Computer CRT Research Articles

The influence of addition of CRT Glass cullet on selected parameters of concrete composites

In recent years, with the abandonment of use of CRT television and computer screens the waste dumps observe systematic growth of amounts of CRT glass. This type of waste is non-biodegradable and unsafe for the environment. The best way to overcome this negative influence of glass waste on the nature surrounding us is to reuse it. The article investigates the influence of addition of CRT glass cullet on selected mechanical properties of concrete and mortar. Composition of two batches of concrete utilized 0-2 mm fraction of glass cullet, as replacement of sand, in amounts of 10 and 15%. The remaining 3 batches utilized CRT glass cullet as addition to dust fraction, calculated in relation to the mass of cement (5, 7.5 and 10% respectively) with volumetric deduction of aggregate. The following were measured for 6 resulting batches of concrete: compression strength after 2, 7 and 28 days of curing; frost resistance for 100 cycles of freezing and defrosting, water absorption and specific gravity. The CRT glass cullet was added to mortar in the following quantities: 5, 7.5 and 10% of cement mass, deducing cement. Research results indicate the validity of use of the previously unused CRT glass cullet in production of concretes.

Using the virtual reality device Oculus Rift for neuropsychological assessment of visual processing capabilities.

Neuropsychological assessment of human visual processing capabilities strongly depends on visual testing conditions including room lighting, stimuli, and viewing-distance. This limits standardization, threatens reliability, and prevents the assessment of core visual functions such as visual processing speed. Increasingly available virtual reality devices allow to address these problems. One such device is the portable, light-weight, and easy-to-use Oculus Rift. It is head-mounted and covers the entire visual field, thereby shielding and standardizing the visual stimulation. A fundamental prerequisite to use Oculus Rift for neuropsychological assessment is sufficient test-retest reliability. Here, we compare the test-retest reliabilities of Bundesen’s visual processing components (visual processing speed, threshold of conscious perception, capacity of visual working memory) as measured with Oculus Rift and a standard CRT computer screen. Our results show that Oculus Rift allows to measure the processing components as reliably as the standard CRT. This means that Oculus Rift is applicable for standardized and reliable assessment and diagnosis of elementary cognitive functions in laboratory and clinical settings. Oculus Rift thus provides the opportunity to compare visual processing components between individuals and institutions and to establish statistical norm distributions.

Survey on Effect of EMF Emitted by CRT Computer Monitors in Bangladesh

As the world is being industrialized and technological revolution continues, there has been an unprecedented increase in the number and diversity of electromagnetic sources. While all these devices have made our lives richer, comfortable and easier, they have been accompanied by concerned possible health risks due to their electromagnetic field (EMF) emission. Electro-Magnetic Fields commonly known as Non Ionizing Radiation is emitted from high power transmission lines, computer monitor/video display unit, radio waves of different frequencies (extremely low frequency to microwaves), telecommunication, satellite, radar etc. which causes health hazards to living system and environment. CRT monitors are still being used in various computer composing shops, photocopy machine shops. Their EMF health effects have not been studied in Bangladesh. The data were collected from various places in Dhaka, Bangladesh: Banani Super Market, Mohakhali, Farmgate Green Road, Nilkhet and Uttara. Both Electric and Magnetic fields were measured for CRT monitors. These results showed that in many cases the magnetic field radiated from the different sources are greater than the threshold limit.

An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces

The non-stationary nature and variability of neuronal signals is a fundamental problem in brain-machine interfacing. We developed a brain-machine interface to assess the robustness of different control-laws applied to a closed-loop image stabilization task. Taking advantage of the well-characterized fly visuomotor pathway we record the electrical activity from an identified, motion-sensitive neuron, H1, to control the yaw rotation of a two-wheeled robot. The robot is equipped with 2 high-speed video cameras providing visual motion input to a fly placed in front of 2 CRT computer monitors. The activity of the H1 neuron indicates the direction and relative speed of the robot's rotation. The neural activity is filtered and fed back into the steering system of the robot by means of proportional and proportional/adaptive control. Our goal is to test and optimize the performance of various control laws under closed-loop conditions for a broader application also in other brain machine interfaces.

An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces

The non-stationary nature and variability of neuronal signals is a fundamental problem in brain-machine interfacing. We developed a brain-machine interface to assess the robustness of different control-laws applied to a closed-loop image stabilization task. Taking advantage of the well-characterized fly visuomotor pathway we record the electrical activity from an identified, motion-sensitive neuron, H1, to control the yaw rotation of a two-wheeled robot. The robot is equipped with 2 high-speed video cameras providing visual motion input to a fly placed in front of 2 CRT computer monitors. The activity of the H1 neuron indicates the direction and relative speed of the robot's rotation. The neural activity is filtered and fed back into the steering system of the robot by means of proportional and proportional/adaptive control. Our goal is to test and optimize the performance of various control laws under closed-loop conditions for a broader application also in other brain machine interfaces.

Imperceptibly rapid contrast modulations processed in cortex: Evidence from psychophysics

Rapid fluctuations in contrast are common in our modern visual environment. They arise, for example, in a room lit by a fluorescent light, when viewing a CRT computer monitor and when watching a movie in a cinema. As we are unconscious of the rapid changes, it has been assumed that they do not affect the operation of our visual systems. By periodically reversing the contrast of a fixed pattern at a rapid rate we render the pattern itself, as well as the modulations, invisible to observers. We show that exposure to these rapidly contrast-modulated patterns alters the way subsequent stationary patterns are processed; patterns similar to the contrast-modulated pattern require more contrast to be detected than dissimilar patterns. We present evidence that the changes are cortically mediated. Taken together, our findings suggest that cortical stages of the visual system respond to the individual frames of a contrast-reversed sequence, even at rates as high as 160 frames per second.

Pointer device for thin-film transistor and cathode ray tube computer screens

A system is described that depicts where a user is pointing on either a CRT or TFT computer screen. The system uses a kaleidoscope of colours flashed onto the screen around a colour sensor at a speed that is not registered by a human user. This is made possible by using an artificial neural network (ANN) to predict the next pointer position of the sensor on the screen.

Theoretical calculation of product contents: battery and cathode ray tube examples.

Most product environmental assessments are based on manufacturer-supplied data on the material content of the product. This paper explores the potential for the material content of key components to be estimated with theoretical calculations. Two examples, the amount of cadmium in a nickel-cadmium battery and the amount of lead in a TV or computer CRT monitor, are developed. Both an upper and a lower limit on the amount of cadmium in a nickel-cadmium battery are calculated on the basis of the battery's chemical reaction. The amount of lead shielding needed in a TV or CRT computer monitor is estimated on the basis of the potential difference through which electrons are accelerated and the absorption length of photons in lead. Such calculations can be used as benchmarks in product environmental assessments, providing validation of manufacturer-supplied data and providing insight into the composition and design of products.

Users' behavior and performance of general-purpose color CRT monitors of PACS in the wards

The hospital-wide PACS uses personal computer and general-purpose color CRT monitor as a client because many clients are demanded in the wards, but medical CRTs are too expensive; and the PACS stored and delivered endoscopic color images. Users should adjust each CRT monitor because of fewer administrators and too many clients. But the adjustment of color CRT monitors is not simple. It will be so complicated to meet the luminance characteristics, including maximum and minimum luminance and regional contrasts. We were afraid that the maladjustment of CRT caused misunderstanding in the daily practice. We should have an easy way of adjusting general-purpose CRT monitors from the recognition of CRT characteristics. In this paper, we focused on the adjustment of the contrast and brightness of color CRT monitors, and the users' behavior on this adjustment. The characteristic curves of luminance on several contrast and brightness settings were measured. The characteristic curve on the lower brightness and higher contrast seemed to be similar to the ideal curve of the medical CRT monitor. Users' settings were also similar to that according to clinical images.

Discussion of "Magnetic field effects on CRT computer monitors"

The author comments on the paper by B. Banfai et al. (see ibid., vol.15, no.1, p.307-12, 2000). The author discusses the evolution of CRT technology and compares the data from B. Banfai et al. with two further papers.

Using MEL to present Chinese characters at brief display times

Most studies that present Chinese characters at brief display intervals (10–100 msec) use tachistoscopic presentation. The present paper describes a way of using software packages NJSTAR (for generating Chinese characters) and MEL (for programming an experiment) to achieve computer CRT presentation. Techniques for (1) enlarging and smoothing characters, and (2) presenting characters at brief display times are featured. The techniques can be applied to brief CRT presentation of any graphics. A replication study is presented to demonstrate that the techniques produce reliable data.

Multimode high definition and personal computer monitor chip set

A new family of devices to simplify the design of multimode computer displays has been developed. This cost-effective and highly integrated system has been developed for personal computer and high-definition CRT displays. The range of signals with which the chip set can operate includes TTL (transistor transistor logic) and/or analog video, and composite or separate H and V TTL level sync. The horizontal timebase has frequency agility, enabling it to lock over a range of 15.5 kHz to 50 kHz automatically. The analog video bandwidth is in excess of 50 MHz. Four integrated circuits are included in the family: one is used exclusively for TTL-to-analog video conversion, the other three are variants of the timebase/video circuit. The main system functions are TTL-to-analog conversion, DC video contrast and brightness controls, video cascode drivers for video output stages, automatic sync source and polarity control, a vertical oscillator and ramp generator, a frequency agile horizontal timebase, and programmable drivers for horizontal frequency-dependent power MOSFET switching.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operation with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross α-count methods and α-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of α-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose mode. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airbone radionuclides provided adequate analytical procedures are developed or included in the already existing computer software.

The Perception of Flicker and Glare on Computer CRT Displays

Subjects rated their discomfort due to direct glare, reflected glare, and flicker while viewing a CRT display under various conditions of ambient illuminance, video luminance, and video polarity. The angle away from the CRT at which the subjects first noticed flicker was also measured. Levels of these design and environmental variables that minimize discomfort are suggested. Video luminance was shown to have the greatest impact on comfort. Methods of reducing glare and flicker are discussed.

The Perception of Flicker and Glare on Computer CRT Displays

Twenty-one subjects rated their discomfort due to direct glare, reflected glare, and flicker while viewing a CRT display under various conditions of ambient illuminance, video luminance, and video polarity. The angle away from the CRT at which the subjects first noticed flicker was also measured. Levels of these design and environmental variables which minimize discomfort are suggested. Video luminance was shown to have the greatest impact on comfort. Methods of reducing glare and flicker are discussed.

A new curve fitting method using a CRT computer display

This paper presents a new curve fitting method especially suitable for implementation on CRT graphic systems. An iterative inversion algorithm is developed for a uniform cubic B-spline. The algorithm is extremely simple and fast. No multiplication or division is required. By making the most use of the fast property of the inversion algorithm the new curve fitting method enables us interactively to find the best fitted curve by changing a curve knot continually on a CRT scope and by effectively increasing the number of curve segments. A formula is proposed for increasing curve segments. After a few trials of the knot perturbation and step-by-step increase of curve segments, a suitable B-spline representation is achieved with a minimum number of curve segments.

Dual-channel diffractometer utilizing linear image sensor charge-coupled devices.

A position-sensitive dual-channel light diffracometer has been developed to allow the real-time monitoring of light diffraction patterns produced by the myofibrillar sarcomeres of single skeletal muscle fibers and small bundles of fibers during contraction. The diffractometer utilizes two linear image devices to permit the analysis of two or more diffraction lines. The sensors are highly sensitive (1.67×10−4 lux sec), lag-free, self-scanning 256-element charge-coupled devices driven by Schottky and standard TTL logic circuitry at a data transfer rate/element of about 20–400 kHz. Video output from the diffractometer can be displayed directly on an oscilloscope screen or can be connected to an ADC and minicomputer system so that diffraction spectra can be corrected for dark signal and element nonuniformities and displayed on-line by the computer CRT. The computer-evaluated spacing between diffraction lines provides an accurate measure of mean sarcomere length within the muscle, while line shape and width are indicative of the length distribution among sarcomeres. Sarcomere length resolution attainable with the instrument ranges from about 10 to 100 Å at a nominal length of 2.5 μ, depending on muscle-to-sensor spacing and whether one or two channels of the instrument are operated.

Luminance control of a small computer CRT display: A very cheap technique

An inexpensive way to produce continuous variation in the luminance of a computer-controlled CRT display is described. One application of that system to the study of motion-analyzers in human vision is discussed briefly.

On-line real-time digital computer separation of extracellular neuroelectric signals.

An on-line real-time spike recognition and separation system for up to six different spikes in multiple unit extracellular records has been developed using the Micro-LINC 300 computer. Assuming biphasic potentials, the computer extracts four unambiguous variables, two in amplitude and two in time. One variable of a selected pair is plotted against the other on the computer CRT. Points representing the same class of signal will fall into clusters. Cluster boundaries for spike separation are set visually by the investigator. Output is in the form of pulses on different relay lines. The system permits waveforms to overlap up to 15 percent. Examples of system performance with real signals are presented. A comparison is made with other spike recognition systems. A simple system is presented for generating artificial test signals and a technique described for testing any spike recognition system.

An inexpensive gain stabilizer controlled by a time-shared computer

An electronic pulse amplifier is described for automatic gain correction in high-resolution high-rate pulse-height analysis systems. The circuit gain is controlled by a PDP-7 computer devoting less than 4 ms per second of its time to provide gain correction signals for up to 8 ampliers. Necessary control voltages are developed in the computer's CRT display circuits and transferred to a “sample and hold” circuit associated with each gain stabilizer. Gain control is accomplished by adjusting the gate voltage of an FET which shunts a small fraction of the total signal.