By Topic

Systems Science and Cybernetics, IEEE Transactions on

Issue 2 • Date April 1970

Filter Results

Displaying Results 1 - 20 of 20
  • [Table of contents]

    Page(s): c1
    Save to Project icon | Request Permissions | PDF file iconPDF (89 KB)  
    Freely Available from IEEE
  • IEEE Systems Science and Cybernetics Group

    Page(s): c2
    Save to Project icon | Request Permissions | PDF file iconPDF (137 KB)  
    Freely Available from IEEE
  • SSC Group ADCOM Members

    Page(s): 77 - 78
    Save to Project icon | Request Permissions | PDF file iconPDF (1696 KB)  
    Freely Available from IEEE
  • SSC Group Associate Editors

    Page(s): 79 - 80
    Save to Project icon | Request Permissions | PDF file iconPDF (1592 KB)  
    Freely Available from IEEE
  • Queueing Requirements in an Automatic Radar Target Detection System Operating with a Narrow Bandwidth Data Link

    Page(s): 81 - 91
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1447 KB)  

    Automation of the radar target detection process for remotely located scanning radars in an air traffic control system results in a queueing requirement for target reports when the communication link transfer rate is less than that of the radar. To determine the nature of this queueing requirement, a systems model was developed which incorporates the effects of aircraft target spacing at random intervals, in flight corridors, and in close formation clusters. The entire system was simulated to determine the queueing statistics as a function of the target spacing parameters, the load, the total number of targets, and the mixture of different message lengths. Verification of the simulation for one case which used a simplified target location model with all targets randomly located was obtained by mathematical analysis. A comparison of the two types of target location models showed that the complex target location model created a queue whose mean and variance were significantly larger than that created by the simplified model with all targets randomly located. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fundamental Structure of Input-Output Stability for Feedback Systems

    Page(s): 92 - 96
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1097 KB)  

    An approach to the input-output stability of feedback systems is discussed. This approach incorporates the natural inverse operator model to describe these systems. Using this operator, the input-output stability problem is decomposed into five subproblems. One of these subproblems involves the causality of the input-output operator, a property not recognized in previous feedback system stability studies. Following the development of the model and the stability definition some general stability theorems are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Learning Applied to Successive Approximation Algorithms

    Page(s): 97 - 103
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1142 KB)  

    A linear reinforcement learning technique is proposed to provide a memory and thus accelerate the convergence of successive approximation algorithms. The learning scheme is used to update weighting coefficients applied to the components of the correction terms of the algorithm. A direction of the search approaching the direction of a "ridge" will result in a gradient peak-seeking method which accelerates considerably the convergence to a neighborhood of the extremum. In a stochastic approximation algorithm the learning scheme provides the required memory to establish a consistent direction or search insensitive to perturbations introduced by the random variables involved. The accelerated algorithms and the respective proofs of convergence are presented. Illustrative examples demonstrate the validity of the proposed algorithms. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Visual Target Tracking with Active Head Rotation

    Page(s): 103 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3771 KB)  

    Visual target tracking during active head movements is investigated. Transient response and frequency response both indicate that the eye tracking behavior relative to the target is independent of head movement. The explanation of this phenomenon is pursued. It seems most likely that the vestibulo-ocular reflex, the eye movements elicited by head rotation, plays an essential role. Compensation for head motion is accomplished by this reflex at relatively high frequencies, making visual fixation on stationary objects quite easy. The dynamics of head motion are also investigated. Unusual nonlinear responses are found at high frequencies. Namely, the response frequency is slightly lower than that of the target. A model of the whole system is proposed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the Extraction of Pattern Features from Continuous Measurements

    Page(s): 110 - 115
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (914 KB)  

    A suboptimum method of extracting features, by linear operations, from continuous data belonging to M pattern classes is presented. The set of features selected minimizes bounds on the probability of error obtained from the Bhattacharyya distance and the Hajek divergence. The random processes associated with the pattern classes are assumed to be Gaussian with different means and covariance functions. For M=2, in the two special cases in which, respectively, the means and the covariance functions are the same, both the above distance measures yield the same answer. The results obtained represent an extension of the existing results for two pattern classes with the same means and different covariance functions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Studies in Postural Control Systems Part I: Torque Disturbance Input

    Page(s): 116 - 121
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (941 KB)  

    The postural control system in normal humans is studied by applying a mechanical torque disturbance to the system. It is shown that the response of the system can be approximated by a second-order differential equation where the parameters depend on the state of the system. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Studies in Postural Control Systems Part II: Tendon Jerk Input

    Page(s): 122 - 126
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (928 KB)  

    The postural control system in normal humans is studied by applying a tendon jerk disturbance to the system. A stretch reflex was elicited in the gastrocnemius-soleus muscle by a tap on the achilles tendon. It is shown that the initial conditions (muscle tension or the length of the muscle) and the stimulus (strength of the hammer force) have strong influence on the reflex response (change in foot torque or angle). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Studies in Postural Control Systems Part III: A Muscle Spindle Model

    Page(s): 127 - 132
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1021 KB)  

    A linear lumped-parameter mechanical model of the muscle spindle is presented. It is shown that the model simulation on a digital computer exhibits the spindle behavior in most aspects of transient ramp-stretch performance. The requirements that such a model places on the mechanisms of fusimotor control are discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Shrinking Boundary Algorithm for Discrete System Models

    Page(s): 133 - 140
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1489 KB)  

    Improved mathematical optimization procedures are steadily finding wider use in engineering system studies, but the difficulties associated with the solution of discrete decision variable models remain formidable. An algorithm is described which will solve a certain class of problems formulated as linear integer programs. The procedure employs parallel shifts of selected boundary planes. This is accomplished by incrementing the appropriate slack variables which are constrained to be integers when the restraint conditions are formulated as diophantine equations. A hierarchy of variables is established to direct the boundary shifts. Feasibility and sensitivity tests truncate the search. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On How Often the Supervisor Should Sample

    Page(s): 140 - 145
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1025 KB)  

    A procedure is presented for specifying how long a supervisor or monitor of a process should wait between input samples to maximize a given value or payoff function, assuming he resets the controls with each sample as a function of the best information he has. The procedure is based upon Bayesian preposterior information analysis. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Multistage Solution of the Template-Layout Problem

    Page(s): 145 - 151
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1045 KB)  

    The template-layout problem is to determine how to cut irregular-shaped two-dimensional pieces out of given stock sheets in an optimum manner without making an exhaustive search of all possible arrangements of the pieces. An algorithm is described for solving template-layout problems with a digital computer. The method of solution requires that the irregular shapes be enclosed, singly or in combination, in minimum area rectangles called modules. Individual modules will contain from one to perhaps eight optimally fitted irregular pieces. The modules are then packed into the given stock sheet(s) so as to optimize a specified objective function. The packing is carried out with a dynamic programming algorithm, which converts the multivariable problem into a multistage one. Successive iterations of the algorithm are used to determine whether higher order modules (containing more irregular-shaped pieces) improve the solution. A detailed description of the algorithm is given. An illustrative example is included and its computer solution is described. The paper concludes with an extension of the algorithm to an improved version which can be expected to yield solutions more closely approaching the true optimum. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Unsupervised Learning Problem Using Limited Storage Capacity

    Page(s): 151 - 152
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (385 KB)  

    In unsupervised learning pattern recognition problems, the need arises for updating conditional density functions of uncertain parameters using probability density function mixtures. In general, the form of the density mixtures is not reproducing, invoking the need for unlimited system storage requirements. One suboptimal method for achieving limited storage is to restrict the uncertain parameters in question to come from finite sets of values. An alternate method is proposed for a class of problems and its performance is shown to converge to that of the optimum unlimited storage system. A generalization of the procedure is also discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Recognition of Handprinted Numerals by Two-Stage Feature Extraction

    Page(s): 153 - 154
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (359 KB)  

    An optical character recognition system for handprinted numerals of noisy and low-resolution measurement is proposed. The system consists of the two-stage feature extraction process. In the first stage a set of primary features insensitive to the quality and format of a black-white bit pattern are extracted. In the second stage, a set of properties capable of discriminating the character classes is derived from primary features. The system is simple and reliable in that only three kinds of primary features are needed to be detected. The recognition is based on the decision tree which tests the logic statements of secondary features. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Constraint Theory Applied to the Kinematics of Free-Fall Weapons

    Page(s): 154 - 157
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1451 KB)  

    A recent application of many of the principles established in [1]-[3] is presented. Although the fundamental motivation of the theory is to analyze constraint in mathematical models of very high dimension, it is hoped that this ten-dimensional example will clarify the techniques and provide a focus for the utility of the constraint concept. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contributors

    Page(s): 157 - 160
    Save to Project icon | Request Permissions | PDF file iconPDF (3884 KB)  
    Freely Available from IEEE
  • Information for authors

    Page(s): 160b
    Save to Project icon | Request Permissions | PDF file iconPDF (172 KB)  
    Freely Available from IEEE