53,388 research outputs found
The Effect of Lamp Types on the Growth and Production of Lettuce Grown in an Indoor Hydrophonic System
The objective of this research was to evaluate responses of grand rapid lettuce (Lactuca sativa L.) grown in anindoor hydrophonic system(awick system) under the treatments of some different types of lighting. The researchwas conducted in April to June 2015. The treatment in this reearch consisted of a single factor (types of lighting)with five levels: Sun lighting (N0), 2 tubes of 18Watt fluorescent lamp (N1), 2 sets of 36Watt LED + 1 tube of 150Watt halogenlamp (N2), 2 setsof 36Watt LED+ 2 tubes of18Watt fluorescent lamp (N3), and 150Wattbulb (N4).Each treatment consisted of four plantswhichwere grown in a 60 cmx 60 cmx 120 cmgrowth chambermade ofplywood, except for sun light treated plantswhich were placed inamini greenhouse. Results showed that amongthe plants in the growth chambers, the best vegetative growthwas shown by the lettuce in the treatment of 2 setsof 36Watt LED + 2 tubes of 18Watt fluorescent lamp (N3), However; compared to those plants grown under thesun light, the lettuce inN3 still looked etiolation because light intensitywas not optimal yet
Opinion Mining on Non-English Short Text
As the type and the number of such venues increase, automated analysis of
sentiment on textual resources has become an essential data mining task. In
this paper, we investigate the problem of mining opinions on the collection of
informal short texts. Both positive and negative sentiment strength of texts
are detected. We focus on a non-English language that has few resources for
text mining. This approach would help enhance the sentiment analysis in
languages where a list of opinionated words does not exist. We propose a new
method projects the text into dense and low dimensional feature vectors
according to the sentiment strength of the words. We detect the mixture of
positive and negative sentiments on a multi-variant scale. Empirical evaluation
of the proposed framework on Turkish tweets shows that our approach gets good
results for opinion mining
Predicting cortical bone adaptation to axial loading in the mouse tibia
The development of predictive mathematical models can contribute to a deeper understanding of the specific stages of bone mechanobiology and the process by which bone adapts to mechanical forces. The objective of this work was to predict, with spatial accuracy, cortical bone adaptation to mechanical load, in order to better understand the mechanical cues that might be driving adaptation. The axial tibial loading model was used to trigger cortical bone adaptation in C57BL/6 mice and provide relevant biological and biomechanical information. A method for mapping cortical thickness in the mouse tibia diaphysis was developed, allowing for a thorough spatial description of where bone adaptation occurs. Poroelastic finite-element (FE) models were used to determine the structural response of the tibia upon axial loading and interstitial fluid velocity as the mechanical stimulus. FE models were coupled with mechanobiological governing equations, which accounted for non-static loads and assumed that bone responds instantly to local mechanical cues in an on–off manner. The presented formulation was able to simulate the areas of adaptation and accurately reproduce the distributions of cortical thickening observed in the experimental data with a statistically significant positive correlation (Kendall's τ rank coefficient τ = 0.51, p < 0.001). This work demonstrates that computational models can spatially predict cortical bone mechanoadaptation to a time variant stimulus. Such models could be used in the design of more efficient loading protocols and drug therapies that target the relevant physiological mechanisms
An Exact Formula for the Average Run Length to False Alarm of the Generalized Shiryaev-Roberts Procedure for Change-Point Detection under Exponential Observations
We derive analytically an exact closed-form formula for the standard minimax
Average Run Length (ARL) to false alarm delivered by the Generalized
Shiryaev-Roberts (GSR) change-point detection procedure devised to detect a
shift in the baseline mean of a sequence of independent exponentially
distributed observations. Specifically, the formula is found through direct
solution of the respective integral (renewal) equation, and is a general result
in that the GSR procedure's headstart is not restricted to a bounded range, nor
is there a "ceiling" value for the detection threshold. Apart from the
theoretical significance (in change-point detection, exact closed-form
performance formulae are typically either difficult or impossible to get,
especially for the GSR procedure), the obtained formula is also useful to a
practitioner: in cases of practical interest, the formula is a function linear
in both the detection threshold and the headstart, and, therefore, the ARL to
false alarm of the GSR procedure can be easily computed.Comment: 9 pages; Accepted for publication in Proceedings of the 12-th
German-Polish Workshop on Stochastic Models, Statistics and Their
Application
Cadaveric renal transplantation at the University of Pittsburgh: a two and one-half-year experience with the point system.
From January 1, 1986 to July 30, 1988, 530 consecutive cadaver kidney transplantations were performed with patient selection by a point system that took into account time awaiting an organ, donor-recipient matching, degree of presensitization, and some less important factors. The effect of the system was to diminish judgmental factors in case selection which in the past, had probably operated to the disadvantage of "undesirable" potential recipients, including older ones. Primary 1-year graft survival (74%) and graft survival after retransplantation (71%) were lower than in the earlier time. However, the results with triple-drug therapy using CsA, AZA and P demonstrated 88% 1-year graft survival for primary graft recipients and 74% in highly sensitized patients, with comparable patient mortality. These latter observations provide some assurance that the concepts of equitable access and efficient utilization of a scarce resource are not mutually exclusive
Effectiveness of the Chebyshev Approximation in Magnetic Field Line Tracking
The tracking of magnetic field lines can be very expensive, in terms of computational burden, when the field sources are numerous and have complex geometries, especially when accuracy is a priority, because an evaluation of the field is required in many situations. In some important applications, the computational cost can be significantly reduced by using a suitable approximation of the field in the integrated regions. This paper shows how Chebyshev polynomials are well-suited for field interpolation in magnetic field-line tracking, then discusses the conditions in which they are most appropriate, and quantifies the effectiveness of parallel computing in the approximation procedures
Characterizing normal crossing hypersurfaces
The objective of this article is to give an effective algebraic
characterization of normal crossing hypersurfaces in complex manifolds. It is
shown that a hypersurface has normal crossings if and only if it is a free
divisor, has a radical Jacobian ideal and a smooth normalization. Using K.
Saito's theory of free divisors, also a characterization in terms of
logarithmic differential forms and vector fields is found and and finally
another one in terms of the logarithmic residue using recent results of M.
Granger and M. Schulze.Comment: v2: typos fixed, final version to appear in Math. Ann.; 24 pages, 2
figure
Radio pulsar populations
The goal of this article is to summarize the current state of play in the
field of radio pulsar statistics. Simply put, from the observed sample of
objects from a variety of surveys with different telescopes, we wish to infer
the properties of the underlying sample and to connect these with other
astrophysical populations (for example supernova remnants or X-ray binaries).
The main problem we need to tackle is the fact that, like many areas of
science, the observed populations are often heavily biased by a variety of
selection effects. After a review of the main effects relevant to radio
pulsars, I discuss techniques to correct for them and summarize some of the
most recent results. Perhaps the main point I would like to make in this
article is that current models to describe the population are far from complete
and often suffer from strong covariances between input parameters. That said,
there are a number of very interesting conclusions that can be made concerning
the evolution of neutron stars based on current data. While the focus of this
review will be on the population of isolated Galactic pulsars, I will also
briefly comment on millisecond and binary pulsars as well as the pulsar content
of globular clusters and the Magellanic Clouds.Comment: 16 pages, 6 figures, to appear in Proceedings of ICREA Workshop on
The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain,
2010 April 12-16 (Springer
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