Showing papers by "RAND Corporation published in 1973"

Stein's Estimation Rule and Its Competitors- An Empirical Bayes Approach

Abstract: Stein's estimator for k normal means is known to dominate the MLE if k ≥ 3. In this article we ask if Stein's estimator is any good in its own right. Our answer is yes: the positive part version of Stein's estimator is one member of a class of “good” rules that have Bayesian properties and also dominate the MLE. Other members of this class are also useful in various situations. Our approach is by means of empirical Bayes ideas. In the later sections we discuss rules for more complicated estimation problems, and conclude with results from empirical linear Bayes rules in non-normal cases.

Flexible carrier and interconnect for uncased ic chips

Abstract: A printed circuit lead frame that functions as a carrier of an integrated circuit (IC) uncased chip for initial handling and testing and later as a means for bonding the chip''s contacts to printed circuitry on a supporting substrate is disclosed. The lead frame includes a flexible insulating sheet member having a plurality of inner via holes arranged in a pattern to match that of the terminal contacts on the associated chip and a plurality of outer via holes arranged in a pattern to match that of the terminal pads on the supporting substrate member. Gold bumps in each of the inner and outer via holes extend beyond the bottom surface of the sheet member to make a conductively bonded contact with the associated terminal contacts on the associated chip and the associated terminal pads on the supporting substrate member while printed circuit leads affixed to the top surface of the sheet member conductively intercouple associated pairs of inner and outer gold bumps to complete the electrical coupling of the associated chip to the supporting substrate member.

Combining Possibly Related Estimation Problems

Abstract: SUMMARY We have two sets of parameters we wish to estimate, and wonder whether the James-Stein estimator should be applied separately to the two sets or once to the combined problem. We show that there is a class of compromise estimators, Bayesian in nature, which will usually be preferred to either alternative. "The difficulty here is to know what problems are to be combined togetherwhy should not all our estimation problems be lumped together into one grand melee ?" GEORGE BARNARD commenting on the James-Stein estimator, 1962.

Compact wide-angle scanning antenna system

Abstract: A compact, rapidly scannable, high frequency directional antenna system provides wide-angle space scanning in one or more dirctions by employing a moving feed for commutating energy flow through a wave guide array illuminating or receiving high frequency energy from a cylindrical or spherical energy collimator.

Square Root Laws for Fire Engine Response Distances

Abstract: An inverse square-root function is developed for the relation between average response distance and the number of locations at which response units are stationed in a region. Analysis of theoretical models, simulation data, and empirical measurements are used to confirm the square-root model. The square-root response distance model is combined with response distance---response time relations to resolve decision problems important to the management of urban fire departments. The results can be used to find optimal resource allocations given resource constraints and response time standards, or to describe the response time consequences of proposed allocation plans.

Blood Bank Inventory Control

Abstract: Essentially, blood banks are facilities which procure, store, process, and dispense blood. To operate effectively in the face of both random supply and random demand, sizable buffer stocks of blood are maintained. The resulting inventory control problem is an extremely complex one for several reasons: 1 both supply and demand are random; 2 approximately 50 percent of all bloods demanded, “crossmatched,” and held for a particular patient are eventually found not to be required for that patient; 3 blood is perishable, the present legal lifetime being 21 days in most areas; and 4 each blood bank typically interacts with a number of other banks. This paper presents a framework for the analysis of the whole blood inventory problem at the individual hospital as well as at the regional level, presents a realistic model of blood inventories for both the individual and regional cases, and analyzes the effects of several alternative inventory policies.

Tumor growth and chemotherapy: Mathematical methods, computer simulations, and experimental foundations

Abstract: Mathematical methods and computer simulation techniques for describing tumor growth in the presence or absence of chemotherapy are reviewed. The experimental and clinical background is discussed briefly, and several major current issues are identified. These include the development of appropriate descriptions for variable tumor growth rates and kinetic parameters over the entire range of tumor size or maturity, the effects of cell-cycle specific therapy on tumor growth, and the possible implications during treatment of cell-cycle time distributions and degree of correlation between succeeding generations of tumor cells.

Hydraulic actuator controls

Abstract: A device for controlling a hydraulic actuator comprises two servo loops having in common a fluid pressure operated main valve and an electrically operated pilot valve for controlling the main valve. One of the servo loops is for flow control and contains a flow transducer for producing an electrical feedback signal responsively to fluid flow to the actuator and a comparator for comparing the flow feedback signal with a first electrical input signal. The other servo loop is for force control and contains pressure transducing means for producing an electrical feedback signal responsively to the pressure drop across the actuator and a second comparator for comparing the force feedback signal with a second electrical input signal.

Common storage controller for dual processor system

Abstract: Control devices for permitting two or more general purpose digital computers, each with its own main storage module, to share a common data base. The control devices, termed "Common Storage Controller(s)" contain the logic circuitry for interfacing the central processors to their storage units such that when a predetermined area of the storage is being addressed by its associated processor for a write operation, a duplicate copy of the information will be written into the corresponding area of the storage unit associated with the other processor(s).

Data communication apparatus for use in a telephone system

Abstract: A data transmission system utilizing the telephone voice communication network for transmitting data between the location of a telephone subscriber's handset and a central station. A data transmitter is capacitively coupled to a bridge tap on the subscriber loop at the subscriber's handset and a data receiver is capacitively coupled to a bridge tap on the subscriber loop at the associated telephone company central office. The data transmissions occur at frequencies outside the standard telephone voice transmission frequency band of the system thereby providing continuous data transmission service without interfering with the normal voice communication function of the system.

On Volcanic and Other Particulate Turbidity Anomalies

Abstract: Publisher Summary The effects of global atmospheric turbidity on weather and climate is evaluated based on the available information on anomalous, long-lived charges of turbidity over large portions of the Earth in order to estimate the amount and nature of the turbid components in each case. One type of large turbidity anomaly is that produced by recorded extraordinary volcanic explosions capable of injecting massive quantities of so-called volcanic dust into the atmosphere and thereby of altering considerably its normal optical properties. The chapter summarizes the findings of a recent extensive critical review of the pertinent literature and analyzes the available data in terms of valid scattering criteria in order to estimate the amount and type of turbidity in each case. Specific examples of this situation are three volcanic events that occurred within the last one hundred years and produced widespread turbidity anomalies. These are Krakatoa, Katmai, and Agung. The chapter examines and compares the effects of these three major volcanic events. The survey reveals that the three eruptions resulted in clearly recognizable turbidity anomalies over large areas of the Earth for periods of a few years; little solid evidence exists of climatological (or weather) effects in terms of anomalies in the conventional meteorological parameters. This chapter reveals little evidence of volcanically induced climatic effects.

Programmable diffraction grating

Abstract: An electrically alterable apparatus and method of operation thereof that permits the optical processing of an image is disclosed. The apparatus includes an array of optical cells comprised of a plurality of XY stripline arrays and a stripedomain film element. The stripe-domain wall separation and wall orientation at each point in the film element are selectively controllable for generating in the optical cell array an electrically alterable hologram. Domain wall configurations to perform various optical processing tasks are disclosed.

Multi-processor system with multiple cache memories

Abstract: A digital data multi-processing system having a main memory operating at a first rate, a plurality of individual processors, each having its own associated cache memory operating at a second rate substantially faster than the first rate for increasing the throughput of the system. In order to control the access of the main memory by one of the plural processors to obtain information which may not be present in its associated cache memory, a Content Addressable Cache Management Table (CACMT) is provided.

Belt having interchangeable decorative strips

Abstract: A belt of the type intended to be fastened around the torso of the user has one or more decorative strips detachably fastened to the outside of the belt. The decorative strips are readily removable so that they may be replaced by other strips in order to be coordinated with the garment being worn.

Method and means for reducing data transmission rate in synthetically generated motion display systems

Abstract: A digitally controlled synthetically generated motion display system in which the data to be displayed is provided in bit serial fashion from a master computer to a stroke writing symbol generator for displaying the resulting pictures. Words defining picture frames to be displayed at a relatively low repetition frequency (for example, one frame per second) are generated in the master computer and transmitted to and stored in the symbol generator. Interspersed with the frame defining words, translation and rotation increment words are generated in the master computer and transmitted to the symbol generator at a relatively high repetiton frequency (for example, 20 times a second) wherein they are combined with the previously transmitted frame defining words to generate incremented frame defining words which when utilized by the symbol generator result in the display of sequentially related picture frames providing the illusion of smooth motion without the necessity of generating and transmitting all of the words required to define each displayed frame.

Theoretical Issues in the Design of Population Mobility Models

Abstract: This paper identifies major theoretical guidelines that emerge from recent migration research, and explores their bearing on model design. A conjunctive framework combining two phases is proposed. The first phase is a retention model based on a theory of differential perception and responsiveness; it portrays the decision to move in relation to a socially structured decision threshold. The second phase is an allocation model that portrays the aggregate process whereby a system of destinations compete with each other for shares of available outmigrants.

Acoustic surface wave convolver with bidirectional amplification

Abstract: Apparatus for the convolution of two input signals introduced at opposite ends of an acoustic surface wave propagation medium provides amplification of the two oppositely propagating signals and their integration in an intermediate semiconductor film cooperating with a contiguously overlying electrode pattern serving both as the signal output transducer and for coupling unidirectional electrical bias fields for amplifying the convolved output.

Information theory and privacy in data banks

Abstract: The problem of providing privacy and security in retrieval systems falls into two rather modern disciplines: information theory and computer science. In this paper the concern is primarily with the former, i.e., how to relate security of data records in computerized retrieval systems and data banks with Shannon's information-theoretic treatment of secrecy systems for natural language messages in communication systems. In doing so, it is useful to establish first the analogy between retrieval systems and certain communication channels.

Transient turn-on protection circuit for power supplies

Abstract: A protection circuit for a transistor switching regulator type power supply which prevents damage to the regulating transistor upon initial application of power to the system. The normal feedback control signal pulses used to control the "on-time" of the regulating transistor are combined with second control signal pulses whose pulse width increases as a function of time during a predetermined interval such that the regulating transistor will initially conduct for an extremely short period of time, but for longer and longer periods as time preogresses until the output voltage from the regulator circuit is within the regulation band provided by the normal feedback control circuit.

Processor state and storage limits register auto-switch

Abstract: A means for automatically changing from a first to a second processor state register (PSR) when the relative address represented by the base value contained in the first of the PSR''s does not fall within first predetermined limits. Logic means respond to such limits test failure to automatically switch active PSR''s and recompute the absolute address using the base value contained in the other second PSR, followed by another limits test using second predetermined limits. When both limits tests fail a guard mode bit is tested which, if clear, will permit execution of the instruction outside the predetermined limits. When a jump instruction is involved, the switch of PSR''s is made permanent until the occurrence of the next jump instruction requiring an automatic switching of PSR''s.

Martian surface coordinates.

Abstract: This paper presents methods and results for primary and secondary triangulation of the Martian surface. The primary network is based on multiphotograph stereophotogrammetry in which the pictures are rotated around fixed centers; these centers are provided as spacecraft stations from the tracking data. The computations use the latest Mars spin axis determined by Mariner 9 experiments and the new first meridian passing through a small crater, Airy-0, seen on Mariner 9 imagery. The secondary triangulation is performed in the map plane using rectified pictures as map fragments, assumed to be of correct shape. In this paper, 1205 primary positions are given.

Concurrent data address and refresh control for a volatile lsi memory system

Abstract: A novel internal organization of an LSI memory chip for optimum refresh control is disclosed. The chip is organized in a plurality of N similar memory loops in which the M data bits that are stored in each memory loop are serially shifted therethrough in an end-around fashion for the data reading, writing and refreshing operations. The novel internal organization includes partitioning the N memory loops into S subgroups of 2n memory loops per subgroup, N = S2n, where n is a positive integer of 0 or greater and then refreshing the 2n memory loops of each of the S subgroups at a refresh clock signal frequency FR that is a submultiple of the fundamental data clock signal frequency FD, FD = SFR, at which the normal data read/write operations are performed. A fundamental data clock signal source of frequency FD drives a refresh clock signal source that sequentially and continuously refreshes each of the N memory loops at the refresh clock frequency FR using the internal selection gates of the LSI memory chip rather than using the internal memory loop address decoder; this permits the refresh operation to be an entirely internal operation independent of external memory control.

Clean air system for magnetic storage disk pack

Abstract: A clean air system for a disk pack having a source of clean filtered air which terminates intermediate adjacent disks and at a point radially inward of the read-write heads. The amount and flow of the clean filtered air being sufficient to supply the pumping action of the disks surfaces and therefore sufficient to prevent ambient air surrunding the disks pack from being pumped into the disk pack. The disk pack is enclosed in a shroud formed from curved panels shaped to provide openings for the outflow of clean air.

Privacy transformations for databank systems

Abstract: The term databank implies a centralized collection of data to which a number of users have access. A computerized databank system consists of the data files, the associated computer facility, a management structure, and a user community. Several classes of databank systems can be defined on the basis of the nature of the organization supported by the databank, and its activity; the nature of the data and its uses; and the structure of the associated computer facility. Such classifications have been discussed in detail elsewhere.

Magnetic disk memory

Abstract: A magnetic disk memory for digital computers particularly suitable for airborne applications, including a rotating disk and a large plurality of gas bearing supported read/write heads arranged over the surface of the disk in staggered, overlapping triads (at the apexes of a substantially equilateral triangular support member), each magnetic core element of each triad having its leading edge tapered to form a separate ramp inlet gas bearing and each triad assembly having a first flexure member for supporting the triad with freedom about its pinch and roll axis (relative to disk velocity) for accommodating any disk undulations and rigidity about its yaw axis, and a second flexure member for applying a preload for the supporting gas pressure. Simultaneous retraction of all triads is accomplished by a lift finger associated with each support spring and all simultaneously actuated by a common, electromagnetically operated member; each triad further including means for imparting an initial rotational bias about its pitch axis so that upon release of the retraction means, in response to a disk speed monitor, each triad approaches its ''''landing'''' with an initial angle of attack to thereby eliminate any divergent friction-produced pitching moments during initial alignment.

High frequency diode having simultaneously formed high strength bonds with respect to a diamond heat sink and said diode

Abstract: High frequency diodes are manufactured by methods forming an efficient heat path from the active diode junction through a diamond heat conducting member to a heat sink. A planar preformed element which becomes a permanent part of the diode structure is used to transfer the forces which form the bond between the diamond heat conducting member and the heat sink; simultaneously, the preformed element is bonded to an opposite side of the diamond, becoming a permanent part of the high frequency circuit of the diode.

Transmission line coupling and combining network for high frequency antenna array

Abstract: An improved transmission line network includes signal coupling and combining sub-networks for interchange of high frequency energy between elements of a planar lineal antenna array and a monopulse radar transmitter and receiver having sum and difference channels.