128 research outputs found

    Illinois Government Research no. 47 1978: Illinois Municipalities: Where have all the voters gone?

    Get PDF
    Politicians often lament the declining importance of local government in the United States. They point to an ever-growing, more inclusive federal government as evidence of the passing of government at the grassroots level. But judging by statistics from the last twenty years, Illinois municipalities, at least, can hardly be considered dead or even slightly ill. Thanks to the home rule provisions of the new constitution and to increased revenue from sources such as the state income tax and the federal revenue sharing programs, city governments are more active than ever before.published or submitted for publicatio

    The effects of air-water two phase flow on the performance of a centrifugal pump

    Get PDF
    This study investigates the performance of a 1-inch long 4-vane open impeller centrifugal pump under two phase flow conditions. The paddle wheel pump, as branded by its manufacturer the Worthington Corporation, had a specific speed of 3400 (based on gallons per minute, feet of water and revolutions per minute) corresponding to a 7-inch impeller diameter. A 1/8-inch perforated steel pipe carried the compressed air to within four inches of the impeller eye where the air was injected into the water stream (See figures 18 and 20). The three variable inputs were, water flow rate, pump speed and air flow rate. The output parameters measured were discharge, suction pressure, and torque. While measuring the outing parameters, various combinations of the input variables were employed in order to find the maximum air-water volumetric ratio at which water flow stopped and the discharge head dropped to zero. At the pump speeds and air flow rates ranging from 1500 PPM to 3500 PPM and from 1.72 x 10-3 cubic feet/second to 2.65x10-3 cubic feet/second respectively, it was found that increasing the water flow rate from zero capacity to a certain limit resulted in an increase of the discharge head (See figure 1 to 5). This limiting capacity varied from 40 to 60 per cent of the pump\u27s design capacity (35 GPM at 3500 RPM and 220 feet of water). A further increase of the water flow rate beyond the limiting capacity resulted in a quick drop of the discharge head. This characteristic behavior of the head-capacity curve was particularly noticeable at the higher air flow rates which ranged from 1.72x10-3 cubic feet/second to 2.65 x 10-3 cubic feet/second. It was also observed that at a given pump speed, increasing the volumetric air flow rate caused the head-capacity curve to peak at a lower discharge pressure. Finally, increasing the air content caused a shift in the efficiency curves such that peaked at a lower efficiency value as well as a lower flow capacity

    Endoscope and System and Method of Operation Thereof

    Get PDF
    An endoscope including a rigid section having opposed first and second ends and an opening situated between the first and second ends, the rigid section defining a longitudinal axis; a handle portion coupled to a first end of the rigid section and having first and second scissor-type handles suitable for grasping by a user; and a base part situated at the second end of the rigid section and coupled to the first handle of the scissor-type handles such that displacement of the first handle causes a rotation of the base part

    Endoscope and System and Method of Operation Thereof

    Get PDF
    An endoscope including a rigid section having opposed first and second ends and an opening situated between the first and second ends, the rigid section defining a longitudinal axis; a handle portion coupled to a first end of the rigid section and having first and second scissor-type handles suitable for grasping by a user; and a base part situated at the second end of the rigid section and coupled to the first handle of the scissor-type handles such that displacement of the first handle causes a rotation of the base part

    Stereo Imaging Miniature Endoscope with Single Imaging Chip and Conjugated Multi-Bandpass Filters

    Get PDF
    A dual objective endoscope for insertion into a cavity of a body for providing a stereoscopic image of a region of interest inside of the body including an imaging device at the distal end for obtaining optical images of the region of interest (ROI), and processing the optical images for forming video signals for wired and/or wireless transmission and display of 3D images on a rendering device. The imaging device includes a focal plane detector array (FPA) for obtaining the optical images of the ROI, and processing circuits behind the FPA. The processing circuits convert the optical images into the video signals. The imaging device includes right and left pupil for receiving a right and left images through a right and left conjugated multi-band pass filters. Illuminators illuminate the ROI through a multi-band pass filter having three right and three left pass bands that are matched to the right and left conjugated multi-band pass filters. A full color image is collected after three or six sequential illuminations with the red, green and blue lights

    Programmable Spectral Source and Design Tool for 3D Imaging Using Complementary Bandpass Filters

    Get PDF
    An endoscopic illumination system for illuminating a subject for stereoscopic image capture, includes a light source which outputs light; a first complementary multiband bandpass filter (CMBF) and a second CMBF, the first and second CMBFs being situated in first and second light paths, respectively, where the first CMBF and the second CMBF filter the light incident thereupon to output filtered light; and a camera which captures video images of the subject and generates corresponding video information, the camera receiving light reflected from the subject and passing through a pupil CMBF pair and a detection lens. The pupil CMBF includes a first pupil CMBF and a second pupil CMBF, the first pupil CMBF being identical to the first CMBF and the second pupil CMBF being identical to the second CMBF, and the detection lens includes one unpartitioned section that covers both the first pupil CMBF and the second pupil CMBF

    Automated test sequence generation for finite state machines using genetic algorithms

    Get PDF
    Testing software implementations, formally specified using finite state automata (FSA) has been of interest. Such systems include communication protocols and control sections of safety critical systems. There is extensive literature regarding how to formally validate an FSM based specification, but testing that an implementation conforms to the specification is still an open problem. Two aspects of FSA based testing, both NP-hard problems, are discussed in this thesis and then combined. These are the generation of state verification sequences (UIOs) and the generation of sequences of conditional transitions that are easy to trigger. In order to facilitate test sequence generation a novel representation of the transition conditions and a number of fitness function algorithms are defined. An empirical study of the effectiveness on real FSA based systems and example FSAs provides some interesting positive results. The use of genetic algorithms (GAs) makes these problems scalable for large FSAs. The experiments used a software tool that was developed in Java.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Estimating the feasibility of transition paths in extended finite state machines

    Get PDF
    There has been significant interest in automating testing on the basis of an extended finite state machine (EFSM) model of the required behaviour of the implementation under test (IUT). Many test criteria require that certain parts of the EFSM are executed. For example, we may want to execute every transition of the EFSM. In order to find a test suite (set of input sequences) that achieves this we might first derive a set of paths through the EFSM that satisfy the criterion using, for example, algorithms from graph theory. We then attempt to produce input sequences that trigger these paths. Unfortunately, however, the EFSM might have infeasible paths and the problem of determining whether a path is feasible is generally undecidable. This paper describes an approach in which a fitness function is used to estimate how easy it is to find an input sequence to trigger a given path through an EFSM. Such a fitness function could be used in a search-based approach in which we search for a path with good fitness that achieves a test objective, such as executing a particular transition, and then search for an input sequence that triggers the path. If this second search fails then we search for another path with good fitness and repeat the process. We give a computationally inexpensive approach (fitness function) that estimates the feasibility of a path. In order to evaluate this fitness function we compared the fitness of a path with the ease with which an input sequence can be produced using search to trigger the path and we used random sampling in order to estimate this. The empirical evidence suggests that a reasonably good correlation (0.72 and 0.62) exists between the fitness of a path, produced using the proposed fitness function, and an estimate of the ease with which we can randomly generate an input sequence to trigger the path
    • ā€¦
    corecore