Optimal control of the effects from industrial transportation on the environment

The paper discusses optimal control of ecosystem state for observation of a generalized monotonically varying random parameter. A model is proposed for the controlled vector random process, whose components are assigned acceptable ranges and the observations are performed discretely. __________ Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 6, pp. 40–44, June, 2006.     

WWTP dynamic disturbance modelling--an essential module for long-term benchmarking development.

Intensive use of the benchmark simulation model No. 1 (BSM1), a protocol for objective comparison of the effectiveness of control strategies in biological nitrogen removal activated sludge plants, has also revealed a number of limitations. Preliminary definitions of the long-term benchmark simulation model No. 1 (BSM1_LT) and the benchmark simulation model No. 2 (BSM2) have been made to extend BSM1 for evaluation of process monitoring methods and plant-wide control strategies, respectively. Influent-related disturbances for BSM1_LT/BSM2 are to be generated with a model, and this paper provides a general overview of the modelling methods used. Typical influent dynamic phenomena generated with the BSM1_LT/BSM2 influent disturbance model, including diurnal, weekend, seasonal and holiday effects, as well as rainfall, are illustrated with simulation results. As a result of the work described in this paper, a proposed influent model/file has been released to the benchmark developers for evaluation purposes. Pending this evaluation, a final BSM1_LT/BSM2 influent disturbance model definition is foreseen. Preliminary simulations with dynamic influent data generated by the influent disturbance model indicate that default BSM1 activated sludge plant control strategies will need extensions for BSM1_LT/BSM2 to efficiently handle 1 year of influent dynamics.     

Experimental studies of the bond response of three-wire strands and some influencing parameters

The bond behavior of prestressing strands is of great importance for the capacity of precast prestressed concrete structures. In the present study, the bond behavior of three-wire strands, and some influencing parameters, were examined by means of steel encased pull-through and push-in tests. The three mechanisms: adhesion, friction and other mechanical actions were found to be present at the strand-concrete interface at different slip values. The results from the experiments showed that the micro roughness of the strand surface strongly affected the initial bond response of the strand, that is the adhesion in the interface. The maximum bond capacity of indented three-wire strands was found to be directly connected to the geometric properties of the strand indents. The influence of the concrete strength on the bond capacity of the strand was hard to interpret. However, the density of the concrete matrix was found to be a better parameter for determine the influence of the concrete rather than the compressive strength.     

Note on B-splines, wavelet scaling functions, and Gabor frames

Let g be a continuous, compactly supported function on such that the integer translates of g constitute a partition of unity. We show that the Gabor system (g,a,b), with window g and time-shift and frequency-shift parameters a,b>0 has no lower frame bound larger than 0 if b=2,3,... and a>0. In particular, (g,a,b) is not a Gabor frame if g is a continuous, compactly supported wavelet scaling function and if b=2,3,... and a>0. We give an example for our result for the case that g=B/sub 1/, the triangle function supported by [-1,1], by showing pictures of the canonical dual corresponding to (g,a,b) where ab=1/4 and b crosses the lines N=2,3,.     

On the origin of strain hardening in glassy polymers

The influence of network density on the strain hardening behaviour of amorphous polymers is studied. The network density of polystyrene is altered by blending with poly(2,6-dimethyl-1,4-phenylene-oxide) and by cross-linking during polymerisation. The network density is derived from the rubber-plateau modulus determined by dynamic mechanical thermal analysis. Subsequently uniaxial compression tests are performed to obtain the intrinsic deformation behaviour and, in particular, the strain hardening modulus. At room temperature, the strain hardening modulus proves to be proportional to the network density, irrespective of the nature of the network, i.e. physical entanglements or chemical cross-links. With increasing temperature, the strain hardening modulus is observed to decrease. This decrease appears to be related to the influence of thermal mobility of the chains, determined by the distance to the glass-transition temperature (T−T_g).     

Methods of Verifying Continuous Automatic Belt Weighers: State and Prospects

The basic methods of verifying continuous automatic belt weighers are described. A comparative analysis of these methods on the basis of experimental studies is made and ways of implementing the results in industry are recommended.     

Managing Fashion Goods Inventories: Dynamic Recourse for Retailers with Outlet Stores

The proliferation of both online and bricks and mortar outlet stores underscores the observation that secondary markets are readily accessible to retailers of short-life-cycle products. These secondary markets provide recourse channels for retailers to sell excess inventory of out-of-favor items at reduced prices when overstocking occurs in a primary market. We study the problem of determining when a retailer should terminate its primary selling season by selling remaining inventory on a secondary market. The retailer has a single opportunity to procure prior to a primary selling season consisting of multiple periods. Demand in each period is random, but correlated. At the end of each period, any remaining inventory incurs a holding cost. Then, based upon the current level of inventory and the cumulative demand-to-date, the retailer decides either to terminate the primary selling season by selling all or part of the remaining inventory on a secondary market, or to extend the current primary selling season by another period. We develop structural properties of the optimal policy for determining when to terminate the primary selling season, and we develop corresponding implications for procurement.     

The anisotropic effect of a weak magnetic field on the photoconductivity of C<Subscript>60</Subscript> single crystals

The effect of crystal orientation on the photogeneration of free charge carriers was studied for C₆₀ single crystals in a weak magnetic field. The photoconductivity sharply depends on the orientation of magnetic field with respect to the crystallographic directions, showing a 5–8% increase for seven axes of the C₆₀ crystal.     

Thermodynamic stability of GaInSb,InAsSb, and GaInP epitaxial films

The miscibility gaps and the critical temperatures of spinodal decomposition of ternary semiconducting Ga-In-Sb, Ga-In-P, and In-As-Sb systems are calculated by taking into account the deformation energy and the effect of plastic relaxation caused by the misfit dislocations. It is shown that taking into consideration elastic energy narrows the ranges of spinodal decomposition and lowers its critical temperature. The introduction of the phenomenological parameter into Matthews-Blakeslee formula makes it possible to reach a satisfactory agreement between theoretically calculated values of critical thickness of epitaxial films and the experimental data.     

Modellierungs- und Simulationsverfahren für die optische Verbindungstechnik auf elektrischen Leiterplatten

Optical interconnection technology on the printed circuit board level is a key technology for future microelectronic equipment. The consideration of functional, technological, and economical requirements results in a hybrid solution, where electrical and optical interconnects are integrated into one substrate called electrical optical printed circuit board. The significant part of the entire design process for electrical optical printed circuit boards is marked by the design supporting modelling and simulation of optical interconnects. Based on an abstract model for an entire optical interconnect a simulation model for optical multimode-waveguides is presented, taking into account all significant waveguide properties. Apart from that, the modeling of active components (laser- and photo-diodes) is addressed.