1,362 research outputs found
The value of information in a multi-agent market model
We present an experimental and simulated model of a multi-agent stock market
driven by a double auction order matching mechanism. Studying the effect of
cumulative information on the performance of traders, we find a non monotonic
relationship of net returns of traders as a function of information levels,
both in the experiments and in the simulations. Particularly, averagely
informed traders perform worse than the non informed and only traders with high
levels of information (insiders) are able to beat the market. The simulations
and the experiments reproduce many stylized facts of stock markets, such as
fast decay of autocorrelation of returns, volatility clustering and fat-tailed
distribution of returns. These results have an important message for everyday
life. They can give a possible explanation why, on average, professional fund
managers perform worse than the market index.Comment: 11 pages, 5 figures, published in EPJ
The number of crossings in multigraphs with no empty lens
Let be a multigraph with vertices and edges, drawn in the
plane such that any two parallel edges form a simple closed curve with at least
one vertex in its interior and at least one vertex in its exterior. Pach and
T\'oth (2018) extended the Crossing Lemma of Ajtai et al. (1982) and Leighton
(1983) by showing that if no two adjacent edges cross and every pair of
nonadjacent edges cross at most once, then the number of edge crossings in
is at least , for a suitable constant . The situation
turns out to be quite different if nonparallel edges are allowed to cross any
number of times. It is proved that in this case the number of crossings in
is at least . The order of magnitude of this bound
cannot be improved.Comment: Appears in the Proceedings of the 26th International Symposium on
Graph Drawing and Network Visualization (GD 2018
Pulling It All Together: Managing the Syriac Galen Palimpsest Project
During a two-year period, from 2009 to 2010, a multidisciplinary team conducted multispectral imaging, digital processing and data management of the Syriac Galen Palimpsest. This contractor-led team applied the turnkey multispectral imaging techniques developed in earlier advanced imaging projects to this palimpsest. This required new management techniques and work processes to provide useful results efficiently and quickly, while minimizing risk. In the initial risk-mitigation study phase, the team first imaged several leaves of the bound SGP in 2009 to characterize the imaging and processing challenges. Building on the findings from this first phase, they then imaged all the disbound leaves in 2010. Management of the SGP imaging and processing focused on integration of the people, processes and technology into an efficient imaging system. This included planning and managing the data flow, data replication, image processing and production of the image product while avoiding bottlenecks. With over 300 GB of data hosted for open access, this project provided opportunity for further study and collaboration, and multispectral imaging work processes used on subsequent programs. This access to the online images allowed a global team of scholars to conduct independent research, during which they also discovered leaves missing from the bound manuscript
Out of Balance: Wrong Turns in Public Employee Speech Law
Although scholars offer a variety of explanations for the modern Supreme Court’s public employee speech jurisprudence, they share a common presumption. According to the standard account, the modern era of public employee free speech law began in 1968, with the Court’s adoption of a balancing test in Pickering v. Board of Education. Contrary to this view, this Article argues that Pickering balancing is better characterized as a relic from a bygone era rather than the start of a new one. Balancing was once the Court’s standard method of judging First Amendment claims. When Pickering was decided, however, balancing was under attack. Consistent with the overall demise of free speech balancing, this Article shows that the Court began abandoning Pickering balancing the moment the standard was announced. Pickering itself was not decided on balancing grounds, and the public employee speech cases that followed it in the Supreme Court have avoided balancing. When Pickering is put into proper perspective, it is possible to identify an overlooked explanation for the modern Court’s public employee speech rulings. This Article tells the story of how the unconstitutional conditions doctrine, unbeknownst to courts and commentators fixated on Pickering balancing, has been the true driving force behind a major area of First Amendment law for nearly fifty years
The value of information in a multi-agent market model
We present an experimental and simulated model of a multi-agent stock market driven by a double auction order matching mechanism. Studying the effect of cumulative information on the performance of traders, we find a non monotonic relationship of net returns of traders as a function of information levels, both in the experiments and in the simulations. Particularly, averagely informed traders perform worse than the non informed and only traders with high levels of information (insiders) are able to beat the market. The simulations and the experiments reproduce many stylized facts of stock markets, such as fast decay of autocorrelation of returns, volatility clustering and fat-tailed distribution of returns. These results have an important message for everyday life. They can give a possible explanation why, on average, professional fund managers perform worse than the market index.Economics; econophysics; financial markets; business and management; information theory and communication theory
Construction And Demolition Debris Recovery And Recycling In Orange County, Fl
In 2008, the State of Florida established a recycling goal of 75% to be achieved by 2020. In response to the Florida goal Orange County (OC), Florida has made the development and implementation of an efficient strategy for landfill diversion of its solid waste a top priority. The Florida Department of Environmental Protection (FDEP) estimated that 23 % of municipal solid waste was generated by construction and demolition (C&D) activities in 2009, with only 30 percent of C&D debris being recycled. Therefore, OC decided to create a solid waste integrated resource plan (SWIRP) initially focused on the recovery and recycling of C&D materials (2010). For SWIRP development, OC decision makers need the best available data regarding C&D debris generation and composition and an understanding of the potential markets available for recycled materials. In this investigation debris generation was estimated over the period of 2001 to 2009 for the largest single governing body within OC, unincorporated OC (UOC), representing 65 percent of county population. The debris generation model was constructed for years 2001-2010 using area values for C&D activities in six sectors obtained from building permits and debris generation multipliers obtained from literature values. The benefit of the model is that as building permit information is received, debris generation estimations can also be expediently updated. Material composition fractions obtained from waste characterization studies of landfills in the Central Florida area were applied to the debris generation model resulting in a material iv composition for all sectors for years 2001-2010. The material composition of the debris stream was found to be, on average, concrete (53%) drywall (20%), wood (12%), a miscellaneous fraction (8%), asphalt roofing material (4%), metal (2%), cardboard (1%) and carpet and padding (1%). A market analysis was performed for concrete, drywall, wood, asphalt roofing shingles and residual screened materials (RSM). It was found that statewide, markets existed for 100 percent of the materials studied and could replace significant amounts of natural material feedstocks, but that the development of more local markets was vital to meeting OC’s diversion goal to minimize the cost of transporting recyclables
Hormonal modulation of reproduction in Polistes fuscatus social wasps: dual functions in both ovary development and sexual receptivity
Hormones are often major regulators of complex behaviors, such as mating and reproduction. In insects, juvenile hormone (JH) is integral to many components of reproductive physiology and behavior, but its role in female sexual receptivity is not well understood. To investigate the influence of JH on receptivity, we utilized the social wasp Polistes fuscatus. In Polistes, mating behavior is temporally separated from other components of reproduction, which allows for examination of the physiology and behavior of mating, disentangled from fertilization and egg-laying. We reared virgin gynes (reproductive females) in the lab and divided them into four groups, in which gynes received multiple topical treatments of either 20ÎĽg, 10ÎĽg, 5ÎĽg, or 0ÎĽg of the JH analog methoprene. Gynes were then placed in petri dishes with 2 unrelated males and we recorded attempted and successful mating. Additionally, we measured gyne ovarian development and survival in each group. We found that methoprene increased both sexual receptivity and ovarian development, but was associated with a decrease in long-term survival. Receptivity increased linearly as methoprene treatment increased, but the effect of methoprene on ovarian development was independent of dose. These results demonstrate the importance of JH in sexual receptivity and mating behavior. We argue that the relatively understudied Polistes gyne has potential as a model for mating and reproduction, and for the internal and external regulation of this complex behavior
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A State Level Analysis of the Marzano Teacher Evaluation Model: Predicting Teacher Value-Added Measures with Observation Scores
The purpose of the study is to close the gap in the literature regarding the Marzano Teacher Evaluation Model (MTEM) that lacks large scale empirical investigations to assess the predictability of the model. The study thoroughly reviews the extant literature from all teacher evaluation frameworks, particularly focusing on the large body of published studies that have investigated the correlations between teacher observation ratings and teacher value-added measures, then outlines the literature specific to the MTEM. The study extracted observation ratings from a collection platform and linked it to the Florida Department of Education teacher value-added measure, which controls for prior testing history and student-level characteristics. The study sample included over 12,000 teachers and validated the use of the MTEM, particularly in Florida, by upholding the magnitude of correlations found in other instructional frameworks and demonstrating that observation ratings were the largest predictor in multilevel models accounting for student, teacher and school level characteristics.Accessed 429 times on https://pareonline.net from July 25, 2019 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right
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