A Tri-State Oriented Parallel Processing System

An ``Alternating Sequential/Parallel' system, the Mopps was introduced a few years ago and is modified despite the fact that it solved satisfactorily a number of real-time problems. The new system, the ``Topps' is described and compared to Mopps in Section II and two applications are chosen to prove it to be superior. In Section III, the advantage of having a third basic, the ``ring' mode, is illustrated when solving sets of linear equations with band matrices. In Section IV, the advantage of having independent I/O for the slaves is illustrated for biomedical signal analysis.     

Validation and calibration of a lateral confinement model for long-rod penetration at ordnance and high velocities

In designing targets for laboratory long-rod penetration tests, the question of lateral confinement often arises, “How wide should the target be to exert enough confinement?” For ceramic targets, the problem is enhanced as ceramics are usually weak in tension and therefore have less self-confinement capability. At high velocities the problem is enhanced even more as the crater radius and the extent of the plastic zone around it are larger. Recently we used the quasistatic cavity expansion model to estimate the resistance of ceramic targets and its dependence on impact velocity [1]. We validated the model by comparing it to computer simulations in which we used the same strength model. Here we use the same approach to address the problem of lateral confinement.

We solved the quasistatic cavity expansion problem in a cylinder with a finite outside radius “b” at which σ_r (b) = 0 (σ_r = radial stress component). We did this for three cases: ceramic targets, metal targets, and ceramic targets confined in a metal casing. Generally, σ_r (a) is a decreasing function of “a” (“a” = expanding cavity radius, and σ_r (a) = the stress needed to continue opening the cavity). In the usual cavity expansion problem b → ∞, σ_r (a) = const., R =−σ_r (a) (R = resistance to penetration). For finite “b” we estimate R by averaging σ_r (a) over a range o ≤ a ≤ a_r, (where a_r, the upper bound of the range, is calibrated from computer simulations).

We ran 14 computer simulations with the CTH wavecode and used the results to calibrate a_r for the different cases and to establish the overall validity of our approach.

We show that generally for D_t/D_p > 30, the degree of confinement is higher than 95% (D_t = target diameter; D_p = projectile diameter; and degree of CONFINEMENT = R/R_∞; R∞ = resistance of a laterally infinite target). We also show the tensile strength of ceramic targets (represented by the spall strength P_min) has a significant effect on the degree of confinement, while other material parameters have only a minor effect.     

Photodynamics of Small Aliphatic Ketones in a Supersonic Jet Expansion

The photodynamics of acetone and some other simple aliphatic ketones in the nπ* state are discussed in the light of recent results obtained in seeded supersonic beams. The Born-Oppenheimer approximation is used to describe the sequence of events beginning with light absorption and ending in molecular fragmentation. Intersystem crossing is shown to be an important process even for the isolated molecule. Its rate increases with the internal energy and may be related to the density of states in the triplet state. For all molecules studied so far, the results can be rationalized by assuming that dissociation takes place on the triplet surface, the S₁ surface being stable in the energy range pertinent to these experiments (up to 35,000 cm⁻¹ above the ground state). Fluorescence spectroscopy may be used also to detect small clusters. In the case of acetone, their presence is indicated by the decrease in the intensity of some spectral lines as a function of cooling efficiency. The results are used to estimate an upper limit for the van der Waals binding energies.     

Implementing a Consistency Criterion in Numerical Solution of the Bioelectric Forward Problem

The bioelectric forward problem is frequently formulated as an integral equation that relates unknown surface potentials with their known current generators, in a given volume conductor. The matrix of the discretized equations is singular, and this may cause difficulties in obtaining a numerical solution to the problem. A consistency criterion for the discretized equations is utilized in a new algorithm for the forward problem. Some examples of sources in a uniform spherical volume conductor were solved employing the new algorithm. It was found that the algorithm is reliable even when the number of discretized elements was relatively small. A comparison with the deflation method was done. In some examples the results were very close to each other. In other examples the results of the new algorithm were better.     

The effect of the gas side resistance on absorption with chemical reaction from binary mixtures

A predictive model based solely on the conservation equations of both phases is presented for the study of the effect of the gas-side resistance in multicomponent absorption with chemical reaction in a laminar liquid film. The model is applicable for short exposure times to a variety of flow patterns, e.g. a cylindrical jet, a wetted-wall column, or an inclined plane. The model may be applied to the wetted-wall column and the inclined plane for any contact time. The numerical scheme for the downstream solution has the advantage of utilising a similarity solution as its starting point. The model is applied to the system CS₂---N₂ where CS₂ is absorbed in an aqueous solution of amine and undergoes pseudo first order reaction. It was found that the a priori neglect of the gas-side resistance is not justified. The error introduced in evaluating the absorption flux by neglecting the gas-side resistance is dependent on the reaction rate constant, bulk concentration of the species, length of the absorber and the total pressure. Errors generally increased with increasing values of the above parameters. The gas-side resistance is reduced when the gaseous atmosphere is under forced convection.     

Stratified turbulent-turbulent gas-liquid flow in horizontal and inclined pipes

A two-dimensional model for stratified turbulent-turbulent gas-liquid flow in inclined pipes is proposed. The gas phase is treated as bulk flow, but an exact solution is carried out for the liquid phase, applying the eddy viscosity theory to model the turbulent viscosity. The interfacial structure is taken into consideration using appropriate correlations for the interfacial shear stress. The model is capable of predicting the liquid velocity field, holdup and pressure drop given gas and liquid flow rates, physical properties, pipe size, and angle of inclination. The results are substantially better than the prediction of Lockhart and Martinelli (1949) correlation and better than the Taitel and Dukler (1976) model for stratified flow.     

Strategies for collection and processing of occupational information in making career decisions.

The dialogs of 384 users of a computerized occupational information and guidance system were monitored and utilized to examine the strategies used in the exploration of occupational information. The analysis was based on the pattern of the use of the major components of the system and on the content of the requested occupational information. An analysis of the users' dialogs with the system revealed the various patterns of exploring occupational information. These patterns were interpreted as reflecting different strategies-search within alternatives across attributes, or search within attributes across alternatives. Different possible strategies, including the sequential elimination approach for career decision making, are reviewed. The implications for career counseling and computerized career decision making systems are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gene Variant of Barrier to Autointegration Factor 2 (Banf2w) Is Concordant with Female Determination in Cichlids

Oreochromis fishes exhibit variability of sex-determination (SD) genes whose characterization contributes to understanding of the sex differentiation network, and to effective tilapia farming, which requires all-male culture. However, O. niloticus (On) amh is the only master-key regulator (MKR) of SD that has been mapped (XY/XX SD-system on LG23). In O. aureus (Oa), LG3 controls a WZ/ZZ SD-system that has recently been delimited to 9.2 Mbp, with an embedded interval rich with female-specific variation, harboring two paics genes and banf2. Developing genetic markers within this interval and using a hybrid Oa stock that demonstrates no recombination repression in LG3, we mapped the critical SD region to 235 Kbp on the orthologous On physical map (p < 1.5 × 10⁻²⁶). DNA-seq assembly and peak-proportion analysis of variation based on Sanger chromatograms allowed the characterization of copy-number variation (CNV) of banf2. Oa males had three exons capable of encoding 90-amino-acid polypeptides, yet in Oa females, we found an extra copy with an 89-amino-acid polypeptide and three non-conservative amino acid substitutions, designated as banf2w. CNV analysis suggested the existence of two to five copies of banf2 in diploidic Cichlidae. Disrupting the Hardy–Weinberg equilibrium (p < 4.2 × 10⁻³), banf2w was concordant with female determination in Oa and in three cichlids with LG3 WZ/ZZ SD-systems (O. tanganicae, O. hornorum and Pelmatolapia mariae). Furthermore, exclusive RNA-seq expression in Oa females strengthened the candidacy of banf2w as the long-sought LG3 SD MKR. As banf genes mediate nuclear assembly, chromatin organization, gene expression and gonad development, banf2w may play a fundamental role inducing female nucleus formation that is essential for WZ/ZZ SD.     

Time-domain analysis of bandgap characteristics of two-dimensional periodic structures by use of a source-model technique

We introduce a time-domain source-model technique for analysis of two-dimensional, transverse-magnetic, plane-wave scattering by a photonic crystal slab composed of a finite number of identical layers, each comprising a linear periodic array of dielectric cylinders. The proposed technique takes advantage of the periodicity of the slab by solving the problem within a unit cell of the periodic structure. A spectral analysis of the temporal behavior of the fields scattered by the slab shows a clear agreement between frequency bands where the spectral density of the transmitted energy is low and the bandgaps of the corresponding two-dimensionally infinite periodic structure. The effect of the bandwidth of the incident pulse and its center frequency on the manner it is transmitted through and reflected by the slab is studied via numerical examples.     

Secure Two-Party Computation via Cut-and-Choose Oblivious Transfer

Protocols for secure two-party computation enable a pair of parties to compute a function of their inputs while preserving security properties such as privacy, correctness and independence of inputs. Recently, a number of protocols have been proposed for the efficient construction of two-party computation secure in the presence of malicious adversaries (where security is proven under the standard simulation-based ideal/real model paradigm for defining security). In this paper, we present a protocol for this task that follows the methodology of using cut-and-choose to boost Yao’s protocol to be secure in the presence of malicious adversaries. Relying on specific assumptions (DDH), we construct a protocol that is significantly more efficient and far simpler than the protocol of Lindell and Pinkas (Eurocrypt 2007) that follows the same methodology. We provide an exact, concrete analysis of the efficiency of our scheme and demonstrate that (at least for not very small circuits) our protocol is more efficient than any other known today.