Showing papers on "Cost effectiveness published in 1975"

Measures of clinical efficacy. Cost-effectiveness calculations in the diagnosis and treatment of hypertensive renovascular disease.

Abstract: The sensitivity and specificity of the hypertensive intravenous pyelogram and the iodohippuran renogram have been determined for the diagnosis of renovascular disease, and cost-effectiveness calculations have been made for the diagnosis and surgical treatment of patients with renovascular hypertension. When the intravenous pyelogram alone is used to screen representative hypertensive population, 78 per cent of patients with renovascular disease are located, but at the same time an equal number of patients without renovascular diasease have abnormal pyelograms. The renogram, on the other hand, is associated with varying true-positive and false-positive ratios. These data can be plotted in the form of a receiver-operating-characteristic curve. The cost of finding a patient with renovascular disease is about $2,000, and that of a surgical cure is about $20,000. The number of deaths for 100 surgical cures is approximately 15. The dollar cost of screening and treating the total American renovascular hypertensive population is of the order of 10 to 13 billion dollars.

Some experience with automated aids to the design of large-scale reliable software

Abstract: This paper summarizes some recent experience in analyzing and eliminating sources of error in the design phase of large software projects. It begins by pointing out some of the significant differences in software error incidence between large and small software projects. The most striking contrast, illustrated by project data, is the large preponderance of design errors over coding errors on large-scale projects, not only with respect to numbers of errors, but also with respect to the relative time and effort required to detect them and correct them.The paper next presents a taxonomy of software error causes, and some analyses of the design error data, performed to obtain a better understanding of the nature of large-scale software design errors and to evaluate alternative methods of preventing, detecting, and eliminating them.Based on this analysis of observational data, a hypothesis was derived regarding the potential cost-effectiveness of an automated aid to detecting inconsistencies between assertions about the nature of inputs and outputs of the various elements (functions, modules, data bases, data sources, etc.) of the software design. This hypothesis was tested by developing a prototype version of such an aid, the Design Assertion Consistency Checker (DACC), using TRW's Generalized Information Management (GIM) system, and using it on a large-scale software project with 186 elements and 967 assertions about their inputs and outputs.Of the 121,000 possible mismatches between input and output assertions, DACC found 818, at a cost in computer time of $30. Most of the mismatches resulted from shortfalls in the initial version of DACC or the initial data preparation, such as a lack of a synonym capability and a lack of a explicit statements about external inputs and outputs. However, a number of serious mismatches were exposed at a time when they were easy to correct, and a most useful work-list generated of items needing resolution before allowing the design effort to proceed to further detail.In general, the data confirmed the hypothesis about the general utility of a DACC capability for large software projects. However, a number of additional features should be considered to compensate for current deficiencies (in areas such as manuscript preparation) and to fully take advantage of having the software design in machine-readable form.

Design of sediment retention basins

Abstract: In the foregoing presentation, the basic concepts and methods for the hydraulic design of sediment retention basins are described. A rational design procedure is also outlined. The information presented is general in nature; thus the limitations and underlying assumptions should be recognized when it is applied to specific site situations. Modification or refinement of the suggested procedures may also be required to accommodate specific design objectives or site conditions. Furthermore, the use of basin trapping should not be viewed as the only means of sediment control. Judicious application of other on-site control measures for preventing excessive soil erosion from the site, in conjunction with a sediment retention basin, normally provide a more cost effective solution to the overall sediment problem. It is hoped that, through application of the methodology presented, the design of a sediment retention facility can be approached in a more effective manner.

Gram-Schmidt algorithms for covariance propagation

Abstract: This paper addresses the time propagation of triangular covariance factors. Attention is focused on the square-root free factorization, P = UDUT, where U is unit upper triangular and D is diagonal. An efficient and reliable algorithm for U-D propagation is derived which employs Gram-Schmidt orthogonalization. Partitioning the state vector to distinguish bias and colored process noise parameters increases mapping efficiency. Cost comparisons of the U-D, Schmidt square-root covariance and conventional covariance propagation methods are made using weighted arithmetic operation counts. The U-D time update is shown to be less costly than the Schmidt method; and, except in unusual circumstances, it is within 20% of the cost of conventional propagation.

Principles and applications of selective solar coatings

Abstract: Several ways that selective coatings can be used to enhance the performance of solar energy collection systems are reviewed. Coatings discussed include vacuum‐deposited, electroplated, and paint‐type selective solar absorber coatings and vacuum‐deposited and chemically etched antireflection and infrared reflecting coatings for glass. The optical and physical requirements for the coatings, as well as their effectiveness at increasing solar collector performance, are discussed.

Will superconducting magnetic energy storage be used on electric utility systems

Abstract: As the cost of fossil fuel has increased and the load factors on electric utilities have decreased, the need for efficient, reliable energy storage systems has increased. Although pumped hydro storage is now used extensively on those utility systems having the appropriate resources nearby, it is only 65% efficient. Superconducting magnetic energy storage which promises to be more than 90% efficient and easily sited may become a competitive energy storage technology. A comparison of the various energy storage systems is presented in terms of performance on electric power systems, and cost. Emphasis is given to the various technologies involved in the development of large superconducting magnets. A brief review of the Los Alamos Scientific Laboratory program on superconducting magnetic energy storage is included.

An Abbreviated Impedance Bridge Technique for School Screening

Abstract: The hearing of 539 children was screened by conventional audiometric techniques and an abbreviated form of impedance audiometry. Otoscopic examination and estimates of the cost to accurately detect...

Cranial computed tomography: An evaluation of cost effectiveness.

Abstract: The impact of cranial computed tomography (CCT) on the cost effectiveness of a neurodiagnostic work-up was evaluated. With the use of CCT, 170 air studies and 171 angiographic procedures were made unnecessary in the 444 patients reviewed. Admission was not necessary in 58 % of the outpatients examined and the hospital stay was shortened significantly for inpatients. Even considering the cost of the examination and the few extra investigations generated, a single CCT unit can effect savings of up to $2,000,000 per year.

Instructional Development for Individualized Learning in Higher Education

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Microcircuit Accelerated Testing Using High Temperature Operating Tests

Abstract: The general validity and effectiveness of accelerated tests of microcircuits using both temperature and voltage as accelerating stresses has been demonstrated. However, the inherent effectiveness of the accelerated tests can only be assured through careful selection of the life-test circuit-configuration, and test temperatures, and the effective analysis of the resulting failure data. Careful selection of the accelerating electrical and thermal stresses is essential for maximum acceleration of use-condition failure-mechanisms without introducing damaging or unrealistic failure modes. Effective mathematical analysis of the test data is necessary to ensure an accurate determination of use-condition failure-rates. A discussion of the techniques utilized to conduct microcircuit accelerated life testing and a detailed description of a recent microcircuit accelerated test study program conducted under contract to the Rome Air Development Center are presented.

Simulator Cockpit Motion and the Transfer of Initial Flight Training

Abstract: : Transfer of flight training from a Singer-Link GAT-2 training simulator, modified to approximate a counterpart Piper Cherokee Arrow airplane, was measured for independent groups of nine flight-naive subjects, each trained in one of three simulator cockpit motion conditions: normal washout motion in bank with sustained pitch angles, washout banking motion in which the direction of motion relative to that of the simulated airplane was randomly reversed 50% of the time as the cab passed through a wings-level attitude, and a fixed-base condition Subjects received predetermined fixed amounts of practice in the simulator on each of 11 flight maneuvers drawn from the Private Pilot flight curriculum Transfer performance measures, including flight time and trials to FAA performance criteria and total errors made in the process, showed reliable transfer for all groups with differential transfer effects and cost effectiveness implications depending upon the type of simulator motion An aptitude estimator measure and the analysis of covariance technique provided increased discrimination among groups in the presence of considerable individual variation in performance within treatment conditions

Interservice Procedures for Instructional Systems Development. Phase 3. Develop

Abstract: : The volume outlines important procedures in developing interservice training effectiveness Elements emphasized are setting guidelines for learning objectives, obtaining instructional cost effectiveness by mixing media, using existing proven materials or devising new ones, evaluating existing materials for appropriateness, developing new instruction where necessary, and validating all instructional materials

Traditional midwives and family planning in Asia.

Abstract: The objectives of this article are (1) review the contribution of traditional midwives to family planning communication in several Asian countries; (2) organize knowledge gathered from various studies into general guidelines for the most effective use of traditional midwives in family planning programs; and (3) present hypotheses for future research. In certain countries where pilot projects have tested the potential performance of traditional midwives in family planning programs, results have been encouraging. In other nations, more research is needed to determine the contribution traditional midwives can make to the family planning program.

Solar‐energy materials preparation techniques

Abstract: The application of materials to the thermal control of structures, photothermal/electrical conversion, and photovoltaic conversion are reviewed. Applications include solar and infrared reflectors, optical filters, transparent conductors, bulk semiconductor materials, semiconductor films, and selective solar absorbers. The use of thin films in many conservation and photothermal applications is presently economical, but the economics of photothermal/electrical and photovoltaic conversion is still being investigated. The means of obtaining selective solar absorbers which have a high solar absorptance and low ir emittance are discussed, and specific data on an electrodeposited black‐chrome selective absorber is presented. It is shown that solar–electric generating plants must be constructed at a cost of about $50/m2 to be competitive with other electrical generating plants, and that a meaningful impact on the electrical energy economy will require a fabrication rate of greater than 1.8 × 108 m2 (50 square miles) per year. Present high‐volume deposition capabilities are reviewed, and it is shown that for some types of deposition, namely electrodeposition, e‐beam vacuum evaporation, and possibly sputter deposition, facilities exist which approach the desired volumes.

Outlook for Si photovoltaic devices for terrestrial solar‐energy utilization

Abstract: The feasibility of silicon solar cells for large scale energy conversion is examined In this context the availability of silicon and the cost of fabrication of devices are discussed It is proposed that a complete rethinking of solar array processing is necessary to achieve large reduction in production costs (AIP)

Subjective Rating and Apparent Magnitude.

Abstract: In category-scaling studies of television impairments, the psychometric functions describing the relationship between subjective rating and stimulus magnitude generally take a simple logistic form. A similar result tends to be approximated in experiments with other kinds of stimuli described by Stevens & Galanter: (1957) as prothetic. It leads to the following simple relationship between category scaling and ratio scaling: t = 1/(1 + N -k ), Here t is subjective rating on a continuous scale varying from 0 to 1, which can be either inferred from the intermediary of a category grading scale or obtained by direct measurement, and Nis apparent magnitude on a ratio scale, normalized to give N = 1 when t = 1/2 The value of the exponent k has not been precisely determined but it is believed to be close to unity. Where unrelated impairments are rated in terms of the same type of response, the scale of apparent magnitude closely approximates a scale of summable subjective magnitude.

Effects of increased enforcement at urban intersections on driver behavior and safety

Abstract: The study described in this paper was initiated in 1972 in an attempt to define the nature and magnitude of the effects on driver behavior and safety resulting from increased levels of enforcement of traffic laws. A major purpose of the study was to investigate the increased benefits to be obtained from higher enforcement levels to determine how police can be cost effectively employed. The results of the study indicated that visible police presence at an urban intersection can significantly reduce the incidence of traffic violations. This effect appeared to be restricted to the time of actual police presence; it disappeared almost immediately after the police left. Traffic conflicts were recorded as representing a measure of safety, but, although their effects were similar to those on violations, results were not judged significant. Based on effectiveness in reducing violations the most significant improvement occurred in employing a single policeman for a period of 1 h/day. Further increases in effort did not produce appreciable further improvement.

The Open University: A Survey and Economic Analysis.

Abstract: Today in higher education, increasing attention is being focused on the problem of maintaining or improving output performance with relatively fewer resource inputs. Despite rapid progress in the communications industry, institutions of higher learning, with few exceptions, have resisted the adoption of new media in the teaching field, even though research shows that quality could be still maintained, at substantially reduced costs. The reasons for the resistance have been well documented in other publications) This paper describes in detail a significant departure from the conventional university and attempts to contrast and compare, in many dimensions, an innovative institution - Britain's Open University - with its traditional counterparts. It attempts also to examine the economic implications of establishing an open learning system in the United States. The Open University of the United Kingdom constitutes the first major attempt in university education to use television and radio for formal lectures in most courses offered. Furthermore, academic or ability prerequisites for the student are nonexistent. Students are allowed to take no more than two full courses per year, and only 10 percent of them have indeed taken two courses; for the large majority only one full course is taken per year. The course lasts from January until examination time in November with two breaks during this period, and typically includes 16 television

Cost-effectiveness and drug therapy.

Abstract: The author has recently spent four years in a medical school in a developing country. During this time he became convinced that Western prescribing habits are extravagant and wasteful by any standards, but especially in the context of a developing country. Many medical schools in developing countries have a strong Western influence, and the teaching hospitals attached to them permit prescribing patterns as extravagant as those found in industrialized countries with far greater resources. Very little is being done to reverse these tendencies. In this article an attempt is made to describe some of the factors responsible for extravagant prescribing, and to discuss the philosophy of cost-effectiveness with respect to drug therapy. No country has an unlimited quantity of money to spend on drugs, and in developing countries the quantity available may be very small indeed. For instance, in Tanzania at the present time the amount available for drugs comes to 3/-T. per head per year (£1 sterling equals 17/-T). Many modem drugs are so expensive as to exhaust this sort of budget many times over, e.g. (I) A one week course of intramuscular ampicillin 250 mg q.d.s, can cost 1401-, which will consume the drug vote ofnearly 50 fellow-citizens. (2) In the treatment of mild hypertension, a year's therapy with Aldomet 250 mg t.d.s. can cost over 3001-, or the drug vote of 100 fellow-citizens. If drug votes of this size are to be used for the optimum benefit of the whole population, it is obvious that a rigorously economical approach is required, in which drug therapy is viewed from the standpoint of cost-effectiveness. In addition, all efforts should be made to ensure that drugs are distributed as fairly as possible throughout the country. These ideals are very seldom attained, and an almost universal finding in developing countries is upcountry dispensaries with shortages ofessential drugs such as penicillin, chloroquine, and iron tablets, contrasting with relatively well-supplied district hospitals, and a national teaching hospital where drug expenditure is really extravagant. While many other factors are involved in creating this state of affairs COST-EFFECTIVENESS AND DRUG THERAPY I 89

NOMAD: A printed wiring board layout system

Abstract: The NOMAD (Nonmodular Or Modular Automated Design) system provides computer-aided support for the layout of a wide range of printed wiring board designs. The system may be used to design both highly irregular nonmodular and more uniform modular printed wiring boards. The nonmodular boards usually contain numerous discrete and some digital components, whereas the modular varieties are almost entirely digital in nature. In order to guarantee flexibility and control of the layout process, the NOMAD system was implemented on a minicomputer-based interactive graphics terminal. The interactive graphics environment permits the NOMAD user to guide the PWB layout process through steps such as component placement and interconnection routing. Through the use of interactive display techniques and both heuristic and algorithmic computational aids, the user can complete the layout with NOMAD in a considerably shorter time than with alternative methods. Although the focal point of the NOMAD system is at the graphics terminal, telecommunication facilities are utilized to access large compute-bound component placement programs. Aside from the placement, all other design activities, including automatic routing aids, occur at the graphics computer. Once a printed wiring board layout is complete, facilities are available through NOMAD to obtain a full array of design documentation. This documentation includes artmasters for printed wiring board fabrication, an assembly drawing, a stocklist, schematic drawings, and a drill table.The NOMAD system has been operational since April, 1974. Improvements and enhancements are being made continually in an effort to further increase the cost effectiveness of the system.