Showing papers by "Mitre Corporation published in 1969"

Simulation of a Computer Aided Routing System (CARS)

Abstract: CARS is s system designed to provide a taxi-like service at a mass transit-like cost. It allows potential passengers to request service from their via telephone, with calls being processed by a central computer facility. The computer periodically executes a routing algorithm which assigns vehicles to passengers and communicates this routing information to the vehicles. The system is 'real time' in that it will pick up a passenger and shortly after a request will deliver him to his destination within a guaranteed time (with a minimum number of deviations for collecting and delivering other passengers). The key to CARS is the routing algorithm. Since labor and vehicular costs are a major portion of the total system cost, an algorithm is required which can provide an effective dynamic service with a minimum number of vehicles. A variety of such algorithms have been proposed, but these algorithms can not be evaluated in an analytic fashion. Hence, a comprehensive simulation model has been developed to test and compare these routing algorithms. The model facilitates the investigation of relationships between such parameters as number of vehicles and quality of service. This paper describes the methodology of the simulation model and the economic gains (in terms of the need for fewer vehicles) realized through its use. The use of an ARDS storage tube display to produce graphical output from the model is also discussed.

A note on the application of Dvoretzky's theorem to nonlinear filtering

Abstract: -Let [X I , X2, - - ) be the states of a nonlinear dynamical system. Given noisy observations of the states, a sequence x.,, xz, - - - ) of estimates is desired such that X, converges to X n as n increases. Pearson [l] suggested a sequence of estimates and proved mean-square convergence. Convergence with probability 1 is proved using an approach which hopefully will lead to further results.

Bellingham, Washington, Control System Cyber Security Case Study

Abstract: Cyber security often focuses on the vulnerabilities of commercial off-the-shelf software and Internet access, with the primary concern being malicious activity. There have been fewer discussions about control system cyber security and how control system cyber security policies and countermeasures can potentially preclude, or minimize, the impacts of a control system cyber security event. This paper examines an actual control system cyber security event that resulted in significant environmental and economic damage as well as deaths. In this case, operating policies and procedures had readily identifiable cyber security vulnerabilities. The paper examines the timelines, control system response, and control system policies that were in effect at the time of the event. The paper then identifies the National Institute of Standards and Technology (NIST) Special Publication (SP) 800-53, Recommended Security Controls for Federal Information Systems, management, operational, and technical safeguards or countermeasures that, if implemented, could have prevented the event.

Computational linguistic techniques in an on-line system for textual analysis

Abstract: For several years we have been involved in the development of an on-line text-processing system intended for use by information analysts in the establishment and manipulation of their own personal files. In the initial implementation of the system, a transformational syntactic analysis was applied to sentences formulated by the analyst as summaries of information content in the text he was scanning on a display scope. This analysis procedure begins with a morphological analysis and a lexical lookup that provides syntactic feature information; then, a context-free parsing takes place; finally, transformations are applied to reject inappropriate parsings, derive the base structure of the sentence, and convert the result into a canonical tree format. These canonical representations are stored and can be searched by analyzing questions in the same manner and then matching their structures against those in the data base for correspondences. On-line interaction allows the analyst to advise the program in case of ambiguity, to expand the lexicon, and to modify previous actions taken.Recently, we have added other, less sophisticated techniques to provide a range of on-line processing capabilities from simple to complex. The analyst can identify or annotate lines, paragraphs, or whole selections, creating files and subfiles for temporary or long-term storage. Text-searching procedures allow him to match on stems, words, or phrases and on combinations of any of these elements--with synonym substitutions. Sets of synonyms can be established on-line to provide a personalized thesaurus. The various components of the system can be used flexibly, and additional features can be added easily without disrupting the ones already established.The augmented system is being used now in studies which will provide information on the differential utility of these techniques in relation to the tasks that text-oriented information analysts undertake.

Radar Calibration Test Satellite

Abstract: A satellite has been designed for application to radar calibration. Electromagnetic and mechanical characteristics of the satellite and their influence on the selection of shape and other parameters are discussed. Theoretical and experimental scattering data are included.

Analysis of a belt-type heat transport device.

Abstract: T is currently a renewed evidence of interest in belttype heat transport devices. Heat is absorbed from a drum and transported by belt rotation away from the source to be radiated to cold space (Fig. 1). In prior analyses the belt has been divided into two zones, one for heat acquirement from the drum and the other for radiation to space. This approach neglects heat conduction longitudinally along the belt. This Note suggests a method of analyzing the problem which includes both conductive and mass transport effects.

Strategy and a Tactic for Generation of Transportation Alternatives

Abstract: Transportation planning strategy is discussed in its relationship to overall regional development policy in the Northeast Corridor. A tactic currently being applied in the Northeast Corridor Transportation Project to generate alternative transportation system descriptions is presented.

Gestalt pattern recognition with arrays of predetermined neural functions

Abstract: A p r e d e t e r m i n e d n e u r a l l i k e f u n c t i o n wh ich makes a t e r n a r y l o g i c a l compar ison t o i t s n e i g h b o r s i n a n a r r a y o f s i m i l a r f u n c t i o n s e x h i b i t s t he a b i l i t y t o c a t e g o r i z e t w o d i m e n s i o n a l geomet r i c p a t t e r n s b y t he d i s t i n c t i v e n e s s o f t h e i r shape d i r e c t l y . T h i s p r o p e r t y f i l t e r i s bu t one o f a f a m i l y o f s i m i l a r p rede te rm ined n e u r a l l i k e f u n c t i o n s wh ich e x h i b i t G e s t a l t r e c o g n i t i o n c h a r a c t e r -

New energy theorems in Fourier transform theory

Abstract: The "least squares" property of the generalized matrix inverse, when utilized with Parseval's theorem from Fourier transform theory, provides frequency domain methods for determining least energy signals having applications in communication and optimal control theory.

Numerical evaluation of geometrical optics radar cross section

Abstract: A numerical technique for evaluation of the geometrical optics radar cross section of a general doubly curved convex conducting body is described. A surface-fitting method is employed where unique surfaces are established utilizing the Schmidt orthogonalization technique for matrix inversion. In this manner linearly dependent data points are discarded prior to their inclusion in the surface-fitting procedure.

Real-time compression and transmission of Apollo telemetry data

Abstract: Data compression and transmission technique for real time system to monitor manned space missions, noting Apollo telemetry data

Methods for Processing Complex Waveforms through Filters for Use in Monte Carlo Noise Studies

Abstract: Any N-pole linear lumped-constant time-invariant network can be represented by a linear homogeneous difference equation. If an arbitrary input waveform is sampled at equally spaced time intervals, so that eight or more samples are available at the highest significant frequency present, the output waveform can be computed in a simple manner from the difference equation. If K input samples are to be filtered, the saving in computer time, when compared to the usage of the convolution integral, is equal to K. The method is illustrated by the simulation of an FM receiver, operating at threshold, in the presence of Gaussian noise.

Multipath Fading in FSK Communication Links - An Experimental al Investigation

Abstract: The results of an experimental investigation of binary error rates in an FSK channel experiencing nonselective fading are presented. For all cases considered, the received frequency uncertainty is large compareded to the bit rate, requiring the use of an envelope detector rather than a matched filter. Both slow and fast fading rates are considered and include the effects of differential Doppler shift between the direct and reflected energy. A simplified mathematical analysis is presented to support the observed results. Both the theoretical examination and the data obtained demonstrate that fast fading and/or differential Doppler generally improve the link error rate performance with respect to the nonfading case.

A new approach to certain problems of identification and control

Abstract: This paper establishes conditions under which a problem of simultaneous identification and control may be treated by solving two separate problems; one an estimation problem on the set of unknown parameters of the plant as well as its external disturbances, and the other a control problem. This property is referred to as a separation and, when it is applicable, solutions can be readily obtained. An example is presented to illustrate how the property may be applied to specific problems.

Interaction of input and Output Filters of a Ring-type Frequency Translator

Abstract: A method is presented for evaluating the interaction between the complex impedances that terminate the ring modulator. The modulator input impedance theorem states that modulator input impedance is a “spectral” function of the impedance of both the output and the input terminations “sampled” at the significant frequencies present at each termination. If the odd-order spectral lines at the output satisfy the uniform spectral ratio, then the modulation input side comprises the signal frequency only. The spectral dependency principle states that each even-order spectral line is a linear combination of all odd-order spectral lines, and that each odd-order spectral line is a linear combination of all even-order spectral lines. The apparent impedance at the modulator input terminals is obtained. The validity of the method is tested and confirmed by comparing the signal voltage at the modulator input evaluated theoretically with measured results.

Comments on "Optimum discrete control by linear programming"

Abstract: The results of the example problem of the above correspondence are examined. The technique of post optimal sensitivity analysis is used to show that an implied conclusion of the item is incorrect. The numerical results of a counterexample are given.

Performance of two-dimensional error detection on digital HF and troposcatter channels

Abstract: The problem of applying horizontal and/or vertical parity checks for error detection to actual burst channels is considered It is demonstrated that a single-dimension parity check will achieve two to four orders-of-magnitude improvement, and, within the limit of the data sample, both dimensions together detect all errors

A Force Effectiveness Model with Area Defense of Targets

Abstract: This paper describes an analytic method for computing the effectiveness of an ICBM force for the assured destruction mission, in which the missile force must attack a number of targets of different value, all protected by a fully preferential area defense. Some targets may also be protected by a terminal defense. The ICBM force is assumed to be composed of several types of re-entry vehicles that differ in lethality and in the numbers of area and terminal interceptors required for intercept. The model assumptions are offense-conservative in that the defense is credited with maximum information and capability. However, the offense allocation is optimum against the best cooperative use of the area and terminal defenses so that the computed force effectiveness is offense-enforceable. The paper derives the optimum employment of the missile force and the area defense, and proves that, in the presence of an area defense, the terminal interceptor stockpile should be allocated among terminally defended targets strictly in proportion to their value. Because of its simplicity, the inclusion of defense penetration parameters, the allowance for several types of re-entry vehicles, and its two levels of defense, the model is useful as a force-evaluation submodel in force-mix, force-defense, and re-entry-vehicle configuration studies.

Microwave-to-light motors

Abstract: A working electronic motor operating at the record frequency 50 GHz is described. Means for bridging the frequency range into light are discussed, and a "Poynting vector motor" is proposed, eliminating the need of rectification and a separate driving unit.