Mechanical Engineering Commons^™

Integrating Scheduling And Control Functions In Computer Integrated Manufacturing Using Artificial Intelligence, Luis Carlos Rabelo, Sema E. Alptekin

Industrial and Manufacturing Engineering

Proper integration of scheduling and control in Flexible Manufacturing Systems will make available the required level of decision-making capacity to provide a flexibly-automated, efficient, and quality manufacturing process. To achieve this level of integration, the developments in computer technology and sophisticated techniques of artificial intelligence (AI) should be applied to such FMS functions as scheduling. In this paper, we present an Intelligent Scheduling System for FMS under development that makes use of the integration of two AI technologies. These two AI technologies — Neural Networks and Expert Systems — provide the intelligence that the scheduling function requires in order to …

Group Set-Up For Printed Circuit Board Assembly, Tali F. Carmon, Oded Z. Maimon, Ezey M. Dar-El

Industrial and Manufacturing Engineering

The current practice in the assembly of electronic components on printed circuit boards (PCBs) is serial production. a process characterized by very long set-up times. However, with the advent of efficient on-line process information .. new production control methods are now possible. This paper proposes a different production method, called the group set-up (GSU) method, which can significantly reduce set-up times. The traditional and the GSU production methods are compared, and it is shown that the GSU always performs better than the traditional method in terms of total production flow (throughput) and labour time However, the traditional method performs better …

The Role Of The Peripheral Vascular Bed In Arterial Pulse Wave Propagation, L. S. Baker, F. A. Anderson, Jr., H. B. Wheeler, William W. Durgin

Office of the Provost Scholarship

An analytical model was developed to simulate human arterial pulse wave propagation in major arteries. It was verified with an experimental model. The models investigated the effects of the peripheral vascular bed on pressure pulse morphology. The models revealed that the capillary bed in normal humans acts as a high resistance, low reflectance, boundary condition.

A Systematic Transition To Flexible Manufacturing, Sema E. Alptekin, Daniel L. Webber

Industrial and Manufacturing Engineering

The transition from basic automation to flexible manufacturing is an expensive and tedious procedure. It requires meticulous planning and almost clairvoyant forecasting to insure that the initial flexibility obtained is sufficient to allow growth and expansion in the future. This paper will suggest a systematic and methodological approach to achieve optimal flexibility and describe the present results of its application to an ongoing system transformation. Conclusions based on existing levels of completion are presented along with identification of critical and non critical flexibility requirements. The considerations and steps taken are summarized in a procedural format which may then be applied …

Proposed Scheduling Methods For Printed Circuit Board Assembly, Tali Freed, Ezey M. Dar-El, Oded Z. Maimon

Industrial and Manufacturing Engineering

The current practice in the assembly of electronic components on printed circuit boards (PCB's) is serial production, a process characterized by very long set-up times.

However. with the advent of efficient on-line process information, new production control methods are now possible. This paper proposes two new production methods - the Grouped Set-up (GSU) method and the Sequence-Dependent Scheduling (SDS) method, which can significantly reduce set-up times.

It is shown that the GSU always performs better than the SDS method in terms of total production flow (throughput). while the SDS performs better than the GSU method in terms of work-in-process (WIP) …

An Update To The Mitre/Wpi Space Shuttle Prgoram: Gascan G-408, Fred J. Looft, William W. Durgin

Office of the Provost Scholarship

The objective of the MITRE/WPI Space Shuttle Program was to develop a set of scientific meaningful experiments that could be flown in a Get Away Special Canister. currently, the first GASCAN is finished (G-408) and ready to be launched. The program has been so successful that the design and development of a second set of experiments has been started (G-533). This paper will describe and summarize both of these programs.

The Use Of Ultrasound Imaging In The In-Vivo Determination Of Normal Human Arterial Compliance, Lauren I. Stratouly, Paul A. Cardullo, Frederick A. Anderson Jr., William W. Durgin, H. Brownell Wheeler

Office of the Provost Scholarship

Elastic properties of major arteries were measured in vivo in ten normal volunteers, age 26 to 44 years (mean = 32 years). A B-mode ultrasound imager was used to noninvasively measure mean diameter and pulsatile diameter change at five locations along the main arteries in the abdomen and the lower extremities. Together with pulsatile pressure (measured by the auscultatory method), strain (ε), compliance (C) and the pressure-strain elastic modulus (Ep l/C) were calculated. Ep increased significantly along the arterial tree; mean values (x10⁵ N/m^-2 ) were: 0.99 aorta, 1.21 common iliac artery (CIA), 1.43 common femoral artery (CFA), …

Tone Generation By Flow Past Deep Wall Cavities, D. D. Erickson, William W. Durgin

Office of the Provost Scholarship

Flow past deep wall cavities exhibits strong interaction with the standing wave system in the cavity. The shear layer separating the exterior flow from the cavity flow supports instabilities which excite the normal cavity modes. In turn, the cavity wave system reinforces the instabilities. Experimental studies have shown that two distinct instability modes are encountered as the external velocity is increased. The pressure coefficient versus Strouha1 number behavior reveals two maxima which correspond to different instability modes of the shear layer. Flow visualization studies have shown that these modes correspond to distinct shear 1ayer vortex structures. At high velocities, single …

A Transient Electromagnetic Flowmeter, Paul J. Lefebvre, William W. Durgin

Office of the Provost Scholarship

An electromagnetic flowmeter was developed to measure transient flows with a frequency response of 60 Hz. The approach taken was to develop suitable electronics to replace the electronics of a commercially available electromagnetic flowmeter normally used for steady-state operation. Use of the commercially available flowmeter body, which includes the magnetic coils, core, and signal electrodes, provided a relatively economical means of fabricating the transient flowmeter. A transient flow calibration facility consisting of a free-falling water column was also designed and built. Results of the calibrations are presented and show that the flowmeter can accurately measure transient flows up to the …

Shear Layer Coupling With Side-Branch Resonators, D. D. Erickson, William W. Durgin, C. F. Maguire Iii, M. J. Moeller

Office of the Provost Scholarship

High velocity flow past the junction of a side branch with a pipe can result in the excitation of depth-mode standing waves in the branch. The shear layer separating the main stream flow and the cavity provides coupling between the driving and the driven flow. Photographic evidence indicates that large scale vortex structures develop at the shear layer. The vortex formation process involves strongly non-linear instability of the shear layer and may be characterized as a non-linear fluid mechanical oscillator. The standing wave system formed in the cavity is essentially an acoustic wave system of nearly linear character. The principle …

Interpretation Of Venous Occlusion Plethysmography Using A Nonlinear Model, F. A. Anderson, Jr., William W. Durgin, H. Brownell Wheeler

Office of the Provost Scholarship

Venous occlusion plethysmography (VOP) is a noninvasive technique widely employed for the detection of deep-vein thrombosis. Previous reports that VOP outflow curves are closely fit by a first-order exponential suggest that venous compliance and resistance are nearly constant. Typically, however, the venous compliance function has a sigmoid shape; in addition, the resistance in a collapsing tube must increase. This paradox was resolved by the surprising finding that for realistic nonlinear compliance and resistance these nonlinearities cancel, producing a quasilinear venous outflow that approximates a simple exponential.

Ultrasonic Fluid Measurement, William Durgin

Office of the Provost Scholarship

Objective: Determination of liquid quantity and configuration under static and dynamic conditions.
Important for: consumption resupply manufacturing

Utilization Of Electronic Spreadsheets For Laboratory Data Analysis, C. F. Maguire Iii, William W. Durgin

Office of the Provost Scholarship

The utilization of business spreadsheets for laboratory data manipulation is discussed. The spreadsheet, LOTUS 1-2-3, is presently being utilized to store and analyze data obtained from a deep cavity resonator type apparatus. Methodology for the analysis, from non dimensionalization of parameters, to relevant plotting of data pairs, is presented. All discussions are based upon current theory, and laboratory observations of flow induced resonance in deep cavities.

Noninvasive Detection Of Arterial Occlusive Disease: A Theoretical And Model Study, Lauren I. Stratouly, William W. Durgin, Frederick A. Anderson Jr., H. Brownell Wheeler

Office of the Provost Scholarship

To develop a noninvasive method of detecting arterial occlusive disease, pulse waveforms were recorded at two locations on the lower extremities of young normal volunteers and patients with arteriographically confirmed arterial occlusive disease. Pulses were monitored using impedance plethysmography at the knee· and the iliac regions. The frequency spectra of the abnormal iliac waveforms contained 4-5 harmonics as compared to the 2-3 harmonics present in normals'. It was hypothesized that the occurrence of high frequencies resulted from pulse wave interactions with diseased portions of the vessel. This paper will present the results of a theoretical and experimental model developed to …

Modeling Of Purge Valve Closure, William W. Durgin, Benito Zannini

Office of the Provost Scholarship

In some nuclear reactor containment isolation applications, butterfly valves with pneumatic actuators are used to close pipelines in the event of containment pressure transients resulting from postulated accidents. A model is developed which predicts the closure time history of such valve/actuator systems under prescribed transients. Examples are presented which show the importance of the valve and actuator characteristics. It was found that actuation delays of sufficient magnitude could allow the dynamic torque to exceed the available actuator torque, thus preventing valve closure.

Augmentation Of Free Surface Heat And Mass Transfer Due To Electrostatic Fields, Alan F. Smelewicz, Mark P. Majcher, James B. Nystrom, William W. Durgin

Office of the Provost Scholarship

Experiments were conducted to measure heat transfer rates and mass transfer rates from a water surface in the presence of electrostatic fields of various strengths generated between the water surface and a wire grid above the surface.

Heat transfer rates were determined by the temperature decay after heating the test and control basins. Mass transfer rates were determined by measuring the water loss while holding the basins at fixed temperatures.

It was found that very little increase in transfer coefficients took place for voltages below an onset voltage which depended on atmospheric conditions and test geometry. The heat transfer coefficient …

The Design, Construction, And Evaluation Of A Thermosiphon Solar Water Heater, James R. Coughlin, Mark R. Bender

Mechanical Engineering

The purpose of this senior project was to design, construct and evaluate a thermosiphon solar water heater. The project was to be used as a department demonstration of a passive solar water heating system. Overall maximum dimensions of the system needed to be maintained to insure the system's transportability through doors and corridors.

The Performance Of Crossed-Vane Swirl Meters, H. L. Lee, William W. Durgin

Office of the Provost Scholarship

Vortimeters consisting of vanes rotating about pipe axes are frequently used to indicate the swirl present in pump columns and feedlines from sumps and in piping networks. Since the design of such devices varies widely, the study described herein was undertaken to identify salient design parameters and to evaluate a device designed according to information available in the literature.

An apparatus which could produce known amounts of angular momentum in a pipeline was verified by direct measurement of axial and tangential velocity profiles. By using the assumption that a vortimeter, with vanes spanning only the rotational core, responded to an …

Lower Mode Response Of Circular Cylinders In Cross-Flow, William W. Durgin, P. A. March, Paul J. Lefebvre

Office of the Provost Scholarship

Transverse amplitude responses of a circular cylinder in cross-flow were determined as a function of reduced velocities for a variety of spring constants and damping coefficients. Maxima were found at reduced velocities of 5 and 16, and were of comparable amplitude. The first resonance, designated the "fundamental mode, " was due to normal vortex street excitation of the spring-mass system. The second resonance, designated the "lower mode," occurred when the natural frequency was approximately one-third of the normal vortex shedding frequency. By assuming that the driving force was sinusoidal, it was possible to evaluate the lift coefficients at resonance. Lift …

Laser Doppler Anemometry For Flow Measurement, William W. Durgin, Lawrence C. Neale

Office of the Provost Scholarship

Laser doppler anemometers are non-invasive, linear, and inherently precise. Calibration, in the usual sense, is not necessary; length and frequency measurements suffice to establish velocity at a spatial point. Measurements were made at points in the cross-sections of two square ducts containing water flow. The points were selected in conformance with a numerical integration scheme to be used for volumetric flow rate determination from the velocity measurements. The experiments were performed in a primary calibration facility at flows up to 1.25 m³/sec using ducts with sides 46 and 92 cm. The anemometer, operating in forward scatter differential mode …

Wave Induced Pressures On Submerged Plates, William W. Durgin, Jong C. Shiau

Office of the Provost Scholarship

The prediction of forces, or more precisely, the pressure distributions, experienced by submerged structures due to the passage of gravity waves has become important with the advent of large offshore structures. If the size of a structure is small compared to the wavelength then the forces can be evaluated by the assignment of suitable drag and inertia coefficients using an approach similar to that of Morison (6) in which case it is necessary to determine the coefficients experimentally for any given geometry (2). If the size of the structure is a significant fraction of the wavelength, the preceding method is …

On The Phenomenon Of Vortex Street Breakdown, William W. Durgin, Sture K.F. Karlsson

Office of the Provost Scholarship

A von Kármán vortex street generated in the usual way was subjected to a deceleration, thereby changing the ratio of longitudinal to lateral spacing between the vortices. Distortion of the individual vortices followed which resulted in annihilation of concentrated vortex regions and creation of a stationary wake flow. This wake flow was itself dynamically unstable and developed into a new vortex street of a different frequency from the initial one. The breakdown of the initial vortex street is qualitatively explained by considering the convection of a concentrated vortex region due to the motion imposed by all the other vortices.