Image processing with VLSI

The development and implementation of systems for the more complex realtime image processing and scene understanding tasks, such as robot vision and remote surveillance, calls for faster computation than that possible using the traditional serial computer. The advent of VLSI has made feasible the consideration of more specialized processing architectures, designed to support these datarates, while keeping systems compact and relatively cheap. Two approaches are discussed: the use of a programmable processor array, and the customizing of image processing algorithms in silicon. This paper examines designs based upon each approach in the light of the techniques and constraints of VLSI. In particular we describe in some detail an example of a VLSI parallel array processor, the Grid (GEC rectangular image and data processor), and a number of special-purpose CMOS/SOS chips based on systolic design techniques.     

Electronic properties of Pb1−xHgxSSi heterojunctions

Two types of heterojunctions have been prepared by electroless deposition of Pb_1?xHg_xS (x = 0–0.33) films with α′ and β′ structures on n-type silicon single crystal substrates. Functional behaviour of the forward characteristics is explained on the basis of band to band tunnelling coupled with the recombination processes. The energy band diagram is given for both types of Pb_1?xHg_xS/Si heterojunctions in agreement with the experimental results.     

Evidence that intravenously administered alpha-galactosyl carbohydrates reduce baboon serum cytotoxicity to pig kidney cells (PK15) and transplanted pig hearts

Methods of inhibiting the hyperacute antibody-mediated rejection that occurs when pig organs are transplanted into primates have been investigated using the baboon as a potential recipient. Baboons were treated with different regimens that included combinations of (1) splenectomy, (2) pharmacologic immunosuppression (CsA, cyclophosphamide, corticosteroids +/- methotrexate), and (3) intravenous infusion of oligosaccharides. The cytotoxicity of the serum was then assessed on cultures of pig kidney cells (PK15). Unmodified serum caused approximate 65-100% pig cell destruction. Splenectomy and/or pharmacologic immunosuppression, and infusions of dextran, dextrose or mannitol, did not result in any reduction of cytotoxicity. Infusions of melibiose and/or arabinogalactan, both of which have terminal non-reducing alpha-galactose, however, decreased relative PK15 cell damage significantly in a dose-dependent manner. At high concentrations (< or = 50 g/hr), complete inhibition of cytotoxicity was achieved in 4 of 15 baboons. The extracorporeal immunoadsorption of baboon serum utilizing immunoaffinity columns of melibiose also resulted in a significant reduction (of approximately 80%) in cytotoxic effect. In 1 baboon, melibiose and arabinogalactan infusion delayed vascular rejection of a pig cardiac xenograft from 10 min to about 12 hr, at which time the baboon died from the toxic effects of the carbohydrate infusion. These observations (1) add further support to the role that anti-alpha-galactosyl antibodies play in the hyperacute rejection of pig tissues transplanted into primates, and (2) demonstrate that serum cytotoxicity can be reduced by the intravenous infusion of alpha-galactosyl oligosaccharides or by extracorporeal immunoadsorption using these carbohydrates.     

Effects of wearing the Bausch & Lomb SoflensTM while skydiving

The use of Soflenses as a method of ametropic correction and ocular protection while skydiving is explored. The use of the Soflens with and without the addition of protective goggles is compared. Vision is seen to be relatively stable and clear while jumping with the Soflens, yet stability and clarity improve significantly when protective goggles are worn over the Soflenses. Stability and clarity improve significantly when protective turbulence in the facial area increases due to more involved skydiving maneuvers. A definite short-term corneal epithelial disturbance is observed when lenses are blown off the eyes due to wind turbulence.     

Design of optimum compressed air energy-storage systems

Compressed air energy storage (CAES) power systems are being considered by electric utilities for load-leveling application. Their economic benefit and the extent of premium fuel conservation is dependent on their design. An optimum design approach for CAES is presented in this paper. It is based on decomposition of the overall CAES plant/utility grid system into three partially-decoupled sybsystems. Technical and economic models of the subsystems are used in a constrained optimization procedure. The constraints are imposed by the physical characteristics of the subsystems, by interaction among the subsystems and by the interfacing requirements imposed by the utility.To illustrate the concepts, models for the system comprising the compressor train, piping, and an aquifer reservoir have been used in the optimization procedure. Results from these studies show that substantial reductions in capital cost and total operating cost can be achieved using optimization techniques.     

Electron beam lithography — influence of molecular characteristics on the performance of positive resists

Polymers are widely used as resists in electron beam lithography. This paper is concerned with theoretical modelling of the electron beam lithographic process and establishing criteria which need to be satisfied for a polymer to behave as a good positive resist. The effects of molecular weight, tacticity, solvent selection and sequence structure are discussed. Criteria are presented upon which the design of a new resist material may be based.     

Evaluation of relative nutritive value in cultivars of triticale with shrivelled grain characteristics,using Aspergillus flavus

Aspergillus flavus Link ex Fr., was used to evaluate the Relative Nutritive Value (RNV) in a set of triticale cultivars having shrivelled grain characteristics. The protein content in these samples ranged from 11.8 to 24.0%. The milled material was tested at 3 mg nitrogen level. Biomass of the fungus was measured as the total dry weight of the mycelium produced after 72 h of shaking and taken as the index of Relative Nutritive Value. The fungal biomass was negatively correlated with protein content and dye binding capacity while a positive correlation existed with protein index. With the use of glucose as an extra energy source, the basic pattern of response remained the same but the magnitude of correlation decreased.     

Right upper quadrant abdominal pain. Diagnosis in patients without evident gallstones

Right upper quadrant abdominal pain is often of biliary origin. Negative results on an ultrasound examination do not exclude biliary pathology. A logical diagnostic approach to the patient should be based on clues obtained from careful history taking, physical examination, and review of routine laboratory studies. Endoscopy, radiography, and nuclear medicine studies may identify specific causes for pain. The use of sophisticated tests, such as endoscopic retrograde cholangiopancreatography with sphincter manometry, may enable diagnosis in refractory cases. Therapy specific for a correctly diagnosed cause provides rewarding results and avoids unnecessary and unsuccessful procedures.