Getting expert systems off the ground: Lessons learned from integrating model-based diagnostics with prototype flight hardware

As an initial attempt to introduce expert system technology into an onboard environment, a model based diagnostic system using the TRW MARPLE software tool was integrated with prototype flight hardware and its corresponding control software. Because this experiment was designed primarily to test the effectiveness of the model based reasoning technique used, the expert system ran on a separate hardware platform, and interactions between the control software and the model based diagnostics were limited. While this project met its objective of showing that model based reasoning can effectively isolate failures in flight hardware, it also identified the need for an integrated development path for expert system and control software for onboard applications. In developing expert systems that are ready for flight, artificial intelligence techniques must be evaluated to determine whether they offer a real advantage onboard, identify which diagnostic functions should be performed by the expert systems and which are better left to the procedural software, and work closely with both the hardware and the software developers from the beginning of a project to produce a well designed and thoroughly integrated application

The effect of stellar limb darkening values on the accuracy of the planet radii derived from photometric transit observations

We study how the precision of the exoplanet radius determination is affected by our present knowledge of limb darkening in two cases: when we fix the limb darkening coefficients and when we adjust them. We also investigate the effects of spots in one-colour photometry. We study the effect of limb darkening on the planetary radius determination both via analytical expressions and by numerical experiments. We also compare some of the existing limb darkening tables. When stellar spots affect the fit, we replace the limb darkening coefficients, calculated for the unspotted cases, with effective limb darkening coefficients to describe the effect of the spots. There are two important cases. (1) When one fixes the limb darkening values according to some theoretical predictions, the inconsistencies of the tables do not allow us to reach accuracy in the planetary radius of better than 1-10% (depending on the impact parameter) if the host star's surface effective temperature is higher than 5000 K. Below 5000 K the radius ratio determination may contain even 20% error. (2) When one allows adjustment of the limb darkening coefficients, the a/Rs ratio, the planet-to-stellar radius ratio, and the impact parameter can be determined with sufficient accuracy (<1%), if the signal-to-noise ratio is high enough. However, the presence of stellar spots and faculae can destroy the agreement between the limb darkening tables and the fitted limb darkening coefficients, but this does not affect the precision of the planet radius determination. We also find that it is necessary to fit the contamination factor, too. We conclude that the present inconsistencies of theoretical stellar limb darkening tables suggests one should not fix the limb darkening coefficients. When one allows them to be adjusted, then the planet radius, impact parameter, and the a/Rs can be obtained with the required precision.Comment: Astronomy & Astrophysics Vol. 549, A9 (2013) - 11 page

PRODUCT CHARACTERISTICS AFFECTING CONSUMERS' FRESH BEEF CUT PURCHASING DECISIONS IN THE UNITED STATES, JAPAN, AND AUSTRALIA

The effects of product and economic characteristics on consumers who purchase six cuts of fresh beef (blocks/parts, steak, thinly sliced, diced, chopped, and ground) in urban areas of the United States, Japan, and Australia will be examined in this paper. Certain product characteristics (such as product freshness and display case cleanliness) were important to consumers of beef in all three countries while other product characteristics (such as price considerations for ground beef consumers) were important for consumers of different beef cuts in all three countries. Some product characteristics varied in importance across consumers from different countries and consumers of different beef cuts.Consumer/Household Economics,

Characterization of CoRoT target fields with BEST: Identification of periodic variable stars in the IR01 field

We report on observations of the CoRoT IR01 field with the Berlin Exoplanet Search Telescope (BEST). BEST is a small aperture telescope with a wide field of view (FOV). It is dedicated to search for variable stars within the target fields of the CoRoT space mission to aid in minimizing false-alarm rates and identify potential targets for additional science. CoRoT's observational programm started in February 2007 with the "initial run" field (IR01) observed for about two months. BEST observed this field for 12 nights spread over three months in winter 2006. From the total of 30426 stars observed in the IR01 field 3769 were marked as suspected variable stars and 54 from them showed clear periodicity. From these 19 periodic stars are within the part of the CoRoT FOV covered in our data set

Pengaruh Investment Opportunity Set (IOS), Mekanisme Good Corporate Governance dan Reputasi KAP terhadap Kualitas Laba Perusahaan (Studi Empiris pada Perusahaan Property And Real Estate yang Terdaftar di Bursa Efek Indonesia 2010-2012)

This study aimed to examine the effect of investment opportunity set (IOS), good corporate governance mechanism (audit committee, independent directors, institutional ownership, managerial ownership) and public accounting firms reputation on quality of corporate earnings. The sample was taken using the method of purposive sampling from property and real estate company listed on the Indonesia Stock Exchange in 2010 until 2012. Obtained 81 samples from 33 property and real estate company for 3 years. Hypothesis testing is performed using multiple linear regression analysis. The results of this study indicate that audit committee have significant effect on corporate earnings. While investment opportunity set (IOS), independent directors, managerial ownership and institutional ownership of the firms reputation does not have significant effect on quality of corporate earnings.Keyword: Investment opportunity set (IOS), good corporate governance mechanism, public accounting firms, quality of corporate earnigs

Structure and dynamics of a model glass: influence of long-range forces

We vary the amplitude of the long-range Coulomb forces within a classical potential describing a model silica glass and study the consequences on the structure and dynamics of the glass, via molecular dynamics simulations. This model allows us to follow the variation of specific features such as the First Sharp Diffraction Peak and the Boson Peak in a system going continuously from a fragile (no Coulomb forces) to a strong (with Coulomb forces) glass. In particular we show that the characteristic features of a strong glass (existence of medium range order, bell-shaped ring size distribution, sharp Boson peak) appear as soon as tetrahedral units are formed.Comment: 5 pages, 4 figures. To be published in J.Phys.: C

Variability survey in the CoRoT SRa01 field: Implications of eclipsing binary distribution on cluster formation in NGC 2264

Time-series photometry of the CoRoT field SRa01 was carried out with the Berlin Exoplanet Search Telescope II (BEST II) in 2008/2009. A total of 1,161 variable stars were detected, of which 241 were previously known and 920 are newly found. Several new, variable young stellar objects have been discovered. The study of the spatial distribution of eclipsing binaries revealed the higher relative frequency of Algols toward the center of the young open cluster NGC 2264. In general Algol frequency obeys an isotropic distribution of their angular momentum vectors, except inside the cluster, where a specific orientation of the inclinations is the case. We suggest that we see the orbital plane of the binaries almost edge-on.Comment: 18 pages, 8 figures, accepted for publication in Ap

The Berlin Exoplanet Search Telescope II. Catalog of Variable Stars. I. Characterization of Three Southern Target Fields

A photometric survey of three Southern target fields with BEST II yielded the detection of 2,406 previously unknown variable stars and an additional 617 stars with suspected variability. This study presents a catalog including their coordinates, magnitudes, light curves, ephemerides, amplitudes, and type of variability. In addition, the variability of 17 known objects is confirmed, thus validating the results. The catalog contains a number of known and new variables that are of interest for further astrophysical investigations, in order to, e.g., search for additional bodies in eclipsing binary systems, or to test stellar interior models. Altogether, 209,070 stars were monitored with BEST II during a total of 128 nights in 2009/2010. The overall variability fraction of 1.2-1.5% in these target fields is well comparable to similar ground-based photometric surveys. Within the main magnitude range of $R\in\left[11,17\right]$, we identify 0.67(3)% of all stars to be eclipsing binaries, which indicates a completeness of about one third for this particular type in comparison to space surveys.Comment: accepted to A

An analog computer study of hydraulic servomechanism nonlinearlities

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautical Engineering, 1954.Includes bibliographical references (p. 105-106).by Keith A. Erikson, William R. Greenwood, Philip J. Bonomo.M.S