ARON, G, BALL, JE & SMITH, TA 1991, 'FRACTAL CONCEPT USED IN TIME-OF-CONCENTRATION ESTIMATES', JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING-ASCE, vol. 117, no. 5, pp. 635-641.
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In present hydrologic practice, it is generally recognized that the shallow overland sheet flow through the upper portions of a watershed is very slow, and that runoff gradually accelerates as it concentrates into gullies and, finally, streams. In this paper, the fractal concept is applied by testing whether a watershed's stream-and-swale system branches in a characteristic pattern that repeats itself into successively finer but similar segments. Commonly used geometric, geomorphologic, hydraulic, and hydrologic equations are combined to reduce the number of parameters. Kinematic wave equations are then developed for the runoff movement in the channels, and integrated to obtain an equation for the time of concentration. © ASCE.
Bone, DJ 1991, 'Fourier fringe analysis: the two-dimensional phase unwrapping problem', Applied Optics, vol. 30, no. 25, pp. 3627-3627.
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Boonthanon, S, Dharmappa, HP, Vigneswaran, S & Ben Aim, R 1991, 'Use of a backflush technique in cross-flow microfiltration for treating natural water and filter backwash wastewater in water works', Aqua London, vol. 40, no. 2, pp. 103-109.
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Cross-flow microfiltration (CFMF), is useful in treating natural water for potable purpose, as it is very efficient in completely removing all particles within the size range 0.01-10 μm, including bacteria. It can also be used to treat the filter backwash wastewater produced in a water-treatment plant. Although CFMF is a very effective technique for treating natural water and filter backwash wastewater, problems like fouling, deposition and internal clogging affect the efficiency of the process. The backflush technique in CFMF is one of the most useful techniques for minimizing these problems. In this study, laboratory-scale CFMF experiments were carried out using backflush technique in treating natural water and filter backwash wastewater to study the effect of operating parameters like backflush frequency and backflush duration on CFMF performance. In the case of natural-water treatment, the permeate flux increased by 24% using the backflush technique and in the case of backwash wastewater treatment, it was found to increase by 400%.
Boonthanon, S, Hwan, L, Vigneswaran, S, Aim, R & More, JC 1991, 'Application of pulsating cleaning technique in crossflow microfiltration', Filtration & Separation, vol. 28, no. 3, pp. 199-201.
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Crossflow microfiltration (CFMF), is a pressure driven membrane process allowing better permeate flux by shearing action of flow. It can remove most of the impurities found In water and wastewater. But there are still major problems to be solved caused by fouling, deposition and internal clogging, which reduce the efficiency of separation. The pulsation cleaning technique is one of the methods used to avoid or minimise these drawbacks. Laboratory scale microfiltration using a clay suspension was carried out to study the effect of the pulsation cleaning technique on overall CFMF performance at various pulsation times of flux. It was found that the higher permeate flux was obtained when the operation of pulsation was more frequent. Also the study performed showed that this technique improved the permeate flux by 80%. © 1991.
BRAUN, RM 1991, 'CREATING SCIENTIFIC FORMULAS USING STANDARD WORD-PROCESSORS IS EASY', IEEE TRANSACTIONS ON EDUCATION, vol. 34, no. 1, pp. 138-139.
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This paper describes a method for entering scientific formulae into text using standard word processors. The described technique places a grid matrix on the screen into which the terms of the equation may be conveniently placed. The technique relies on
BRAUN, RM & MEYEROWITZ, GJ 1991, 'METEOR BURST COMMUNICATIONS .2. INVESTIGATION INTO ADAPTIVE-RATE MODEMS FOR METEOR BURST COMMUNICATION', ELECTRONICS & COMMUNICATION ENGINEERING JOURNAL, vol. 3, no. 5, pp. 213-222.
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Current meteor burst communication systems operate at constant bit rates of 4 kbit/s and are limited to average throughputs of 50 bit/s. The paper documents the design and implementation of an adaptive-bit-rate modem for optimising the throughput. A nove
BRISCOE, BJ, STUART, BH, THOMAS, PS & WILLIAMS, DR 1991, 'A COMPARISON OF THERMAL-INDUCED AND SOLVENT-INDUCED RELAXATION OF POLY(ETHER ETHER KETONE) USING FOURIER-TRANSFORM RAMAN-SPECTROSCOPY', SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, vol. 47, no. 9-10, pp. 1299-1303.
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The paper describes a study of the application of Fourier transform Raman spectroscopy as a means of identifying the extent of the surface plasticisation of a poly(ether ether ketone) by a known plasticising solvent, toluene. Spectra are described for t
Burnett, IS & Holbeche, RJ 1991, 'The application of the DFT to CELP architectures', IEEE Workshop on Speech Coding for Telecommunications, pp. 83-84.
CAO, HT & SIRIVIVATNANON, V 1991, 'CORROSION OF STEEL IN CONCRETE WITH AND WITHOUT SILICA FUME', CEMENT AND CONCRETE RESEARCH, vol. 21, no. 2-3, pp. 316-324.
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Deakin, MAB 1991, '‘Thermodynamic’ calculation of integrals', International Journal of Mathematical Education in Science and Technology, vol. 22, no. 1, pp. 121-165.
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It is shown that the total lifespan of a component operating at time t in a renewal process is stochastically larger than the underlying lifespan distribution. © 1991 Taylor and Francis Group, LLC.
Dissanayake, MWMG, Goh, CJ & Phan-Thien, N 1991, 'Time-optimal Trajectories for Robot Manipulators', Robotica, vol. 9, no. 2, pp. 131-138.
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SUMMARYA computational technique for obtaining minimum-time trajectories for robot manipulators is described in this paper. In the analysis, limitations to link movements due to design constraints are taken into consideration. Numerical examples based on a two-link planar robot arm shows the feasibility of the technique proposed. A physical explanation for the general characteristics of the observed trajectories is also presented. The importance of appreciating optimal control issues in designing robot manipulators and in planning robot workstation layouts is emphasised.
Eigenbrod, KD, Knutsson, S & Sheng, D 1991, 'Measurement of pore water pressures in freezing and thawing soft, fine grained soils', Canadian Geotechnical Conference, no. pt 1.
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Laboratory freezing tests were performed on laterally confined samples of lightly overconsolidated fine grained soil, exposed to one-dimensional freezing at a constant temperature gradient. Pore water pressures and temperatures were measured at the perimeter of the specimens at various points along their height, during freezing and thawing. Vertical heave and water in- and outflow in the sample were also recorded. X-ray pictures were taken at various points during freezing to correlate ice lens formation to the measured data. Of particular interest were occurences of high pore water pressures shortly after the freezing front had stabilized. Subsequently cyclic increases and decreases of pore water pressures, and in- and outflow were observed. During thawing sudden temperature increases were accompanied by sudden decreases of pore water pressures. The hydraulic conductivity of the unfrozen fringe was directly determined from the measured pore water pressure and temperature profiles, records of water in- and outflow, and X-ray photographs.
Esselle, KP & Stuchly, SS 1991, 'A broad-band resistively loaded V-antenna: experimental results', IEEE Transactions on Antennas and Propagation, vol. 39, no. 11, pp. 1587-1591.
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Esselle, KP & Stuchly, SS 1991, 'An electrically large antenna for transient electromagnetic field measurements', IEEE Transactions on Instrumentation and Measurement, vol. 40, no. 2, pp. 460-464.
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Green, TK, Ball, JE & Conkright, K 1991, 'Rate of benzene sorption by O-alkylated Illinois No. 6 coal', Energy & Fuels, vol. 5, no. 4, pp. 609-610.
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Guang-Quan, Z 1991, 'Fuzzy continuous function and its properties', Fuzzy Sets and Systems, vol. 43, no. 2, pp. 159-171.
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Horita, E, Miyanaga, Y & Tochinais, K 1991, 'Characteristic extraction of speech using arma model with double inputs', Electronics and Communications in Japan (Part III: Fundamental Electronic Science), vol. 74, no. 3, pp. 67-81.
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AbstractThis paper proposes a method of speech analysis using a new stochastic model. This model represents two different kinds of MA parts associated with pseudo‐periodical pulse train input and Gaussian process input. Therefore, the new model describes individually two different production models for voiced and unvoiced sound in the frequency domain and can precisely realize speech production models in comparison with an ARMA model. It has been shown from experimental results that the proposed stochastic model can extract more accurate characteristics of real speech than an ARMA model.
Houwing, AFP, Boyce, RR, Bone, DJ & Johnston, DK 1991, 'Measurement of recombination rate parameters in nonequilibrium supersonic expansions of ionized argon and neon', Shock Waves, vol. 1, no. 3, pp. 177-185.
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Two wavelength interferometry techniques and a two dimensional Fourier transform analysis are used to produce contour maps of the heavy particle densities and ionization fractions for supersonic corner expansions of ionized argon and neon. A new phase unwrapping algorithm is employed to minimize noise problems previously encountered because of phase discontinuities associated with shock waves and flow luminosity. Determination of recombination rate coefficients is achieved through the measurement of gradients in the ionization fraction. © 1991 Springer-Verlag.
Indraratna, B & Nutalaya, P 1991, 'Some engineering characteristics of a compacted lateritic residual soil', Geotechnical and Geological Engineering, vol. 9, no. 2, pp. 125-137.
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In many parts of the world, particularly in humid tropical regions, residual soils are abundant. In this paper the suitability of a residual lateritic soil as a construction material is investigated, with respect to its strength and compaction characteristics. In comparison with other typical construction fills available in Southeast Asia, compacted lateritic soils produce excellent shear strengths and CBR values. However, the brittleness and tensile cracking of this compacted material become enhanced on the dry side of the optimum moisture content, or if excessive compaction is imparted. Nevertheless, at a moisture content of 2% wetter than the optimum, the tensile mode of failure is suppressed and the lateritic fills become ideally suited for the construction of high embankments and impervious dam cores. © 1991 Chapman & Hall.
Indraratna, B, Nutalaya, P & Kuganenthira, N 1991, 'Stabilization of a dispersive soil by blending with fly ash', Quarterly Journal of Engineering Geology, vol. 24, no. 3, pp. 275-290.
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Abstract This paper is concerned with the influence of fly ash (pozzolanic) on the stabilization of a dispersive soil commonly found in northeast Thailand. The effect of various proportions of fly ash on the rate of erosion, dispersiveness, strength and frictional properties and the compaction and consolidation characteristics, are discussed. It is noted that in general the addition of fly ash not only inhibits erosion and dispersiveness but also contributes to a significant improvement in strength and deformation characteristics. Nevertheless, excessive quantities of fly ash (>8%) generate diminishing returns and in fact promote segregation (erosion) of the stabilized soil again due to insufficient cohesion. Mineralogical studies based on X-ray diffraction analysis indicate that the reduction in the rate of erosion of the blended soil is associated with fine particle flocculation. The long term properties, however, are directly linked with the self-hardening nature of fly ash which contributes to time-dependent strengthening of the stabilized soil.
Indraratna, B, Nutalaya, P, Koo, KS & Kuganenthira, N 1991, 'Engineering behaviour of a low carbon, pozzolanic fly ash and its potential as a construction fill', Canadian Geotechnical Journal, vol. 28, no. 4, pp. 542-555.
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Detailed laboratory investigations were conducted on Mae Moh fly ash from northern Thailand for the determination of its grain size distribution, mineralogy, pozzolanic activity, compaction and strength characteristics, and the collapse potential. On the basis of the experimental results, this fly ash is classified as ASTM class C, which is considered to be pozzolanic. It has good potential to be utilized as an effective fill for embankments (roads and dams), airfields, pavements, and building bricks, as well as for the stabilization of compressible or erodible foundations. Because of the fact that Mae Moh fly ash contains only a negligible amount of unburned carbon, its pozzolanic reactivity is accelerated, in comparison with the relatively inert, high-carbon fly ash produced elsewhere in Thailand and many other parts of Asia. It is also demonstrated that Mae Moh fly ash can be easily compacted to produce acceptable dry densities over a wide range of water contents. Curing with an adequate moisture supply in the presence of calcium oxide plays an important role in accelerating the pozzolanic reactions, hence improving the time-dependent-properties. This study further proposes that a curing period of 2–3 weeks is sufficient for this material to approach its maximum strength. Although the behaviour of one specific fly ash cannot generalize the wide array of other ashes, the test results obtained for Mae Moh fly ash may be applied to lignite ashes in the category of ASTM class C. Key words: fly ash, structural fill, compaction, compressive strength, shear strength, collapse potential, pozzolanic activity.
Indraratna, B, Satkunaseelan, KS & Rasul, MG 1991, 'Laboratory Properties of a Soft Marine Clay Reinforced with Woven and Nonwoven Geotextiles', Geotechnical Testing Journal, vol. 14, no. 3, pp. 288-295.
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Abstract This paper is concerned with the laboratory properties of a geotextile-reinforced compacted soft marine deposit with respect to its compaction, compressive strength, and time-dependent settlement characteristics. Two different geotextiles, namely, Polyfelt TS-500 (nonwoven) and Cardon SG PP 150 (woven) have been investigated. It was observed from the experimental study that a nonwoven geotextile contributes very differently as compared to a woven geotextile when placed within soft clay soils. This is because of the fact that the nonwoven Polyfelt fabric allows better drainage (dissipation of pore pressures) in comparison with the woven Cardon geotextile, particularly at high moisture contents. The compactibility of the reinforced sample is affected by the moisture content, number of fabric layers, and the type of geotextile. With the presence of geotextiles, the compressive strength of the soil is dictated not only by the internal mode of failure induced in the samples, but also by the spacing and the drainage capacity of the geotextile layers.
Lin, C-T & Lee, CSG 1991, 'Fault-tolerant reconfigurable architecture for robot kinematics and dynamics computations', IEEE Transactions on Systems, Man, and Cybernetics, vol. 21, no. 5, pp. 983-999.
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Lin, C-T & Lee, CSG 1991, 'Neural-network-based fuzzy logic control and decision system', IEEE Transactions on Computers, vol. 40, no. 12, pp. 1320-1336.
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LOPEZFROEDGE, L, BALL, JE, CHEN, MW & GREEN, TK 1991, 'FLORY INTERACTION PARAMETERS FOR ILLINOIS NUMBER-6 COAL EXTRACTS AND BENZENE', ACS SYMPOSIUM SERIES, vol. 461, pp. 137-158.
Manandhar, UK & Vigneswaran, S 1991, 'Effect of media size gradation and varying influent concentration in deep-bed filtration: Mathematical models and experiments', Separations Technology, vol. 1, no. 4, pp. 178-183.
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A new model for deep-bed filtration that considers the presence of medium size gradations and the variation of influent concentration with time is proposed. In formulating the model, the rate of filtration is assumed to be either enhanced or retarded by the deposited particles, and the increase in the headloss necessary to maintain a given flow is estimated from the Kozeny equation. Simulated filter performance based on the model was found to agree with pilot plant data on the filtration of clarified effluent from a water treatment plant.
Nakagaki, A, Miyanaga, Y & Tochinai, K 1991, 'A time‐varying parameter estimation of a minimum realization ARMA lattice model', Electronics and Communications in Japan (Part III: Fundamental Electronic Science), vol. 74, no. 6, pp. 106-115.
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AbstractThis paper proposes a time‐varying parameter estimation of a minimum realization ARMA lattice model. The model consists of four types of elementary sections. Since each elementary section has only a design parameter after normalization, its characteristics can be represented more compactly. To estimate time‐varying characteristics, several methods with the constant weighting factor have been proposed.This paper shows the limits of the methods using the constant weighting factor and proposes an estimation method with a new variable weighting factor. The new method directly weights observed signals and can arbitrarily change the weighting factor at any time.
NWACHUKU, DA & LOGANATHAN, P 1991, 'THE EFFECT OF LIMING ON MAIZE YIELD AND SOIL PROPERTIES IN SOUTHERN NIGERIA', COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS, vol. 22, no. 7-8, pp. 623-639.
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Effects of four rates of lime applications to maize grown in 12 strongly acidic soils of southern Nigeria belonging to Ultisol and Inceptisol orders were studied under greenhouse conditions. Five of these soils (A1 saturation, 26%-33%; Ca saturation, 3%-16%) showed marked responses to lime with % relative yield (percentage of maximum yield) ranging from 5 to 73, 2 soils (A1 saturation, 1% and 5%; Ca saturation, 52% and 59%) showed no response (about 95% relative yield) and the remaining 5 soils (A1 saturation, 15%-28%; Ca saturation, 10%-31%) showed marginal responses (79% to 90% relative yield). Percent relative yield was highly correlated with initial soil values of % A1 saturation (r = 0.923), 0.02M CaCl2 soluble A1 (r = 0.906), % Ca saturation (r = 0.806) and exchangeable Ca (r = 0.729) and poorly correlated with soil pH (r = 0.559). Overall, A1 saturation, soluble Al, Ca saturation and exchangeable Ca values corresponding to 90% relative yield were 27%, 13 mg/L, 21% and 0.7 cmol(+)/kg, respectively. On an individual soil basis, near maximum yield was obtained when liming reduced the soil Al saturation to 25% and increased Ca saturation to 28%. No increase in yields was obtained by liming beyond pH 5.5. © 1991, Taylor & Francis Group, LLC. All rights reserved.
Ollerton, RL & Shannon, AG 1991, 'Difference equations and an artificial pancreatic beta‐cell', International Journal of Mathematical Education in Science and Technology, vol. 22, no. 4, pp. 545-554.
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Some difference equations are developed to model glucose–insulin kinetics. The resulting algorithm permits continuous subcutaneous insulin infusion for hospitalized insulin-dependent diabetics. Three venal catheters infuse glucose and insulin and sample the plasma glucose levels to constitute an artificial pancreatic beta-cell. This application of a discrete segments approach to modelling illustrates the need for a balanced approach to the undergraduate mathematics curriculum. © 1991 Taylor & Francis Ltd.
SHANNON, AG, TURNER, JC & ATANASSOV, KT 1991, 'A GENERALIZED TABLEAU ASSOCIATED WITH COLORED CONVOLUTION TREES', DISCRETE MATHEMATICS, vol. 92, no. 1-3, pp. 329-340.
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This paper considers the tableaux arising from the colors at different levels of arbitrary order convolution trees. The results are related to the elements which constitute the Pascal-Lucas-Turner triangles and to various generalizations of the Fibonacci numbers, some formed by altering the order of the recurrence relations and some by coupling some second order recurrence relations. © 1991.
Sirivivatnanon, V & Cao, HT 1991, 'Quality assurance of concrete structures analysis of in-situ concrete cover', Transactions of the Institution of Engineers, Australia. Civil engineering, vol. CE33, no. 2, pp. 111-118.
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This paper presents a brief review of durability problems in reinforced concrete structures caused by lack of sufficient concrete cover and a statistical concept to analyse and to quantify in-situ concrete cover in buildings. The use of non-destructive procedures to measure the cover in building elements under construction is discussed. Cover data of a large number of buildings in Australia and Japan were analysed. It was found that the Levels of Confidence (LOC) for achieving minimum concrete cover for durability were poor, with less than 50 per cent of the structures achieving a 90% LOC. The use of the non-destructive technique of cover measurement and the statistical concept to quantify the in-situ cover as a quality auditing tool are described. The effectiveness of such a tool, coupled with a series of corrective measures implemented during the construction, to improve the LOC is demonstrated using an example of projects in Singapore. With improvements in design detailing, selection of suitable spacers and good installation practice, it is suggested that an LOC of 90% could be achieved and should be specified. These, together with the correct choice of the concrete type, cover thickness and good concreting practice, could prove to be the most economical way of achieving the design service life of concrete structures.
Stewart, BW, Kavallaris, M, Catchpoole, D & Norris, MD 1991, 'Two classes of single-stranded regions evident in deproteinized preparations of replicating DNA isolated from mammalian cells', Experimental Cell Research, vol. 192, no. 2, pp. 639-642.
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In DNA isolated from proliferating human lymphoblastoid CCRF-CEM cells which had been pulse-labeled by exposure to [3H]thymidine for periods from 30 s to 10 min, single-stranded regions were analyzed by caffeine-gradient elution from benzoylated DEAE-cellulose. Two classes of structural defect were evident. Some replicating DNA exhibited single-stranded regions of approximately 200 nucleotides, while most newly incorporated radioactivity was associated with DNA containing single-stranded regions from 900 to approximately 4000 nucleotides. The distribution of thymidine-derived radioactivity did not suggest sequential or preferential labeling of these DNA fractions as the incorporation time was varied. The findings may be correlated with recent proposals regarding the structural basis of eukaryotic DNA replication. © 1991.
Stewart, MG 1991, 'Probabilistic risk assessment of quality control and quality assurance measures in structural design', IEEE Transactions on Systems, Man, and Cybernetics, vol. 21, no. 5, pp. 1000-1007.
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It is generally accepted that the majority of structural failures are caused by the presence of human error. A Probabilistic risk assessment approach used to examine the effects of human error on a typical structural engineering design task (design of a steel I-beam) is reported. This approach utilizes event-tree methodology and Monte-Carlo simulation analysis. An investigation of the efficiency of a quality control measure (e.g., design checking) is reported that includes design checking guidelines for the structural engineering profession. The use of safe load tables (for steel member design) as a quality assurance measure is also investigated. It is indicated that a designer using safe load tables (or similar design aids) will be more “cost-effective” and less prone to error than designers not using such design aids. Comparisons between the efficiency of design checking and the use of safe load tables will be made. © 1991 IEEE
Stewart, MG 1991, 'Safe load tables: A design aid in the prevention of human error', Structural Safety, vol. 10, no. 4, pp. 269-282.
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It is conventional wisdom that design error causes a significant proportion of structural failures. The use of safe load tables (for steel member design) as a task complexity reduction measure is investigated. The development and analysis of a model for a member design task is described in the present paper. The model uses a design sequence based on either direct use of code provisions or use of safe load tables. It is shown that the use of safe load tables reduces design time by approximately 65% (and hence cost), reduces human error in a design and leads to an increase in structural safety. The use of an 'economic decision' model found that such a design sequence is 'cost-effective' when compared to using the design codes rules directly. A model representing the checking of a designer's own work is also described. It is demonstrated that design checking further reduces the error content in a design, and can be as effective as independent checking of a design using code provisions directly. The main reason for this is the 'rounding-up' of tabulated values in the safe load tables, and this results in a design with safety levels nearer that of an 'error free' design. © 1991.
Stewart, MG & Melchers, RE 1991, 'Closure to “ Checking Models in Structural Design ” by Mark G. Stewart and Robert E. Melchers (June, 1989, Vol. 115, No. 6)', Journal of Structural Engineering, vol. 117, no. 7, pp. 2188-2189.
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Stewart, MG & Melchers, RE 1991, 'Discussion of paper', Civil Engineering Systems, vol. 8, no. 1, pp. 59-60.
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TIPPING, PG, LEONG, TW & HOLDSWORTH, SR 1991, 'TUMOR-NECROSIS-FACTOR PRODUCTION BY GLOMERULAR MACROPHAGES IN ANTIGLOMERULAR BASEMENT-MEMBRANE GLOMERULONEPHRITIS IN RABBITS', LABORATORY INVESTIGATION, vol. 65, no. 3, pp. 272-279.
Vigneswaran, S & Chang, J-S 1991, 'Effect of media pore size distribution on deep-bed filtration', Separations Technology, vol. 1, no. 5, pp. 259-266.
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One important parameter of filtration, the media pore size distribution, has not been explicitly considered in modeling deep-bed filtration models by previous investigators. In this study, we propose, based on the hypothesis of O'Melia-Ali and the use of the effective medium approximation theory, a new transient-state model and examine the effect of the media pore size distribution on filter performance. From the simulation results based on six different pore size distribution functions, it is clear that the pore size distribution plays an important role in determining the removal efficiency as well as headloss development
Vigneswaran, S, Casiano, VL & Polprasert, C 1991, 'Application of Coarse-Media Slow Sand Filtration in Aquaculture', Water Science and Technology, vol. 23, no. 10-12, pp. 1817-1824.
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Laboratory experiments were carried out with pilot-scale experimental unit of Coarse Media Slow Sand Filter (CMSSF). A 2.7 m high filter column with a diameter of 0.56 m was operated with the filter media size of 1-2 mm and media depth of 1.0 m at filtration rates of 0.5 and 0.2 m3/m2h. This was connected to a circular concrete fish tank with a diameter of 1.16 m. The performance of CMSSF was compared with the 1.5 m × 1.0 m × 1.0 m Biological Filter (BF) operated at a filtration rate of 1.92 m3/m2h which was connected to 8 fish tanks. Experimental results showed that CMSSF has comparatively higher removal efficiency than BF for turbidity, total phosphorous, nitrogen and organic carbon. This study is an initial attempt to introduce CMSSF as a treatment unit in a recirculating aquaculture system which would be an economical solution to improve the water quality and production in aquaculture.
VOINOV, AA & ZHAROVA, NA 1991, 'AUTOMATIZATION SYSTEM FOR SIMULATION OF AQUATIC BODIES - SPATIALLY HETEROGENEOUS ECOSYSTEMS', ZHURNAL OBSHCHEI BIOLOGII, vol. 52, no. 6, pp. 868-884.
Waldron, KJ & Hunt, KH 1991, 'Series-Parallel Dualities in Actively Coordinated Mechanisms', The International Journal of Robotics Research, vol. 10, no. 5, pp. 473-480.
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A deep symmetry between serial chain manipulators and fully parallel systems such as the Stewart platform is dem onstrated. This symmetry is shown to be a result of the well-known duality of motion screw axes and wrenches. The appearance of the inverse of the Jacobian matrix in force decomposition in the same role as the Jacobian in rate decomposition is also a consequence of this same duality and of the reciprocity relationship between the motion screw system and the wrench system of a kine matic joint. A geometric meaning of the columns of the Jacobian is demonstrated. A simple example of the appli cation of the ideas presented here to the understanding of the complex combinations of serial and parallel chains found in vehicle and multifingered hand problems is also presented.
Watterson, PA 1991, 'A generalization of the Taylor constraint to the advection of axisymmetric poloidal magnetic fields', Journal of Plasma Physics, vol. 46, no. 2, pp. 255-270.
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The range of ▿ ∧ (u ∧ B) is determined for an axisymmetric poloidal incompressible B and incompressible u, by solving ▿ ∧ (u ∧ B) = ▿ ∧ v for u, assumed to be confined to within a surface of revolution. Two constraints on V are shown to be necessary for the existence of solutions, viz that the integral of rç/|B| must vanish on each flux surface, and that the integral of v1 around any dosed field line must vanish. The construction of the general solution proves that the constraints are sufficient conditions, providing also that the second derivative, with respect to the poloidal flux function, of the volume contained by flux surfaces does not vanish. The general solution is stated for the homogeneous case, v = 0. For the particular case of poloidal v1 an integral property of the solution u is established.
Watterson, PA 1991, 'Analytical solutions for the current driven by a rotating magnetic field in a spherical plasma', Journal of Plasma Physics, vol. 46, no. 2, pp. 271-298.
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The steady currents driven in a spherical plasma by a rotating magnetic field via the Hall effect are studied analytically. The total field is shown to be symmetric across the origin. Integral relationships are obtained between Ohmic dissipation, angular momentum and the oscillating axial current density. The topology of the sum of a Hill's vortex field and a rotating field is documented. Analytical solutions for the driven current are obtained by expansion for the limits corresponding to small rotation frequency, to small number density, to large rotating-field magnitude, to small resistivity, and to small rotating-field magnitude combined with very small resistivity. The latter solution, relevant to the reactor limit, indicates that, with control of the vertical field magnitude, an MHD equilibrium can be generated with total current any fraction of the currentcorresponding to synchronous rotation of the electrons. Oscillating currents sufficient to drive the synchronous current are determined.
YING, MS 1991, 'A NEW APPROACH FOR FUZZY TOPOLOGY (I)', FUZZY SETS AND SYSTEMS, vol. 39, no. 3, pp. 303-321.
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We point out a new approach for fuzzy topology with fuzzy logic, and discuss the neighborhood structure of a point and the convergence of nets and filters in this new framework.
YING, MS 1991, 'DEDUCTION THEOREM FOR MANY-VALUED INFERENCE', ZEITSCHRIFT FUR MATHEMATISCHE LOGIK UND GRUNDLAGEN DER MATHEMATIK, vol. 37, no. 6, pp. 533-537.
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NA
Yokoyama, Y, Miyanaga, Y & Tochinai, K 1991, 'Automatic design of a parallel/pipelined VLSI architecture for signal processing', Electronics and Communications in Japan (Part III: Fundamental Electronic Science), vol. 74, no. 11, pp. 39-48.
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AbstractThis paper discusses the system for automatic design of the parallel/pipelined VLSI architecture based on the signal processing algorithm. A new design language is introduced into the proposed system. The language is defined so that the time variable used in the signal processing algorithm can easily be described. The system has a high modularity, and the modules can be combined into a hierarchical structure. By this scheme, the algorithm with a high complexity can easily be described.The algorithm inputted to the system may contain a backward time‐flow of the delayed data as well as a complex hierarchical structure, which makes it difficult to execute the data‐flow graph obtained directly from the algorithm by the parallel/pipelined structure.From such a viewpoint, this paper adopts the following procedure. The data‐flow graph is derived from the given algorithm. A sufficient parallelism and a highly efficient pipelined mechanism are extracted from the obtained graph. Then the parallel processing architecture is designed. As an example, a parallel/pipelined architecture is designed for a simple adaptive signal processing algorithm. The result is compared with the traditional design examples, and it is shown that the efficient data‐flow architecture is derived.
Zhou, JL & Banks, CJ 1991, 'Removal of humic acid fractions by Rhizopus arrhizus: Uptake and kinetic studies', Environmental Technology, vol. 12, no. 10, pp. 859-869.
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Zhou, JL & Banks, CJ 1991, 'The adsorption of humic acid fractions by fungal biomass', Environmental Technology, vol. 12, no. 6, pp. 519-529.
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Zhou, JL & Kiff, RJ 1991, 'The uptake of copper from aqueous solution by immobilized fungal biomass', Journal of Chemical Technology & Biotechnology, vol. 52, no. 3, pp. 317-330.
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AbstractThe removal of cupric ions from aqueous solution by a biosorption column in which the Rhizopus arrhizus fungal biomass was immobilized in reticulated foam biomass support particles was studied. Solution pH was found to be crucial to copper uptake, with the optimum range being 6·7–7·0. The removal efficiency was usually higher at low influent copper concentration and long residence time. The presence of other cations and anions inhibited copper uptake in the following order: for the cations, Mn2+ ≫ Zn2+ > Cd2+ > Mg2+ > Ca2+; for the anions, EDTA ≫ SO ≫ Cl−. The biosorption process was fully reversible and regenerated columns showed undiminished performance.
Cecez-Kecmanovic, D, Sretenovic, V, Krusevac, O & Sadikovic, A 1970, 'Activity representation language--The means for formal communications', Melecon, 6TH MEDITERRANEAN ELECTROTECHNICAL CONF ( MELECON 91 ), I E E E, CULTURAL & CONGRESS CTR, LJUBLJANA, YUGOSLAVIA, pp. 1169-1172.
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The authors consider organizational activities as knowledge processors. Knowledge from the activities is represented and communicated by means of activity models. An activity representation language (ARL) enables a description to be given of an activity type and actual activity execution. It assumes actors in their capacity to perform actions that change the state of affairs concerning any organizational aspect of existence. The ARL is based on predicate logic and includes some elements of temporal logic. The ARL is illustrated by an example.
Esselle, KP & Stuchly, M 1970, 'Analysis Of Neural Stimulation With Magnetically Induced Fields', Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society Volume 13: 1991, Annual International Conference of the IEEE Engineering in Medicine and Biology Society Volume 13: 1991, IEEE, ORLANDO, FL, pp. 845-846.
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Guo, YJ, Barton, SK & Wright, TMB 1970, 'Design of high efficiency Fresnel zone plate antennas', AP-S International Symposium (Digest) (IEEE Antennas and Propagation Society), pp. 182-185.
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With a family of ideal radiation patterns, the theory for designing high-efficiency phase-correcting FZP (Fresnel zone plate) antennas is presented. The optimum 3-dB beamwidth of the feed pattern as a function of F/D (focal length/diameter) of the plate, the relation between the phase efficiency of the antenna and the number of subzones used in each full-wave zone, and the total efficiency limits of various versions are given. It is found that the maximum efficiency of a practical FZP antenna is usually less than 70%. The theory has been employed in designing a four-layer experimental FZP reflector antenna, and good agreement between the theoretical expectation and the measured value is obtained.
Guo, YJ, Barton, SK & Wright, TMB 1970, 'Focal field distribution of Fresnel zone plate antennas', IEE Conference Publication, pp. 6-8.
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With the arrival of high power direct broadcasting satellites, there is an increasing demand for low-cost, environmentally unobtrusive antennas. An interesting candidate in this respect is the improved Fresnel zone plate, on which research is being carried out at the University of Bradford in colaboration with Mawzones Ltd. In this paper, a theoretical study on the focal field distributions of the simple Fresnel zone plate (FZP) antenna and its phase-correcting versions is reported.
Indraratna, B & Nilaweera, S 1970, 'Seismic relationships for rockbursting using energy considerations', 7th ISRM Congress, pp. 1121-1124.
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The following paper discusses the phenomenon of rockbursitng on the basis of seismic energy release, due to the change in potential energy of deforming mine openings. A simplified analytical solution (two-dimensional) for a deep circular excavation is presented to illustrate, how the seismic energy release can be linked to the enlargement of the opening. The paper also reflects upon the empirical formulation of the relationships between the potential fault-slip bursts and the corresponding precursor time and seismic magnitudes for deep mining conditions.
LI, SY, ZHANG, YM & SU, WD 1970, 'INTELLIGENT SAMPLING FUZZY DECOUPLING CONTROL OF AN ARC-WELDING ROBOT', INFORMATION AND SYSTEMS, VOLS 1-3, INTERNATIONAL CONF ON INFORMATION AND SYSTEMS, INT ACADEMIC PUBL, ASSOC MODELLING & SIMULAT ENTERPRISES, HANGZHOU, PEOPLES R CHINA, pp. 333-336.
Lin, CT & Lee, CSG 1970, 'A multivalued Boltzmann machine', [Proceedings] 1991 IEEE International Joint Conference on Neural Networks, 1991 IEEE International Joint Conference on Neural Networks, IEEE, pp. 2546-2552 vol.3.
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LOPEZFROEDGE, L, BALL, JE, CHEN, MW & GREEN, TK 1970, 'FLORY INTERACTION PARAMETERS FOR ILLINOIS NUMBER-6 COAL EXTRACTS AND BENZENE', COAL SCIENCE II, SYMP AT THE 198TH NATIONAL MEETING OF THE AMERICAN CHEMICAL SOC : COAL SCIENCE 2, AMER CHEMICAL SOC, MIAMI BEACH, FL, pp. 137-158.
Miyanaga, Y, Teraoka, M & Tochinai, K 1970, 'Parallel and adaptive clustering method suitable for a VLSI system', 1991 IEEE International Symposium on Circuits and Systems (ISCAS), 1991 IEEE International Symposium on Circuits and Systems (ISCAS), IEEE.
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ROPER, H & BAWEJA, D 1970, 'CARBONATION-CHLORIDE INTERACTIONS AND THEIR INFLUENCE ON CORROSION RATES OF STEEL IN CONCRETE', DURABILITY OF CONCRETE, VOLS 1 AND 2, pp. 295-315.
Saleh, A & Stutzki, C 1970, 'Application of large deflection theory to the stability analysis of lattice shells', Computational Mechanics, ASIAN PACIFIC CONF ON COMPUTATIONAL MECHANICS ( APCOM ), A A BALKEMA, HONG KONG, HONG KONG, pp. 53-57.
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The stability of a large lattice shell with radome geometry is investigated numerically using large deflection theory. The theoretical background of the analysis is discussed and the iteration algorithm which utilises the method of orthogonalised load-deflection states is outlined.
SIRIVIVATNANON, V & CAO, HT 1970, 'THE NEED FOR AND A METHOD TO CONTROL CONCRETE COVER', QUALITY CONTROL OF CONCRETE STRUCTURES, INTERNATIONAL SYMP ON QUALITY CONTROL OF CONCRETE STRUCTURES, E & FN SPON, GHENT, BELGIUM, pp. 237-246.
Vigneswaran, S, Manandhar, UK, Janssens, JG & Ben Aim, R 1970, 'Mathematical modelling of the effect of size distribution of suspended particles in deep-bed filtration - Experimental testing', Water Supply.
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A mathematical model for granular bed filtration incorporating the influent particle size distribution was tested using extensive experimental results obtained from laboratory-scale filter experiments with sikron particles. This study gives an approach which reduces the nos. of model coefficients to be estimated by expressing these as functions of particle diameter. The predicted result fits reasonably well for the case of finer particles than the bigger ones, specially at the ripening stage.
