A small pixel CMD image sensor

A charge modulation device (CMD) imager with pixel dimensions of 7.3 μm(H)×7.6 μm(V) was designed, fabricated, and examined. These pixel dimensions are suitable for an HDTV imager with a 1-in image format. The optical aperture ratio is 34%. The effective number of pixels in the imager is 660 horizontal and 492 vertical. The saturation signal current is 17 μA/pixel at an exposure of 1 lx-s with good linearity of photoconversion characteristics. The peak of its spectral response occurs at a wavelength of 575 nm. The blooming suppression ratio of the CMD was measured to be -122 dB. The sensor produces a high-quality image with no degradation in spatial resolution and no image lag. These features show that the CMD imager is eminently suitable for a further high-resolution imager sensor     

Detection and Quantitation of Left-to-Right Shunts from Radionuclide Angiocardiography Using the Homomorphic Deconvolution Technique

The homomorphic filtering method is described for the detection and quantitation of left-to-right shunts from radionuclide angiocardiography. First, the method is investigated theoreticatly and numerically using a realistic model with systemic recirculation. It is demonstrated that even in a noisy situation the shunt flow fraction can be relatively well estimated, if only the characteristics of the fiters used are suitable. Second, the method is applied to real data, i.e., the pulmonary time-activity curves from radionucUde anglocardiography. The presence or absence of a left-to-right shunt is determined using the ratio AT/MTT. The pulmonary-to-systemic flow ratios calculated from the areas of the two decomposed curves are compared with those from oximetry at cardiac catheterization. Good agreement between the Qp/Qs ratios calculated by oximetry and radionucUide angiocardiography is obtained.     

A Quantitative Approach for Correction of Background Counts: Determination of Left Ventricular Ejection Fraction by Radionuclide Angiocardiography

A quantitative approach for correction of background counts is described for determination of the left ventricular ejection fraction from first-pass radionuclide angiocardiography. First, the method is investigated theoretically and numerically using a mathematical model. It is demonstrated that the ejection fraction can be estimated relatively well, even in a noisy situation. Second, the method is applied to the left ventricular time-activity curves from two different regions of interest, the carefully selected and the laxly selected, and these are compared to each other. Good agreement (correlation coefficient = 0.96) for 20 patients was obtained between the ejection fractions from the carefully selected region of interest and those from the laxly selected one.     

Analysis of graded-index polymer optical fiber link performance under fiber bending

Bending effects on bandwidth and loss of a graded-index polymer optical fiber (GI POF) were investigated, and those influences on the optical link performance were discussed simultaneously for the first time. The numerical apertures (NAs) of the GI POFs were deliberately varied from 0.154 to 0.292. A bending radius larger than 10 mm induced little mode coupling and little change in the bandwidth of the GI POF. A bending radius smaller than 10 mm caused degradation in the bandwidths of the higher NA GI POFs. On the other hand, in the lower NA GI POFs, even more severe bending could cause little change in their bandwidths. Thus, the lower NA GI POF seemed preferable in suppressing the bandwidth change. However, the higher NA GI POF exhibited the lower bending loss. The preferable NAs for both characteristics were completely opposite. Moreover, the bending loss under underfilled launch (UFL) could be lower than that under overfilled launch (OFL). On the other hand, the bending loss was equivalent to the bandwidth degradation in view of the link power penalty. Therefore, the bandwidth change and loss caused by the bending were the critical factors to optimize the optical link considering the link power budget. The high-NA GI POF with almost ideal refractive-index profile could provide stable high performance in overgigabit communication even under any bending conditions.     

六输入监控器为汽车系统提供准确电源监视

引言 凌力尔特公司最新的一组电源监控器(包含三款器件)是6输入电压监视器,对当今那些需要进行准确电源监视的多电压系统提供了一种理想选择.LTC2930、LTC2931和LTC2932能够在-40℃至125℃的温度范围内保持1.5%的门限准确度.     

Radiation from the transmission line with an acute bend

The transmission and radiation characteristics at an acute bend of a transmission line are investigated analytically. First, in consideration of the strong coupling to the adjacent conductor, the current distributions are decomposed into even and odd modes. Applying the traveling-wave mode method to these modes, it is shown that transmission characteristics of the line with an acute bend can be easily obtained. The abrupt variation of the voltage near the bend is noted. Next, the discontinuities of the traveling wave currents are regarded as radiating sources and the radiation field from the bend in the transmission line is derived by the summation of fields created by each of the discontinuities. It is found that there exist the electric field component radiating strongly in the directions of propagation of the current and another electric field component radiating strongly into the intermediate direction. Finally, by comparing with the former method and experimental results, the validity of the method is confirmed     

Multidimensional feedforward compensator for industrial systems through pole assignment regulator and observer

A feedforward-compensator-design technique is presented for industrial control systems. The proposed feedforward compensator can improve dynamic characteristics of multidimensional systems by modifying the input signals. The multidimensional feedforward-compensator design is based on the pole assignment regulator, the minimal-order observer, and the conversion from a closed-loop system to an open-loop system. The effectiveness of the proposed feedforward compensator is demonstrated by a simulation study of temperature control of a thermal power plant and by experiments of the contour control of an articulated robot arm.     

Multiobjective genetic algorithm applied to aerodynamic design ofcascade airfoils

A multiobjective genetic algorithm (GA) based on Fonseca-Fleming's Pareto-based ranking and fitness-sharing techniques has been applied to aerodynamic shape optimization of cascade airfoil design. Airfoil performance is evaluated by a Navier-Stokes code. Evaluation of GA population is parallelized on the Numerical Wind Tunnel, a parallel vector machine. The present multiobjective design seeks high pressure rise, high flow turning angle, and low total pressure loss at a low Mach number. Pareto solutions that perform better than existing control diffusion airfoils were obtained     

A low-impedance open-bitline array for multigigabit DRAM

The noise-generating mechanisms inherent in the open-bitline DRAM array using the 6F² (F: feature size) memory cells and techniques for reducing the noise are described. The sources of differential noise coupled to the paired bitlines laid out in two arrays are the p-well, cell plate, and the group of nonselected wordlines. It was found, by simulation and by experiment with a 0.13-μm 256-Mb test chip, that the level of noise is dramatically reduced by using a low-impedance array with careful layout featuring low-resistivity materials, tight bridging between pairs of adjacent arrays, and a small array, achieving a comparable level of noise to that seen in the twisted and folded-bitline array. On basis of these results, it turns out that the open-bitline array has a strong chance of revival in the multigigabit generation, as long as these noise reduction techniques are applied     

Evaluation of antioxidative activity of vegetable extracts in linoleic acid emulsion and phospholipid bilayers

The antioxidative effects of vegetable extracts were evaluated using linoleic acid emulsion and liposomal phospholipid suspension systems. First, the antioxidative activities of water, ethanol and 2% metaphosphoric acid extracts of the vegetables were investigated by measuring the rate of oxygen consumption in the peroxidation of linoleic acid initiated by a radical generator, 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), with a Clark electrode in the absence of metal chelators. Ethanol extracts of moroheiya and perilla exhibited the highest antioxidative activities. Without metal chelators, 12 ethanol extracts and one water extract acted as prooxidants, and this phenomenon could be attributed to the prooxidant action of ascorbic acid in the presence of free transition metal ions. Next, peroxyl radical-scavenging activities of vegetable extracts were examined by adding a metal chelator, diethylenetriaminepentaacetic acid (DTPA), to the linoleic acid emulsion system. The results were compared with their antioxidative activities in phospholipid bilayers by measuring the inhibition of lipid peroxidation in large unilamellar vesicles composed of egg yolk phosphatidylcholine (PC). A good correlation was observed between the antioxidative activities obtained from these two systems. The antioxidative activities in the liposomal phospholipid suspension system correlated with total contents of ascorbic acid and polyphenols in vegetable extracts. © 1999 Society of Chemical Industry