1,787 research outputs found
Flight test results for a separate surface stability augmented Beech model 99
A flight evaluation of a Beech model 99 equipped with an attitude command control system incorporating separate surface stability augmentation (SSSA) was conducted to determine whether an attitude command control system could be implemented using separate surface controls, and to determine whether the handling and ride qualities of the aircraft were improved by the SSSA attitude command system. The results of the program revealed that SSSA is a viable approach to implementing attitude command and also that SSSA has the capability of performing less demanding augmentation tasks such as yaw damping, wing leveling, and pitch damping. The program also revealed that attitude command did improve the pilot rating and ride qualities of the airplane while flying an IFR mission in turbulence. Some disadvantages of the system included the necessity of holding aileron force in a banked turn and excessive stiffness in the pitch axis
The SNFC in The Civil Rights Movement in Carbondale, Illinois
The Civil Rights Movement reached its peak in the 1960s and Southern Illinois University Carbondale (SIUC) students did more than their part in this monumental effort to teach the nation that democracy really meant equality. With the formation of the Student Nonviolent Freedom Committee (SNFC) in July of 1962, SIU students placed themselves on the frontlines of the Civil Rights Movement. Black and white, male and female students fighting to uphold the belief that all people were created equal. Their philosophical and religious ideals of nonviolence to end racial discrimination in southern Illinois became the organization’s foundation for social change. Not only did these students help their own community overcome racial injustice, but they initiated movements in Cairo and Murphysboro, Illinois. This paper carefully examines the activism of SIUC students and the manner in which they fought to eliminate the social injustices of the time
Formation of a quasicrystalline Pb monolayer on the ten-fold surface of the decagonal Al-Ni-Co quasicrystal
Lead has been deposited on the ten-fold surface of decagonal Al72Ni11Co17 to
form an epitaxial quasicrystalline single-element monolayer. The overlayer
grows through nucleation of nanometer-sized irregular islands and the coverage
saturates at 1 ML. The overlayer is well-ordered quasiperiodically as evidenced
by LEED and Fourier transforms of STM images. Annealing the film to 600 K
improves the structural quality, but causes the evaporation of some material
such that the film develops pores. Electronic structure measurements using
X-ray photoemission spectroscopy indicate that the chemical interaction of the
Pb atoms with the substrate is weak.Comment: 12 pages, 5 figure
Flight test evaluation of a separate surface attitude command control system on a Beech 99 airplane
A joint NASA/university/industry program was conducted to flight evaluate a potentially low cost separate surface implementation of attitude command in a Beech 99 airplane. Saturation of the separate surfaces was the primary cause of many problems during development. Six experienced professional pilots who made simulated instrument flight evaluations experienced improvements in airplane handling qualities in the presence of turbulence and a reduction in pilot workload. For ride quality, quantitative data show that the attitude command control system results in all cases of airplane motion being removed from the uncomfortable ride region
Dispersal Movements of Subadult Cougars From the Black Hills: The Notions of Range Expansion and Recolonization
Dispersal plays a vital role in cougar (Puma concolor) population ecology, creating genetic viability and maintaining gene flow between populations. The naturally recolonized cougar population in the Black Hills is at the edge of the species’ range in North America and completely surrounded by the grasslands of the Northern Great Plains. Our objective was to document dispersal movements and possible range expansion of subadult cougars captured within the Black Hills ecosystem of southwestern South Dakota and eastern Wyoming. Twenty-four (n ¼ 14 males, n ¼ 10 females) subadult cougars were captured in the Black Hills. Independence of cougars from females averaged 13.5 months (range ¼ 10–16 months) from parturition; dispersal occurred 1–3 months post independence. Males dispersed (mean ¼ 274.7 km SE 88.3) farther than females (mean ¼ 48.0 km SE 10.9), with females exhibiting 40% philopatry. We documented several (n ¼ 6) long-distance dispersal movements (.250 km) of male cougars and hypothesize that males making long-distance movements were in search of available mates. The long distance cougar dispersal movements documented by our study indicate that range expansion and habitat recolonization are occurring and further suggest proactive efforts to increase public knowledge of cougar ecology in areas where cougars are recolonizing previously occupied range
Chewing gum modifies state-anxiety and alertness under conditions of social stress
Objectives: The finding that chewing gum can moderate state-anxiety under conditions of acute stress¹ has proved difficult to replicate.2,4 The present study examines the extent to which chewing gum can moderate state-anxiety under conditions of acute social stress.
Method: In a between-participants design, 36 participants completed a task comprising a mock job interview (a variation on the Trier Social Stress Task3, which included a mental arithmetic component) whilst either chewing gum or without gum. Self-rated measures of mood and anxiety were taken at baseline, after a 10-minute presentation preparation stage, after the 10-minute presentation, and following a 5-minute recovery stage.
Results: Post-presentation measures reflected increased state-anxiety and decrease self-rated calmness and contentedness. Chewing gum attenuated the rise in state-anxiety whilst increasing self-rated alertness. Chewing gum did not affect contentedness or calmness.
Conclusions: The findings indicate that chewing gum can act to reduce anxiety under conditions of acute social stress: a finding consistent with Scholey et al.1 Furthermore, the data add to the growing body of literature demonstrating that chewing gum can increase alertness.1,2,4,
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Exchange Effects and CIDEP
Väitöskirjassa on tutkittu tilastollisen koesuunnittelun teoriaa. Koesuunnittelua tarvitaan, kun tilastollisiin mittauksiin on käytettävissä vain rajallinen määrä resursseja mutta samalla kuitenkin halutaan luotettavaa tietoa.
Tutkimuksen kolmessa ensimmäisessä artikkelissa on kehitetty koesuunnitelmia satunnaiskertoimisille regressiomalleille. Malleja voidaan soveltaa, kun tehdään usealle yksilölle peräkkäisiä mittauksia, esimerkiksi eri aikapisteissä. Väitöskirjan artikkeleissa sovelluskohteena ovat olleet puiden rungot, joista on mitattu läpimittoja eri korkeuksilla. Kutakin yksilöä, tässä tapauksessa puunrunkoa, vastaavat omat regressiomallin kertoimet. Koesuunnitelma käsittää tiedon siitä, miten mittausten määrä jakaantuu eri yksilöiden välillä ja yksilöiden sisäisesti. Tavoitteena on joko arvioida mallin keskimääräiset parametrit mahdollisimman tarkasti tai ennustaa uusia havaintoarvoja. Ensimmäisessä artikkelissa on ennustealue on sama kuin havaintoväli ja toisessa se on havaintovälin ulkopuolella. Kolmannessa artikkelissa on esillä käänteisennusteongelma, kun halutaan arvioida pistettä, jossa vastemuuttuja, esim. puun läpimitta, saavuttaa tietyn tason.
Koesuunnitelmia vertaillaan keskenään käyttämällä erilaisia optimaalisuuskriteereitä. Kolmannessa ja neljännessä väitöskirjan artikkelissa tarkastellaan DS-kriteeriä, jota on tutkittu vain vähän tähän mennessä. DS-kriteeri on siinä mielessä yleinen, että koesuunnitelman ollessa DS-optimaalinen se on optimaalinen myös monen perinteisen optimaalisuuskriteerin suhteen. Yleensä DS-optimaalista suunnitelmaa ei ole olemassa, mutta suunnitelmia voidaan parantaa DS-kriteerin suhteen. Tutkimuksessa on rajoituttu yksinkertaisiin polynomimalleihin, joten lisätutkimus on tarpeen DS-kriteerin käytöstä laajemmissa yhteyksissä.The thesis consists of five papers and a summary. It has two main themes in the area of experimental design. Firstly, optimal designs for estimation, prediction and inverse prediction are developed in random coefficient linear regression models. Mainly first-degree models are dealt with. The results can be applied in repeated measurements situations.
Secondly, a relatively new design criterion, the distance optimality criterion, is introduced. Its properties are studied and some results in estimation and prediction problems deduced. The criterion can be used to find optimal designs or to improve designs in polynomial regression models. It has interesting relations to traditional D- and E-optimality criteria
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