Active Noise Control using Variable step-size Griffiths’ LMS (VGLMS) algorithm on Real-Time platform

This paper proposes implementation of Griffith’s Variable step-size algorithm for Active Noise Control (ANC) on ADSP-TS201 EZ-Kit Lite. The dual computational units and execution of up to four instructions per cycle which are special features over other processors are best utilized to generate an optimized code. The VGLMS provides improved secondary path estimation and computations involved are marginal as the same gradient is used for step-size computation and coefficient adaptation. The improved secondary path estimate, in turn improves the ANC performance. Further, variable step-size algorithm is used for the main-path to achieve faster convergence. Both for narrowband (fundamental and its harmonics) and broadband noise fields, for a duct the attenuation achieved is 25 dB and 15 dB respectively. The program execution time was only 1.25% for an input sampling rate of 1 KHz which indicates the utility of the special features of the processor considered. Further these features have enabled in bringing down the program memory requirement in the implementation of the algorithm

A Hydro-Quality Model to Predict the Effects of Biological Transformations on the Chemical Quality of Return Flow

A computerized mathematical model has been developed to simulate the system hydrology and water-salinity (as indicated by seven major ions constituting the salt) of a river basin, in which irrigation is the major beneficial water user. The overall system simulation model consists of three submodels: (1) a general hydrologic submodel programmed on a hybrid computer; (2) a chemical submodel to predict the quality of percolated water through the soil profile; and (3) a biological transformation submodel in respect of microbial nitrogen transformations, which is utilized by the chemical submodel. Both the chemical and biological submodels are programmed on a digital computer and are combined with the general hydrologic submodel to form the system simulation model. The overall model operates on monthly time intervals with variable spatial resolution. The hydrologic portion of the model simulates the various hydrologic processes which are linked together by the continuity-of-mass principle and predicts the monthly runoff from the area. The chemical quality component of the model considers the complex chemistry of soilwater-plant system, including cation exchange on the soil complex, the dissolution or precipitation of lime (CaCO3), and calcium and magnesium sulphates ion pairs in solution. The biological transformations submodel uses the kinetic approach in simulating the microbial nitrogen transformations within the root zone of a soil profile. The transformation reactions included are: (1) hydrolysis of Urea-nitrogen; (2) immobilization of ammonium-nitrogen; (3) mineralization of organic-nitrogen; and (4) immobilization of nitrate-nitrogen. The chemical composition of return flow is a function of these chemical and biological processes within the soil profile, in addition to blending of undiverted flows, evapotranspiration, and mixing of subsurface return flow with groundwater. Uptake of nitrate by aquatic biomass in the surface runoff of return flow has also been considered. The seven ions considered in the study are calcium, magnesium, sodium, sulphate, chloride, bicarbonate, and nitrate. The total dissolved solids outflow is a summation of these individual ions. In order to demonstrate its capabilities, the hydro-quality model is applied to a large irrigated area of the Snake River Plains, near Twin Falls, Idaho. The model successfully simulated measured outflows of water and the concentration of seven ions for a 24 month period. The correlation coefficients range from 0.79 to 0.96 for the quantity and quality components of outflow, except for the sulphate ion, the correlation coefficient of which is 0.66. The model is general in nature and with suitable adjustments it can be applied to other areas and also to various kinds of management situations, including land application of waste water and studies involving nitrate pollution of groundwaters

On the naturality of the Mathai-Quillen formula

We give an alternative proof for the Mathai-Quillen formula for a Thom form using its natural behaviour with respect to fiberwise integration. We also study this phenomenon in general context.Comment: 6 page

Verb representation and thinking-for-speaking effects in Spanish-English bilinguals

Speakers of English habitually encode motion events using manner-of-motion verbs (e.g., spin, roll, slide) whereas Spanish speakers rely on path-of-motion verbs (e.g., enter, exit, approach). Here, we ask whether the language-specific verb representations used in encoding motion events induce different modes of “thinking-for-speaking” in Spanish–English bilinguals. That is, assuming that the verb encodes the most salient information in the clause, do bilinguals find the path of motion to be more salient than manner of motion if they had previously described the motion event using Spanish versus English? In our study, Spanish–English bilinguals described a set of target motion events in either English or Spanish and then participated in a nonlinguistic similarity judgment task in which they viewed the target motion events individually (e.g., a ball rolling into a cave) followed by two variants a “same-path” variant such as a ball sliding into a cave or a “same-manner” variant such as a ball rolling away from a cave). Participants had to select one of the two variants that they judged to be more similar to the target event: The event that shared the same path of motion as the target versus the one that shared the same manner of motion. Our findings show that bilingual speakers were more likely to classify two motion events as being similar if they shared the same path of motion and if they had previously described the target motion events in Spanish versus in English. Our study provides further evidence for the “thinking-for-speaking” hypothesis by demonstrating that bilingual speakers can flexibly shift between language-specific construals of the same event “on-the-fly.

flatIGW - an inverse algorithm to compute the Density of States of lattice Self Avoiding Walks

We show that the Density of States (DoS) for lattice Self Avoiding Walks can be estimated by using an inverse algorithm, called flatIGW, whose step-growth rules are dynamically adjusted by requiring the energy histogram to be locally flat. Here, the (attractive) energy associated with a configuration is taken to be proportional to the number of non-bonded nearest neighbor pairs (contacts). The energy histogram is able to explicitly direct the growth of a walk because the step-growth rule of the Interacting Growth Walk \cite{IGW} samples the available nearest neighbor sites according to the number of contacts they would make. We have obtained the complex Fisher zeros corresponding to the DoS, estimated for square lattice walks of various lengths, and located the $\theta$ temperature by extrapolating the finite size values of the real zeros to their asymptotic value, $\sim 1.49$ (reasonably close to the known value, $\sim 1.50$ \cite{barkema}).Comment: 18 pages, 7 eps figures; parts of the manuscript are rewritten so as to improve clarity of presentation; an extra reference adde

Empirical Method for the Prediction of Heat of Formation of Organic High Energy Molecules

An empirical method based on additive procedures is proposed for estimating the heats offormation of aliphatic, aromatic, and ring molecules containing nitro and other energetic groupsat standard state. The method uses only molecular structural information. Calculation of heatof formation is carried out in three stages, first the heat of formation for gaseous state is calculated,followed by incorporation of heat of vapourisation/sublimation, and finally, corrections are donefor interactions. Some interaction terms, based on hydrogen bonding strength for variouscompounds and experimental heat of formation of isomeric compounds, are also proposed. Theresults are in good agreement with the experimentally determined values. The method providesquick and sufficiently accurate values of heat of formation of organic high energy molecules