2,595 research outputs found
Agents Play Mix-game
In mix-game which is an extension of minority game, there are two groups of
agents; group1 plays the majority game, but the group2 plays the minority game.
This paper studies the change of the average winnings of agents and
volatilities vs. the change of mixture of agents in mix-game model. It finds
that the correlations between the average winnings of agents and the mean of
local volatilities are different with different combinations of agent memory
length when the proportion of agents in group 1 increases. This study result
suggests that memory length of agents in group1 be smaller than that of agent
in group2 when mix-game model is used to simulate the financial markets.Comment: 8 pages, 6 figures, 3 table
Forage Management for Extending the Grazing Season
Studies were conducted to determine ways to extend grazing season with forages adequate to meet the needs of grazing animals and to reduce the cost of livestock production. Perennial grasses were swathed, windrowed and left in the field until they were winter-grazed with bred heifers. Corn (Zea mays L.) was stockpiled for winter grazing with lambs and ewes. Windrowed grasses increased in acid detergent fiber (ADF) and neutral detergent fiber (NDF) compared with stored hay, but crude protein content, heifer weight gain and body condition change was similar for both forages. An economic value of 75 ha-1. Leaving windrows of perennial grasses in the field and stockpiling corn for winter grazing have potential for reducing reliance on stored forages
A Light Calibration System for the ProtoDUNE-DP Detector
A LED-based fiber calibration system for the ProtoDUNE-Dual Phase (DP) photon
detection system (PDS) has been designed and validated. ProtoDUNE-DP is a 6x6x6
m3 liquid argon time-projection-chamber currently being installed at the
Neutrino Platform at CERN. The PDS is based on 36 8-inch photomultiplier tubes
(PMTs) and will allow triggering on cosmic rays. The system serves as prototype
for the PDS of the final DUNE DP far detector in which the PDS also has the
function to allow the 3D event reconstruction on non-beam physics. For this
purpose an equalized PMT response is desirable to allow using the same
threshold definition for all PMT groups, simplifying the determination of the
trigger efficiency. The light calibration system described in this paper is
developed to provide this and to monitor the PMT performance in-situ.Comment: 15 pages, 5 figure
Generalized Hurst exponent and multifractal function of original and translated texts mapped into frequency and length time series
A nonlinear dynamics approach can be used in order to quantify complexity in
written texts. As a first step, a one-dimensional system is examined : two
written texts by one author (Lewis Carroll) are considered, together with one
translation, into an artificial language, i.e. Esperanto are mapped into time
series. Their corresponding shuffled versions are used for obtaining a "base
line". Two different one-dimensional time series are used here: (i) one based
on word lengths (LTS), (ii) the other on word frequencies (FTS). It is shown
that the generalized Hurst exponent and the derived curves
of the original and translated texts show marked differences. The original
"texts" are far from giving a parabolic function, - in contrast to
the shuffled texts. Moreover, the Esperanto text has more extreme values. This
suggests cascade model-like, with multiscale time asymmetric features as
finally written texts. A discussion of the difference and complementarity of
mapping into a LTS or FTS is presented. The FTS curves are more
opened than the LTS onesComment: preprint for PRE; 2 columns; 10 pages; 6 (multifigures); 3 Tables; 70
reference
Modelling diffusion of innovations in a social network
A new simple model of diffusion of innovations in a social network with
upgrading costs is introduced. Agents are characterized by a single real
variable, their technological level. According to local information agents
decide whether to upgrade their level or not balancing their possible benefit
with the upgrading cost. A critical point where technological avalanches
display a power-law behavior is also found. This critical point is
characterized by a macroscopic observable that turns out to optimize
technological growth in the stationary state. Analytical results supporting our
findings are found for the globally coupled case.Comment: 4 pages, 5 figures. Final version accepted in PR
Characterization of the Hamamatsu S8664 Avalanche Photodiode for X-Ray and VUV-light detection
We present the first operation of the Avalanche Photodiode (APD) from
Hamamatsu to xenon scintillation light and to direct X-rays of 22.1 keV and 5.9
keV. A large non-linear response was observed for the direct X-ray detection.
At 415 V APD bias voltage it was of about 30 % for 22.1 keV and about 45 % for
5.9 keV. The quantum efficiency for 172 nm photons has been measured to be 69
+/- 15 %.Comment: 11 pages, 3 figures, submitted to Elsevie
Rapid, Heuristic Discovery and Design of Promoter Collections in Non-Model Microbes for Industrial Applications
This is the author accepted manusript. The final version is available from American Chemical Society via the DOI in this recordAccession Codes:
The sequence data for the four Geobacillus spp. used in this study have been submitted to the NCBI Sequence Read Archive and are available under the accession number PRJNA521450.Well-characterized promoter collections for synthetic biology applications are not always available in industrially relevant hosts. We developed a broadly applicable method for promoter identification in atypical microbial hosts that requires no a priori understanding of cis-regulatory element structure. This novel approach combines bioinformatic filtering with rapid empirical characterization to expand the promoter toolkit and uses machine learning to improve the understanding of the relationship between DNA sequence and function. Here, we apply the method in Geobacillus thermoglucosidasius, a thermophilic organism with high potential as a synthetic biology chassis for industrial applications. Bioinformatic screening of G. kaustophilus, G. stearothermophilus, G. thermodenitrificans, and G. thermoglucosidasius resulted in the identification of 636 100 bp putative promoters, encompassing the genome-wide design space and lacking known transcription factor binding sites. Eighty of these sequences were characterized in vivo, and activities covered a 2-log range of predictable expression levels. Seven sequences were shown to function consistently regardless of the downstream coding sequence. Partition modeling identified sequence positions upstream of the canonical -35 and -10 consensus motifs that were predicted to strongly influence regulatory activity in Geobacillus, and artificial neural network and partial least squares regression models were derived to assess if there were a simple, forward, quantitative method for in silico prediction of promoter function. However, the models were insufficiently general to predict pre hoc promoter activity in vivo, most probably as a result of the relatively small size of the training data set compared to the size of the modeled design space
Economic Fluctuations and Diffusion
Stock price changes occur through transactions, just as diffusion in physical
systems occurs through molecular collisions. We systematically explore this
analogy and quantify the relation between trading activity - measured by the
number of transactions - and the price change ,
for a given stock, over a time interval . To this end, we
analyze a database documenting every transaction for 1000 US stocks over the
two-year period 1994-1995. We find that price movements are equivalent to a
complex variant of diffusion, where the diffusion coefficient fluctuates
drastically in time. We relate the analog of the diffusion coefficient to two
microscopic quantities: (i) the number of transactions in
, which is the analog of the number of collisions and (ii) the local
variance of the price changes for all transactions in , which is the analog of the local mean square displacement between
collisions. We study the distributions of both and , and find that they display power-law tails. Further, we find that
displays long-range power-law correlations in time, whereas
does not. Our results are consistent with the interpretation
that the pronounced tails of the distribution of w_{\Delta t}|
G_{\Delta t} |N_{\Delta t}$.Comment: RevTex 2 column format. 6 pages, 36 references, 15 eps figure
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