Showing papers by "Naval Postgraduate School published in 1974"

Slot-Line Transitions (Short Papers)

Abstract: Coax-slot and microstrip-slot transitions are discussed Experimental VSWR and impedance data are presented and compared with values computed using equivalent circuits for these transitions Thick-film chip terminations are also investigated

Effect of the Adverse Pressure Gradient on Vortex Breakdown

Abstract: of the Influence of the Turbulent Boundary Layer on the Pressure Distribution over a Rigid Two-Dimensional Wavy Wall," TN D-6477, Aug. 1971, NASA. 4 Lighthill, M. J., "On Boundary Layers and Upstream Influence II. Supersonic Flows without Separation," Proceedings of the Royal Society, Vol. A217, 1953, pp. 478 and 504; see also Quarterly Journal of Mechanics, Vol. 3, 1950, p. 303. 5 Benjamin, T. B., "Shearing Flow over a Wavy Boundary," Journal of Fluid Mechanics, Vol. 6, 1959, p. 161. 6 Miles, J. W., "On Panel Flutter in the Presence of a Boundary Layer," Journal of Aerospace Sciences, Vol. 26, No. 2, Feb. 1959, pp. 81-93. 7 McClure, J. D., "On Perturbed Boundary Layer Flows," Rept. 62-2, June 1962, M.I.T. Fluid Dynamic Research Lab., Cambridge, Mass. 8 Anderson, W. J. and Fung, Y. C, "The Effect of an Idealized Boundary Layer on the Flutter of Cylindrical Shells in Supersonic Flow," GALCIT Structural Dynamics Rept. SM62-49, Dec. 1962, Graduate Aeronautical Lab., California Institute of Technology, Pasadena, Calif. 9 Zeydel, E. F. E., "Study of the Pressure Distribution on Oscillating Panels in Low Supersonic Flow with Turbulent Boundary Layer," NASA CR-691, Feb. 1967, Georgia Institute of Technology, Atlanta, Ga. 10 Do well, E. H., "Generalized Aerodynamic Forces on a Flexible Plate Undergoing Transient Motion in a Shear Flow with an Application to Panel Flutter," AIAA Journal, Vol. 9, No. 5, May 1971, pp. 834-841. 11 Ventres, C. S., "Transient Panel Motion in a Shear Flow," AMS Rept. 1062, Aug. 1972, Princeton Univ., Princeton, N.J. 12 Garrick, I. E. and Rubinow, S. I., "Theoretical Study of Air Forces on an Oscillating or Steady Thin Wing in a Supersonic Main Stream," TN 1383, July 1947, NACA. 13 Yates, J. E., "A Study of Panel Flutter with the Exact Method of Zeydel," NASA CR-1721, Dec. 1970, Aeronautical Research Associates of Princeton, Princeton, N.J. 14 Do well, E. H. and Ventres, C. S., "Derivation of Aerodynamic Kernel Functions," AIAA Journal, Vol. 11, No. 11, Nov. 1973, pp. 1586-1588.

Coefficient reduction for inequalities in 0–1 variables

Abstract: For a given inequality with 0-1 variables, there are many other "equivalent" inequalities with exactly the same 0-1 feasible solutions. The set of all equivalent inequalities is character- ized, and methods to construct the equivalent inequality with smallest coefficients are des- cribed.

Faculty Job Satisfaction and Bargaining Sentiments: A Case Study

Abstract: Faculty demographic and job satisfaction measures are related to perceptions of and sentiments toward collective bargaining at one institution which is unorganized but which has experienced substan...

Observational results on the influence of stability and wind-wave coupling on momentum transfer and turbulent fluctuations over ocean waves

Abstract: Turbulence data obtained over ocean waves during the BOMEX experiment of 1969 are presented. Procedures in measurement and analyses are described which include adjustments for possible platform, R/V FLIP, motion. Momentum transfer is shown to have been influenced by both stability and wind-wave coupling. The wind-wave coupling influence is separated from the stability influence and is described in terms of a linear dependence of the deviation from the logarithmic profile on C/u*, where C is the phase speed corresponding to the wave spectrum peak. As observed by others, a value of C/u* near 25 is associated with minimal wind-wave coupling influence. For C/u* greater than 25, momentum transfer is decreased relative to the neutral profile prediction. Expressions are also presented for the wind-wave coupling influence on relative intensities, Σ u /u*, Σ u /u* and δw/u*. Values of the relative intensities approximate neutral overland values when the expressions are written such that the wave influence is zero near a C/u* value of 25.

Exact Dynamics of Automatic Gain Control

Abstract: The exact input-output relationship is derived for a firstorder automatic gain control loop wherein the variable gain is an exponential function of the gain control voltage. The exact solution is compared to the linearized solution, and the condition for valid linearization is given.

Hydrodynamics of Large Objects in the Sea Part I-Hydrodynamic Analysis

Abstract: This paper deals with the hydrodynamic forces exerted on a rigid object describing harmonic oscillations under or on a free surface as well as the forces resulting from the interaction of the object held fixed in a train of regular surface waves. The problem is formulated for a body of arbitrary shape in water of finite depth and the development of a numerical scheme for carrying out the calculations is described. An energy balance as well as Haskind's relations are used as a check on the accuracy of the numerical results. Numerical results are presented for a floating sphere, a vertical circular cylinder, and a practical semi-immersed caisson configuration. Nomenclature a = characteristic dimension of body Ct = wave force (or moment) coefficient, Eqs. (36) and (40) Cij - ith component force (or moment) coefficient associated with the ;th component motion d_ = depth of submergence dS - differential surface area / = source strength function G = Green's function g - acceleration of Gravity gi = (i = 1,2,...7) See Eq. (19) h_ - water depth H = wave height i,l,k = cartesian unit vectors L = wavelength Mtj — added mass coef., (added mass /pa3) or (added mom. of I/pa5) Ntj = damping coef., (linear damping/po-a3) or (angular damp

Numerical Simulation of Steady-State Fronts

Abstract: The numerical frontogenesis model of Williams is modified to include horizontal and vertical turbulent diffusions of heat and momentum. The turbulent diffusions are represented with constant coefficients, and an Ekman layer is added to the basic deformation field. The numerical solutions show realistic quasi-steady fronts forming within 1–2 days. These solutions are examined and compared over a wide range of the various coefficients.

An Experimental Investigation of the Temperature Field Produced by a Cryosurgical Cannula

Abstract: Liquid crystals, a material that exhibits brilliant changes in color over narrow temperature bands, have been successfully used to study the temperature field that is produced by a cryosurgical cannula (cryoprobe). Cryoprobe tip temperatures ranging from −36 to −117 C were used to produce frozen regions in a clear gel. Experimental results compare within experimental uncertainty with results of a one-dimensional analytical solution for predicting ice growth rates.

Lanchester-Type Models of Warfare and Optimal Control

Abstract: This research was supported by the Office of Naval Research as part of the Foundation Research Program at the Naval Postgraduate School.

On generation of test problems for linear programming codes

Abstract: Users of linear programming computer codes have realized the necessity of evaluating the capacity, effectiveness, and accuracy of the solutions provided by such codes. Large scale linear programming codes at most installations are assumed to be generating correct solutions without ever having been “bench-marked” by test problems with known solutions. The reason for this failure to adequately test the codes is that rarely are there large problems with known solutions readily available. This paper presents a theoretical justification and an Illustrative implementation of a method for generating linear programming test problems with known solutions. The method permits the generation of test problems that are of arbitrary size and have a wide range of numerical characteristics.

Dynamic Response Of Floating Bodies

Abstract: A numerical scheme is developed utilizing a Green's function and digital computer calculations to determine the excitation forces and moments as well as added mass and damping coefficients for floating bodies. The analysis is carried out within the framework of linear theory for bodies of arbitary shape, either submerged or semi-submerged, in water of finite depth. The calculated hydrodynamic coefficients associated with both the wave excitation and response of the body are utilized in conjunction with the equations of motion in order to determine the response of a free-floating body to wave excitation. In addition, the steady-state drift force and uplift force are discussed for the case of free-floating and fixed bodies. Numerical results are presented for several configurations.

Ammonium perchlorate and ammonium perchlorate - binder sandwich combustion

Abstract: order of 300 \i in width. The deflagration of all three burners appeared laminar, with a definite temperature peak above the center of the burner. The PP-COMM AP had a scalloped surface which accounted for a more unsteady appearance of the gas flow above the deflagrating AP. A yellow-green zone was visible within the SC-UHP AP extending from the burner surface to a depth of approximately 200 \i. This zone is thought to be related to the phase change from an orthorhombic crystalline structure to a cubic structure (the 243°C isotherm) as reported by Boggs and Kraeutle,2 Hightower and Price,3 and Beckstead and Hightower.4 Beckstead and Hightower4 found this phase change zone to be approximately 22 ju deep in single crystals of AP burned at pressures of 400 psi. The three studies just mentioned investigated quenched samples to determine the phase change zone thickness. The difference between their results and the results of this study may be due to removal of surface material during quench and/or to an inaccurate measurement of the penetration depth of the cubic structure obtained from the recrystallized quench samples. More likely, however, is the possibility of light scattering (due to small cracks, etc.) and/or other than phase change phenomena causing the larger thickness

Error Quantization Effects in Compensatory Tracking Tasks

Abstract: A series of experiments were performed to determine the effect of error signal quantization on human operator compensatory tracking performance. Single-axis, dual-axis, and cross-coupled critical tracking tasks were utilized with a variety of quantization formats. The controlled element dynamics were chosen so as to force the operator to generate varying amounts of lead equalization. The single-and dual-axis critical tasks served as sensitive indicators of display format effects, with the single-axis task yielding information concerning the operator's effective time delay while tracking. The cross-coupled task allowed measurement of the operator's attentional workload margin while using the quantized displays. The results indicate increased operator time delays and attentional workload when using the quantized display formats.

The Industrial Mathematician Views his Profession: A Report of the Committee on Corporate Members

Abstract: (1974). The Industrial Mathematician Views his Profession: A Report of the Committee on Corporate Members. The American Mathematical Monthly: Vol. 81, No. 7, pp. 699-716.

Performance of a combined manual and decision task with discrete uncertainty

Abstract: A combined manual and decision task may be viewed as an arrangement of manual components, one or more of which involves uncertainty due to some input random process. An experiment was run involving a task containing a 4-alteniative choice element for the decision component. The other components involved motions that have been found to be typical of many operational environments. The probabilistic conditions that were varied over the choice element consisted of 6 discrete probability functions for each of independent (random sequences) and Markov dependent structures. The component performance times were found to be gamma distributed, but tended to independent normals as subjects progressed toward fully-learned states. For fully-learned subjects, only the decision component was affected by the uncertainty, and these effects did not vary significantly between the independent and Markov structures. Subjects employed a motion strategy at the decision component that was a function of the most probable...

Two‐characteristic markov‐type manpower flow models

Abstract: : A two-dimensional state space markov model fo a manpower system with special structure is analyzed. Examples are given from the military services. The probabilistic properties are discussed in detail with emphasis on computation. The basic equations of manpower stocks and flows are analyzed.

Target selection in lanchester combat: Heterogeneous forces and time‐dependent attrition‐rate coefficients

Abstract: We develop solutions to two fire distribution problems for a homogeneous force in Lanchester combat against heterogeneous enemy forces. The combat continues over a period of time with a choice of tactics available to the homogeneous force and subject to change with time. In these idealized combat situations the lethality of each force's fire (as expressed by the Lanchester attrition-rate coefficient) depends upon time. Optimal fire distribution rules are developed through the combination of Lanchester-type equations for combat attrition and deterministic optimal control theory (Pontryagin maximum principle). Additionally, the theory of state variable inequality constraints is used to treat the nonnegativity of force levels. The synthesis of optimal fire distribution policies was facilitated by exploiting special mathematical structures in these problems.

A computerized acoustic imaging technique incorporating automatic object recognition

Abstract: A computerized technique combining backward wave propagation and an automatic edge detection scheme has been developed and tested. The class of objects considered is limited to those with edge boundaries since it can be shown that a universal automatic reconstruction scheme cannot be obtained for all possible objects. Using samples of the acoustic diffraction pattern as input data, this technique enables the computer to predict the most likely locations of objects and to produce graphical output of the objects. A simplified edge detection scheme conserving both memory space and computer time was used. Test results are presented for both computer generated diffraction patterns and one set of experimental data.

Application of Holographic Interferometry to Density Field Determination in Transonic Corner Flow

Abstract: The present report is believed to be the first quantitative measurements obtained by holographic interferometry of the density field in transonic corner flow. The technique offers a new method to obtain quantitative transonic flow measurements without disrupting the flow. Finite fringe interferometry has been used to investigate the threedimensional density field about a partially transparent wing-body structure. The resulting asymmetric density field and shock wave structure are shown to be an accurate representation of the phenomena encountered in aerodynamic corner flow. The double pulse technique allows the interferogram to be taken through the transparent nonflat optical elements in the wing. The depth focusing and angular viewing properties of a hologram although of possible use in transonic flows were not used in the present experiment.