Metamodel-based collaborative optimization framework

This paper focuses on the metamodel-based collaborative optimization (CO). The objective is to improve the computational efficiency of CO in order to handle multidisciplinary design optimization problems utilising high fidelity models. To address these issues, two levels of metamodel building techniques are proposed: metamodels in the disciplinary optimization are based on multi-fidelity modelling (the interaction of low and high fidelity models) and for the system level optimization a combination of a global metamodel based on the moving least squares method and trust region strategy is introduced. The proposed method is demonstrated on a continuous fiber-reinforced composite beam test problem. Results show that methods introduced in this paper provide an effective way of improving computational efficiency of CO based on high fidelity simulation models.     

Mid-range metamodel assembly building based on linear regression for large scale optimization problems

In this work an approach to building a high accuracy approximation valid in a larger range of design variables is investigated. The approach is based on an assembly of multiple surrogates into a single surrogate using linear regression. The coefficients of the model assembly are not weights of the individual models but tuning parameters determined by the least squares method. The approach was utilized in the Multipoint Approximation Method (MAM) method within the mid-range approximation framework. The developed technique has been tested on several benchmark problems with up to 1000 design variables and constraints. The obtained results show a high degree of accuracy of the built approximations and the efficiency of the technique when applied to large-scale optimization problems.     

New Insights into the Structure of Kappa/Beta-Carrageenan: A Novel Potential Inhibitor of HIV-1

New insights into the structure of the hybrid κ/β-carrageenan (κ/β-CRG) of the red alga Tichocarpus crinitus have been obtained. Carrageenan oligosaccharides were prepared through the chemical and enzymatic depolymerization of κ/β-CRG with κ-carrageenase and its the enzyme-resistant fraction. The composition and distribution of the repetition units of κ/β- CRG were investigated by using the negative ion tandem MALDI-TOFMS and ESIMS method, which made it possible to prove and characterize the hybrid structure of this polysaccharide. An analysis revealed the blockwise distribution of the long β-blocks along the polysaccharide chain, with the inclusion of κ/β, μ/ν-blocks and some ι-blocks. Furthermore, the desulfated κ/β-CRG was shown to contain of –G–D– repeating units up to 3.5 kDa. Previous studies have demonstrated that CRGs suppress the replication of several viruses. Here, we established that κ/β-CRG and its oligosaccharides significantly inhibit the transduction efficiency of replication-defective lentiviral particles pseudotyped with the envelope proteins of three different viruses. We found that the polysaccharide and its oligosaccharides strongly reduced the transduction efficiency of lentiviral particles pseudotyped with GP160—the envelope protein of the human immunodeficiency virus HIV-1—when added to T-lymphocyte Jurkat cells. The CRG oligosaccharides displayed significantly higher antiviral activity.     

Experimental study of the thermal conductivity of weakly absorbing liquids in layers transparent to infrared radiation

The thermal conductivities of a number of organic liquids are determined by a transient method under irregular thermal conditions.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 30, No. 6, pp. 972–978, June, 1976.     

Spectral characteristics of scalar higher-dimensional bremsstrahlung

We consider scalar higher-dimensional bremsstrahlung to explore the possibility of classical probes of extra dimensions, since higher-dimensional Minkowski space-time is a flat limit of cosmological backgrounds. The applicability of this results to models of ADD type has been proven by Galtsov, Kofinas, Spirin, and Tomaras in a number of papers. We develop classical perturbation theory which describes interaction between point particles moving on the observable 3-dimensional space, that simulates a 3-brane, and mediated by scalar fields. Applying this to the scattering problem, we find that the scattering angle is finite and contrary to the corresponding quantum result. Then we calculate scalar bremsstrahlung from ultrarelativistic particles colliding in D-dimensional Minkowski space and show that the radiation loss increases as a power of the Lorentz factor γ of the collision, increasing with D.