2,174 research outputs found
A Computer Graphic Teaching Aid for the Synthesis of Four-Bar Linkages
This project involves developing software for the use as a teaching tool in the classroom. The four-bar linkage mechanism , often used in kinematic movement, is the main subject
The software provides a working environment to perform a graphical synthesis of a four- bar linkage to move one of the links through three specified positions in the plane. The construction process is facilitated by the built in kinematic intelligence so that the student can quickly and easily visualize the process. The construction lines are dynamically updated as the free parameters in the design are modified. This is particularly beneficial because it allows the student to see the dynamic nature of the solution, as opposed to considering it as a static situation. Once the synthesis task is completed, the four-bar linkage is animated to provide immediate verification of the satisfaction of the original motion specifications.
The software can be run on the Mechanical Engineering Department computer network
Methods of Use and Manufacture of Silver-Doped, Nano-Porous Hydroxyapatite
A silver-doped, nano-porous hydroxyapatite material is provided that can be utilized to capture radioactive iodine, 129I. Methods of using the silver-doped, nano-porous hydroxyapatite material to remove radioactive iodine, and methods of manufacturing the material are also provided
Risk measurement and management in a crisis-prone world
The current subprime crisis has prompted us to look again into the nature of risk at the tail of the distribution. In particular, we investigate the risk contribution of an asset, which has infrequent but huge losses, to a portfolio using two risk measures, namely Value-at-Risk (VaR) and Expected Shortfall (ES). While ES is found to measure the tail risk contribution effectively, VaR is consistent with intuition only if the underlying return distribution is well behaved. To facilitate the use of ES, we present a power function formula that can calculate accurately the critical values of the ES test statistic. This in turn enables us to derive a size-based multiplication factor for risk capital requirement
The other side of the trading story: evidence from NYSE
We analyse the well-known TORQ dataset of trades on the NYSE over a 3-month period, breaking down transactions depending on whether the active or passive side was institutional or private. This allows us to compare the returns on the different trade categories. We find that, however we analyse the results, institutions are best informed, and earn highest returns when trading with individuals as counterparty. We also confirm the conclusions found elsewhere in the literature that informed traders often place limit orders, especially towards the end of the day (as predicted on the basis of laboratory experiments in Bloomfield, O�'Hara, and Saar (2005)). Finally, we find that trading between institutions accounts for the bulk of trading volume, but carries little information and seems to be largely liquidity-driven
Information-based trade in the Shanghai stock market
We show that the probability of information-based trade (PIN) played a significant role in explaining monthly returns on Shanghai A shares over the period 2001 to 2006. In particular, PIN, as approximated by order imbalance as a proportion of total transactions, appears to explain returns even after controlling for risk in the much-cited Fama and French (1992) three-factor model. However, we also find that some of the PIN effect appears to be indistinguishable from a turnover effect
Form 990: Useful in Analyzing Not-For-Profit Ministries?
The major purpose of this article is to analyze the Forms 990 filed with the IRS by some religious organizations including television evangelists. Specifically, this article (1) examines the financial operations of religious organizations, such as revenue generation, spending, investment and borrowing; (2) investigates their accounting practices and conformance to generally accepted accounting principles; and (3) discusses the usefulness of Form 990 in monitoring tax-exempt religious organizations. The results of this study will provide evidence on whether the Form 990 filed by religious organizations conforms to generally accepted accounting principles and fairly represents their financial operations. The results will also be useful to the IRS and other governmental agencies in determining the informational value and usefulness of the current Form 990
Hydro-chemical study of the evolution of interstellar pre-biotic molecules during the collapse of molecular clouds
One of the stumbling blocks for studying the evolution of interstellar
molecules is the lack of adequate knowledge of the rate co-efficients of
various reactions which take place in the Interstellar medium and molecular
clouds. Some of the theoretical models of rate coefficients do exist in the
literature for computing abundances of the complex pre-biotic molecules. So far
these have been used to study the abundances of these molecules in space.
However, in order to obtain more accurate final compositions in these media, we
find out the rate coefficients for the formation of some of the most important
interstellar pre-biotic molecules by using quantum chemical theory. We use
these rates inside our hydro-chemical model to find out the chemical evolution
and the final abundances of the pre-biotic species during the collapsing phase
of a proto-star. We find that a significant amount of various pre-biotic
molecules could be produced during the collapsing phase of a proto-star. We
study extensively the formation these molecules via successive neutral-neutral
and radical-radical/radical-molecular reactions. We present the time evolution
of the chemical species with an emphasis on how the production of these
molecules varies with the depth of a cloud. We compare the formation of adenine
in the interstellar space using our rate-coefficients and using those obtained
from the existing theoretical models. Formation routes of the pre-biotic
molecules are found to be highly dependent on the abundances of the reactive
species and the rate coefficients involved in the reactions. Presence of grains
strongly affect the abundances of the gas phase species. We also carry out a
comparative study between different pathways available for the synthesis of
adenine, alanine, glycine and other molecules considered in our network.Comment: 12 pages, 4 figure
A GMM skewness and kurtosis ratio test for higher moment dependence
This article extends the variance ratio test of Lo and MacKinlay (1988) to tests of skewness and kurtosis ratios using the generalized methods of moments. In particular, overlapping observations are used in which dependencies are explicitly modeled to make the tests more powerful and have better size properties. The proposed higher-order ratio tests can be useful in risk management where risk models are estimated using daily data but multiperiod forecasts of tail risks are required for the determination of risk capital. Application of the tests finds significant higher moment dependence in the U.S. stock market returns
Polymer Translocation in Crowded Environments
We study the effect of the crowded nature of the cellular cytoplasm on the
translocation of a polymer through a pore in a membrane. By systematically
treating the entropic penalty due to crowding, we show that the translocation
dynamics are significantly altered, leading to novel scaling behaviors of the
translocation time in terms of chain length. We also observe new and
qualitatively different translocation regimes depending upon the extent of
crowding, transmembrane chemical potential asymmetry, and polymer length.Comment: 4 figure
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