
فرزاد زرگری
اصل
author
محمود کمره
ای
author
محمدرضاالشریف
author
بهمن
دولتشاهی
author
text
article
2000
per
Classical methods of video coding exploit the stochastic properties of images such as temporal and spatial correlation. By exploiting structural features of images, new methods can be introduced for video coding and image compression, which are useful at very low bit rate transmission systems such as telephony. Since these methods are mainly used in videophone, their main object is coding of face images. With this assumption, to code these images it is needed to locate important features of the face in one frame and determine their variation with respect to previous frames. This method consists of two levels, analysis level and synthesis level. In the analysis level, the location of face features is determined automatically and their variation with respect to previous frames is encoded using a feature code book. In the synthesis level the image can be reconstructed by the received codes and using the same feature code book.
The “cut and paste” technique is used for modelbased coding in this paper. The given method uses pictures of eyes and mouths and a single full face image. The main problems tackled in realizing an automatic model based system were to locate the eyes and mouth in a face, to drive pictures of eyes and mouth areas from a lead moving sequence, and to select the eye and mouth pictures that are best match for the eye and mouth areas in the sequence. The method which is used in this paper can detect the eye locations without any constraint. Based on the location of eyes and the relationship among face features, the mouth location and dimensions of sub images needed in cut and paste method are estimated.
It is shown that the coding system based on realized automatic offline model reduces transmission rate to a great extent and the reconstructed images have such a good quality that the pronounced words in the reconstructed image sequence are “lip readable”.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16878_d4b7ced7663b0bccc515833f10d785cf.pdf

علیرضا
فریدونیان
author
حمید
لسانی
author
کارولوکس
author
text
article
2000
per
The state of the power distribution system must be estimated for determining control strategies and making decisions by a pattern recognizer system. In this system, each state is a class of measured data which describes system status in that moment of the time.
In this paper two classifier systems are designed and compared using Radial Basis Function (RBF) and Multi Layer Perception (MLP) neural networks. It is shown that MLP performs better than RBF in this’ application. Also the effect of different sorts of data distribution in classification space, scaling operations, preprocessing, normalization, and conformal mappings on the classification space, adding noise to system input, optimum selection of error function order ( its Lebesgue norm) and maximum error reduction on learning, generalization, interpolation and extrapolation of neural networks are studied. Finally, a practical example is presented including simulation results to test performance of designed system
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16879_c1f3625e40a85c39682727df18071fc7.pdf

محمدرضا
کاخی
author
محمدرضا نوری
بیات
author
text
article
2000
per
Design procedures and concepts of optimization for an earth dam is investigated and a practical numerical method is suggested. The numerical problem is produced based on constrained nonlinear optimization formulation, in which variables are effective parameters required to specify dam. The goal function usually is constructed based on the price of materials and cost of contraction and constrains are some code requirements for material and geometry to reach a safe and economical structure and/or specify some limits to variables. Based on designer experience a conceptual model is defined. Polynomial functions are used in the mathematical model for estimating dam responses. These functions are constructed from results of analyzing a few number of selected dams. Nonlinear regression is used to calculate their coefficients. This mathematical model is optimized and an approximate optimum design attained. Accuracy is examined by analysis and comparison of results with approximate results obtained from mathematical model.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16880_c2dd5c5473dfe8d67b664233b66d34b5.pdf

محمدحسن پنجه
شاهی
author
حمیدرضا
فلاحی
author
text
article
2000
per
One of the most recent methods in the retrofit of heat exchanger networks is a procedure that assumes fixed values for stream allowable pressure drops. This means that no consideration is taken into account for pump and / or compressor replacement study iii the network.
In this research, pressure drop optimization is incorporated into the previous method (i. e. : a three way tradeoff is carried out between energy consumption, surface area and pressure drop), to achieve the most beneficial retrofit project. The method is then applied to a crude oil preheat train and the result is compared to the fixed pressure drop method.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16881_751572e91e6eefa5703973f11332992a.pdf

علی اصغر
حمیدی
author
مجید
عبادی
author
text
article
2000
per
Furfural is an important and widely used organic compound produced from the Acid catalyzed hydrolysis of agricultural wastes. In this work continuous and batch hydrolysis of these wastes are investigated using saturated steam and saturated water respectively. For each of the hydrolysis methods investigated, effective parameters are identified and based on the experimental work carried out the optimum range for each of these parameters is found. The most important parameters are:
feed type, reaction time, reaction temperature, type and the amount of the catalyst used and the amount of water or steam fed to the reactor. In the batch method it was seen that the best feed is Bayess producing 8.61 gr furfural for every 100 gr of dry feed. In the continuous method the best result was obtained for rice husk with a yield of 6.84 gr of furfural for every 100 gr of dry feed. The effect of the parameters mentioned above are presented based on extensive parametric study.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16882_650d54ed7a035e0ccd3711c06df508aa.pdf

رضا
روستاآزاد
author
محمدتقی
فرقدانی
author
text
article
2000
per
Effect of various parameters on the extraction of penicillin from the broth by the method of emulsion liquid membrane using butylactate as the extractor was studied. The relative amount of the internal, membrane and external phases were 1, 1, and 12 respectively. Diluting the solvent with equal amount of paraffin oil to control the viscosity enhanced the extraction yield. However using Tween 40 to increase the Hydrophile Lipophile Blance (HLB) of the Span 80 surfactant did not show a positive effect. A 1:9 mixture of Diocthyl Amine and Amberlite LA2 gave the best composition as the carrier in the liquid membrane. Setting the internal and external phase pH at 8.9 and
4.5 by sodium carbonate and citrate buffer, respectively, increased the efficiency of the extraction. Intensity of mixing the emulsion influenced both stability and mass transfer and hence yield of penicillin extraction; its optimum level was determined to be between 400 and 600 rpm.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16883_e3a756590b64042cbeaa4a883e6a91ba.pdf

کاظم سید
امامی
author
text
article
2000
per
In the Kerman — Ravar area and its northern extension to Nabibandan and Tabas areas, there are a number of evaporitic strata and salt diapirs, belonging to Cambrian, Silurian, Devonian, late Jurassic and early Cretaceous. But their exact stratigraphic position, in tectonically disturbed areas and along main faultlines is often unclear.
The aim of the present study is to determine the exact stratographic position of the middle and upper Jurassic sedimentary sequences and evaporitic strata in the Ravar and Kerman areas. Based on previous studies and personal observations and in accordance with Huckriede et a!. (1962), it is proposed to apply “Ravar Formation”, to the late Jurassic evaporitic strata lying upon the “Pectinid Limestone” and below a thick clastic and pink sequence at the base of the BarremianAptian RudistOrbitolina limestones. For the older (early Cambrian) evaporitic strata, analogous to the “Hormoz Formation” of Southwest Iran, the name “Desu Formation” is proposed. The name “Bidou Formation” should be applied only to the red and clastic sequence lying upon the Hojedk Formation and Cretaceous clastic sequences.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16884_f95dd1296a82673b61626c04b9924038.pdf

احمدرضا
شاهوردی
author
منوچهر
اولیازاده
author
مجتبی طباطبایی
یزدی
author
سید علی سید
باقری
author
text
article
2000
per
A. R. Shahverdi, Dept. of Biotechnology,
Faculty of Pharmacy, Tehran Medical Sciences
University
M. Oliazadeh, Dept. of Mining Engineering,
Faculty of Engineering, University of Tehran
B. M. Tabatabae Yazdi , Dept. of
Biotechnology, Faculty of Pharmacy, Tehran
Medical Sciences University
S. A. Seyed Bagheri, Hydrometallurgy
Section, R&D, Sarcheshmeh Copper Complex
A moderately thermophilic bacterium designated as TSB isolated from Gotovosii acidic hot spring. This strian was a Gram positive rods which oxidized pyrite and sulfur as sole energy source.
Mouteh pyritic concentrate was leached in shake flasks at different pulp density. After biotreatment the recovery of gold by CIL method compared with nontreated concentrate. The results show significant improvement in gold recovery that can be obtained using this integrated process
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16885_f81cff90db4afad599538f173b646d82.pdf

وحید
اصفهانیان
author
مرتضی بهبهانی
نژاد
author
فرشاد
کوثری
author
text
article
2000
per
In this study, Boundary Element Method (BEM) is applied to the NavierStokes equations in the driven cavity. BEM plays an important role in CFD analysis especially heat transfer computations. One of its main advantages is reduction of the problem dimensionality by one, since it will be required to discretize only the boundary of computational domain. The main difficulty of applying BEM to general nonlinear problems, e.g., NavierStokes equations, is the lack of a fundamental solution for such equations. To overcome this difficulty one can separate nonlinear term and treat it as a nonlinear source term. This approach generates an additional problem, i.e., existence of source term which produces an integral term on the whole domain. Initial attempts to deal with volume integral term are domain discretization and numerical integration over the whole domain that makes the method rather time consuming and inefficient. Dual Reciprocity Method (DRM) is an alternative that can be used to transform volume integral to the equivalent boundary integrals and therefore saves the unneeded volume cell integration. These steps are discussed in detail and the results are compared with finite difference method by Ghia et al.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16886_5a288e55d2b81fec40237902da88279a.pdf

کیوان
صادقی
author
text
article
2000
per
A simple technique is described for investigating the elasticity of polymeric liquids. The method is based on the extensional flow through a typical converging channel , i.e., a conical channel. It is shown that, by measuring flow rate and pressure drop for the laminar flow of a viscoelastic liquid through a conical channel of known shape, it is possible to detect its elasticity level. As the first step in using this method, it is necessary to obtain the CpRe data (i. e., the pressure drop coefficient vs Reynolds number data) for several Newtonian fluids. As expected from dimensional analysis, for Newtonian fluids, the CpRe curve is found to be unique with the property that at sufficiently low Reynolds numbers, Cp data are inversely proportional to the Re. The unique curve obtained this way can then be used as the baseline (or reference line) representing all inelastic liquids. In the next step, tests are performed with the solution of interest (for example, a polymer solution). Any probable deviation is between their CpRe data from that of the inelastic baseline, is attributed to the elasticity of the material, and so the fluid is labeled as elastic. To investigate the applicability of the method, tests were conducted with two different polymer solutions (i, e., the 0.2% w/w
PAA solution and the Ml fluid) both having known elastic behavior in “steady
shear flow”. Based on the data obtained using the conical channel, and as judged by the extent of the deviation from the inelastic baseline, it is concluded that, the Ml fluids is more elastic than the PAA solution in both steady shear flow and extensional flow. The technique thus seems to be capable of investigating the elastic behavior of polymeric liquids quite successfully.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16887_102b6edc1e23df752f42f673c2875dbe.pdf

محمدصادق صادقی
پور
author
حمید
مهدیقلی
author
علیرضا
میرزاآقایی
author
text
article
2000
per
The high head bottom outlet slide gates, which are used to regulate the flow rate, operate under severe conditions, and may be exposed to vibrations of different sources. Such that, improper working conditions and / or uncontrolled vibrations may cause a failure of the gate resulting in human and financial damages.
One degree of freedom models may be used to study the flow induced vibration of the small gates. However, for the gates with large dimensions, one degree of freedom models usually don’t work and, therefore, the hydro elastic model tests and the modal analysis are recommended for them. In the present investigation, the bottom outlet slide gate of one of the dams presently under construction in Iran, has been hydro elastic modeled and modal
analysis is performed for it.
University College of Engineering
دانشکده فنی
08031026
33
v.
4
no.
2000
https://jfe.ut.ac.ir/article_16888_b7387958be86db247ac65ed788295afe.pdf