Αi Values Research Articles

Adaptive Control and Multi-variables Projective Synchronization of Hyperchaotic Finance System

This paper introduces a new hyperchaotic finance system and show that it is a self-excited hyperchaotic attractor with the coexistence of double attractor with difference initial conditions for the same set of parameter values. Nonlinear feedback control function u i (t), (i= 1,2,3,4) via adaptive control laws are design for the control and synchronization of the 4D-hyperchaotic finance system with the multiple values of the economics scaling factor αi , (i = 1,2,3,4), a special case of projective synchronization. The proposed schemes are able to stabilize as well as globally synchronize the two identical finance systems evolving from different initial conditions with uncertain parameter for the different values of α i (i = 1,2,3,4) . The analytical results were verified through numerical simulation.

Millimeter-wave spectroscopy of syn formyl azide (HC(O)N3) in seven vibrational states

Millimeter-wave spectra for formyl azide (HC(O)N3) were obtained from 240 to 360GHz at ambient temperature. For the ground state of syn formyl azide, over 1500 independent rotational transitions were measured and least-squares fit to a complete S-reduced 8th order centrifugal distortion/rigid rotor Hamiltonian. The decomposition of formyl azide was monitored over a period of several hours, the half-life (t½=30min) was determined, and its decomposition products were investigated. Transitions from five vibrational satellites of syn formyl azide (ν9, ν12, 2ν9, ν9+ν12, and ν11) were observed, measured, and least-squares fit to complete or nearly complete octic centrifugally-distorted, single-state S-reduced models. A less complete single-state fit of 3ν9 (509.3cm−1) was obtained from an unperturbed subset of its assignable transitions. This state is apparently coupled to the fundamental ν8 (489.4cm−1) and the overtone 2ν12 (503.6cm−1), but the coupling remains unanalyzed. Anharmonic CCSD(T)/ANO1 estimates of the vibrational frequencies of syn formyl azide were in close agreement with previously published experimental and computational values. Experimentally determined vibration-rotation interaction (αi) values were in excellent agreement with coupled-cluster predicted αi values for the fundamentals ν9, ν12, and ν11.

Millimeter-Wave Spectroscopy, X-ray Crystal Structure, and Quantum Chemical Studies of Diketene: Resolving Ambiguities Concerning the Structure of the Ketene Dimer.

The pure rotational spectrum of diketene has been studied in the millimeter-wave region from ∼240 to 360 GHz. For the ground vibrational state and five vibrationally excited satellites (ν24, 2ν24, 3ν24, 4ν24, and ν16), the observed spectrum allowed for the measurement, assignment, and least-squares fitting a total of more than 10 000 distinct rotational transitions. In each case, the transitions were fit to single-state, complete or near-complete sextic centrifugally distorted rotor models to near experimental error limits using Kisiel's ASFIT. Additionally, we obtained less satisfactory least-squares fits to single-state centrifugally distorted rotor models for three additional vibrational states: ν24 + ν16, ν23, and 5ν24. The structure of diketene was optimized at the CCSD(T)/ANO1 level, and the vibration-rotation interaction (αi) values for each normal mode were determined with a CCSD(T)/ANO1 VPT2 anharmonic frequency calculation. These αi values were helpful in identifying the previously unreported ν16 and ν23 fundamental states. We obtained a single-crystal X-ray structure of diketene at -173 °C. The bond distances are increased in precision by more than an order of magnitude compared to those in the 1958 X-ray crystal structure. The improved accuracy of the crystal structure geometry resolves the discrepancy between previous computational and experimental structures. The rotational transition frequencies provided herein should be useful for a millimeter-wave or terahertz search for diketene in the interstellar medium.

Discussion of sensitivity factors and dominating variable for design value method

The partial factor method is considered to be one of the most reliable design methods. However, engineers have examined the shortcomings of the partial factor method, primarily its flexibility and generality in searching for the values of partial factors. In order to improve upon the partial factor method, the design value method has been established on the basis of probability. The design value method is more flexible, general, and represents the developing direction of the reliability design method. However, based on experience, a set of sensitivity factors αi values has been developed. The sum of squares may be greater than 1.0 as a result of conservatism. Although some researchers have revised the values of αi by using the enumeration optimization method, the results are not ideal. This paper focuses on the recommended values of sensitivity factors that are applicable to the safety design as well as the serviceability design. It will be shown that these recommended values can improve the accuracy of the reliability index and present specific ranges of relative errors. This makes it possible to establish a practical design value method based on probability. In addition, a method to determine the dominating parameter is illustrated.

Testing WHAM-FTOX with laboratory toxicity data for mixtures of metals (Cu, Zn, Cd, Ag, Pb).

The Windermere humic aqueous model using the toxicity function (WHAM-FTOX ) describes cation toxicity to aquatic organisms in terms of 1) accumulation by the organism of metabolically active protons and metals at reversible binding sites, and 2) differing toxic potencies of the bound cations. Cation accumulation (νi , in mol g(-1) ) is estimated through calculations with the WHAM chemical speciation model by assuming that organism binding sites can be represented by those of humic acid. Toxicity coefficients (αi ) are combined with νi to obtain the variable FTOX (= Σ αi νi ) which, between lower and upper thresholds (FTOX,LT , FTOX,UT ), is linearly related to toxic effect. Values of αi , FTOX,LT , and FTOX,LT are obtained by fitting toxicity data. Reasonable fits (72% of variance in toxic effect explained overall) were obtained for 4 large metal mixture acute toxicity experiments involving daphnids (Cu, Zn, Cd), lettuce (Cu, Zn, Ag), and trout (Zn, Cd, Pb). Strong nonadditive effects, most apparent in results for tests involving Cd, could be explained approximately by purely chemical competition for metal accumulation. Tentative interpretation of parameter values obtained from these and other experimental data suggests the following order of bound cation toxicity: H < Al < (Cu Zn Pb UO2 ) < (Cd Ag). Another trend is a strong increase in Cd toxicity relative to that of Zn as organism complexity increases (from bacteria to fish).

Metal mixture toxicity to aquatic biota in laboratory experiments: Application of the WHAM-FTOX model

The WHAM-FTOX model describes the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (FTOX), a linear combination of the products of organism-bound cation and a toxic potency coefficient (αi) for each cation. Organism-bound, metabolically-active, cation is quantified by the proxy variable, amount bound by humic acid (HA), as predicted by the WHAM chemical speciation model. We compared published measured accumulations of metals by living organisms (bacteria, algae, invertebrates) in different solutions, with WHAM predictions of metal binding to humic acid in the same solutions. After adjustment for differences in binding site density, the predictions were in reasonable line with observations (for logarithmic variables, r2=0.89, root mean squared deviation=0.44), supporting the use of HA binding as a proxy. Calculated loadings of H+, Al, Cu, Zn, Cd, Pb and UO2 were used to fit observed toxic effects in 11 published mixture toxicity experiments involving bacteria, macrophytes, invertebrates and fish. Overall, WHAM-FTOX gave slightly better fits than a conventional additive model based on solution concentrations. From the derived values of αi, the toxicity of bound cations can tentatively be ranked in the order: H<Al<(Zn–Cu–Pb–UO2)<Cd. The WHAM-FTOX analysis indicates much narrower ranges of differences amongst individual organisms in metal toxicity tests than was previously thought. The model potentially provides a means to encapsulate knowledge contained within laboratory data, thereby permitting its application to field situations.

Prey preferences of aquatic insects: potential implications for the regulation of wetland mosquitoes

Wetlands are potential sites for mosquito breeding and are thus important in the context of public health. The use of chemical and microbial controls is constrained in wetlands in view of their potential impact on the diverse biota. Biological control using generalist aquatic insects can be effective, provided a preference for mosquito larvae is exhibited. The mosquito prey preferences of water bugs and larvae of odonate species were evaluated using chironomid larvae, fish fingerlings and tadpoles as alternative prey. Manly's selectivity (αi ) values with 95% confidence intervals (CIs) were estimated to judge prey preference patterns. Multivariate analysis of variance (manova) and standardized canonical coefficients were used to test the effects of density on prey selectivity. The αi values indicated a significant preference (P < 0.05) in all of the insect predators tested for mosquito larvae over the alternative prey as a density-dependent function. On a comparative scale, chironomid larvae had the highest impact as alternative prey. In a multiple-prey experiment, predators showed a similar pattern of preference for mosquito larvae over alternative prey, reflecting a significant (P < 0.05) niche overlap. The results suggest that, in a laboratory setting, these insect predators can effectively reduce mosquito density in the presence of multiple alternative prey.

QM/MM-Based Fitting of Atomic Polarizabilities for Use in Condensed-Phase Biomolecular Simulation.

Accounting for electronic polarization effects in biomolecular simulation (by using a polarizable force field) can increase the accuracy of simulation results. However, the use of gas-phase estimates of atomic polarizabilities αi usually leads to overpolarization in condensed-phase systems. In the current work, a combined QM/MM approach has been employed to obtain condensed-phase estimates of atomic polarizabilities for water and methanol (QM) solutes in the presence of (MM) solvents of different polarity. In a next step, the validity of the linear response and isotropy assumptions were evaluated based on the observed condensed-phase distributions of αi values. The observed anisotropy and low average values for the polarizability of methanol's carbon atom in polar solvents was explained in terms of strong solute-solvent interactions involving its adjacent hydroxyl group. Our QM/MM estimates for atomic polarizabilities were found to be close to values used in previously reported polarizable water and methanol models. Using our estimate for αO of methanol, a single set of polarizable force field parameters was obtained that is directly transferable between environments of different polarity.

Characterizing Time‐Dependent Contact Angles for Sands Hydrophobized with Oleic and Stearic Acids

Capillary barriers (CBs) represent useful, low‐cost systems for limiting water infiltration and controlling seepage at solid waste landfills in semiarid and arid regions. The application of CBs in wet regions can be problematic due to loss of water‐impermeable properties under high‐frequency precipitation. A potential solution is to alter soil grain surfaces to become water repellent by mixing or coating the soil cover material with hydrophobic agents (HAs). In this study, hydrophobic CBs comprised of sands mixed with environmentally friendly HAs (oleic acid [OA] and stearic acid [SA]) were studied. Water repellency (WR) characteristics for hydrophobized sand samples with different HA contents and representing different coating methods (mixing in and solvent aided) were measured. Initial contact angles (αi) for OA‐coated samples sharply increased with increasing HA content and reached peak values of 97 to 101° at 0.75 to 1.0 g HA kg−1 sand, whereafter αi gradually decreased. Measured αi values for SA‐coated samples increased sharply to 90° and then gradually reached a maximum of 108° at 6.0 g kg−1 HA content. Each test sample exhibited a decrease in contact angle (α) with time (t) and reached an apparent equilibrium after around 1200 s. The time dependence of α was expressed by an exponential function, α = αi exp (−At), where A is the coefficient of temporal change in WR (s−1). While the A values for the solvent‐aided OA‐coated samples were relatively constant (between 3 × 10−4 and 6 × 10−4 s−1), A values for the mixing‐in OA‐coated samples fluctuated. Generally, the solvent‐aided coating method yielded less time dependency of α and higher WR persistence.

Comment on “Derivation of effective hydraulic parameters of a karst aquifer from discharge hydrograph analysis” by S. J. Baedke and N. C. Krothe

Comment on “Derivation of effective hydraulic parameters of a karst aquifer from discharge hydrograph analysis” by S. J. Baedke and N. C. Krothe

Multi-parameterized Schwarz alternating methods for elliptic boundary value problems

Abstract The convergence rate of a numerical procedure based on Schwarz Alternating Method (SAM) for solving elliptic boundary value problems (BVPs) depends on the selection of the so-called interface conditions applied on the interior boundaries of the overlapping subdomains. It has been observed that the weighted mixed interface conditions ( g(u) = ωu + (1 − ω)ϖu ϖn ), controlled by the parameter ω, can optimize SAMs convergence rate. In this paper, we present a matrix formulation of this method based on finite difference approximation of the BVP, review its known computational behavior in terms of the parameter α = /gf(ω, h), where h is the discretization parameter and /gf is a derivable relation, and obtain analytically explicit and implicit expressions for the optimum α. Moreover, we consider a parameterized SAM where the parameter ω or α is assumed to be different in each overlapping area. For this SAM and the one-dimensional (1-D) elliptic model BVPs, we determine analytically the optimal values of αi. Furthermore, we extend some of these results to two-dimensional (2-D) elliptic problems.

Simple relationships for the Ångström parameter of disperse systems

Simple relationships for calculating the Ångström parameter a of any disperse system are obtained (a) for a polycomponent system, through values of ai of individual components, and (b) for the simplest disperse systems, consisting of large, small, and soft particles. It is shown that the parameter a of a monodisperse particle system is sensitive to the exact structure of the spectral variability optical thickness of the system curve τ(λ) and that when calculating α, one should not use the van de Hulst approximate formula for τ(λ) when ripples and another important details are not accounted for. The error connected with the use of the van de Hulst formula when one is estimating a depends on the value of optical hardness of the particle. It is small when particles are soft, and it becomes noticeable as particles get harder.

Direction-of-arrival and frequency estimations for narrowband sources using two single rotation invariance algorithms with the marked subspace

In array signal processing, one is frequently interested in simultaneously estimating the directions of arrival and the centre frequencies of the uncorrelated narrowband radiating sources having different centre frequencies. By using single spatial rotation invariance and temporal rotation invariance algorithms, e.g. the original ESPRIT, we can individually estimate the spatial frequencies αi and the temporal frequencies ωi of the sources. If detecting radiating sources only in azimuths is of interest, the spatial frequency αi is defined as αi= ωi sin (θi), where θi is the location of the ihe source relative to the broadside of the array, and we need decide which of the ωi and αi values belong to the same radiating source to obtain the pair {θi, ωi} for each source. In this paper, we propose a technique, the marked subspace technique, which is applied to the original ESPRIT to obtain the parameter pair {θi, ωi}. By using both single spatial invariance and single temporal invariance algorithms along with the marked subspace, the parameter pair {θi, ωi} of each radiating source can be more easily obtained than using the original ESPRIT without the marked subspace.

Performance of Layer-Type Chickens as Related to Body Conformation and Composition. 1. A Static Analysis of Shank Length and Body Weight at 20 Weeks of Age

The growth of an animal part (y) relative to the whole (x), is expressed in terms of an exponential equation, y=αxβ, where α and β are growth constants. For the present study x is body weight and y is shank length determined for 10 lines of chickens at 20 weeks of age. The derived values of α and β, assumed to be limiting relative growth constants for bone, were estimated by least squares of the log-transformed (linear) exponential equation. From the means of α and β, calculated for each of seven Leghorn and three Fayoumi lines, individual values of αi and βi were calculated for more than 24,000 pedigreed birds included in 9 years of records. The individual values (i) were calculated as: αi=antilog(logyi−βlogxi) and: βi=logα−logyilogxiIf the initial growth constant, α, is the primary hereditary growth parameter governing conformation, then the parameter, β, should not be as highly heritable as α. To test this hypothesis, the heritability (h2) of both α and β were calculated for each of the 10 lines. For α sire component h2 values ranged from .12 ± .05 to .45 + .10 and for β from .05 to .41. The pooled h2 estimate of α over lines (.31 ± .02) was not significantly different from that for β (.31 ± .02). Compared with the original data on body weight and shank length, the transformation significantly reduced the heritability estimated. We conclude that the parameters, α and β, are useful only in describing phenotypic and not genetic differences in relative growth.

Rotation-Vibration Spectra of Diatomic and Simple Polyatomic Molecules with Long Absorbing Paths VII. The Spectrum of Dideuteroacetylene (C2D2) in the Photographic Infrared

Twelve absorption bands of C2D2 have been observed in the photographic infrared. Eleven of these bands show simple P and R branches with intensity alternation, i.e., they are Σu+—Σg+ bands while one band, without intensity alternation, is a difference band of type Π—Π. From the positions of the bands some of the vibrational constants ωi0 and xik are determined. In addition, from the rotational fine structure, the rotational constants B[v] and D[v] are determined. For B[0] the value 0.84787 cm−1 is obtained. The αi values are α1=+0.00578, α2=+0.00302, α3=+0.00455, α4=−0.00120, α5=−0.0026 cm−1. From the αi and B[0] one obtains Be=0.85075 cm−1. Combining Be(C2D2) with Be(C2H2) yields, for the internuclear distances in the acetylene molecule, re(C≡C)=1.2010×10−8 and re(C–H)=1.0637×10−8 cm in very satisfactory agreement with the values previously obtained from Be(C2HD) and Be(C2H2). Evidence for l-type doubling in C2D2 is given and approximate values for the l-type doubling constants q4 and q5 are obtained.