نتایج جستجو برای: 919

تعداد نتایج: 1383  

2013
Matthias Dehmer Frank Emmert-Streib Shailesh Tripathi

Molecular descriptors have been explored extensively. From these studies, it is known that a large number of descriptors are strongly correlated and capture similar characteristics of molecules. In this paper, we evaluate 919 Dragon-descriptors of 6 different categories by means of clustering. Also, we analyze these different categories of descriptors also find a subset of descriptors which are...

2002

Under 5 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 972 5.5 5 to 9 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 945 5.3 10 to 14 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,059 6.0 15 to 19 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,049 5.9 20 to 24 years . . . . . . . . . . . . . . . . . . ....

ژورنال: :مجله دانشگاه علوم پزشکی شهرکرد 0
مرتضی سدهی mortaza sedehi شهرکرد- رحمتیه- دانشکده بهداشت- گروه آمار زیستی و اپیدمیولوژی یداله محرابی yadolah mehrabi 2research institute for endocrine sciences, shahid beheshti university of medical sciences, tehran, iran, عباس خدابخشی abbas khodabakhshi 3environmental health engineering dept., shahrekord university of medical sciences, shahrekord, iran.

زمینه و هدف: در فرآیند مدل سازی، زمانی که بین متغیرهای کمکی همبستگی های نسبتا قوی وجود داشته باشد، هم خطی چندگانه ایجاد شده و باعث کاهش کارآیی مدل می گردد. هدف از این مطالعه استفاده از تحلیل مولفه های اصلی برای تعدیل اثر هم خطی چندگانه در مدل های رگرسیون لجستیک و شبکه عصبی مصنوعی و بررسی تاثیر آن بر صحت و دقت پیش بینی سندرم متابولیک بود. روش بررسی: در این مطالعه توصیفی – تحلیلی تعداد 347 نفر از...

2009
Xiang Zhou Scott C. Schmidler

Ising and Potts models are discrete Gibbs random field models originating in statistical physics, which are now widely used in statistics for applications in spatial modeling, image processing, computational biology, and computational neuroscience. However, parameter estimation in these models remains challenging due to the appearance of intractable normalizing constants in the likelihood. Here...

2009
Daniel Dorn Günter Strobl

The disposition effect is a longstanding puzzle in financial economics. This paper demonstrates that it is not intrinsically at odds with rational behavior. In a rational expectations model with asymmetrically informed investors, trading strategies as predicted by the disposition effect can arise as an optimal response to dynamic changes in the information structure. The model generates several...

Journal: :Electronic Commerce Research and Applications 2005
Robert J. Kauffman Charles A. Wood

An increasing number of reports of online auction fraud are of growing concern to auction operators and participants. In this research, we discuss reserve price shilling, where a bidder shills in order to avoid paying auction house fees, rather than to drive up the price of the final bid. We examine the effect that premium bids have upon the final selling price, since they are linked with reser...

1998
Wayne E. Ferson Campbell R. Harvey

This paper provides a global asset pricing perspective on the debate over the relation between predetermined attributes of common stocks, such as ratios of price-to-bookvalue, cash̄ow, earnings, and other variables to the future returns. Some argue that such variables may be used to ®nd securities that are systematically undervalued by the market, while others argue that the measures are proxies...

2012
Simon Gervais Günter Strobl

We construct and analyze a model of delegated portfolio management in which money managers signal their investment skills via their choice of transparency for their fund. We show that a natural equilibrium is one in which highand low-skill managers pool in opaque funds, while medium-skill managers separate in transparent funds. In this equilibrium, high-skill managers rely on their eventual per...

2015
Cecil C. Bozarth Donald P. Warsing Barbara B. Flynn E. James Flynn

This paper puts forth a model of supply chain complexity and empirically tests it using plant-level data from 209 plants across seven countries. The results show that upstream complexity, internal manufacturing complexity, and downstream complexity all have a negative impact on manufacturing plant performance. Furthermore, supply chain characteristics that drive dynamic complexity are shown to ...

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