Estimating the Fair Insurance Premium for Dungeness Crab Yields in the Western U.S. Coast

The Dungeness is a popular food and the most commercially important crab in the western states in the U.S. Like all agricultural production, the crab fisherman face yield risks and must manage these risks. In addition to weather risk, crab fisherman may experience low yields if the crabs are over fished in previous years. Farmers for many traditional agricultural crops can purchase crop insurance to insure against low yields. However, crab fishermen at this time do not have this option. The purpose of this paper is to estimate a fair insurance premium based on the historical yields of the Dungeness crab. This information can then be used in risk/return models for crab fishing to determine if it would be optimal for fisherman to purchase crop insurance. An important input into the fair insurance premium estimation is the yield distribution. Sherrick et al. estimated alternative yield distributions to evaluate traditional crop insurance. However, no one has looked at the yield distributions for the Dungeness crab nor explored possible crop insurance. Much of the past literature for the fishing industry has focused on production functions, cost function models, and optimal catching yields for specific fish species. Moreover, most research has focused on the endangered commercial ocean species such as tuna and swordfish. Data and Methodology This research collects the annual landing data including metric tons, pounds, and price per pound from NOAA's National Marine Fisheries Service (NOAA Fisheries Service) to analyze the yield distributions of Dungeness crab in California, Oregon, Washington, and Alaska from 1950 to 2009. Dickey Fuller test is conducted for each state to test if the data is stationary. The Durbin-Watson test was used to make sure the data did not have autocorrelation problems. We find that the detrended data has positive Skewness contrary to traditional crop yield data. The positive Skewness indicates that the tail on the right sides is longer than the left side and the mass of the distribution is concentrated on the left. It also has relatively few high values. The candidate distributions used include normal, Gamma, Weibull, logistic, lognormal, and loglogistic distributions. The fitted distributions are compared with formal goodness- of- fit tests including Chi-Square, Anderson-Darling, and Kolmogorov-Smirnov. The loglogistic distribution is best to estimate the yield losses of Alaska, Oregon, and California respectively while the logistic is best for Washington. The Gamma and normal distribution are the worst for the four states. Actual Production History (APH) policies insure crop producers against yield losses due to natural causes. After Just and Weninger found that crop yield losses were nonnormally distributed, many agricultural researchers use parametric (Goodwin and Ker) and nonparametric distributions (Sherrick et al) and the insured price to estimate the insurance premium. The premium refers to the periodic payment made on the insurance policy. When the yields are below the insured level (the predicted level each year), the insurance company has to pay indemnities to the producers to compensate them for their losses. Our study uses different parametric distributions to forecast the crab yields. Along with the yield distributions and yield forecasts, we assume that the crop insurance insures up to 80% of the yield distribution. We also assume that the insured price is the predicted price per pound for 2010 (since the price model are Pth-order autoregressive (AR(p)) processes) to estimate the fair insurance premium. The insured prices per pound of the four states from north to south are $1.88,$2.39, $1.94, and$1.99 respectively. If the random value (that the realized yields fall below the guaranteed yields) generated by the best distributions which may generate different parametric value for the four states falls below zero, it will means that the fisherman suffer yield losses, and that the insurance company has to compensate the fishermen’s revenue. The insurance company pays the fishermen the dollars that the insured price times 80% of the yield that the fishermen suffer from loss. The indemnities will be either zero or positive. Next, we adopt Latin hypercube sampling (LHS) to simulate the indemnities 500 times to calculate the average indemnities. If we don’t consider the capital and administration fees of the insurance company, the average indemnities will be the actuarially fair insurance premium. The average indemnity and thus the actuarially fair premiums of the overall crab industry are $1,380,924,$702,344, $2,823,855, and$3,470,998 one year for the all ships in Alaska, Washington, Oregon, and California respectively. Unlike traditional crop insurance that estimates the premium per acre, we use the total premium shared by all fishing vessels in the state and account for the total tons that the fishing vessels load because the crabs and the fishing vessel move everywhere. After simulated, half of the time the insurance company must pay indemnities. To avoid the high risk of yield losses and uncertainty, the existence of insurance is necessary to protect the fishermen’s revenue. Finally, we will try to use non-parametric method to estimate the fair premium and compare the results of the parametric and non-parametric distributions for the rigorous study. We will also estimate the potential welfare gain of fishermen from this insurance policy.Dungeness Crab, Fair Insurance Premium, Simulation, Agricultural and Food Policy, Agricultural Finance, Risk and Uncertainty,

Atomic oxygen effects on boron nitride and silicon nitride: A comparison of ground based and space flight data

The effects of atomic oxygen on boron nitride (BN) and silicon nitride (Si3N4) were evaluated in a low Earth orbit (LEO) flight experiment and in a ground based simulation facility. In both the inflight and ground based experiments, these materials were coated on thin (approx. 250A) silver films, and the electrical resistance of the silver was measured in situ to detect any penetration of atomic oxygen through the BN and Si3N4 materials. In the presence of atomic oxygen, silver oxidizes to form silver oxide, which has a much higher electrical resistance than pure silver. Permeation of atomic oxygen through BN, as indicated by an increase in the electrical resistance of the silver underneath, was observed in both the inflight and ground based experiments. In contrast, no permeation of atomic oxygen through Si3N4 was observed in either the inflight or ground based experiments. The ground based results show good qualitative correlation with the LEO flight results, indicating that ground based facilities such as the one at Los Alamos National Lab can reproduce space flight data from LEO

Simulation of valveless micropump and mode analysis

In this work, a 3-D simulation is performed to study for the solid-fluid coupling effect driven by piezoelectric materials and utilizes asymmetric obstacles to control the flow direction. The result of simulation is also verified. For a micropump, it is crucial to find the optimal working frequency which produce maximum net flow rate. The PZT plate vibrates under the first mode, which is symmetric. Adjusting the working frequency, the maximum flow rate can be obtained. For the micrpump we studied, the optimal working frequency is 3.2K Hz. At higher working frequency, say 20K Hz, the fluid-solid membrane may come out a intermediate mode, which is different from the first mode and the second mode. It is observed that the center of the mode drifts. Meanwhile, the result shows that a phase shift lagging when the excitation force exists in the vibration response. Finally, at even higher working frequency, say 30K Hz, a second vibration mode is observed.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

A comparison of ground-based and space flight data: Atomic oxygen reactions with boron nitride and silicon nitride

The effects of atomic oxygen on boron nitride (BN) and silicon nitride (Si3N4) have been studied in low Earth orbit (LEO) flight experiments and in a ground-based simulation facility at Los Alamos National Laboratory. Both the in-flight and ground-based experiments employed the materials coated over thin (approx 250 Angstrom) silver films whose electrical resistance was measured in situ to detect penetration of atomic oxygen through the BN and Si3N4 materials. In the presence of atomic oxygen, silver oxidizes to form silver oxide, which has a much higher electrical resistance than pure silver. Permeation of atomic oxygen through BN, as indicated by an increase in the electrical resistance of the silver underneath, was observed in both the in-flight and ground-based experiments. In contrast, no permeation of atomic oxygen through Si3N4 was observed in either the in-flight or ground-based experiments. The ground-based results show good qualitative correlation with the LEO flight results, thus validating the simulation fidelity of the ground-based facility in terms of reproducing LEO flight results

Economic Analysis of Insect Control Strategies Using an Integrated Crop Ecosystem Management Model

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 8 (2006): Economic Analysis of Insect Control Strategies Using an Integrated Crop Ecosystem Management Model. Manuscript IT 06 001. Vol. VIII. September, 2006

Phonon quarticity induced by changes in phonon-tracked hybridization during lattice expansion and its stabilization of rutile TiO2_2

Although the rutile structure of TiO$_2$ is stable at high temperatures, the conventional quasiharmonic approximation predicts that several acoustic phonons decrease anomalously to zero frequency with thermal expansion, incorrectly predicting a structural collapse at temperatures well below 1000\,K. Inelastic neutron scattering was used to measure the temperature dependence of the phonon density of states (DOS) of rutile TiO$_2$ from 300 to 1373\,K. Surprisingly, these anomalous acoustic phonons were found to increase in frequency with temperature. First-principles calculations showed that with lattice expansion, the potentials for the anomalous acoustic phonons transform from quadratic to quartic, stabilizing the rutile phase at high temperatures. In these modes, the vibrational displacements of adjacent Ti and O atoms cause variations in hybridization of $3d$ electrons of Ti and $2p$ electrons of O atoms. With thermal expansion, the energy variation in this "phonon-tracked hybridization" flattens the bottom of the interatomic potential well between Ti and O atoms, and induces a quarticity in the phonon potential.Comment: 7 pages, 6 figures, supplemental material (3 figures

A quotient of the Lubin-Tate tower II

In this article we construct the quotient M_1/P(K) of the infinite-level Lubin-Tate space M_1 by the parabolic subgroup P(K) of GL(n,K) of block form (n-1,1) as a perfectoid space, generalizing results of one of the authors (JL) to arbitrary n and K/Q_p finite. For this we prove some perfectoidness results for certain Harris-Taylor Shimura varieties at infinite level. As an application of the quotient construction we show a vanishing theorem for Scholze's candidate for the mod p Jacquet-Langlands and the mod p local Langlands correspondence. An appendix by David Hansen gives a local proof of perfectoidness of M_1/P(K) when n = 2, and shows that M_1/Q(K) is not perfectoid for maximal parabolics Q not conjugate to P.Comment: with an appendix by David Hanse

Numerical investigation on hydrodynamic performance of a novel shaftless rim-driven counter-rotating thruster considering gap fluid

Shaftless rim-driven thruster (RDT) has recently become the research focus for marine propulsion, primarily due to low vibration, low noise, and energy saving as its advantage. This study is based on CFD theory and used the Ansys-Fluent software to examine the hydrodynamic performance of a novel rim-driven counter-rotating thruster (RDCRT). It takes a No.19A+Ka4-70 duct propeller and a 20 kW RDT as examples, as it verifies the feasibility of the simulation method. It establishes three geometric models for RDCRT's hydrodynamic performance to determine whether it is necessary to consider the motor stator/rotor gap. It examines the flow distribution characteristics of the gap fluid friction force and flow channel and investigates the gap's influence on the hydrodynamic performance. Relevant case studies indicate that, when considering the gap, the calculation outcomes of the simulation model are between the stationary model and the rotational model of the rotor inner wall when ignoring the gap. In the Forward and Aft regions, the total frictional power of the gap channel correspondingly accounts for 1.7% and 1.35% of the rated power. Additionally, compared to situations with a gap, the pressure coefficient of the inner surface of the Forward and Aft rim without a gap is more significant. Thus, the hydrodynamic simulation model should not ignore the gap. For the RDCRT, the thrust coefficient, the torque coefficient, and the maximum efficiency value are more significant than those of the single-propeller RDT, hence validating its advantages

A multiple exp-function method for nonlinear differential equations and its application

A multiple exp-function method to exact multiple wave solutions of nonlinear partial differential equations is proposed. The method is oriented towards ease of use and capability of computer algebra systems, and provides a direct and systematical solution procedure which generalizes Hirota's perturbation scheme. With help of Maple, an application of the approach to the $3+1$ dimensional potential-Yu-Toda-Sasa-Fukuyama equation yields exact explicit 1-wave and 2-wave and 3-wave solutions, which include 1-soliton, 2-soliton and 3-soliton type solutions. Two cases with specific values of the involved parameters are plotted for each of 2-wave and 3-wave solutions.Comment: 12 pages, 16 figure