Portability Requirements Research Articles

Designing low-power digital CMOS

The increasing levels of circuit integration are leading to the implementation of highly sophisticated algorithms. Many of the commercial application areas have a requirement for portability, which leads to the need for low-power design. This paper considers the issues and design solutions for complex low-power digital CMOS IC design.

Silent energy source for tactical applications

Power source requirements for the Soldier System, which includes all items/equipment worn, consumed, or carried by the soldier in the field for his or her individual use, are discussed. The use of fuel cells, which offer silence and high efficiency, is considered. It is concluded that the proton exchange membrane (PEM) fuel cell coupled with a good hydrogen source offers a very attractive power source for the Soldier System and for other portable requirements needing power in the range of 50 to 500 W. >

A compact low-radiance multichannel reference source of diffuse visible and near-infrared radiation for airglow studies

A description is given of a reference light source constructed for use with a three-channel airglow spectrometer. It uses the principle of the integrating sphere, to meet the requirements of compactness and portability, supplying approximately white light of low and uniform radiance and of selected intensity into each of three apertures of diameter about 100 mm.

Pension wealth and job changes: the effects of vesting, portability and lump-sum distributions.

Workers who change jobs tend to have lower retirement benefits than single-job workers with similar lifetime earnings. This loss in pension benefits is attributable to vesting rules, portability requirements, and availability of lump-sum cash distributions. The importance of each of these issues in determining the loss in pension wealth associated with job changes is analyzed and a simulation model is used to illustrate their magnitude for a hypothetical worker. Finally, changes in public policy aimed at reducing the loss in benefits for job changers are examined.

Application enabling in SAA

The Common Programming Interface (CPI), one of the four key elements of Systems Application Architecture, comprises a growing set of programming languages and services. The CPI indirectly offers end-user access through the Common User Access by providing the application developer with the necessary interfaces. The CPI addresses the application development requirement for portability of applications and programmer skills. As the CPI continues to expand, it addresses the requirements for access to host data through intelligent workstations and for transparent access to remote data and applications.

Demonstration of a portable device for predicting vehicle tractive performance in snow

This workshop study program which was sponsored by the ISTVS Snow Mechanics Committee examined the problems of snow traction and methods of predicting vehicle mobility on snow. This study presents one aspect of the field prediction problem where a portable, hand-held instruments is used and prescribed by requirements for simplicity, portability and facility.

A system plan for a 900-MHz portable radio telephone

The system concepts for a high capacity personal radio telephone system are described. Previous systems for mobile radio telephone service have been based on a rigid assignment of frequencies to specific small geographic areas within the total coverage area. This approach has led to conservative geographic frequency reuse constraints and the requirement for accurate location techniques in the system. Through the utilization of the power imbalance that exists in the proposed portable radio telephone system between base and portable unit transmitters these constraints are eliminated. It will be shown how this power imbalance allows the selection of the optimum signal for the portable unit and relaxed requirements on location and reuse of frequencies. The required signal-to-interference ratios must be obtained within a design reliability level over the coverage area. Computer simulation of the frequency reuse plan and the propagation variability over the area indicates the nominal repeat intervals necessary as a function of this reliability level. A reuse plan that obtains the required repeat intervals with a high degree of spectral efficiency, through the combined use of geographic and frequency separation, will be presented. This system called tertiary offset, achieves a significant increase in interference protection by splitting each channel into a group of three channels and utilizing each subgroup in a different pattern of reuse over the area. The improvement due to this plan will be shown.

Field research model of the rod-and-frame test.

Field research makes size and weight demands upon instruments which are sometimes not as important in the laboratory. A portable model of the rod-and-frame test, which had been standardized against the original laboratory model, was considered too bulky for easy transportation as hand baggage where air travel was necessary. Another portable version of the rod-and-frame test did meet portability requirements but suffered from design limitations which invalidated its results, as well as an absence of standardization data. Successful modifications of this lightweight instrument overcoming the handicaps and a successful comparison with scores on another standardized portable apparatus was made with 51 men and 97 women of college age.

Television and Film Applications of Tungsten-Halogen Lamps

Tungsten-halogen lamps for TV and film applications have been rapidly developed with design requirements of portability, compact size and efficient performance. Families of these lamps provide interchangeability in wattage and color temperature. First came the group of double-ended lamps; later, single-ended lamp designs were developed. Because the lamp filaments are very compact and the bulb envelopes are small, optical system design is facilitated. The usefulness of these lamps has been shown by their providing increased light output and/or increased life, including their use in projection systems.

A COMPARISON STUDY OF VARIOUS TYPES OF OZONE AND OXIDANT DETECTORS WHICH ARE USED FOR ATMOSPHERIC AIR SAMPLING.

Four continuous automatic analyzers for measurement of atmospheric levels of ozone were used in a calibration and field study. These were (1) a colorimetric instrument based upon detection of iodine released from neutral potassium iodide reagent, (2) a coulometric instrument utilizing the polarization current as a measurement of iodine released by ozone in a cell contacted by potassium iodide reagent, (3) a galvanic cell measuring bromine release by ozone, and (4) an ultraviolet photometer. Some ozone determination by the manual rubber cracking procedure were included. After calibration with ozone the average relative response to atmospheric ozone levels for each instrument was determined using the colorimetric oxidant analyzer as an arbitrary standard. These responses ranged from 77% for the galvanic cell to 98% for the photometer. The instrument of choice for any given application would seem to be governed by requirements for precision, specificity, portability, reliability, and ease of operation. 10 references, 7 figures.

AN INSTRUMENT FOR SIGNALING HEART RATE TO I NRESTRAINED HUM AN SUBJECIS

ABSTRACTThe circuit described represents a relatively simple and economical solution to the problem of presenting to the human S his heart rate data in the form of an auditory signal. The requirements of portability, low cost, and long‐term unattended operation have been met. In addition, portions of the circuit have additional uses in the general area of psychophysiological instrumentation.

Designing Dynamic Test Sets for Use Optimization

Problems resulting where test sets must be both dynamic (or system exercising), and portable are analyzed and discussed, with a study of maintenance philosophy applicable to the system being tested. Three basic problems are covered, relating to the questions: Is there actually a portability requirement? - What is the optimal component density? - What is the optimal degree of automaticity? This report describes and compares two generations of a representative test set. The pressing need to minimize down-time in electronic systems has increased the use of test sets, test set testers, and even test sets for test set testers. Compared with the older, better-known laboratory and shop testers, these are generally elaborate units, actually diagnostic subsystems, a term especially appropriate for the dynamic or system exercising types. When a tester is required to do both the dynamic (as to test philosophy) and be portable (as to packaging) a challenging set of problems result.