sub-1-nm HfN--HfO/sub 2/-gated nMOSFETs could be attributed to the low interfacial and bulk traps charge density of HfO/sub 2/ layer due to the 950/spl deg/C high-temperature source/drain activation annealing process after deposition of the HfN--HfO/sub 2/ gate stack.     

Refractive‐index matching between liquid crystals and photopolymers

Abstract— Refractive indices of two photocurable polymers, NOA65 and NOA81 (Norland Optical Adhesive), and two series of Merck liquid crystals, E‐series (E44, E48, and E7) and BL‐series (BL038, BL003 and BL006), and two UCF high‐birefringence liquid‐crystal mixtures were measured using an Abbe refractometer in the visible spectral region and 15–55°C temperature range. Some liquid crystals have excellent index matching with NOA65 in the red, while some fit better in the blue spectral region. To validate this index‐matching property found in the material level, we prepared some polymer‐dispersed liquid‐crystal devices. Good correlations between material and device performances are obtained.     

Feedforward control of the lateral position of a moving web using system identification

Many mathematical models have been developed to describe the lateral dynamics of a moving web, including Shelton's model. Experimental results in this study showed that the existing model does not fully describe the characteristic of the lateral dynamics for some typical operating conditions. An experimental model was derived by means of system identification using a well-known least-square method to improve the prediction capability of the lateral dynamics. A commercial guidance system usually has the proportional and integral control structure. Sometimes it may not eliminate the effect of periodic lateral disturbances efficiently which are transferred from upstream spans because the controller relying solely on feedback generates control action only when an output measurement signal differs from a reference value. However, if the disturbance is deterministic, a feedforward control structure may offer simple and effective disturbance rejection performance. In this paper, the lateral position of a web at the upstream span and the identified model of lateral dynamics for the span were used to estimate the effect of disturbance on the lateral dynamics of a moving web at the exit span of the guidance system. A feedforward controller was designed to reject the deterministic disturbance of lateral dynamics of a moving web. The disturbance rejection performance of the proposed controller was verified by computer simulation and experiments. These results showed that the proposed feedforward scheme with an improved mathematical model greatly improved control performance in overcoming the dynamic disturbance.     

A charge-trapping-based technique to design low-voltage BiCMOSlogic circuits

New BiCMOS logic circuits employing a charge trapping technique are presented. The circuits include an XOR gate and an adder. Submicrometer technologies are used in the simulation and the circuits' performances are comparatively evaluated with the CMOS and that of the recently reported circuits. The proposed circuits were fabricated using a standard 0.8-μm BiCMOS process. The experimental results obtained from the fabricated chip have verified the functionality of the proposed logic gates     

64-KByte sum-addressed-memory cache with 1.6-ns cycle and 2.6-nslatency

Address base-plus-offset summing is merged into the decode structure of this 64-KByte (512-Kbit), four-way set-associative cache. This address adder avoids time-consuming carry propagation by using an A+B=K equality test. The combined add and access operations are implemented using delayed-reset logic and a 0.25-μm process, This wave pipelined RAM achieves a 1.6-ns cycle time and 2.6-ns latency for the combined address add and cache access