Directly converting images from the noninterlaced format used by high resolution monitors to the interlaced NTSC standard can result in several artifacts which are visually disturbing. One of the most noticeable of these is a flickering effect visible on sharp horizontal edges which is due to the interlace of the NTSC video signal. This flickering effect can be significantly reduced using an appropriately designed spatial filter to remove abrupt horizontal changes in the image without excessive blurring of the image.Due to the availability of application specific integrated circuits which convert images between different color spaccs, it is practical to filter in any of several color spaces. Therefore, our current research focuses on comparing traditional interfield spatial filtering in the YIQ color space to new spatial filtering techniques developed by the authors using the HSI color space.Results based on an extended version of the CCIR impairment scale are presented. The present experiments are based on renderings of computation grids obtained from the MSUiNFS Engineering Research Center for Computational Field Simulation.The paper also demonstrates how a red fringe occurs in wire grid images with gray scale backgrounds when these images are spatially filtered in the HSI color space. Further, a means of correcting this red shift is demonstrated. INTRODUCTLONCurrent research at Mississippi State University in the area of scientific visualization has resulted in thc generation of large numbers of wire grid images. These images are normally displayed on high resolution workstations which use a noninterlaced display format. When these images are transferred to a standard NTSC monitor, they display an annoying flickering effect visible on horizontal lines. This effect can be reduced without excessive degradation of the image by using an appropriately designed spatial filter. The availability of application specific integrated circuits which convert to the HSI color space in real time and image processing hardware which operates in the HSI color space provide the motivation for research directed towards evaluating the effectiveness of performing these filtering operations in the HSI color space. BASICS OF HUMAN VISIONTo process color imagery effectively, it is necessary to understand the basics of human vision and the terms used to describe the stimuli perceived due to color vision. Human vision is a means of perceiving the outside world by reception and processing of electromagnetic radiation in the range known as the visible spectrum. This spectrum covers the wavelengths in the range of 380 nm (nm=nanometers) to 780 nm. The sensation of color comes from the different wavelengths of light. The longer wavelength radiation is perceived as being on the red end of the color spectrum and the shorter wavelengths are perceived as being toward the violet end.

The relationship of the form of ventricular anodal strength-interval curves to the types of arrhythmias induced by trains of low-intensity stimuli was studied in 16 dogs. Strength-interval curves were determined after basic atrial driven beats and after induced premature ventricular depolarizations. The test stimuli for these determinations were 2-msec anodal square waves delivered in 1-msec decrements during the first half of the cardiac cycle and in 10-msec decrements during the last half of the cycle. At each time step, the stimulus intensity was increased in 5-µamp steps until a ventricular response occurred or a level of 1.2 mamp was reached. Three types of strength-interval curves were observed. Each form of the strength-interval curve was associated with a specific type of arrhythmia induced by a train of 50-Hz, 2-msec anodal stimuli of minimum threshold intensity which was applied for periods of up to several minutes. When the minimum threshold in the strength-interval curve following the basic driven beat was lower than the minimum threshold following the induced premature ventricular depolarization, the train of stimuli induced stable ventricular bigeminy. Accelerating ventricular tachycardia followed by ventricular fibrillation resulted if there were deep dips in the strength-interval curves following both the basic driven beats and the premature ventricular depolarizations. When the strength-interval curves following both the basic driven beats and the premature ventricular depolarizations smoothly approached diastolic levels without deep dips or supernormal periods, the train of stimuli caused either occasional premature ventricular depolarizations with long coupling intervals or slow ventricular tachycardia. These relationships may participate in the initiation and the maintenance of arrhythmias.

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Mobile roof sunwrt (MRS) machines are used as roof .. . . ~ ~~~ suppiirt during pillar rccovery in retreat operations in lieu of wooden posts, cribs, or hydraulic props. A Mine Safely and Hrdlth Administmtion-perniissihle load rate monituring sydrm was developed fnr the hlRS by researchers at the Spokane Research Laboratnry of the Satiunnl Institute for Occupational Safety and Hedth. The system uses a dedicated embedded processor to monitor changes in pressure inside the hydraulic cylinders of the hIRS through multiplexed data acquisition channels and converts these pressure changes to load rntcs Lhdt xquentid~y activate three load-rate-indicator lighh mounted on the mchinc. Each light represents a different luading rate to alert mine personnel t u dangerous ronditiuns during pillar rxtraction.

Summary Data acquisition in extreme environments of high pressure and/or high temperature (HPHT) with pressures up to 30,000 psi and temperatures up to 500°F requires not only specialist technology capable of surviving these conditions but also many months of preparation and planning to ensure a successful operation. The aim of this publication is to provide an overview of what is involved in the planning, preparation, and execution of an extreme HPHT wireline data acquisition—from the customer setting the information objectives through to data delivery. This includes developing an agreed quality plan between the data provider and the customer covering testing and deployment of the latest extreme HPHT logging equipment. One must consider all aspects to minimize risks including detailed tailoring of the logging programs to manage time in hole, to ensure accurate depth control, and, by using a deployment risk-management process, to ensure that what goes in the hole comes out again. The implementation of these procedures is illustrated with a case history of a series of HPHT exploration wells drilled in the Central Graben of the North Sea (the "HPHT Heartland" of the North Sea). Bottomhole conditions were predicted to approach 400°F and 15,000 psi. These extreme conditions negated the use of conventional wireline tools, and so, from initial early planning discussions between client and service provider, new detailed programs were designed and implemented as a specific "Quality Plan" to use the advanced HPHT wireline-logging tools.