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CONSERVATION GENETICS OF PADDLEFISH: GENETIC EFFECTIVE POPULATION SIZE AND RANGEWIDE GENETIC STRUCTUREAsher, Allison Marie 01 May 2019 (has links)
Paddlefish (Polyodon spathula) is a commercially and recreationally important species, with a native range that extends over 22 US states. This is a large, long-lived, highly mobile riverine species that has been negatively impacted by habitat fragmentation, historic overharvest, and hatchery supplementation. Dams are the primary cause of habitat fragmentation, blocking migration routes, flooding spawning grounds, and isolating populations. A common management action to mitigate the impacts of habitat fragmentation and maintain harvestable populations is hatchery propagation and stocking. Reduction in stock size, isolation of populations, and stocking can all negatively impact the genetic integrity of Paddlefish. I evaluated the impacts of isolation and hatchery supplementation on the effective population size (Ne) of Paddlefish as well as the range-wide genetic structure of Paddlefish.
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Sample Size Determination in Auditing Accounts Receivable Using a Zero-Inflated Poisson ModelPedersen, Kristen E 28 April 2010 (has links)
In the practice of auditing, a sample of accounts is chosen to verify if the accounts are materially misstated, as opposed to auditing all accounts; it would be too expensive to audit all acounts. This paper seeks to find a method for choosing a sample size of accounts that will give a more accurate estimate than the current methods for sample size determination that are currently being used. A review of methods to determine sample size will be investigated under both the frequentist and Bayesian settings, and then our method using the Zero-Inflated Poisson (ZIP) model will be introduced which explicitly considers zero versus non-zero errors. This model is favorable due to the excess zeros that are present in auditing data which the standard Poisson model does not account for, and this could easily be extended to data similar to accounting populations.
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A comparison of some lot-sizing heuristic rules independent of EOQ-assumptions.January 1986 (has links)
by Siu Wai-man, Raymond. / Bibliography: leaves 75-76 / Thesis (M.B.A.)--Chinese University of Hong Kong, 1986
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The size distribution of plants and economic developmentBhattacharya, Dhritiman 01 July 2010 (has links)
The plant size distribution differs systematically across developed and developing countries. For example, in developing countries, less than one fifth of 1% of plants are large (employ 100 or more employees) and account for about one fifth of total employment. In sharp contrast, in developed countries, more than 1.6% of plants are large and account for more than two fifth of total employment. In this dissertation, I develop a model of plant size to account for the differences in the plant size distribution observed in the data.
In the first chapter, I explore the link between plant size distribution and economic development. I also discuss the main features of the plant size distribution data. The purpose of this data set is to provide evidence of systematic differences in plant size distribution across developed and developing countries.
In the second chapter, I present a dynamic employment choice model in a life cycle setting. Then I calibrate the benchmark model to match some key features of the U.S. plant size distribution. I find that my model can capture the critical features of U.S. plant size distribution, including the upper tail which accounts for the bulk of the employment and output in the U.S. economy.
In the third chapter, I explore how exogenous differences in aggregate barriers to investment and technology across countries affect the plant size distribution. Results indicate that exogenous differences in aggregate barriers to investment and technology across countries can account for more than 50% of the variation in both the fraction of large plants and employment share in large plants across countries. For the same group of countries, exogenous differences in aggregate barriers also account for 36% of the variation in the mean size.
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Particles in the eastern Pacific ocean : their distribution and effect upon optical parametersCarder, Kendall L. 30 September 1969 (has links)
The distribution of particles in the Eastern Pacific Ocean was
investigated from 2 January to 14 February, l969, on the YALOC-69
cruise of Oregon State University. The size distributions were well
fitted by the two-parameter Weibull distribution function, with a
predominant number of them nearly exponential in distributional
shape. Although particles smaller in diameter than 1i could not be
measured, extrapolation of the Weibull distribution into the small
particle range indicated the median particle diameter was smaller than
1μ.
Measurements of light scattering were taken simultaneously
with the particle size determinations. A linear relationship between
the total particulate surface area and the volume scattering function,
β(45°) was indicated, as well as between β(45°)/β(135°) and the
mean particle diameter of distributions sharing a common shape
parameter. Five different characteristic distributional shapes
were found which typified all but a few of the distributions. No
direct relationship was found between the distributional shapes and
the water types encountered on the cruise. The first-order exponential
shapes of the size distributions suggest that a detrital decay
mechanism of the larger particles (i. e. phytoplankton) could be a
dominant factor in determining the small particle end of oceanic
particle distributions. / Graduation date: 1970
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Formation of secondary organic particulate matter by reactions of gas phase organic compounds with aerosol particles /Zhang, Jin. January 2004 (has links)
Thesis (M.Sc.)--York University, 2004. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 117-120). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL:http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss&rft%5Fval%5Ffmt=info:ofi/fmt:kev:mtx:dissertation&rft%5Fdat=xri:pqdiss:MQ99407
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Partiformning och beläggning av artiklar i produktionssystemBornholm, Martin, Samuelsson, Gustaf, Pavic, Robert January 2012 (has links)
Sammanfattning På grund av ökad konkurrens måste företag öka sin konkurrenskraft. Ett sätt för företag att öka sin konkurrenskraft är att utnyttja de resurser de besitter på ett mer effektivt sätt. Hur ett producerande företag styr sin produktion påverkar hur effektivt de utnyttjar sitt produktionssystem, lager och personal. Ett företag kan styra sin produktion genom att välja hur de partiformar och belägger de artiklar som utnyttjar ett produktionssystem. Syftet med det här arbetet är att öka förståelsen för hur en modell för partiformning och beläggning av artiklar med varierande efterfrågan i ett produktionssystem där kapacitetsbrist råder kan se ut. Arbetet är en fallstudie där partiformning och beläggning av artiklar i ett produktionssystem analyseras. Kvalitativ forskning har bedrivits för att nå en djup förståelse för problemet. I arbetet beskrivs teorier om flöden, planering, partiformning och beläggning. Empirisk data som nämns i arbetet är beskrivningar av fallstudiens produktionssystem, de artiklar som produceras i systemet och planeringsprocessen företaget i fallstudien använder vid partiformning och beläggning. I analysen undersöks hur väl olika teorier passar för planering, partiformning och beläggning av fallstudiens produktionssystem. Genom en allmän diskussion om hur de beskrivna teorierna påverkar ett produktionssystems förmåga att ta tillvara på begränsad kapacitet och hantera varierande efterfrågan av artiklar nås en ökad förståelse för hur en modell kan se ut. De slutsatser som dras i arbetet är att partiformning och beläggning som sker för att optimera flödet kan öka effektiviteten i resursutnyttjandet. Ett sätt att optimera flödet är att belägga den resurs som anses vara kritisk först, beläggningen av den kritiska resursen styr därefter beläggningen av övriga produktionssystemet. Fler slutsatser som dras i arbetet är att en modell för partiformning och beläggning av artiklar med varierande efterfrågan i ett produktionssystem där kapacitetsbrist råder bör vara dynamisk. För att skapa en dynamisk modell kan beläggning och partiformning ske parallellt, det vill säga att partistorleken för en artikel påverkar beläggningen av en resurs, vilket i sin tur bör påverka partistorleken för resterande artiklar.
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The effect of stock repurchase on market liquidity ¡V Empirical evidence from Taiwanese listed firmsLi, Chung-ho 02 June 2010 (has links)
¡@¡@Treasury stock system allows listed companies to buy back their own shares in the open market. In general, when the company announced stock repurchase event, investors are optimistic about the prospects of the company. Therefore, the company's stock price usually rises. But will investors buy more stocks, leading to increased liquidity of stocks? This study combines with stock repurchase and liquidity to investigate the impact of stock repurchase on liquidity. Further events will be studied by different factors stratified, including firm size, stock price, industry, the purpose of stock repurchase, the proportion of execution, the holding ratio of insiders and institutional investors. By using three types of liquidity measures, the study is to observe the changes of liquidity of stocks in the different situations.
¡@¡@After conducting mean difference in pair-sample test, the empirical results indicate that the sample stocks in the stock repurchase announcement, the outcome supports liquidity increase hypothesis. In terms of the stratification factors, the smaller of the company size or lower stock price will help increase the liquidity of the stock in the market. Non-electronics sector, aims to buy back equity write-off shares can improve market liquidity. Higher or lower percentage of insider ownership shares in¡@companies will lead to the increase of stock liquidity. Higher holding shares proportion of institutional investor in companies will increase liquidity. The amount of execution ratio is of no factors, but the liquidity of the stock repurchase still supports the liquidity increase hypothesis.
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Study on Wave Field with Caisson on Multiple Porous LayersChou, Chun-ting 07 September 2010 (has links)
In the study, wave reflection, transmission, and energy dissipation with a caisson-type breakwater have been investigated experimentally. Three different sizes of grain are used to construct the porous base, they are 16mm, 25mm, and 35mm, respectively.Single and double layers of porous base are considered.
Hydraulic test, porous media choice is glass ball.Wave conditions must be consistent with the scope of the linear wave theory. Two different depths are used to construct,they are 40 cm and 72 cm. Do a single trial of all size. Double size 16mm and 35mm
diameter glass ball is a test. Recording the test process, and then analyze energy
consumption. Water area's characteristics and pore area's characteristics are calculated
by the Newton¡¦s method and the Ward¡¦s method. It is the substitute for the dispersion
equation is also correct. During the course of a series, the draft of caisson is deeper, the
convergence is harder. But the increase and decrease the mode number or the draft, and
sometimes increase the possible of convergence. As the number of cutting layer are
more complex than other predecessors, particularly in the large number of required
mode, when the composition of the matrix of boundary conditions greater complexity.
In the caisson area calculated pore velocity, or on behalf of the later is very large, so it's
easy in the solution process, generate positive infinity or negative infinity error.
As the caisson-type breakwater with a shorter wavelength, the frictional resistance influences bigger. At this time, reflectance and transmittance has the Drop tendency.When the wavelength is longer, the frictional resistance influences smaller. Most of the
energy reflection because the caisson of less permeable. The caisson-type breakwater got the wave force to increase. The effect is bad in the Wave force reduced. If the static water surface above the pore structure, the caisson-type breakwater can be reduction of about 30% to 40% off the energy. If the static water surface under the pore structure, the
caisson-type breakwater wave damping efficiency is better. Usually remove 30% to 70% energy. Sometimes, it¡¦s up to about 90%.Reflectivity of the caisson breakwater is larger, but the transmissivity is lower. For the waters behind the breakwater, the
protective effect is significant. Transmissivity trend is arranged according to media size. As the media size smaller, the transmissivity is smaller, the reflectivity is higher. At the same depth, double-size model compared with other single-size model of the wave
forces reduced is better. Whether long or short period, double-size model's performance is relatively stable. Except to a long cycle time, the wave damping efficiency has a larger range. Other cycles are at the lower position.
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Two higher order elasticity theories: their variational formulations and applicationsPark, Sung Kyoon 15 May 2009 (has links)
Classical elasticity cannot be used to explain effects related to material
microstructures due to its lack of a material length scale parameter. To mitigate this
deficiency, higher order elasticity theories have been developed. Two simple higher
order theories and their applications are studied in this research. One is a modified
couple stress theory and the other is a simplified strain gradient theory, each of which
contains only one material length scale parameter in addition to the classical elastic
constants. Variational formulations are provided for these two theories by using the
principle of minimum total potential energy. In both cases, the governing equations and
complete boundary conditions are determined simultaneously for the first time. Also, the
displacement form is explicitly derived for each theory for the first time.
The modified couple stress theory is applied to solve a simple shear problem, to
develop a new Bernoulli-Euler beam model, and to derive the constitutive relations for
hexagonal honeycomb structures, while the simplified strain gradient theory is used to
solve the pressurized thick-walled cylinder problem. All these models/solutions are
obtained for the first time and supplement their counterparts in classical elasticity.
Numerical results obtained from the newly developed models and derived solutions
and their comparisons with their counterpart results in classical elasticity reveal that the
higher order theory based models and solutions have the capacity to account for
microstructural effects; their counterparts in classical elasticity do not have the same
capability. Nevertheless, the former are shown to recover the latter if the microstructural
effects are suppressed or ignored.
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