A compact, high-performance HDTV camera with four-CCD chips

A compact, high-performance and yet less-expensive camera is urgently needed to create more diverse and flexible HDTV program productions. In order to meet the demand, we propose a completely new image acquisition system with four CCDs, two CCDs for green light, one for red, and the other for blue. The major purpose of our system is to obtain high-quality pictures with less pixel-number CCDs. The reduction in the number of pixels results in wider dynamic range, higher aperture ratio and low cost. The resolution power is secured by adding one more CCD to the conventional three-CCD system. We succeeded in improving the resolution by introducing spatial pixel offset imaging, in which the two G-CCDs are aligned by one-half pitch of a pixel and one of them is aligned with the R-CCD and the other with the B-CCD. This new method has two major advantages: it prevents resolution degradation caused by chromatic aberration and improves the resolution of colored signals over a wide range. The prototype camera has fully satisfied HDTV quality requirements: limiting resolution 1200 TV lines, sensitivity F5 at 2000 lux, dynamic range 500%, SNR 52 dB     

Preparation of Fe-N films by r.f. sputtering

Fe-N films over a wide compositional range have been prepared by the reactive sputtering method. Fe-N sputtered films were composed of a single or two phases such as-Fe₂N,-Fe_3.02N,-Fe_3.82N,-Fe₄N and-Fe; however, an unknown phase was observed at a higher nitrogen pressure. A remarkable preferred orientation of the-Fe_3.02N (110) plane parallel to the film surface was observed. The Curie temperature of the sputtered -Fe_3.82N sample was 490° C, which was almost the same as that of-Fe₄N prepared by metal nitriding. The saturation magnetization, _s, of the sputtered Fe-N samples decreased from 151.8 to 42.4 e.m.u.g^–1 with increasing nitrogen content from 7.94 to 24.87 at%, and its coercive force,₁ H _c was found to lie in the range 150 to 600 Oe in the powder form at room temperature.     

Selective separation of water from water–ethanol solution through quarternized poly(4-vinylpyridine-co-acrylonitrile) membranes by pervaporation technique

Polymer membranes having cationic charge site, poly(1-alkyl-4-vinylpyridinium iodide-co-acrylonitrile) (alkyl: methyl, butyl, or octyl) were prepared in terms of coulombic interaction for separation of water–ethanol mixtures. The incorporation of cationic charge site into the membrane led to improve not only separation factors (selectivity toward water) but also flux number in the separation of aqueous ethanol solution by pervaporation technique. Target values, which were requested to have from the viewpoint of industrial utilization for separation of aqueous ethanol solution were attained as follows: separation factor toward water over 50 and flux value over 500 g m^?2 h^?1, through poly(1-methyl-4-vinylpyridinium iodide-co-acrylonitrile) (membrane 3 ) (quarternized fraction of pyridinium moiety, 89.5%; mol fraction of pyridinium moiety, 0.034) and poly(1-butyl-4-vinylpyridinium iodide-co-acrylonitrile) (membrane 5 ) (quarternized fraction, 100%; mol fraction of pyridinium moiety, 0.038). It was found that the introduction of cationic charge site into the membrane was one of feasible methods to obtain suitable membranes for water permselective membranes in the separation of water–ethanol mixtures.     

Effect of Yb3+-Codoping on the Upconversion Emission Intensity in Er3+-Doped ZBLAN Fluoride Glasses under 800-nm Excitation

The effect of Yb³⁺-codoping on the upconversion emission intensity in Er³⁺-doped ZBLAN fluoride glasses is investigated. The codoping of Yb enhanced the emission intensity for the samples excited by an 800-nm laser diode beam. The enhancement in a constant YbF₃ content (2 mol%) increased with increasing ErF₃ content was about 70% of the initial value at 550 nm for the glasses containing 8 mol% of ErF₃. The emission intensity at 550 nm in a constant ErF₃ content (5 mol%) increased remarkably with the addition of YbF₃ and was maximized around 7 mol% of YbF₃ content, giving an increased ratio of about 200% of the initial value. The reason for the enhancement is discussed and it is derived mainly from two-step excitation of Er³⁺ assisted by Yb³⁺ excited through the energy transfer from Er³⁺.     

Active transport membrane for chlorine ion

A specific functional group that could interact with ions was introduced in a synthetic membrane to achieve an active transport of ions. One way to synthesize the active transport membrane was to introduce a functional group which has a tautomerism upon pH changes in an aqueous solution. A polymer having pendent N-hydroxyethyl amide groups was synthesized to form a membrane, and the membrane was fixed in a cell as a partition film, in which one side of the solution was adjusted to be acidic and the other side basic. It was then possible to transport chlorine ion through the membrane owing to the carrier functions caused by tautomerism of the N-hydroxyethyl amide group from the acidic to the basic sides. The transport of the chlorine ion was not dependent on diffusion control.     

EPR studies of the valence states of thulium in thulium monochalcogenides

We have studied theGd ³⁺ EPR at 9.2 HGz in 0.1 at % GdS inTmS, 1 at %GdTe inTmTe, and 1 at %GdSe inTmSe. From the temperature dependence of theGd ³⁺ linewidth we have concluded thatTm inTmS is trivalent. The temperature variation of theGd ³⁺ linewidth inTmTe has been interpreted as the result of the delocalization of the extra electron localized aroundGd ³⁺ . Theg-value and linewidth data are consistent with the identification thatTm inTmTe is divalent. The linewidth and theg-value of theGd ³⁺ resonance inTmSe have been found to be temperature independent. These striking results have been attributed to the motional narrowing effect arising from valence fluctuations ofTm inTmSe.Work performed under the auspices of the U.S. ERDA.Supported in part by NSF.     

Direct conversion of methane to acetylene or syngas at room temperature using non-equilibrium pulsed discharge

Non-catalytic direct conversion of methane to valuable products was studied using non-equilibrium pulsed discharge under the conditions of ambient temperature and atmospheric pressure. Acetylene was produced with 95% selectivity and 52% methane conversion. An addition of oxygen, carbon dioxide and steam contributed significantly to suppress the carbon deposition and produced carbon monoxide as well as acetylene. Methane conversion increased with an increase in the pulse frequency while the product selectivity remained almost constant. The selectivity depended on the composition of the feed gas. The effect of the partial pressure of oxygen was examined, and it was found that the pulsed discharge would be able to produce synthesis gas by partial oxidation of methane. Carbon monoxide selectivity of 79% with methane conversion of 76% was obtained under the conditions of CH₄/O₂=25/25 cm³ min⁻¹, gap distance of 10 mm and the frequency of 45 Hz.     

Multi‐temporal analysis of MODIS data to classify sugarcane crop

This paper presents a feasibility study using multi‐temporal Enhanced Vegetation Index (EVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) data to classify sugarcane crop. This study was carried out in São Paulo State which is the major sugarcane producer in Brazil, occupying more than 3.1 million hectares. Cloud‐free MODIS images (16 days mosaics) were acquired over a period of almost 15 months. Samples of sugarcane and non‐sugarcane were randomly selected and cluster analysis was performed to establish similar EVI temporal behaviour clusters. It was observed that EVI was sensitive to variations in land‐use cover mainly due to phenology and land management practices. Therefore, selection of sugarcane samples with similar EVI temporal behaviour for supervised classification was difficult due to both large planting and large harvesting periods. Consequently, cluster analysis was chosen to carry out an unsupervised classification. The best results were obtained in regions occupied by: natural and planted forest, soybean, peanuts, water bodies and urban areas which contrasted with the temporal‐spectral behaviour of sugarcane. The lowest performance was observed mainly in regions dominated by pasture, which has similar temporal‐spectral behaviour to sugarcane. This study provided useful information to define a MODIS image classification procedure for sugarcane crop for the whole State area based on the large amount of cloud‐free MODIS images when compared with other currently available optical sensors.     

A novel pixel memory using integrated voltage‐loss‐compensation (VLC) circuit for ultra‐low‐power TFT‐LCDs

Abstract— A novel pixel memory using an integrated voltage‐loss‐compensation (VLC) circuit has been proposed for ultra‐low‐power TFT‐LCDs, which can increase the number of gray‐scale levels for a single subpixel using an analog voltage gray‐scale technique. The new pixel with a VLC circuit is integrated under a small reflective electrode in a high‐transmissive aperture‐ratio (39%) 3.17‐in. HVGA transflective panel by using a standard low‐temperature‐polysilicon process based on 1.5‐μm rules. No additional process steps are required. The VLC circuit in each pixel enables simultaneous refresh with a very small change in voltage, resulting in a two‐orders‐of‐magnitude reduction in circuit power for a 64‐color image display. The advanced transflective TFT‐LCD using the newly proposed pixel can display high‐quality multi‐color images anytime and anywhere, due to its low power consumption and good outdoor readability.     

Gfarm Grid File System

Gfarm Grid file system is a global distributed file system to share data and to support distributed data-intensive computing. It federates local file systems on compute nodes to maximize distributed file I/O bandwidth, and allows to store multiple file replicas in any location to avoid read access concentration of hot files. Data location aware process scheduling improves the file I/O performance of distributed data-intensive computing. This paper discusses the design and implementation of the Gfarm Grid file system, and reports the performance.