Military Electronics, IEEE Transactions on
This Transactions ceased publication in 1965. The new retitled publication is IEEE Transactions on Aerospace and Electronic Systems.
Latest Published Articles

An Example of Design for Minimum Total Cost, CounterFlow Heat Exchangers
Nov12 2007 
Future Trends in Energy Conversion on a Very Large Scale
Nov12 2007 
Analog Networks for Word Association
Nov12 2007 
Fundamental Principles of Inertial Heading
Nov12 2007 
Hectometer Cosmic Static
Nov12 2007
Popular Articles

Observing the State of a Linear System
Nov12 2007 
An Optimal Data Association Problem in Surveillance Theory
Nov12 2007 
MatchedFilter Theory for HighVelocity, Accelerating Targets
Nov12 2007 
System Analysis of SemiMarkov Processes
Nov12 2007 
Stellar Augmented Inertial Guidance for Ballistic Missiles
Nov12 2007
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Popular Articles (November 2014)
Includes the top 50 most frequently downloaded documents for this publication according to the most recent monthly usage statistics.
1. Observing the State of a Linear System
Page(s): 74  80In much of modern control theory designs are based on the assumption that the state vector of the system to be controlled is available for measurement. In many practical situations only a few output quantities are available. Application of theories which assume that the state vector is known is severely limited in these cases. In this paper it is shown that the state vector of a linear system can be reconstructed from observations of the system inputs and outputs. It is shown that the observer, which reconstructs the state vector, is itself a linear system whose complexity decreases as the number of output quantities available increases. The observer may be incorporated in the control of a system which does not have its state vector available for measurement. The observer supplies the state vector, but at the expense of adding poles to the overall system. View full abstract»

2. An Optimal Data Association Problem in Surveillance Theory
Page(s): 125  139This paper contains a theoretical analysis of the data association problem of a common type of surveillance system. By a method of inverse probability, the optimal data processor is obtained which permits maximum likelihood estimates to be made of the true datasurveillance object association. The maximum likelihood estimator is given in a form that lends itself to sequential computations performed in real time as the data arrives. Examples of the use of this estimator make clear the precise mathematical meaning of such terms as tentative, confirmed, and established data tracks, and the concept of search areas. The analytical technique is of general use in a variety of surveillance situations. Computer implementations are possible. View full abstract»

3. MatchedFilter Theory for HighVelocity, Accelerating Targets
Page(s): 56  69Two modifications of the conventional radar theory of matched filters and ambiguity functions are discussed. The first modification is to make the theory valid for highvelocity targets and wideband signals, and the second is to include the effects of acceleration. The ability of a radar to measure target acceleration has previously been discussed in terms of measurement accuracy for isolated targets. This paper is concerned with the form of data processing necessary for the measurement and with the effects of acceleration on the clutter problem. View full abstract»

4. System Analysis of SemiMarkov Processes
Page(s): 114  124Flow graph analysis has proved a valuable approach to the study of probabilistic systems. This paper extends the analytic procedures to semiMarkov processes, Markov processes whose transition times can also be arbitrary random variables. First we present the basic theory of the semiMarkov process. We derive expressions for the interval transition probabilities, the probabilities that the system will be in each state after the passage of a time interval of length t, and find the limit of these probabilities when t is large. Then we develop the flow graph interpretation of these relations. We consider the special cases of counting transitions, transient processes, and first passage times. We investigate the effect on interval transition probabilities of starting the process in different ways, including choosing a time at random to begin observation of the process. We find that results are often most conveniently expressed by the matrix flow graph for the process. View full abstract»

5. Stellar Augmented Inertial Guidance for Ballistic Missiles
Page(s): 19  22The principle of correcting for inertial guidance error by means of star sighting has been successfully incorporated in automatic inertial navigators for aircraft such as the MK1 guidance system for the SM62A pilotless bomber. The purpose of this paper is to discuss the application of stellar sighting techniques to the augmentation of inertial guidance for ballistic missiles. View full abstract»

6. A Model of the Plastic Neuron
Page(s): 243  253Substantial physiological evidence indicates that neuron thresholds and synaptic weights in living creatures are adjusted by mechanisms quite different from those that have ordinarily been proposed in neural net investigations. This paper presents a theoretical model of the plastic neuron in which threshold and synaptic weights are adjusted solely on the basis of the time history of afferent and efferent activity of the neuron. Physiological, psychological and mathematical evidence is presented which supports the postulate that each neuron in living creatures is an autonomous, dynamically selfadjusting unit which is advised (not directed) by higher centers during the adjustnent process. The model duplicates much of the behavior of neurons in experimental preparations, and simulations of small nets have yielded learning behavior apparently similar in some respects to that of living creatures. View full abstract»

7. Radar System Performance Charts
Page(s): 255  263The fundamental limits to radar performance in search and tracking can be expressed on three charts, in terms of products involving transmitted power, antenna gain, and effective aperture area. Locations of past and present radar systems on these charts disclose evolutionary trends in system design and indicate regions of practical and economic balance between transmitter and antenna complexity, in terms of ratios of power to gain and aperture. The basis of choice for operating frequency is clarified for different applications of radar, such as air surveillance, precision tracking, weapon control, and combinations of these tasks. It is suggested that these historical trends, derived from a large sample of successful radar systems, will furnish a better guide to economic optimization than will empirical cost equations. They are also helpful in comparing diverse approaches to radar system design, and in estimating the dependence of proposed systems upon new component and technique developments. The examples used in this paper are drawn primarily from groundbased radar systems, and serve to clarify the relationships between conventional and phasedarray radar systems used for aircraft and missile detection, tracking, and weapon control. View full abstract»

8. Radio Telescopes
Page(s): 187  198A radio telescope is used in radio astronomy to measure the intensity of the radiation received from various parts of the sky. Such a telescope must be able both to detect and to locate faint radio sources of small angular size, and also to measure the brightness distribution across extended radio sources or over large sky areas. Ideally the telescope should be capable of making such measurements over a wide frequency range and for different types of polarization of the incoming waves. The noise powers available in radio astronomy are very small, and some of the radio sources have angular sizes or angular structure of, perhaps, only one second of arc, so that a radio telescope needs both high gain and good resolving power. The paper describes various types of radio telescopes which have been built and tested, and outlines the astronomical needs which they fulfill. The parabolic reflector antenna is first described, with particular reference to the fully steerable 210foot telescope at the Australian National Radio Astronomy Observatory and to the 300foot transit telescope at the U. S. National Radio Astronomy Observatory. Of the telescopes which use fixed or partly fixed reflector surfaces, those at the University of Illinois, at the NanÃ§ay station of the Paris Observatory, and at the Arecibo Ionospheric Observatory in Puerto Rico are described in some detail. Instruments in which the resolution is improved without a corresponding increase of collecting area, such as the crosstype antennas, are briefly described. View full abstract»

9. Future Trends in Energy Conversion on a Very Large Scale
Page(s): 67  73The expected philosophy in the future trend for energy conversion on a large scale is outlined in this paper. Following a brief review of the basic concepts of irreversible thermodynamics a scheme is described which outlines a method of searching for new conversion processes. Some examples are then given to demonstrate the method. View full abstract»

10. Pulsed HeliumNeon Gas Laser Applications
Page(s): 3  12The pulsed heliumneon gas laser has provided pulse power more than three orders of magnitude above the average power afforded by CW operation. Analyses of the powerlimiting factors show that still greater increases may be expected. By increasing the size of the laser tube several times, by optimizing the gas ratio and pressure, by optimizing reflectivity and transmissivity of the reflecting mirrors, and by controlling the shape and application of the exciting voltage pulse, peak power outputs in the kilowatt range are theoretically possible. A power of 100 watts has been achieved in the laboratory at pulse rates up to 250 cps. Such a result brings the gas laser out of the low power category and into the intermediate power range. The results of range calculations show that 100 w pulse power will provide a radar range of approximately 10 km against a target having a diffuse reflectivity of 0.1, and a range of over 100 km with a cooperative target. Against a bright cloud background only the cooperative target can be used. The range will then be reduced to approximately 20 km. An automatic tracking radar system has been synthesized utilizing the pulsed gas laser as a transmitting component. A brief parametric analysis has beem made and some of the advantages of the optical radar over its microwave counterpart have been outlined. View full abstract»

11. An Optimum Design of Ambiguity Function, Antenna Pattern, and Signal for SideLooking Radars
Page(s): 264  278The design of antenna pattern and transmitted signal for a coherentsidelooking (rangeazimuth) synthetic antenna radar is studied. The general design criterion is to minimize all spurious responses in the ambiguity function under the restraints of finite antenna aperture and signal bandwidth. The problem is completely solved for any set of consistent constraints. The interplay between aperture size, range and azimuth resolution, and spurious response level for the optimum design is exhibited, and antenna aperture illuminations, signal amplitude and phase modulation, and pulse repetition frequency are specified. View full abstract»

12. Troposcatter for Tactical Communications
Page(s): 137  143Tactical communications systems are characterized by severe limitations on size, weight, and setup time, which are dictated by the mobility requirements of the tactical environment. Conventional troposcatter systems, which almost universally use frequency modulation and space diversity, are inherently at a disadvantage in such an environment. By combiing pulse modulation with frequency diversity, a competely new system has been evolved, one which is more nearly optimum for use in tactical situations. This system achieves quadruple diversity over paths of 100 miles or more while requiring only a single antenna, transmitter power amplifier, and receiver "frontend" at either end of the path. In addition, the multiplefrequency feature which makes possible frequency diversity is used to provide multiplexing of 24 voice channels plus the usual orderwire facility. View full abstract»

13. An Example of Design for Minimum Total Cost, CounterFlow Heat Exchangers
Page(s): 63  66Many types of equipment have two costs: the cost of the work potential dissipated by the equipment in operation, and its initial capital cost. The correct design minimizes the total cost. A mathematical technique has recently been developed for obtaining algebraic expressions for the minimum cost, as well as for the optimum design parameters in terms of the physical parameters of the system and of various unit costs, such as electric power and fuel costs. The present paper illustrates this mathematical optimization technique through its application to the design of a counterflow heat exchanger. Algebraic expressions are obtained for the following design parameters: flow velocities and surface area per unit rate of heat exchanged. This mathematical technique is equally applicable to design problems where properties other than cost are to be minimized, such as weight. View full abstract»

14. The Accuracy of Maximum Likelihood Angle Estimates in Radar and Sonar
Page(s): 39  45By extending the results of Kelly, Reed, and Root, formulas are derived for the variances of maximum likelihood estimates of azimuth, and azimuth and elevation, jointly, by dense, discrete and discretecontinuous apertures for the strong signal case. The accuracy of angle measurements depends upon 1) total signal energy captured by the aperture, 2) the meansquare aperture size, 3) carrier frequency, 4) the meansquare signal bandwidth. Meansquare quantities are the second moments about the centroids. The actual signal form and aperture form do not matter, except as they affect the meansquare quantities. When joint estimates of azimuth and elevation are made, the errors are generally coupled. Minimum variances are obtained when the errors are uncoupled. This condition is obtained, in the narrowband case, when the twodimensional illumination function is factorable into the product of onedimensional functions. The formulas for the dense and discrete apertures are identical in form, the various factors being discrete or continuous analogs of one another in which integrations are replaced by summations. The formulas for the discretecontinuous array differs in form by the presence of terms which reflect the anisotropy of the beam patterns. View full abstract»

15. Pattern Recognition as a Problem in Decision Theory and an Application to Speech Recognition
Page(s): 186  189After a general discussion of pattern recognition as a problem in statistical decision theory, an application of these concepts is made to the recognition of speech sounds by a method which uses the same principles for preprocessing of sound as does the human auditory system. The decision rule found for minimizing the average risk for a specified cost matrix is determined and it is shown that under appropriate conditions a pattern recognition technique which maximizes the cross correlation coefflicient of the signal with a set of functions representing the patterns is equivalent to this optimum decision rule. View full abstract»

16. Radar Investigations of the Planets
Page(s): 199  206Planetary radar astronomy's greatest handicap is the extremely feeble power content of an echo. This echo is always masked by relatively strong background noise so that special signal processing is required. The basic task is the detection and measurement of the echo power. However, when the signal strength is greater than the requirements of simple detection, it is desirable to measure the power distribution in time or in frequency. When the signal is still stronger, it is possible to divide the power into the two dimensions of time delay and frequency shift simultaneously, and thus produce a radar "map" of the target. Some of the special techniques and devices which are required to make these measurements, as well as some of the results of applying these techniques to Venus, Mars, Mercury, and Jupiter, are described. There are several groups working in this field and the author has stressed the work at the Jet Propulsion Laboratory merely because of his familiarity with it. View full abstract»

17. Recognition of Sounds by Cochlear Patterns
Page(s): 179  185An electrical analog of the human ear has been developed to provide realtime cochlear patterns of subjective loudness along the basilar membrane. Resulting spatial patterns may be analogous to those found in the auditory centers of the central nervous system. It is hypothesized that cochlear pattern shapes are of primary importance in the recognition of sound. It is further hypothesized that the cochlea performs a partial analysis of the sound and that the higher analysis centers of the central nervous system perform additional analyses. Concepts and processes of analysis and recognition are developed. Analysis is discussed from the viewpoint of an information mapping process in a multidimensional space. Recognition is discussed as a process of locating unknown points (patterns) in multidimensional space by relative measures to known points. An experiment is described which demonstrates the similarity in recognition between the human and the analog using a recognition function based on cross correlation. View full abstract»

18. BionicsStatus and Plans
Page(s): 261  266A brief discussion of the past and present progress in bionics is presented. Directions for future research are indicated. Emphasis is placed on some of the United States Air Force bionics programs, both present and planned. Short descriptions are given of each area of endeavor. View full abstract»

19. Glial Control of Neuronal Activity
Page(s): 144  155The concept that the activity of neurons is both passively and actively modified by the surrounding glial and other nonneuronal cells is found in this review to be supported, but not conclusively demonstrated, by recent and previously unreported experiments. The evidence makes such nonneuronal control seem highly likely in the vertebrate retina. In particular, the nonneuronal horizontal cells of the retina were found to sunumate, and apparently to transmit, changes in their membrane potentials (the Lresponse type of Spotential) over distances many times the span of a single such cell. Available evidence is consistent with the idea that these potential changes can affect the neuronal transmission of excitation from the photoreceptors to the ganglion cells. This is proposed as the basis for a mechanism accounting for the lowluminance portion of light adaptation and for certain retinal functions of spatial summation and movement detection. View full abstract»

20. Radio Astronomy Receivers
Page(s): 264  272A general survey of the principles of radio astronomy receivers is presented. System noise temperature, the sensitivity of different receiver types, and the calibration of receivers are studied. A totalpower receiver is analyzed as a basic radio telescope receiver and. the results are used to obtain the performance of other receiver types such as the Dicke receiver, Graham's receiver, correlation receiver, and phaseswitching receiver. View full abstract»

21. Testing of StellarInertial Guidance Systems
Page(s): 29  35The ever growing demands for improvement in performance of guidance equipment to be used in missiles and space vehicles has led to intensive interest in stellaraided inertial reference systems. A stellarinertial system uses star position information to correct for gyro drift and misalignment errors and serves as a means for updating position and velocity information generated by the guidance system computer. This capability becomes particularly attractive for extended space flights and for mobile ballistic missile systems. The design configurations assumed by stellarinertial guidance systems may vary widely. Variations arise from the types of guidance equations dictated by the applications and also as a consequence of the instruments used as stellar sensors. The guidance problem may be solved by a variety of computational schemes, using explicit equations or schemes such as Q matrices. The star sensing devices are usually categorized by their detector mechanisms. The three main types used in systems now operational or under development are photomultipliers, vidicon tubes, and solidstate elements. The scanning methods used with these devices range from mechanical drives to electronic schemes using no moving parts. Each of these methods has merits and disadvantages which influence the guidance system designer in his selection. The intended application is the criterion in the type of computational scheme and components that are selected. This paper presents a survey of the abovementioned aspects of stellarinertial guidance equipment with a view toward establishing the validity and applicability of conventional inertial guidance test methods to the testing of stellarinertial equipment. View full abstract»

22. Random Processes in Control and Communications
Page(s): 275  280Over the past three centuries, the application of mathematics to physics has produced some of the deepest insights into the nature of the universe and into the limitations of human knowledge. Recent indications are that similar insights may come of the application of mathematics to engineering. This article is an account of the field in which this seems to be happening. It surveys the main results of information theory, and of related theories, from the point of view which is likely to become useful in this connection. This article was written originally for the audience of Science, a publication chiefly for persons of nonengineering background. It is reprinted here at the suggestion of the Editor of these TRANSACTIONS, in the hope that it will be diverting, and perhaps also instructive, to an audience of engineers. View full abstract»

23. Measurements of UHF and LBand Radar Clutter in the Central Pacific Ocean
Page(s): 39  44Measurements of clutter with the TRADEX radar at UHF and L band are described. Clutter is shown to be due to sea return and returns from clouds. Sea clutter predominates at ranges less than 13 nmi, values of Â¿0 of 100 dB being typical at both frequencies. Coherent scattering from clouds is postulated, and the observed frequency independence of the cloud retums is offered as supporting evidence. Values of cloud cross section per unit volume are given. Below 15,000 ft altitude, values of 140 dB (reference m1) are typical at both frequencies. Clutter spectra are presented. View full abstract»

24. On Active Attitude Control of Satellites
Page(s): 107  115Three phases of active attitude control of an orbiting satellite are examined: the despinning mode, the reorientation mode, and the control mode. Each of these modes is considered in the light of requirements for longlife mission, where the ratio of control torque to satellite inertia must be minimized. Investigations of the minimum amount of information necessary for a gravitationally stabilized satellite are also included. It is shown that yaw information may be dispensed with in many cases. The paper also includes a discussion of a novel method of providing controlled damping of a gravitationally stabilized satellite by means of internal moving parts and frictional dissipation involving feedback. Some numerical results are given. View full abstract»

25. Effects of Phase Errors on Resolution
Page(s): 4  9The mathematical problem consists of determining the spread of the Fourier transform of function when the function is modified by a multiplicative factor exp jÂ¿(t), where Â¿ is a stationary random process. Let F(Â¿) be the Fourier transform of f(t) and Fm(Â¿) be the transform of f(t) exp jÂ¿(t). For example, f may be the illumination function of a linear antenna and Â¿ accounts for imperfect phasing of the antenna. The major results consist of simple formulas for the rms tilting (or shifting) of the pattern Fm2 and the rms radius of gyration (or beamwidth) of the pattern. These positional errors and resolution degradations are formulated in terms of the pattern in the absence of phase errors and the power density spectrum of Â¿Â¿. The problem of calculating the best obtainable resolution, i.e., minimizing the meansquare resolution over all possible illumination functions, requires numerical solution; however, it is shown that it is always possible to obtain a rms resolution better than the smaller of rms Â¿Â¿ and Â¿rms Â¿Â¿. The actual numerical solution is compared to this simple approximation for the case of sinusoidal phase errors. The general results have a broad scope of applications, and here the spreading of the ambiguity function in time and frequency in the presence of time phase errors and dispersion (frequency phase errors) is described with particular attention to linear FM pulses. Finally, some observations are made about quadratic phase errors, signaltonoise performance, and meansquare pointtarget response. View full abstract»

26. CHILD and SPOCK
Page(s): 156  159In order to study the structure and acquisition of perception and motor skills, we are simulating on a digital computer some features of a baby's sensorimotor development. The baby comes to be able to recognize and manipulate objects, taking into account their movements and other spatial relationships. He performs purposeful actions naturally described in terms of their effects on his environment rather than in terms of particular muscle movements. For instance, we say that he picks up his rattle rather than saying that he moves certain muscles because from our usual point of view, we care about the act as related to other acts. The movements could have been any of a large number of movements performed by different sets of muscles so long as they combined to produce the desired effect of picking up the rattle. We are trying to learn more about the sequence of development which brings about this purposive regulation of movements. There have been a number of different approaches to problems like these. One is to deal with elements at the neural network level adjusting connection strengths of thresholds, while another is to write computer programs in which symbols may designate complex behavioral acts. We are working somewhere between these levels. View full abstract»

27. Systems Approach to Theory of Computing Systems
Page(s): 94  102A formal system is introduced which is capable of representing a universal Turing machine. This enables the input, stateoutput representation of the computing systems that allows the study on a unified basis of the larger systems involving computerlike subsystems. It has been shown how some problems and concepts associated with the theory of Turing machines can be applied to engineering system and viceversa. This has been made possible by using the proposed formal system. View full abstract»

28. Effect of Shipboard Inertial Navigation System Position and Azimuth Errors on SeaLaunched Missile Radial Miss
Page(s): 45  56The effect of position and azimuth errors in a shipborne inertial navigation system on the radial miss of a sealaunched ballistic missile which uses the shipborne system as a reference is discussed. The shipborne system is assumed to be reset and biased, using external position fixes. As a result of this resetting procedure, the latitude, longitude and azimuth errors are found to be statistically highly correlated. This correlation affects the resulting radial miss to a great extent for certain firing angles. It is also illustrated that improved techniques for resetting the shipborne system yield much reduced radial miss. Normalized numerical results are presented. View full abstract»

29. The Design and Implementation of Automated Military Information Systems
Page(s): 148  152Information systems serve in a variety of ways in military environments but have the common objectives of supporting decision processes. Systems engineers have had difficulty in developing automated systems for this purpose because of the amount of lead time required to analyze a problem situation, to procure hardware and to design and prepare computer programs, and because the problems and the problem situation are highly dynamic. Extrapolating requirements for some time in the future from current problems and methods of operation have tended to result in inadequate or incomplete systems designs when systems are developed and tested against the actual requirements in an operational environment. A variety of approaches to system development have been employed. These have ranged from the "job shop" approach at one extreme to the "turnkey" approach at the other. The job shop approach is typified by many independent, specialpurpose programs, each written to perform a particular job with its own data base. The programs are executed under job controls established by machine operators. New capabilities are developed and operated in the same way. This approach is usually responsive to individual staff elements since each program is designed for the specific purpose of the particular group which will have considerable input to the design, a good knowledge of the logic employed, and confidence in the products obtained from it. It has growth potential limited only by total machine capacity. Operational capability is provided and can be evaluated with relatively short lead time. View full abstract»

30. A Discrete Model for Eye Tracking Movements
Page(s): 113  115A sampled data model was developed to describe the major characteristics of the eye movement control system for nonpredictive tracking. It agrees with experimental transient responses and frequency characteristics for normal eye movements during following of a moving target in a horizontal plane. Furthermore, the model predicts the observed changes in transient and frequency characteristics and the limits of stability as the effective visual feedback is varied by adding the measured eye position to the target command signal. View full abstract»

31. Tuning between Central Auditory Pathways and the Ear
Page(s): 131  143Emphasis in research on auditory signal reception has shifted in recent years from studies of the peripheral area alone to include more and more the central portion of the auditory pathways. The findings are characterized by timing mechanisms well balanced between excitatory and inhibitory processes on the one hand and both the selection of auditory information and the concept of two channels of the auditory transmission system on the other. Data on two types of optimizing processes will be presented: the process involved in selecting auditory information and the system responsible for the synergism of frequency (pitch)and periodicityanalysis. The human CNS selects the 100 bits/sec processed for conscious perception from the 109 bits/sec offered from all sensory receptors in two principal ways: 1) "Specific auditory information" is modulated by "unspecific" information processed through the recticular formation of the brain stem; 2) The descending fiber systems alter selectively the informationflow on every level of the auditory pathway. The filtered information perceived in turn triggers a set of inborn and learned behavioral responses such as speech, mimicry and motor, altogether representing approximately 107 bits/sec. The system for frequencyand periodicityanalysis of the sensory excitation uses space and time attributes, respectively. Psychophysiological as well as electrophysiological data allow the relating of these two attributes to the two sets of sensory sources, the space on the basilar membrane (inner hair cells) and the time dependence of excitation (predominantly outer hair cells). View full abstract»

32. Relational Biology and Bionics
Page(s): 160  162"Relational Biology" is the name given by N. Rashevsky to an approach to biological systems in which, roughly speaking, one seeks to understand the properties of these systems in terms of a decomposition into functional components, rather than into structural components as is commonly done in (metric) biology. An approach of this type seems a most natural way of comprehending the types of organization manifested by biological systems. A number of preliminary results, typical of those obtained by relational techniques, are cited to indicate the scope and potential fruitfulness of this type of approach. The emphasis on a functional rather than a structural orientation, characteristic of Relational Biology, naturally opens the possibility for the realization of systems of biological significance at the engineering level, rather than exclusively at the molecular or biochemical level, as is the case in actual biological systems. The possibility thus arises that close analogs of real biological systems may be constructed and studied, with a resulting enrichment both of our understanding of biological systems in themselves, and of our techniques for the simulation of important biological processes in engineering applications. Some theoretical problems connected with the realizability of abstract functional organizations, which are connected with the above possibilities, are here briefly outlined and discussed. View full abstract»

33. Constraint AlgebraA Supervisory Programming Technique and a Cognitive Process
Page(s): 163  167Mathematical models of complex physical or bionic systems involve many simultaneous nonlinear equations. These groups of relationships are difficult to manipulate and even simulalation on a computer is unwieldy because most computational paths are multidirectional and are either overor underconstrained. The foundation and purposes for an algebra of contraints are outlined in this paper. A typical application of constraint algebra would be as a supervisory routine for a digital program that operates on the topological properties of the set of the equations and determines the allowable computational paths. At the conclusion of these logical operations, which are performed with the aid of a constraint matrix, normal programming can be employed for the quantitative operations on the allowable paths. Thus, one more rational function in the man/computer relationshipthat of the generation of perfectly constrained relationshipscan now be taken over by the computer. The inclusion of a theorem from thermodynamics allows quite a different application: new variables may be deduced from the constraints which, together with their corresponding equations, simplify the model. This ability to synthesize new concepts (variables) and relationships (equations) which tend to simplify models can be considered as an analog for the cognitive process of abstraction. View full abstract»

34. Realizability of Inductive Logic
Page(s): 168  173The basic model is a twoway communication system in which observer O transmits axioms A, interprets received message S* by rules R of a Post normal logic. O's strategy is to generate (applying R to A) derivations S that minimze d(S, S*), subject, among other things, to R being Turing universal. This implies1 that (A, R: S*) are analogs of complementary observables and interaction potential in quantum mechanics. Here they represent words of binary information symbols (??1): R is a dictionary of pairs (gi : ki), which still can be universal with the restriction, length m(gi) = m0. If m?? is the maximum of m(ki), then all k words in R are made up to this length by additions of a neutral symbol (O), so that R is an m0tom?? function fR on the three values (O, ??1), realizable n fold redundantly by a nm0tonm probabilistic net with connexion matrices M??ij and thresholds ??j, where ??(m) is random with Poisson distribution. If d(S,S*) is a scalar product, suitable learning algorithm reinforces all connections contributing positively, etc., where input is a current segment of nm0 bits of S*. The quantum condition is realized, essentially, by making Mij periodic in m(S) with period m0. View full abstract»

35. Application of Neural Logic to Speech Analysis and Recognition
Page(s): 189  196This paper describes signalprocessing techniques for the recognition of speech phonemes by machine. An attempt has been made to employ, wherever useful, basic processing functions of the human auditory system. These basic functions include neural interconnections and the mechanical transfer functions of the receptor organs. The neural interconnections bave been simulated by the use of neural logic. The purpose of this paper is to describe the logic networks that have been developed for the abstraction of speech features. View full abstract»

36. A Pattern Recognition Function of Integral Geometry
Page(s): 196  199A function of integral geometry, called the PF image transformation, which is characteristic of the shape of an optical image falling on a viewing retina is defined. Machine programming of the image transformation has been accomplished. Results of the machine computation of the function for a set of random imagery are displayed. It is demonstrated that the transformation yields automatic recognition of general imagery both as to class and as to discrimination between members of the same class. View full abstract»

37. Limits of Genetic Control
Page(s): 200  205Control of behavior and specification of structure requires information. In simple cases lower bounds for the minimum amount of control information required can be computed. The amount of information in the genes of humans and related species is estimated (in different ways). By comparing the information available in the genes with the information required by certain structures and behavior patterns it can be decided what the genes can control and what not. Using an estimate derived from the number of nucleotides in DNA, it is shown that the genes cannot control the interconnections between individual neurons in the human brain in all potential complexity. They must be to some degree random or repetitive. Gene estimates derived from Drosophila studies result in lower estimates (104 to 3.5 ?? 105 bits). A stimulusresponse pattern where all different possible response assignments are equally probable requires a minimum of n log2 n/e bits for n pairs. If antigenantibody formation would satisfy this assumption, then the infonnation would well exceed the total information contained in the genes. Linguistic notions and their denotations may be considered as unconstrained stimulusresponse pairs. A language of 4000 words requires about 5 ?? 104 bits. Hence a language of the complexity of human language cannot be innate. View full abstract»

38. Some Considerations of Polystable Systems
Page(s): 213  220This paper describes some of the results of a study of polystable systems by simulation on a largescale computer. The purpose of the simulation was to investigate the behavior of such systems as a function of the characteristics of the individual parts making up the system and the way in which the parts are joined together. A variety of behaviors has been observed by varying these two parameters for various input conditions. The characteristics of the parts or elements making up the system are those of a twoinput twooutput sequential circuit with four possible internal states. The behavior of the system was observed by plotting the number of elements changing state with time. View full abstract»

39. Functional Electronic Model of the Frog Retina
Page(s): 98  103Based on some earlier concepts, a functional electronic model of the frog retina has been designed and constructed. This system duplicates functionally the four imagefeatureabstraction process found by Lettvin and coworkers in the frog retina. From the input image, the model abstracts 1) edges, 2) moving convexities, 3) contrast changes, and 4) net dimming. Information presented to the receptors flows in a parallel mode through successive separate processing layers of the model; this information is preserved as it flows as a transformed "map" of the input image. Finally, the processed information is displayed as a spatial map of the four abstracted features of the input image, similar to the "mapping" performed in the brain of the frog. The model was constructed using neonlamp/photoconductive (NePc) circuits on separate processing layers. These two elements serve the dual purpose of being principal circuit components as well as providing the interconnections between processing planes. In this manner, the inputs to a processing plane are photoconductive cells and and the outputs are neon lamps. This fabrication technique provides the advantages of easy access to individual components, rapid visual inspection of the operation of individual layers, and the simplicity of modifying the system by inserting or removing a particular layer. View full abstract»

40. A Magnetic Induction Gyroscope
Page(s): 40  44Research has been conducted on a magnetic induction gyroscope which is included in a class of instruments often referred to as nuclear gyroscopes. The magnetic induction gyroscope employs a set of magnetic fields of specified relative orientation, strength, and frequency applied to a sample of paramagnetic material. The theoretical studies that have been performed show that such a system is sensitive to the common rotation of the sample and the field generating structure, and that voltages proportional to the rotational velocity may be induced in a suitably located coil. This device offers the possibility of developing gyroscopic behavior with little mechanical complexity and with very low drift rates. A preliminary experiment has been performed which verifies the theoretical predictions. View full abstract»

41. Ferrielectrics and Their Application in SolidState Devices as an Adaptive Control
Page(s): 254  260The basic properties of the recently discovered ferrielectrics, which are essentially degenerate antiferroelectrics exhibiting ferroelectric properties, will be discussed. Capacitors having a ferrielectric dielectric possess a true switching threshold field similar to ferrites. This material opens up a large field of new applications. A new device which operates similar to the transfluxor and represents an electrostatically controlled circuit impedance with stored settings will be discussed. This device called the "transpolarizer" represents one of the most interesting recent achievements in the semiconductor field. Control of polarization transfer through two or more ferroelectric dielectric sections in series represents a new basic means for storing and gating electrical signals and, in general, a means for controlling circuit impedance in any predetermined manner according to a stored setting. The most interesting feature of the transpolarizer is that, by the application of a control signal, it can be changed from a ferroelectric capacitor into a linear capacitor and can assume any intermediate polarization level between these two limits; furthermore, it is capable of controlling a flow of ac electric power according to its setting. Now, for the first time, it is possible to utilize the combination of electrically controlled resistance, inductance and capacitance in circuit design. Switching and storage properties as well as a threshold switching field are simultaneously present in these new devices. Furthermore, the fact that ferrielectric devices are voltage devices makes these devices extremely useful in the fields of pattern recognition, trainable computers and adaptive control. View full abstract»

42. Analog Networks for Word Association
Page(s): 221  234This paper is concerned with the use of analog electrical networks for the automatic recognition of statistical word associations present in written English text. A general mathematical theory is proposed for the association of linguistic units by means of linear transformations, and it is shown that this theory can be realized through use of passive electrical networks. Smallscale and experimental associative networks have in fact been built for information retrieval applications. These devices generate measures of association among index terms used to characterize a document collection, and between the index terms and the documents themselves. Roughly speaking, measures of two distinct types of linguistic association can thus be generated"synonymy" association, which reflects similarity of meaning, and "contiguity" association which reflects relationships among designates. View full abstract»

43. Spatial Ambiguity and Resolution for Array Antenna Systems
Page(s): 229  237The signal ambiguity function is derived and analyzed for radar (sonar) systems employing array antennas. It is shown that angle resolution is essentially independent of rangeDoppler resolution in the main antenna beam and that the antenna directivity function can have a strong effect on waveform design. It is also shown that angle ambiguity is appreciably influenced by signal bandwidth; in particular, signal bandwidth can be traded for a reduction in angle ambiguity in an array whose element spacing is greater than onehalf wavelength. View full abstract»

44. Delay Line Secondaries in PhaseModulated Sweep Integrators
Page(s): 189  196A video sweep integrator is a device for adding successive radar returns of transmitted pulses. One type of sweep integrator uses an ultrasonic delay line for storage, requiring that the delay line transmission be in the form of a modulated carrier. Addition is obtained by means of a closed regenerative loop that operates for a finite time to provide uniformly weighted addition or operates continuously with exponentially decaying memory. The former type of operation is called iteration to distinguish it from the continuous operation called integration. This paper treats the case of phase modulation imposed upon the carrier. Delay line secondary, or spurious, responses result from multipath propagation through the delay line. The cumulative effect of these secondaries after circulation in the sweep integrator or iterator may set a severe limitation on dynamic range. This paper treats two cases of secondary buildup: 1) the coherent buildup case in which relative buildup of secondaries is much greater than that of the signal, and 2) noncoherent buildup in which the builtup secondary effect is less than in the coherent case. It is suggested that it is possible to assure noncoherent secondary buildup by changing the carrier frequency in an irregular manner upon each circulation around the regenerative loop. View full abstract»

45. The Detection of the OH and Other Molecular Lines in the Radio Spectrum of the Interstellar Medium
Page(s): 156  165The detection of the 2Â¿3/2, J= 3/2 Â¿doublet lines of O16H1 at 1665.36 Mc and 1667.40 Mc has provided radio astronomy with a second spectral line for investigation and has already given rise to a number of significant results. In this paper the nature of Â¿doublet levels are reviewed in an attempt to clarify the origin of the OH lines. The results of the OH observations are presented and the distinction between absorption and emission experiments is discussed in terms of the importance for the OH lines. The frequencies of the astrophysically important OH transitions in various molecular states and isotopic species are given and their detection possibilities are briefly discussed. Detection of the 2Â¿3/2, J= 3/2 transitions of O18H1 appears possible with current techniques. Radio molecular lines of SH, SiH, CH, CN, and NH are also discussed. View full abstract»

46. Status of Military Satellite Communications Research and Development
Page(s): 99  107With the rapid development of the "space age," many applications of orbiting satellites are being implemented primarily for scientific purposes. Among the first practical applications, with broad military and commercial implications, is communicationsvia an active satellite repeater. A military research and development program for such communications capability is underway to satisfy the everpresent need for reliable military communications. This program is broadly reviewed with primary emphasis on the development of the surface (as opposed to space) environment. The paper outlines briefly the military requirements for satellite communications and the advantages to be accrued through its employment. The current military active satellite communication program is presented, including support of NASA's SYNCOM program and development of the Defense Communications Satellite System. Areas of research and development for the improvement of initial capability are described, including communication techniques, system approaches, subsystem design and component development. View full abstract»

47. A Technique for the Generation of Highly Linear FM Pulse Radar Signals
Page(s): 32  38Some radar systems employing a linear FM pulse require FM linearity not easily obtainable from present generation methods. A technique is developed whereby average linearities of better than 0.1 per cent may be realized by active generation methods. Two methods of implementation are described that synthesize the waveform by generating a staircasetype stepped FM waveform and "filling in" the steps with a suitable sawtooth FM signal. Coherence, required number of steps, Doppler, and random phase errors are considered. View full abstract»

48. Parametric Amplifiers for High Sensitivity Receivers
Page(s): 273  281The characteristics of parametric amplifiers, including effective input noise temperature, bandwidth, stability, and gain compression are discussed. Two specific amplifiers, a liquid nitrogen cooled Lband unit for a radio astronomy observatory, and a threechannel unit for a satellite vernier auto track system, are described, and the characteristics of these amplifiers are presented. View full abstract»

49. Radio and Radar Astronomy and the Exploration of the Universe
Page(s): 232  235The role of radio and radar astronomy in space exploration is discussed and compared with present and future techniques that use electromagnetic waves of all lengths, gravity waves, atomic particles, etc. A brief description of the universe is then given with the aid of a series of scale drawings, and the possible ranges of the different techniques are considered. The place of space probes and manned space travel in space exploration is also mentioned. It is pointed out that radio astronomy is not only the most promising technique presently available for observing the most distant parts of our universe but it may be the only one. View full abstract»

50. RadioTelescope Antenna Parameters
Page(s): 225  232Principal antenna parameters which are useful in characterizing the electrical performance of radiotelescope antennas are defined and the relations between them are established. The application of these parameters to radio astronomical measurements is discussed. View full abstract»
Aims & Scope
This Transactions ceased publication in 1965. The new retitled publication is IEEE Transactions on Aerospace and Electronic Systems.
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05361559
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 Aerospace
 Transportation
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Previous Titles
 ( 1963  1965 ) Aerospace and Navigational Electronics, IEEE Transactions on
 ( 1963  1965 ) Aerospace, IEEE Transactions on
 ( 1963  1965 ) Space Electronics and Telemetry, IEEE Transactions on
 ( 1963  1965 ) Military Electronics, IEEE Transactions on
 ( 1961  1962 ) Aerospace and Navigational Electronics, IRE Transactions on
 ( 1957  1962 ) Military Electronics, IRE Transactions on
 ( 1959  1962 ) Space Electronics and Telemetry, IRE Transactions on
 ( 1955  1960 ) Aeronautical and Navigational Electronics, IRE Transactions on
 ( 1955  1958 ) Telemetry and Remote Control, IRE Transactions on
 1954  Radio Telemetry and Remote Control, Transactions of the IRE Professional Group on
 ( 1953  1954 ) Aeronautical and Navigational Electronics, Transactions of the IRE Professional Group on
 ( 1951  1952 ) Airborne Electronics, Transactions of the IRE Professional Group on