Showing papers by "Wrocław University of Technology published in 1998"
TL;DR: A fast and easily implementable approximation algorithm for the problem of finding a minimum makespan in a flow shop with parallel machines and a special advanced method of implementation improves the local search significantly and increases the speed of the algorithm.
168 citations
TL;DR: In this paper, results of bench-scale and pilot-scale investigations on the remediation of contaminated sand and soil using microwave energy are presented, and the experiments suggest that microwave heating is an effective soil remediation technology.
Abstract: Results of bench-scale and pilot-scale investigations on the remediation of contaminated sand and soil using microwave energy are presented. Microwave radiation penetrates the soil and heats water and contaminants. Developing vapors are withdrawn from the soil. The experiments suggest that microwave heating is an effective soil remediation technology. The process is rapid as compared to other methods, and its efficiency depends on the dielectric and physicochemical properties of the soil and the contaminant. It allows for the removal of volatile and semivolatile components, and it is especially effective in the case of polar compounds. In the presence of soil moisture, the removal of both polar and nonpolar compounds can be described quantitatively in terms of steam distillation. The remediation proceeds at a temperature not exceeding 100 °C. It is of particular importance in the case of soil rich in organic matter, where too high a temperature could result in carbonization of humic substances. The remedi...
117 citations
TL;DR: An algorithm has been proposed which solves the transportation problem with fuzzy supply and demand values and the integrality condition imposed on the solution and is exact and computationally effective.
113 citations
TL;DR: In this paper, the structure, mechanical properties and susceptibility to degradation of blends of low density polyethylene (PE) or isotactic polypropylene (PP) and glycerol plasticized starch (GS) was investigated.
102 citations
TL;DR: Algorithms for solving problems to minimize F1 subject to F_2 subject to K and for the construction of the Pareto set and the Paredto set $\epsilon$-approximation for the corresponding bicriterion problems are presented.
Abstract: A bicriterion problem of scheduling jobs on a single machine is studied. The processing time of each job is a linear decreasing function of the amount of a common discrete resource allocated to the job. A solution is specified by a sequence of the jobs and a resource allocation. The quality of a solution is measured by two criteria, F1 and F2. The first criterion is the maximal or total (weighted) resource consumption, and the second criterion is a regular scheduling criterion depending on the job completion times. Both criteria have to be minimized. General schemes for the construction of the Pareto set and the Pareto set $\epsilon$-approximation are presented. Computational complexities of problems to minimize F1 subject to F_2\le K$ and to minimize F2 subject to $F_1\le K$, where K is any number, are studied for various functions F1 and F2. Algorithms for solving these problems and for the construction of the Pareto set and the Pareto set $\epsilon$-approximation for the corresponding bicriterion problems are presented.
92 citations
TL;DR: In this paper, the influence of alkaline solution concentration, type of cation (K+ or Na+) and IPA additive on etching rate of various crystallographic planes and shape of etched figures were examined.
Abstract: The influence of alkaline solution concentration, type of cation (K+ or Na+) and IPA additive on etching rate of various crystallographic planes and shape of etched figures were examined. The simulation of the etching course for concave and convex figures was proposed. The results of the simulation were compared with SEM images.
90 citations
Journal Article•
85 citations
TL;DR: In this paper, a new concept of ideals in BCC-algebras is introduced and connections between such ideals and congruences are described, and a new notion of congruence is defined.
Abstract: We introduce a new concept of ideals in BCC-algebras and describe connections between such ideals and congruences.
85 citations
TL;DR: In this article, a new method of evaluation of scale inhibitors efficiency has been developed and tested based upon solution conductivity measurement, which consists of determining a supersaturation level of any scale forming compound in a given water, at defined conditions, in the presence of a specified amount of scale inhibitor and also without inhibitor.
81 citations
01 Sep 1998
TL;DR: In this article, a new algorithm of power system frequency estimation is presented, which applies orthogonal signal components obtained with use of two Orthogonal FIR filters and ensures 1.5 mHz accuracy of estimation over typical (± 2 Hz) range of measured frequency deviation.
Abstract: A new algorithm of power system frequency estimation is presented. The algorithm applies orthogonal signal components obtained with use of two orthogonal FIR filters. The essential property of the algorithm presented is its outstanding immunity to both signal orthogonal component magnitudes and FIR filter gains variations which ensures 1.5 mHz accuracy of estimation over typical (±2 Hz) range of measured frequency deviation. The results of the algorithm simulation tests using the EMTP software package are also included. It was confirmed that the algorithm dynamics are good enough to track power system frequency even under transient conditions.
73 citations
TL;DR: In this article, a new design for thick film gas sensors was investigated and the sensors were made by the low temperature cofiring ceramics (LTCC) technique with a platinum heater buried inside the multilayer structure.
Abstract: A new design for thick film gas sensors was investigated. The sensors were made by the low temperature cofiring ceramics (LTCC) technique with a platinum heater buried inside the multilayer structure. SnO2 or SnO2 with Pd as catalyst thick films were used as gas sensitive materials. The properties of the gas sensors were measured with methane and carbon monoxide. The results of our study show that LTCC can be successfully applied in sensor technology as well as confirming the correctness of the sensor design.
01 Feb 1998
TL;DR: A complete solution to the inverse problem is presented under assumption that the kinematics are equivalent to the quadratic normal form, and comparisons with other existing methods, including the singularity-robust inverse, reveal advantages of the normal form approach.
Abstract: In this article, a new method of solving the singular inverse kinematic problem for nonredundant robotic manipulators is proposed, based on normal forms of the manipulator kinematics. A complete solution to the inverse problem is presented under assumption that the kinematics are equivalent to the quadratic normal form. Comparisons with other existing methods, including the singularity-robust inverse, are made that reveal advantages of the normal form approach. Experimental results concerned with singular tracking in the AdeptOne manipulator are reported.
TL;DR: In this paper, phase conjugation in dye-doped nematic liquid crystals has been obtained with 532 nm radiation from a cw doubled YAG laser of total power of 50 mW.
TL;DR: In this article, the static and frequency-dependent first hyperpolarizabilities of Reichardt's betaine dye and two simplest pyridinium-N-phenoxide betaines were computed in the gas phase and in aqueous solution.
Abstract: The static and frequency-dependent first hyperpolarizabilities (β) of Reichardt's betaine dye and two simplest pyridinium-N-phenoxide betaines were computed in the gas phase and in aqueous solution. The sum-over-state formalism was used to calculate individual components of the β-tensors. The solvent effect was included via the Langevin dipoles/Monte Carlo approach. The influence of the molecular geometry on the β values of the betaine dyes was investigated as well. The calculations demonstrate that the β values strongly depend on the interplanar angle between the pyridinium and the phenoxide ring. Moreover, we observed dramatically decreased values of β (for all investigated betaines) in aqueous solution as compared to the gas phase.
TL;DR: In this paper, a digital algorithm for on-line dynamic compensation of the secondary voltage of a capacitive voltage transformer (CVT) is presented, based on digital inversion of the CVT transfer function.
Abstract: This paper presents the digital algorithm for on-line dynamic compensation of the secondary voltage of a capacitive voltage transformer (CVT). The adopted CVT model together with the assumed simplifications is given first. Next, the compensating algorithm based on digital inversion of the CVT transfer function is derived. Frequency domain analysis and quantitative evaluation of the compensation follow. The ATP-EMTP simulations are included that show the improvement of the measurement of protective criteria quantities as a result of dynamic compensation of a CVT.
TL;DR: In this paper, experiments were carried out with anisotropic etching of Si(100) in alkaline solutions from the point of view of surface quality, and the circumstances needed to obtain surfaces of various level of smoothness were established.
Abstract: Experiments were carried out with anisotropic etching of Si(100) in alkaline solutions from the point of view of surface quality. The circumstances needed to obtain surfaces of various level of smoothness were established. The problem why etched surface is of mirror-like quality, texturized, i.e., covered on the whole with random inequality (sometime of pyramids shape) as well ones covered with single separated hillocks is discussed in the term of anisotropy. Some analogies between random texturizing, obtaining the hillocks and etching through a patterned SiO 2 mask were stated.
TL;DR: The crystal structure of di-n-butyltin pyridine-2-phosphonate-6-carboxylate, [C14H24NO6PSn]2, features centrosymmetric dimers disposed about a central Sn2O2 core as mentioned in this paper.
TL;DR: In this paper, the problem of reconstruction of nonlinearities in a certain class of non-linear systems of composite structure from their input-output observations when prior information about the system is poor, thus excluding the standard parametric approach to the problem is considered.
Abstract: The paper deals with the problem of reconstruction of nonlinearities in a certain class of nonlinear systems of composite structure from their input-output observations when prior information about the system is poor, thus excluding the standard parametric approach to the problem. The multiresolution idea, being the fundamental concept of modern wavelet theory, is adopted, and the Haar multiresolution analysis in particular is applied to construct nonparametric identification techniques of nonlinear characteristics. The pointwise convergence properties of the proposed identification algorithms are established. Conditions for the convergence are given; and for nonlinearities satisfying a local Lipschitz condition, the rate of convergence is evaluated, With applications in mind, the problem of data-driven selection of the optimum resolution degree in the identification procedure, essential for the multiresolution analysis, is considered as well. The theory is verified by computer simulations.
TL;DR: In this article, a fuzzy logic controller (FLC) for on-load tap change control for distribution transformers is presented, which is optimized from the numerical point of view and proved to be implementable on contemporary programmable logic controllers (PLCs).
Abstract: This paper presents a new fuzzy logic controller (FLC) for on-load tap change control for distribution transformers. The model of a transformer with its tap changing mechanism is given first. Next, the FLC is presented in detail. The proposed algorithm is optimized from the numerical point of view and proved to be implementable on contemporary programmable logic controllers (PLCs). Simulation results are included that compare the proposed control algorithm with the classical inverse-time controller and prove the efficiency of the new solution.
TL;DR: This paper presents an approximation algorithm based on the tabu search approach supported by the reduced neighborhood, search accelerator and technique of back jumps on the search trajectory that provides makespans very close to optimal in a short time.
Abstract: Problems with “blocking” (limited intermediate storage space) are used frequently for modelling and scheduling just-in-time and flexible manufacturing systems. In this paper, an approximation algorithm is presented for the problem of finding the minimum makespan in a two-machine permutation flow-shop scheduling problem with the mediating buffer of finite capacity. The algorithm is based on the tabu search approach supported by the reduced neighborhood, search accelerator and technique of back jumps on the search trajectory. Due to some special properties, the proposed algorithm provides makespans very close to optimal in a short time. It has been shown that this algorithm outperforms all known approximation algorithms for the problem stated.
TL;DR: In this paper, the dielectric properties of porous glasses, obtained from sodium borosilicate glass, were investigated in the frequency range 20 Hz to 1 MHz and temperature range −100°C to +300°C.
Abstract: The dielectric properties of porous glasses, obtained from sodium borosilicate glass, were investigated in the frequency range 20 Hz to 1 MHz and temperature range −100°C to +300°C for the purpose of inferring the geometric properties of porous materials. The features of the dielectric properties due to the geometrical disorder were analysed by using models describing the non-Debye slow decay dynamics. The dielectric response is affected by the geometrical micro- and mesostructural properties of the porous matrix and the properties of the material filling the pores. It provides information on the hindered dynamics of water molecules, located within the pores and affected by the surfaces. An analysis of the dielectric parameters enables us to describe the porosity of the materials.
TL;DR: A new method for evaluating tear film stability on the human eye is reported, and the tear breakup time can be evaluated noninvasively by comparing the value of the second momentum of Fourier spectra calculated from the consecutive interferograms.
Abstract: A new method for evaluating tear film stability on the human eye is reported. The tear film distribution on the cornea is measured by the lateral shearing interference technique. The eye is kept open during approximately a 2-min recording, when blinking has to be prevented. Continuous recording and viewing of interferograms allows the changes in disturbances of the interference fringes to be registered during elapsed time. The changes in fringes are caused by the evaporation of tears from the ocular surface and appearance of the breakups. For precise and repetitive assessment of the tear film breakup time, a fast fourier transform (FFT) is applied to consecutive interferograms. Larger fringe disturbances result in wider Fourier spectra. The tear breakup time can be evaluated noninvasively by comparing the value of the second momentum of Fourier spectra calculated from the consecutive interferograms. © 1998 Society of Photo-Optical Instrumentation Engineers. [S1083-3668(98)01301-X]
TL;DR: New algorithms with a worst-case performance ratio equal to [ m k]ϱ k are proposed, where ϱk is the worst- case performance ratio of an algorithm which solves an auxiliary k-machine problem.
TL;DR: In this article, coal tar pitch with 10% addition of various polymers were prepared under relatively mild conditions and the effect of a polymer on properties of composition and yield and optical texture of resultant semi-coke was assessed.
TL;DR: In this article, the authors compared the performance of different acrylic copolymers for trypsin immobilisation and showed that the most effective carrier was a copolymer of acrylonitrile/trimethylolpropane triacrylate synthesised in the presence of cyclohexanol and 2-ethylhexanol.
TL;DR: In this article, the influence of the content p of carbon black and graphite in resistive inks and curing temperature on sheet resistance and noise intensity C is considered, and it is shown that a higher curing temperature causes a decrease in the resistor's volume and influences and C indirectly, via changes of the parameter p. The relation is found in this case for all measured resistors.
Abstract: noise properties of carbon black/polyesterimide and (carbon )/polyesterimide thick-film resistors are studied. In resistive inks either high-structure carbon black or medium-structure carbon black was used. The influence of the content p of carbon black and graphite in resistive inks and curing temperature on sheet resistance and noise intensity C is considered. It is shown that a higher curing temperature causes a decrease in the resistor's volume and influences and C indirectly, via changes of the parameter p. It is then found that an increase in p leads to a simultaneous decrease of sheet resistance and noise intensity C. The relation is found in this case for all measured resistors. The values of noise exponent are estimated and a comparison with the noise properties of conventional cermet thick-film resistors is made. It is shown that the noise intensities of carbon black/polyesterimide resistors are comparable to those of cermet resistors.
TL;DR: In this article, new types of ecologically benign surfactants with sugar head groups have been described, namely: N-dodecyl-N-methyllactobionamide (C12-MLA), N-decodeyl-n-methylglucoheptonamide (c12-MGHA), n-decideyl-methylgluconamide (12-MGA), ndecodely-nmethylglamine (C 12-GA), and Ndecidely-Nmethylaldonamide (N
Abstract: New types of ecologically benign surfactants with sugar head groups have been described, namely: N-dodecyl-N-methyllactobionamide (C12-MLA), N-dodecyl-N-methylglucoheptonamide (C12-MGHA), N-dodecyl-N-methylgluconamide (C12-MGA), N-dodecyl-gluconamide (C12-GA) and N-octyl-glucoheptonamide (C8-GHA). Their surface properties, such as static surface tension (γ), critical micelle concentration (CMC), surface area demand per molecule (A) and foaming and wetting properties have been analyzed in relation to lactobionamides (Cn-LA) and well-known oligooxyethylene alkyl ethers. The presence of both the amide methyl group, and the additional 1.4-glucose segment, increases significantly the surfactant solubility and decreases its hydrophobicity. The performing properties (foaming and wetting behavior) of N-alkyl-N-methylaldonamide-type surfactant prove that they can make suitable candidates as ecologically favorable surfactants.
TL;DR: The gel mobility-shift experiments showed that UspDBD exhibited higher affinity than EcRDBD toward a 20-hydroxyecdysone response element from the Drosophila hsp 27 gene (hsp 27pal), which indicates the need for caution in interpreting the activities of GST fusion proteins.
TL;DR: The effects of the modification of polyacrylonitrile ultrafiltration membranes with sodium hydroxide are discussed in this paper, which results in membranes with decreasing pore diameter.
Abstract: The effects of the modification of polyacrylonitrile ultrafiltration membranes with sodium hydroxide are discussed. The NaOH-induced hydrolysis of nitrile groups on the membrane surface results in membranes with decreasing pore diameter. The average pore diameter changes from 2.6 to 0.6 nm in the progress of hydrolysis. The modified membranes are less prone for protein deposition. Fouling causes a pore diameter reduction of 80% for the untreated and 20% for the modified membranes. Modification results also in the creation of the membranes working in the nanofiltration mode. The unmodified membrane does not reject salt while a membrane immersed in the modification bath is capable of rejecting about 50% of calcium carbonate.
Der Einflus einer Modifizierung von Polyacrylnitrilmembranen mit Natriumhydroxid auf die Ultrafiltrationseigenschaften wird diskutiert. Die Hydrolyse der Nitrilgruppen an der Membranoberflache mit NaOH fuhrt zu Membranen mit geringerem Porendurchmesser. Der durchschnittliche Porendurchmesser andert sich im Verlauf der Hydrolyse von 2,6 auf 0,6 nm. Die modifizierten Membranen neigen weniger zur Proteinablagerung. Fouling verursacht bei den unmodifizierten Membranen eine Verringerung des Porendurchmessers um 80% und bei den modifizierten Membranen um 20%. Durch die Modifizierung werden Membranen erhalten, die zur Nanofiltration geeignet sind. Wahrend die unmodifizierten Membranen nicht fahig sind, Salze zuruckzuhalten, konnen die modifizierten Membranen rund 50% Calciumcarbonat separieren.
TL;DR: A complex, nonlinear forward model, including exciting signal and static recoil pressure-lung volume descriptions and 132 parameters, has been constructed that enables prediction of flow during forced expiration in the whole range of forced vital capacity.