International Journal of Engineering
Volume:15 Issue: 2, Jul 2002

Automatic identification and localization of cartographic objects in aerial and satellite images have gained increasing attention in recent years in digital photogrammetry and remote sensing. Although the automatic extraction of man made objects in essence is still an unresolved issue, the man made objects can be extracted from aerial photos and satellite images. Recently, the high-resolution satellite images, typically at most 3 meters in panchromatic band ground sample distance (GSD) and up to four multispectral bands in the visible and near infrared spectrum, are suitable for detection and identification of objects. This paper presents a new algorithm for identification of cartographic objects based on Artificial Neural Network (ANN). The algorithm is divided in two modules: image simplification by the Wavelet transform, Mathematical Morphology (MM) operators, and identification of object by the Kohonen Self Organizing Map (KSOM) and split and merge method. The study area included two parts of an orthoimage from Kish, Iran.

The safety of lifelines, as the most important urban facilities, under different conditions highly depends on the safe design and performance of these buried structures. This cannot be achieved unless their actual behaviors are well understood and considered at the designing stage. A new physical model was developed in Amirkabir University of Technology to study the behavior of buried pipes under different loading conditions. The model is capable of simulating and monitoring flexible pipes under different conditions. The depth and the position of the buried pipes as well as the type and density of the surrounding soil can be changed and controlled. The cyclic loads with different amplitudes as well as monotonic loads can be generated and applied to the soil surface. The generated load can be applied on the pipe centrally or eccentrically. The radial deflections of the tested pipes were measured by a special probe and data acquisition system developed for this model. A series of different tests were carried out to study the soil-pipe interaction. The main factors affecting the behavior of these buried structures were studied in the paper. Among them, the soil density and the pipe depth proved to be the most important factors affecting the soil-pipe interaction. The influence of the impact at the first cycle was also found to be one of the main factors affecting the pipe behavior.

Hydraulic fracturing is a phenomenon in which cracks propagate through the porous medium due to high pore fluid pressure. Hydraulic fracturing appears in different engineering disciplines either as a destructive phenomenon or as a useful technique. Modeling of this phenomenon in isothermal condition requires analysis of soil deformation, crack and pore fluid pressure interactions. In this paper a numerical scheme is presented for analysis of soil stresses and deformations and fluid flow in a coupled manner, which is also capable to detect the initiation of fracture in the medium. Applications of the model are shown by illustrative examples.

A novel intelligent neural optimizer with two objective functions is designed for electrical distribution systems. The presented method is faster than alternative optimization methods and is comparable with the most powerful and precise ones. This optimizer is much smaller than similar neural systems. In this work, two intelligent estimators are designed, a load flow program is coded, and a special modified heuristic optimization algorithm is developed and used too. The load pattern concept is used for training ANNs. Finally, the designed optimizer is tested on an example distribution system; simulation results are presented, and compared with similar systems.

This paper proposes a new approach for calibration of dead reckoning process. Using the well-known UMBmark (University of Michigan Benchmark) is not sufficient for a desirable calibration of dead reckoning. Besides, existing calibration methods usually require explicit measurement of actual motion of the robot. Some recent methods use the smart encoder trailer or long range finder sensors such as ultrasonic or laser range finders for automatic calibration. Manual measurement is necessary in the case of the robots that are not equipped with long-range detectors or such smart encoder trailer. Our proposed approach uses an environment map that is created by fusion of proximity data, in order to calibrate the odometry error automatically. In the new approach, the systematic part of the error is adaptively estimated and compensated by an efficient and incremental maximum likelihood algorithm. Actually, environment map data are fused with the odometry and current sensory data in order to acquire the maximum likelihood estimation. The advantages of the proposed approach are demonstrated in some experiments with Khepera robot. It is shown that the amount of pose estimation error is reduced by a percentage of more than 80%.

A functional relationship between two variables, applied mass to a weighing platform and estimated mass using Multi-Layer Perceptron Artificial Neural Networks is approximated by a linear function. Linear relationships and correlation rates are obtained which quantitatively verify that the Artificial Neural Network model is functioning satisfactorily. Estimated mass is achieved through recalling the trained Artificial Neural Network model on a set of waveforms resulting from applied masses over the operating range of the weighing platform. In this work the Least-Squares Fit (LSF) method for straight line and correlation rate R between the applied and estimated masses are used to investigate the accuracy of the estimated masses. The slope of the linear functions together with correlation rates R are computed for both simulation and experimental data. The numerical results confirm the correctness of neural network technique in estimating the applied mass m(t).

An axisymmetric hot closed die-forging process has been studied by physical modeling technique using the plasticine. To observe the material flow pattern, layers of plasticine with different colors were used. The normal direction to the layers was considered a principal direction. The strain distribution was obtained by measuring the thickness of the plasticine layers. Based on the strain distribution, the stress distribution and the forging load were computed, respectively. Several ring compression tests were performed using Vaseline, soapsuds, baby powder, facial tissue and plastic wrapping to determine the effect of different lubricants on the plasticine modeling. In order to verify the validity of the modeling data, a similarity study between plasticine and Ck45 was made. Considering the effect of strain path, the load obtained by this technique matched fairly well with the actual load.

Hydroxyapatite (HA), a material proven to be biocompatible within the human body, has been produced to a high level of purity. This material has been applied as a coating on Ti-6Al-4V alloy by using the air plasma spraying technique. The coat was characterizted with SEM, XRD, FTIR and Raman spectroscopy methods to consist of a mixture of calcium phosphates including HA mainly and traces of tricalcium phosphate, tetra calcium phosphate and calcium oxide phases. This HA phase was dehydrated and partially decomposed to oxyapatite and amorphous HA. EPMA method was used cross-sectionally on the interface in order to determine the depth profiles and elemental maps of Calcium, Phosphorous, Oxygen, Titanium, Vanadium and Aluminum elements. The results clearly showed the evidence of interdiffusion at the interface. Ultimately, the diffusion depth of each element was studied and compared with each other.

The present study was undertaken to improve the quality and increase the life time of magnesia-chromite refractory bricks used in the copper and lead industries. The results show that a decrease in the amount of large chromite particles in the formulation improves the thermomechanical properties and also reduces the slag penetration in the bricks. In addition it was also observed that the use of co-clinker decreases the open porosity in the bricks and thereby improves the mechanical properties. It was also shown that the use of around 4 percent iron oxide has beneficial effect on the bricks properties. Microstructural evaluation on the bricks shows increased formation of spinel phase and more direct bonding in the improved bricks.

Abstract Selective flocculation has long been suggested as a method for the treatment of ultra-fine particles typical of which are those produced in a de-sliming process ahead of flotation. In this paper the results of the coal de-mineralization, using synthetic polyacrylamide polymers, are presented. A prescreening test on the suitability of the polymers using Run-Of-Mine (R.O.M.) coal and artificial mixtures of Shirebrook coal and shale the floe settling rates and supernatant clarity of the suspension was carried out and three polymers. Floe Aid 202 (medium anionic). Floe Aid 204 (high anionic) and Polyethylene oxide (P.E.O.) (non- ionic) were employed in subsequent experimental work. The effectiveness of the polymers was established by carrying out settling rate tests using polymers dosages between 0.00025 to 0.0075 g/25g feed and at various suspension pH values. P.E.O. showed significant differences in the flocculation of coal and shale. The results concerning polymers FA 202 and FA 204 are not discussed. Slurry pH, dispersant concentration and polymer dosages were examined and are discussed. Shale entrapment was believed to be due to three reasons. Firstly the mineral particles not fully liberated from the coal structure. This could be infered from the S.E.M. micrographs. Secondly, once coal floes have been formed, they become larger in size, and on settling collect the much smaller mineral particles, beneath themselves, to the bottom of the container. And thirdly polymers may possess a weak affinity for the shale surface.

Abstract Among different types of controlling systems, the ON/OFF digital relative humidity control was used for measuring electrical properties of cashmere fibers to make the ambient relative humidity fixed. To achieve this goal the required hardware and software were designed and fabricated. The electrical resistance of fine and coarse hair cashmere fiber was measured by charge and discharge condenser method using Rothschild static voltmeter type R-4021 made in Germany. Experimental results show that the electrical resistance of the fine under coat fibers is considerably greater than that of the coarse under coat fibers. The difference depends on the breeds. With increasing relative humidity, difference of electrical resistance of fine under coat and coarse outer coat cashmere fiber is decreased.