Research on computational and display requirements for human control of space vehicle boosters. Part 1 - Theory and results Final report, 22 Jun. - 22 Oct. 1966

Computational and display requirements for man-computer guidance and control techniques for reusable manned spacecraf

Investigation of analytical methods for efficient partitioning of on-board processing functions for remote sensing applications

Risk decomposition and ring theory, lattice techniques and universal algebras, and unary functions are considered

The Rising Age Gap in Economic Well-Being

Compares changes in median net worth of households between 1984 and 2009 by age of head of household. Examines contributing factors, including the housing market bubble, the 2007-09 recession's effect on employment, and longer-term demographic trends

Knot Concordance and Higher-Order Blanchfield Duality

In 1997, T. Cochran, K. Orr, and P. Teichner defined a filtration {F_n} of the classical knot concordance group C. The filtration is important because of its strong connection to the classification of topological 4-manifolds. Here we introduce new techniques for studying C and use them to prove that, for each natural number n, the abelian group F_n/F_{n.5} has infinite rank. We establish the same result for the corresponding filtration of the smooth concordance group. We also resolve a long-standing question as to whether certain natural families of knots, first considered by Casson-Gordon and Gilmer, contain slice knots.Comment: Corrected Figure in Example 8.4, Added Remark 5.11 pointing out an important strengthening of Theorem 5.9 that is needed in a subsequent pape

A tracker alignment framework for augmented reality

To achieve accurate registration, the transformations which locate the tracking system components with respect to the environment must be known. These transformations relate the base of the tracking system to the virtual world and the tracking system's sensor to the graphics display. In this paper we present a unified, general calibration method for calculating these transformations. A user is asked to align the display with objects in the real world. Using this method, the sensor to display and tracker base to world transformations can be determined with as few as three measurements

Investigation of Dental Tissues Using Radioisotope Techniques

This thesis is concerned with the determination of inorganic constituents of dental tissues, mainly tooth enamel. Little is known about the occurrence and distribution of the minor constituents of teeth since analytical difficulties have prevented their estimation. As more sensitive and reliable modern analytical techniques become available more information can be obtained. This thesis deals with the development of methods of analysis for the precise and accurate determination of trace elements using the technique of neutron activation analysis

Accuracy of a Newly Developed Guided Dental Implant Delivery System

Purpose: The purpose of this study was to evaluate the accuracy of a guided dental implant system with one operator comparing the treatment planned location to the actual location using a table top optical scanner. Materials and Methods: Twenty five patients were treated with a cone beam computed tomography (CBCT) scan. A stone cast was made of each patient and scanned using an optical table top scanner. The optical scan of the cast and the CBCT of the patient were superimposed and a single implant was placed virtually in the software program. A sterolithographic three dimensional (3D) surgical guide was printed. Implant sites in the patients were prepared using the surgical guides and the final drill to complete the osteotomy and implant placement was done without the guide. Four to six months after implant placement, impressions were made for the final restoration. A scanning body was placed in the master cast, and the scanning of these casts was performed with the same scanner. The overlay of the final working cast and the virtual planning was performed. Differences between actual and planned implant locations were calculated in linear measurement in millimeters and degrees from the center of the implant body at the most coronal and most apical point. Results: 25 cases were evaluated. The average linear deviation at the shoulder and apex of the implant was: 0.68 +/-0.55mm p \u3c 0.001, and 1.47mm +/-0.92mm p \u3c 0.001 respectively. The average deviation in height was -0.06mm +/-1.27mm p= .966. The average angular deviation from the axis was 5.8 +/- 2.41 degrees p\u3c 0.001 The deviation in height is statistically different in the maxilla -0.95 +/- 1.28mm compared to the mandible 0.47 +/- 0.95mm p\u3c.002 with an alpha level of 05. Conclusion: The actual location of the implant compared to the planned location is significantly different at the location of the shoulder, apex and angle. It did not differ significantly in height except when evaluated by arch