The pioneer projects: Economical exploration of the solar system

The interplanetary Pioneer missions are reviewed in terms of management implications and cost control. The responsibilities, organizational structure, and management practices of the Pioneer Projects are presented. The lines of authority and areas of responsibility of the principal organizational elements supporting the Pioneer missions are identified, and the methods employed for maintaining effective and timely interactions among these elements are indicated. The technical and administrative functions of the various organizational elements of the Pioneer Project Office at Ames Research Center are described in terms of their management responsibilities and interactions with other elements of the Project Office and with external organizations having Pioneer Project responsibilities. The management and control of activities prior to and during the hardware procurement phase are described to indicate the basis for obtaining visibility of the technical progress, utilization of resources, and cost performance of the contractors and other institutions supporting the Pioneer projects

Using multiple criteria decision analysis (MCDA) to assist in estimating residential housing values

Considerable literature exists regarding the complexity of the residential real estate appraisal process and the methods employed to determine initial listing prices as estimates of intrinsic market prices. Deviations in residential real estate intrinsic values occur due to a multiplicity of attributes and explanatory factors requiring consideration. We conduct a panel study using a Multiple Criteria Decision Analysis (MCDA) based framework that utilizes the skills and knowledge of a panel of residential real estate professionals (i.e. appraisers and realtors). We demonstrate how cognitive mapping and the Measuring Attractiveness by a Categorical Based Evaluation Technique (MACBETH) may assist in estimating appropriate offer/sale prices and strengthening current valuation approaches such as using comparables and/or hedonic modeling. The managerial implications of our MCDA-based framework and some avenues for future research are also presented.info:eu-repo/semantics/publishedVersio

Effect of Tail Surfaces on the Base Drag of a Body of Revolution at Mach Numbers of 1.5 and 2.0

Wind-tunnel tests were performed at Mach numbers of 1.5 and 2.0 to investigate the influence of tail surfaces on the base drag of a body of revolution without boattailing and having a turbulent boundary layer. The tail surfaces were of rectangular plan form of aspect ratio 2.33 and has symmetrical, circular-arc airfoil section. The results of the investigation showed that the addition of these tail surfaces with the trailing edges at or near the body base incurred a large increase in the base-drag coefficient. For a cruciform tail having a 10-percent-thick airfoil section, this increase was about 70 percent at a Mach number of 1.5 and 35 percent at a Mach number of 2.0. As the trailing edge of the tail was moved forward or rearward of the base by about one tail-chord length, the base-drag increment was reduced to nearly zero. The increments in base-drag coefficient due to the presence of 10-percent-thick tail surfaces were generally twice those for 5-percent-thick surfaces. The base-drag increments due to the presence of a cruciform tail were less than twice those for a plane tail. An estimate of the change in base pressure due to the tail surfaces was made, based on a simple superposition of the airfoil-pressure field onto the base-pressure field behind the body. A comparison of the results with the experimental values indicated that in most cases the trend in the variation of the base-drag increment with changes in tail position could be predicted by this approximate method but that the quantitative agreement at most tail locations was poor

Measurements in Flight of the Lateral-Control Characteristics of an Airplane Equipped with Full-Span Zap Flaps and Simple Circular-Arc-Type Ailerons

Flight tests were conducted on the OS2U-2 seaplane with simple circular-arc-type ailerons directly connected to the actuating torque tube. Two aileron test installations were made, differing only in the inclination of the projecting surface with the wing's upper surface. The lateral-control characteristics of the airplane were determined from data obtained in stalls and rudder-fixed aileron rolls. The revised ailerons were deficient in maximum rolling effectiveness, but were capable of controlling the rolling tendencies of the airplane near the stall

A rule-based decision support system for real estate brokerage service evaluation

Real estate brokers or realtors are expected to possess superior knowledge of their local markets, and typically require commissions in return for their services. The evaluation of their performance is an important issue in justifying their commissions. We develop a learning-oriented decision-making process for evaluating real estate brokerage services, which concentrates on understanding the nature, the role and the interaction of the evaluation aspects of real estate brokerage service quality by integrating cognitive maps and the Decision EXpert (DEX) approach. Results suggest that this framework permits new rudiments to be considered in the realtor decision-making and sales process, facilitating transparency and understanding of realtor functions that may lead to recommendations to improve the performance and quality of these functions. Avenues for future research are also presented.info:eu-repo/semantics/publishedVersio

Survey Simulations of a New Near-Earth Asteroid Detection System

We have carried out simulations to predict the performance of a new space-based telescopic survey operating at thermal infrared wavelengths that seeks to discover and characterize a large fraction of the potentially hazardous near-Earth asteroid (NEA) population. Two potential architectures for the survey were considered: one located at the Earth-Sun L1 Lagrange point, and one in a Venus-trailing orbit. A sample cadence was formulated and tested, allowing for the self-follow-up necessary for objects discovered in the daytime sky on Earth. Synthetic populations of NEAs with sizes >=140 m in effective spherical diameter were simulated using recent determinations of their physical and orbital properties. Estimates of the instrumental sensitivity, integration times, and slew speeds were included for both architectures assuming the properties of new large-format 10 um detector arrays capable of operating at ~35 K. Our simulation included the creation of a preliminary version of a moving object processing pipeline suitable for operating on the trial cadence. We tested this pipeline on a simulated sky populated with astrophysical sources such as stars and galaxies extrapolated from Spitzer and WISE data, the catalog of known minor planets (including Main Belt asteroids, comets, Jovian Trojans, etc.), and the synthetic NEA model. Trial orbits were computed for simulated position-time pairs extracted from the synthetic surveys to verify that the tested cadence would result in orbits suitable for recovering objects at a later time. Our results indicate that the Earth-Sun L1 and Venus-trailing surveys achieve similar levels of integral completeness for potentially hazardous asteroids larger than 140 m; placing the telescope in an interior orbit does not yield an improvement in discovery rates. This work serves as a necessary first step for the detailed planning of a next-generation NEA survey.Comment: AJ accepted; corrected typ

Lack of in vivo blockade of Fas- and TNFR1-mediated hepatocyte apoptosis by the hepatitis C virus.

In vitro data have shown that the hepatitis C virus (HCV) core protein binds to protein members of the tumour necrosis factor receptor (TNFR) superfamily. Since this interaction could be relevant to HCV persistence and oncogenesis, this study assessed whether HCV may interfere with the apoptotic cascade in vivo. Apoptosis (by TUNEL) and Fas and TNFR1 expression (by immunohistochemistry) were scored in the liver of 60 chronic hepatitis C patients. Results were compared with the liver disease grading and staging scores and the HCV replication level in serum and liver. Apoptotic hepatocytes were stained in 29 cases. Fas was expressed in 35 cases and TNFR1 in 21, 15 patients (25%) being negative for both receptors. Overall, the numbers of TUNEL-, Fas- and TNFR-positive hepatocytes did not correlate with the extent of intrahepatic CD8+ T-lymphocyte infiltration, the grading and staging of liver disease, or the serum or liver HCV RNA levels. Furthermore, when patients expressing either Fas or TNFR1 were stratified according to serum HCV RNA levels, cases with detectable hepatocyte apoptosis had higher HCV viraemias. In conclusion, an HCV-mediated, in vivo blockade of hepatocyte apoptosis via the Fas- or TNFR1-dependent pathways seems unlikely