Materials and Energy Research CenterInternational Journal of Engineering1025-249510419971101A Robust Strucutural Fingerprint Restoration18119071186ENHassan GhassemianElecterical and Computer Engineering, Tarbiat Modarres University0000-0002-2303-1753Journal Article19700101Fast and accurate ridge detection in fingerprints is essential to each AFIS (Automatic Fingerprint Identification System). Smudged furrows and cut ridges in the image of a finger print are major problems in any AFIS. This paper investigates a new online ridge detection method that reduces the complexity and costs associated with the fingerprint identification procedure. The noise in fingerprint is highly correlated and the statistics of such noises are unknown. In this case, image enhancement techniques based on probabilistic approach may not be suitable. In view of imprecise knowledge about the fingerprint noise, a fuzzy set theoretical approach would be more effective. A new structural algorithm for ridge restoration which is based on unsupervised fuzzy classification technique is described. The accuracy and speed of the proposed method are tested for a large number of fingerprint images with different initial qualities, and are found to be superior to the conventional methods.https://www.ije.ir/article_71186_3a33145b302e05bf5e0e35e1ed19481b.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249510419971101A Multivariate Quality Control Procedure in Multistage Production Systems19120871187ENB. Moeinzadeh, University of CincinnatiS.T.A. NiakiIndustrial Engineering, Sharif University of TechnologyJournal Article19700101In this paper a multivariate quality control procedure is offered in which several correlated stages are present in production systems and in each stage there are several correlated control variable. Using Hotelling's T2 statistic, first, each stage is tested for being out of control. Then out of control variables are selected using Murphy's method. The remainder of the research involves evaluating each stage, when the present and the previous stages are both out of control. In this regard, regression of the present stages' T2 statistic on prior stages' P statistics is considered and a residual test between the present stage estimated and observed T2 statistics is made.https://www.ije.ir/article_71187_75c7192f3552cedab22088faa501c0fc.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249510419971101Vibration of Road Vehicles with Non linear Suspensions20921871188ENG. Nakhaie-JazarMechanical Engineering, Sharif University of TechnologyE. EsmailzadehMechanical Engineering, Sharif University of TechnologyB. MehriMathematics, Sharif University of TechnologyJournal Article19700101In order to investigate the effects of non-linear springs in vibrating behavior of vehicles, the independent suspension of conventional vehicles could be modeled as a non-linear single degree of freedom system. The equation of motion for the system would be a non-linear third order ordinary differential equation, when considering the elasticity of rubber bushings in joints of shock absorber. It is desirable that the system be stable, i.e., periodic inputs periodic outputs. In order to obtain the conditions that guarantee the existence of periodic solutions, and therefore, stable responses, the Schauder's fixed point theorem has been implemented to a general third order equation. Thus, the adapted conditions could be used for a wide range of dynamical systems. For the numerical analysis, a rapid convergence method has been developed, and used to solve the model. The correctness of periodic conditions and the numerical algorithm have been demonstrated.https://www.ije.ir/article_71188_2532b243ace5cbd50a15a61287ccd118.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249510419971101Heat Transfer Calculation in the Firebox of the Ethylene Plant Furnaces (RESEARCH NOTE).21922871189ENM. SadrAmeli, Tarbiat Modarres UniversityJournal Article19700101The thermal cracking of hydrocarbons for olefin production is carried out in long tubular reactors inserted in a furnace, in this process the heat flux along the reactor wall determines the feedstock conversion, the olefin selectivity's and rate of coke deposition. A detailed firebox simulation model is therefore a powerful tool in the design and operation of pyrolysis furnaces and reactors to study the effect of process variables. The zone method of analysis is a versatile tool for studying the effects of process variables on furnace operation. A computer program which applies a zoning technique has been written in FORTRAN 77 for analyzing the heat transfer in the radiant chamber of the firebox. The temperature distribution, inside the cracking coils, calculated by the kinetic model [1], has been used for this model. Application of the program to the simulation of the thermal cracking furnace shows that the temperature distributions in such a furnace are highly non-uniform. The results are in agreement with the fundamental results of SPYRO* simulation model [2] for the thermal cracking furnaces.https://www.ije.ir/article_71189_dc47b7457d151037de4abfa58681b99f.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249510419971101Determination of Blasthole Parameters Based on Field Results (TECHNICAL NOTE).22923471190ENM. OsanlooDepartment of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran PolytecJournal Article19700101Correct selection of coefficients for blasthole parameters in Ghalat limestone mine in Shahr-e-kord of Iran has resulted is designing and performing 20 blasting operations. After each blast, fragmented rocks larger than one square meter, called oversize, are estimated and prepared for secondary blasting. Next blasthole pattern were designed based on previous blasting results. The results of these field operations studies have shown that the best ratio between spacing (S) and burden (B) in Ghalat limestone mine is 1.25. The ratio of cut height (H), subdrilling (J) and length of stemming (T) to burden are: 4, 0.5 and 1 (H/B=4,J/B=0.5,T/B=1). Field results of these relations have shown that more than 90 percentage of fragmented rocks have sizes less than one square meter and the cost of production is reduced by 18.9 percentage.https://www.ije.ir/article_71190_01351a48bf32215cf0cb7f297ba64eea.pdf