975 resultados para 116-718
Resumo:
We present a search for the lightest supersymmetric partner of the top quark in proton-antiproton collisions at a center-of-mass energy √s=1.96 TeV. This search was conducted within the framework of the R parity conserving minimal supersymmetric extension of the standard model, assuming the stop decays dominantly to a lepton, a sneutrino, and a bottom quark. We searched for events with two oppositely-charged leptons, at least one jet, and missing transverse energy in a data sample corresponding to an integrated luminosity of 1 fb-1 collected by the Collider Detector at Fermilab experiment. No significant evidence of a stop quark signal was found. Exclusion limits at 95% confidence level in the stop quark versus sneutrino mass plane are set. Stop quark masses up to 180 GeV/c2 are excluded for sneutrino masses around 45 GeV/c2, and sneutrino masses up to 116 GeV/c2 are excluded for stop quark masses around 150 GeV/c2.
Resumo:
This poster describes a pilot case study, which aim is to study how future chemistry teachers use knowledge dimensions and high-order cognitive skills (HOCS) in their pre-laboratory concept maps to support chemistry laboratory work. The research data consisted of 168 pre-laboratory concept maps that 29 students constructed as a part of their chemistry laboratory studies. Concept maps were analyzed by using a theory based content analysis through Anderson & Krathwohls' learning taxonomy (2001). This study implicates that novice concept mapper students use all knowledge dimensions and applying, analyzing and evaluating HOCS to support the pre-laboratory work.
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The influence of 0.03 and 0.08 at. % Ag additions on the clustering of Zn atoms in an Al-4.4 at. % Zn alloy has been studied by resistometry. The effect of quenching and ageing temperatures shows that the ageing-ratio method of calculating the vacancy-solute atom binding energy is not applicable to these alloys. Zone-formation in Al-Zn is unaffected by Ag additions, but the zone-reversion process seems to be influenced. Apparent vacancy-formation energies in the binary and ternary alloys have been used to evaluate the v-Ag atom binding energy as 0.21 eV. It is proposed that, Ag and Zn being similar in size, the relative vacancy binding results from valency effects, and that in Al-Zn-Ag alloys clusters of Zn and Ag may form simultaneously, unaffected by the presence of each other. © 1970 Chapman and Hall Ltd.
Resumo:
Thermal rearrangement of diethylamino5-(m methoxyphenoxy)-pent-2-yne (3) gives 1-(m-methexyphenoxy)-pent-3,4-diene (14) in about 8% yield. Hydration of the latter yields 1-(m-methoxyphenoxy)-pentan-4-one (6), which has been synthesised by an unambiguous route. A mechanism of formation of the allene (14) from the amine (3) has been suggested.
Resumo:
In this study, biodegradable blend of Poly (Ethylene-co-Vinyl Acetate) (EVA) and Ethyl Cellulose (EC) were prepared. Ethylene vinyl alcohol (EVOH) copolymer was used as an interfacial compatibilizer to enhance adhesion between EVA and EC. The melt blended compatibilized biocomposites were examined for mechanical and thermal properties as per the ASTM standards. It has been found that the EC has a reinforcing effect on EVA leading to enhanced tensile strength and also impart biodegradability. Thus, a high loading of 50% EC could be added without compromising Much on the mechanical properties. Analysis of the tensile data using predictive theories showed an enhanced interaction of the dispersed phase (EC) and the matrix (EVA). The compatibilizing effects of EVOH on these blends were confirmed by the significant improvement in the mechanical properties comparable with neat EVA as also observed by SEM microscopy. The TGA thermograms exhibits two-stage degradation and as EC content increases, the onset temperature for thermal degradation reduces. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 1044-1056, 2010
Resumo:
The trade of the financial analyst is currently a much-debated issue in today’s media. As a large part of the investment analysis is conducted under the broker firms’ regime, the incentives of the financial analyst and the investor do not always align. The broker firm’s commercial incentives may be to maximise its commission from securities trading and underwriting fees. The purpose of this thesis is to extend our understanding of the work of a financial analyst, the incentives he faces and how these affect his actions. The first essay investigates how the economic significance of the coverage of a particular firm impacts the analysts’ accuracy of estimation. The hypothesis is that analysts put more effort in analysing firms with a relatively higher trading volume, as these firms usually yield higher commissions. The second essay investigates how analysts interpret new financial statement information. The essay shows that analysts underreact or overreact to prior reported earnings, depending on the short-term pattern in reported earnings. The third essay investigates the possible investment value in Finnish stock recommendations, issued by sell side analysts. It is established that consensus recommendations issued on Finnish stocks contain investment value. Further, the investment value in consensus recommendations improves significantly through the exclusion of recommendations issued by banks. The fourth essay investigates investors’ behaviour prior to financial analysts’ earnings forecast revisions. Lately, the financial press have reported cases were financial analysts warn their preferred clients of possible earnings forecast revisions. However, in the light of the empirical results, it appears that the problem of analysts leaking information to some selected customers does not appear systematically on the Finnish stock market.
Resumo:
Det tysta kunnandet utgör en stor del av kunskapsresursen både hos oss som individer och i arbetsorganisationerna. Trots att vi omger oss med böcker, manualer och databaser, som alla är exempel på explicit kunskap, så är det ”den rätta känslan”, erfarenheten och våra färdigheter som avgör om och hur vi klarar av våra uppgifter. Dessa begrepp är alla relaterade till den tysta dimensionen av kunskap. En dimension som traditionellt karaktäriserats som abstrakt, individuell, omedveten, praktisk, erfarenhetsbaserad och framför allt svår att uttrycka. Alla dessa är karaktärsdrag som ställt speciella krav inom kunskapsforskning och -ledning. Resultatet av detta är att både forskning och ledning av det tysta kunnandet har åsidosatts till förmån för forskning och ledning av explicit kunskap. Ett bidragande problem har varit bristen på lämpliga metoder för att ur ett företagsekonomiskt perspektiv studera och leda tyst kunnande. Ett annat problem har varit oklarhet i begreppet tyst kunskap. Detta har lett till brist på förståelse och/eller missförstånd. För att råda bot på svårigheten att uttrycka vårt tysta kunnande har människan utvecklat olika begrepp som i vår vardagskommunikation symboliserar tyst kunnande. Begrepp som intuition, människokännedom, förhandlingsförmåga och kultur används vanligt och med dem uttrycker vi den tysta dimensionen av kunnande. Dessa begrepp utgör även grunden för den intervjumetod som utvecklats för att empiriskt studera eller i ledningssyfte kartlägga tyst kunnande. Metoden använder dessa ”Epitet för Tyst Kunskap” (ETK) som bas för stimuluskort-intervjuer. Intervjuer som visat sig öka möjligheten att utforska och kartlägga tyst kunnande i organisationer oberoende av om man är forskare eller företagsledare.
Resumo:
Customer value has been identified as “the reason” for customers to patronize a firm, and as one of the fundamental blocks that market exchanges build upon. Despite the importance of customer value, it is often poorly defined, or seems to refer to different phenomena. This dissertation contributes to current marketing literature by subjecting the value concept to a critical investigation, and by clarifying its conceptual foundation. Based on the literature review, it is proposed that customer value can be divided into two separate, but interrelated aspects: value creation processes, and value outcome determination. This means that on one hand, it is possible to examine those activities through which value is created, and on the other hand, investigate how customers determine the value outcomes they receive. The results further show that customers may determine value in four different ways: value as a benefit/sacrifice ratio, as experience outcomes, as means-end chains, and value as phenomenological. In value as benefit/sacrifice ratio, customers are expected to calculate the ratio between service benefits (e.g. ease of use) and sacrifices (e.g. price). In value as experience outcomes, customers are suggested to experience multiple value components, such as functional, emotional, or social value. Customer value as means-ends chains in turn models value in terms of the relationships between service characteristics, use value, and desirable ends (e.g. social acceptance). Finally, value as phenomenological proposes that value emerges from lived, holistic experiences. The empirical papers investigate customer value in e-services, including online health care and mobile services, and show how value in e-service stems from the process and content quality, use context, and the service combination that a customer uses. In conclusion, marketers should understand that different value definitions generate different types of understanding of customer value. In addition, it is clear that studying value from several perspectives is useful, as it enables a richer understanding of value for the different actors. Finally, the interconnectedness between value creation and determination is surprisingly little researched, and this dissertation proposes initial steps towards understanding the relationship between the two.
Resumo:
Mutual funds have increased in popularity among Finnish investors in recent years. In this study returns on domestic funds have been decomposed into several elements that measure different aspects of fund performance. The results indicate that fund managers in the long run tend to allocate fund capital between different stock categories in a profitable way. When it comes to the short term timing of their allocation decisions they are however unable to further improve overall performance. The evidence also suggests that managers possess the ability to pick above average performing stocks within the individual stock categories. During the investigated period most funds returned more than a broad benchmark index even after fees and indirect costs were taken into account.
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In this paper, we present a growing and pruning radial basis function based no-reference (NR) image quality model for JPEG-coded images. The quality of the images are estimated without referring to their original images. The features for predicting the perceived image quality are extracted by considering key human visual sensitivity factors such as edge amplitude, edge length, background activity and background luminance. Image quality estimation involves computation of functional relationship between HVS features and subjective test scores. Here, the problem of quality estimation is transformed to a function approximation problem and solved using GAP-RBF network. GAP-RBF network uses sequential learning algorithm to approximate the functional relationship. The computational complexity and memory requirement are less in GAP-RBF algorithm compared to other batch learning algorithms. Also, the GAP-RBF algorithm finds a compact image quality model and does not require retraining when the new image samples are presented. Experimental results prove that the GAP-RBF image quality model does emulate the mean opinion score (MOS). The subjective test results of the proposed metric are compared with JPEG no-reference image quality index as well as full-reference structural similarity image quality index and it is observed to outperform both.
Resumo:
We present EIS/Hinode and SUMER/SOHO observations of propagating disturbances detected in coronal lines in inter-plume and plume regions of a polar coronal hole. The observation was carried out on 2007 November 13 as part of the JOP196/HOP045 program. The SUMER spectroscopic observation gives information about fluctuations in radiance and on both resolved (Doppler shift) and unresolved (Doppler width) line-of-sight velocities, whereas EIS 40 `'wide slot images detect fluctuations only in radiance but maximize the probability of overlapping field of view between the two instruments. From distance-time radiance maps, we detect the presence of propagating waves in a polar inter-plume region with a period of 15-20 minutes and a propagation speed increasing from 130 +/- 14 km s(-1) just above the limb to 330 +/- 140 km s(-1) around 160 `' above the limb. These waves can be traced to originate from a bright region of the on-disk part of the coronal hole where the propagation speed is in the range of 25 +/- 1.3 to 38 +/- 4.5 km s(-1), with the same periodicity. These on-disk bright regions can be visualized as the base of the coronal funnels. The adjacent plume region also shows the presence of propagating disturbances with the same range of periodicity but with propagation speeds in the range of 135 +/- 18 to 165 +/- 43 km s(-1) only. A comparison between the distance-time radiance map of the two regions indicates that the waves within the plumes are not observable (may be getting dissipated) far off-limb, whereas this is not the case in the inter-plume region. A correlation analysis was also performed to find out the time delay between the oscillations at several heights in the off-limb region, finding results consistent with those from the analysis of the distance-timemaps. To our knowledge, this result provides first spectroscopic evidence of the acceleration of propagating disturbances in the polar region close to the Sun (within 1.2 R/R-circle dot), which provides clues to the understanding of the origin of these waves. We suggest that the waves are likely either Alfvenic or fast magnetoacoustic in the inter-plume region and slow magnetoacoustic in the plume region. This may lead to the conclusion that inter-plumes are a preferred channel for the acceleration of the fast solar wind.