Accurate quantification of radionuclides detected during a scanning survey relies on an appropriately determined scan efficiency calibration factor (SECF). Traditionally, instrument efficiency was determined from a fixed instrument to source geometry. However, as is often the case, the instrument is used in a scanning mode where the source to instrument geometry is dynamic during the observation interval. Three separate procedures were developed to determine the SECF for a 10 cm x 10 cm source passing under the centerline of a 12.7 cm x 7.62 cm NaI(T1) detector. The procedures were first tested for determining the SECF from a series of static point source measurements generated by the Monte Carlo N-Particle (MCNP) code. These static efficiency values were then used to predict the SECF for scan speeds ranging from 10 cm s����� to 80 cm s����� with a one second observation interval. The investigator then used MCNP to directly determine the SECF by simulating a scan of a 10 cm x 10 cm area source for scan speeds ranging from 10 cm s����� to 80 cm s�����. Comparison of the MCNP static simulation with the scan simulation showed the accuracy of the SECF prediction procedures to be within ��5%. Experimental results further show the three procedures developed to predict the actual SECF for a 10 cm x 10 cm source to be accurate to within ��10%. Besides the obvious application to determine an SECF for a given scan speed, this method can be used to determine the maximum detector or source velocity for a desired SECF. These procedures are effective and can likely be extended to determine an instrument specific SECF for a range of source sizes, scan speeds, and instrument observation intervals. / Graduation date: 2002

published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

No description available.

Thesis (M.S. in Engineering Science)--Naval Postgraduate School, December 1990. / Thesis Advisor(s): Lee, Yuh-jeng. Second Reader: Giannotti, B. B. "December 1990." Description based on title screen as viewed on March 30, 2010. DTIC Descriptor(s): Weapons, Simulation, Detectors, Decision Making, Defense Systems, Accuracy, Efficiency, Theses, Targets, Three Dimensional, Shipboard, Expert Systems, Systems Approach, Enemy, Timeliness, Battles, Naval Vessels(Combatant), Preprocessing, Decision Support Systems, Input. DTIC Identifier(s): Rule Based Systems, Decision Aids, Weapon System Effectiveness, Shipboard, KEE(Knowledge Engineering Environment), WSS(Weapon Suggestion System), Target Detection, Threat Evaluation, Naval Vessels(Combatant), Tactical Analysis, Theses. Includes bibliographical references (p. 74-76). Also available in print.

Much of the current research involving the delivery of multimedia data focuses on the need to maintain a constant Quality of Service (QoS) throughout the lifetime of the connection. Delivery of a constant QoS requires that a guaranteed bandwidth is available for the entire connection. Techniques, such as resource reservation, are able to provide for this. These approaches work well across networks that are fairly homogeneous, and which have sufficient resources to sustain the guarantees, but are not currently viable over either heterogeneous or unreliable networks. To cater for the great number of networks (including the Internet) which do not conform to the ideal conditions required by constant Quality of Service mechanisms, this thesis proposes a different approach, that of dynamically adjusting the QoS in response to changing network conditions. Instead of optimizing the Quality of Service, the approach used in this thesis seeks to ensure the delivery of the information, at the best possible quality, as determined by the carrying ability of the poorest segment in the network link. To illustrate and examine this model, a service-adaptive system is described, which allows for the streaming of multimedia audio data across a network using the RealTime Transport Protocol. This application continually adjusts its service requests in response to the current network conditions. A client/server model is outlined whereby the server attempts to provide scalable media content, in this case audio data, to a client at the highest possible Quality of Service. The thesis presents and evaluates a number of renegotiation methods for adjusting the Quality of Service between the client and server. An A djusted QoS renegotiation method algorithm is suggested, which delivers the best possible quality, within an acceptable loss boundary.

This paper studies the quality of synthetic speech produced by integrated circuit (IC) hardware using fixed-point arithmetic and Linear Predictive Coding (LPC). A theoretical model explaining the combined effects of finite wordlength and parametric model order is developed. This model is used to predict the results obtained in the experimental phase of this study. In the experimental phase, selected model utterances are synthesized under finite wordlength constraints using LPC parameters. The synthetic speech is evaluated in terms of the log area ratios which define objective speech quality as a parametric distance. A theoretical model is developed to predict the experimental results. Simulations of this model produce data that predict the experimental results. The same information is extracted from the model as that obtained from actually running the fixed-point synthesizer simulator. Since the predictions of the theoretical model agree quite well with the experimental measurements, it is concluded that fixed-point synthesizer performance can be predicted without actually running a complicated and expensive fixed-point synthesizer. Secondly, results obtained from either method clearly indicate that for 15 or 16 bits, ten is the best number of poles to use. Eight useable poles are indicated for 14 bits, while seven are indicated for 13 bits. Based on the results of this study, the use of less than 13 bits for fixed-point calculations is not recommended.

This study investigated the relative effectiveness of three instructional strategies on the learning of an overarm throw among preadolescent females. Subjects were randomly assigned to one of the following instructional strategies: a correct model supplemented with verbal cues, a learning model supplemented with verbal cues, and verbal cues only. The performance outcome, the quality of the motor reproduction, and the accuracy of the cognitive representation of the skill were measured to elucidate the effectiveness of the instructional strategies. A pictorial-arrangement test and a cognitive recognition test of correct form were used to describe the quality of the cognitive representation. The performance of an overarm throw was evaluated using both a behavioral analysis and biomechanical techniques to provide information about form and outcome. All groups were tested on four occasions, prior to each day of a three day instructional strategy intervention and two days after instructional intervention. A 3 X 4 (Instructional Strategy X Test Session) repeated measures DM MANOVA incorporated the dependent variables: overarm throwing form score, pictorial-arrangement test score, and a dynamic cognitive recognition score. The results of the repeated measures DM MANOVA revealed a significant test session main effect only (Wilks Lambda=.226, F(9,25)=9.40, p<.001). Follow-up univariate F tests and trend analyses indicated that subjects in all groups showed significant improvement in overarm throwing form and in the accuracy of the cognitive representation of the motor skill. A 3 X 4 (Instructional Strategy X Test Session) repeated measures ANOVA's were employed to separately analyze four kinematic variables. The results obtained from the ANOVA's, based on an alpha value of .02, indicated statistically nonsignificant improvement in performance of the overarm throw. However, the kinematic variable pertaining to stride length revealed p=.029 for test session and observed trends indicated increased stride length and hip displacement for all subjects across the four test sessions. In conclusion, the results indicated that all three instructional strategies assisted the learner in the achievement of a more accurate cognitive representation and the ability to reproduce a more mature overarm throwing pattern. This study revealed the importance of verbal cues which describe the critical transitional positions of the body throughout the coordinated movement. In addition, observing a learning model who demonstrated movement errors was not detrimental to the viewer's learning of a skill. / Graduation date: 1994

No description available.

No description available.

No description available.