The hippocampus is necessary for normal memory in rodents, birds, monkeys, and people. Damage to the hippocampus can result in the inability to learn new facts, defined by the relationship among stimuli. In rodents, spatial learning involves learning about the relationships among stimuli, and exemplifies the kind of learning the requires the hippocampus. Therefore, understanding the neural mechanisms underlying spatial learning may elucidate basic memory processes. Many hippocampal neurons fire when behaving rats, cats, or monkeys are in circumscribed regions (place fields) of an environment. The neurons, called place cells, fire in relation to distal stimuli, but can persist in signaling location when the stimuli are removed or lights are turned off (memory fields). In this thesis, computational models of spatial information processing simulated many of the defining properties of hippocampal place cells, including memory fields. Furthermore, the models suggested a neurally plausible mechanism of goal directed spatial navigation which involved the encoding of distances in the connections between place cells. To navigate using memory fields, the models required an excitatory, distributed, and plastic association system among place cells. Such properties are well characterized in area CA3 of the hippocampus. In this thesis, a new electrophysiological study provides evidence that a second system in the dentate gyrus has similar properties. Thus, two circuits in the hippocampus meet the requirements of the models. Some predictions of the models were then tested in a single-unit recording experiment in behaving rats. Place fields were more likely to occur in information rich areas of the environment, and removal of single cues altered place fields in a way consistent with the distance encoding mechanism suggested by the models. It was concluded that a distance encoding theory of rat spatial navigation has much descriptive and predictive utility, but most of its predic

Emergency services are very important in every society and that is why their activities should not be impeded by any avoidable barrier, especially with regard to transportation. One problem that is affecting the smooth running of emergency services in Henry County, Indiana is train movement across the county. The train tracks run through the county preventing road traffic flow when a train is crossing or has stopped. As a result, ambulances, police, or fire service vehicles have to wait for minutes or travel long distances to go around the train. This thesis focuses on developing response service areas maps based on the current response time and two models to generate shortest route around train obstructions. The data used for this thesis was provided by Henry County GIS Department, including shape files of police stations, police service areas, ambulance stations, ambulance service areas, fire stations, fire service areas, railroad and streets. The response service areas were designed based on the current response time. This was accomplished using ArcGIS network analyst extension which provides tools to design series of concentric circles based on the distance from the common center. Apart from the service areas maps for the emergency services which provide an idea as to where the services need to be extended in the county, the results of this thesis also include two models designed to generate shortest possible route as well as selection of a closest emergency facility to an incident site. The thesis could help improve the transportation aspect of emergency services in the county. / Department of Geography

A study was undertaken to better understand the hydrogeologic framework of the Delaware County, Indiana. Arc View GIS 3-D and Spatial Analysts along with VISUAL MODFLOW are used to study the flow patterns by developing a 3-D model of major aquifers in the county, both glacial and bedrock. The GIS platform facilitates the time consuming task of preparing data input and output. In addition, major recharge zones are also identified in GIS using soil and slope data.The bedrock of Delaware County is composed of Silurian bedrock, which is overlain by glacial drift. The drift is mostly till that is interbedded with eight sand and gravel layers which are horizontal and discontinuous. Both, bedrock and sand & gravel glacial aquifers are good sources of groundwater in the county. More than 3000 water wells are located in the area. It is very interesting to note that 50% of the water-wells in the area are in confined sand and gravel and the remaining wells are in carbonaceous bedrock. The bedrock contains numerous preglacial karsts valley systems which are areas of high transmissivity solution features, also adding further interest to modeling this region.The hydraulic conductivity of sand and gravel is assumed to be 0.0015 m/s whereas for bedrock 0.00025 m/s is used. The streambeds in the area are also the source of groundwater discharge. The hydraulic conductivity of streambed is equal to 0.00028 m/s. Recharge to the area occurs as net recharge, which varies spatially depending on the nature of soil.Several simplifying assumptions were made for the conceptualization and simulation of flow in the basins. The main assumptions are as follows: 1) groundwater is in steady-state, 2) pumping does not significantly affect the level of hydraulic heads; therefore only high capacity pumping wells are simulated, 3) Net recharge from precipitation varies spatially, 4) flow in the bedrock aquifer occurs in the uppermost 40 m and is horizontal 5) vertical flow is assumed to be controlled by intervening sand and gravel units. Ground-water flow in the basins was conceptualized as a three-dimensional flow system. The model boundaries selected to represent natural hydrologic boundaries include (1) river leakage boundaries along major rivers; (2) a constant head boundary around the aquifer boundaries; (3) a general head boundary along the major streams; (4) drain boundaries along major drains; and 5) Evapotranspiration losses.The simulated region is an area of 398 square miles. The model consists of over 3600 cells and employed a regular grid spacing of 6o x 60. A variable grid was designed to provide additional detail in areas of special interest and thus allowed these areas to be simulated more accurately in the model.The model was calibrated using a manual trial-and-error adjustment of parameters. Hydraulic conductivity values, and streambed conductance were adjusted during successive simulations until the flow pattern matches the regional flow direction as computed from the water-well derived (static water level) potentiometric surface. The computed potentiometric surface is an adequate or reasonable match on a regional scale, with the general trend of SE-NW. It is observed that the model is extremely sensitive to changes in horizontal hydraulic conductivity and recharge in the form of precipitation. The model is least sensitive to streambed vertical hydraulic conductivity.The water budget for the calibrated model represents the distribution of groundwater inflow and outflow during calibration. The data indicate that 16.5% of the inflow to the modeled groundwater system is flow across model boundaries and 83% from effective recharge from precipitation, and the rest from streams and rivers. Outflow consists of 2% pumpage, 5% seepage to streams and drains, and 93% is flow across boundaries.It is expected that this study will be beneficial to improve the understanding of groundwater in Delaware County, including both vertical and horizontal flow and interaction of flow between surface and groundwater. Also, the results of the modeling study can be used as a predictive tool for long-term management and monitoring of water resources in the region. / Department of Geology

This project discusses the concepton of a web-based simulation. In particular, it will deal with the development of a robotic Mars Pathfinder simulation delivered via the World Wide Web.

No description available.

No description available.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Digitized by Kansas State University Libraries

In this thesis existing models of adaptive computer architecture were modified to adapt actual sorting problems to "divide 'n' conquer" (DQ) coordinator type configuration in which the children processors were expanded from three to four. Two hire/fire strategies, one using packets waiting in queue and the other using the average turn around time, were applied to maintain the hierarchical tree structure. More than 1200 simulation runs were analyzed and compared, finding that the first strategy was best at fast packet arrival rate and the second strategy was best at slow packets arrival rate. Comparing the hire/fire signal generation policies, the "fc-root" was best and the "root-fp" was worst. While comparing the effect of variable weighting factors in processors, using smaller weighting factor in either "partitioner" for the first strategy or "f-computer" for the second strategy may improve the system performance. (Abstract shortened with permission of author.)

This thesis is based on modifications performed on the U.S. Army TACOM (Tank Automotive Command, Warren, Michigan) Thermal Imaging Model (TTIM). It discusses the TTIM computer model of a staring thermal imaging sensor with respect to spatial nonuniformities. The spatial nonuniformities in a staring sensor is caused by fixed pattern noise or responsivity variations across the sensor. The objective of the thesis is to present the correction schemes for spatial nonuniformities present on a staring thermal imaging sensor and the data analysis of the corrections using flat field and bar chart targets of known temperatures. The signal-to-noise ratios (S/Ns) of the images will be calculated and measured before and after the correction. A simulated image after a one-point correction will be evaluated by comparison with an image from a real system using a platinum silicide thermal imaging sensor. The limits and assumptions of the simulation also will be discussed.