Paper Type |
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Research Paper |
Title |
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Enhancement of Mammographic Images |
Country |
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India |
Authors |
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Prachi Mujawar |
Page No. |
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01-04 |
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10.9790/3021-04450104 | |
:: |
0.4/3021-04450104 | |
3021-0404-0504 |
Mammography is an effective method for breast cancer detection and breast tumour analysis. In
mammography, low dose x-ray is used for imaging, due to which the images are poor in contrast and are
contaminated by noise. Hence it is difficult for the radiologist to screen the mammograms for diagnostic signs
such as micro calcifications and masses. This ensures the need for image enhancement to aid radiologist. In this
paper, we present an algorithm for enhancement of digital mammographic images. The proposed methodology
uses mathematical morphology for contrast enhancement and wavelet for denoising. The main contribution of
this report is in differentiating the edge pixels from noise. We adopt wavelet-based level dependent thresholding
algorithm and modified mathematical morphology algorithm to increase the contrast in mammograms to ease
extraction of suspicious regions known as regions of interest (ROIs).The proposed algorithm has been tested on
a large number of clinical images, comparing the results with those obtained by several other algorithms. A
quantitative measure of Contrast Improvement Index (CII) is used to evaluate the performance of the algorithm.
Experimental results show that the proposed algorithm gives significantly superior image quality and better
Contrast Improvement Index (Cll). Here, to prove the efficiency of this method, we have compared this with
various well-known algorithms like VisuShrink and NormalShrink.Through preliminary tests; the method seems
to meaningfully improve the diagnosis in the early breast cancer detection with respect to other approaches.
Keywords: - Dyadic Wavelet transform, denoising, micro calcification, mass detection, thresholding.
A novel robust adaptive PID control scheme is proposed with known upper bound of the external disturbances, to solve the dynamic coupling and strong nonlinearity problems in flexible joint robot manipulator control. Invoking the proposed controller, the bounded external disturbances can be compensated and the global asymptotical stability with respect to the manipulator positions and velocities is able to be guaranteed. The designed control law can enlarge the tolerable external disturbances, enhance the accuracy of trajectory tracking error, and improve the dynamic performance of the manipulator systems. The stability and convergence properties of the closed-loop system are analytically proved using Lyapunov stability theory and Barbalat's lemma. Simulation for the proposed control system is performed for a two-degree of freedom flexible joint robot, each joint modeled by two-equations of second order to illustrate its viability, and advantages.
Keywords: - Adaptive PID controller, Dynamic coupling, Flexible joint robot, Bounded external disturbances, Lyapunov stability theory, Trajectory tracking error.
An experiment was conducted to study the yield response of salad cucumber under different drip irrigation levels to determine the most suitable irrigation requirement for salad cucumber grown under naturally ventilated polyhouse. Drip irrigation applied at the rate of 2 litre plant-1 day-1 to the control plants was reduced by 5, 20, 35 and 50% by applying corresponding irrigation rates of 1.9, 1.6, 1.3 and 1 litre plant-1 day-1 under different treatments. Lowering irrigation level to 65% sustained the production and increased water use efficiency without decreasing the yield of cucumber. However, irrigation level of less than 65% reduced the yield without increasing water use efficiency. The maximum fruit number (49), fruit weight (7.194 kg plant-1) and fruit yield (88.8 t ha-1) were obtained from drip irrigation level of 65% (1.3 litre plant-1 day-1) and the lowest fruit number (35), fruit weight (5.043 kg plant-1) and fruit yield (62.26 t ha-1) from drip irrigation level of 50% (1 litre plant-1 day-1), with the lowest water application rate . Irrigation treatments had significant effects (P < 0.05) on yield. However, interaction within groups was found to be non significant. There were significant positive correlations (P < 0.01) between fruit number, fruit weight and fruit yield. The total quantity of water applied through 65% drip irrigation level was 144.4 mm and which showed 35 per cent water saving over control with highest water use efficiency (6148.31 kg ha-1cm-1) and benefit cost ratio (3.41).
Keywords: - Cucumis sativus, Drip irrigation, Economics, Naturally ventilated polyhouse, Water use efficiency
[1] Zhang, Z., Yu, J., "Design Process of a Double Wish-Bone Suspension"Proceedings of the 2008 SAE Interntional Powertrains, Fuels and Lubricants
[2] 2008, Supercars, "Supercar Operations Manual", The Official Website of Supercars Australia. [Online] [Cited: 10th October 2008] http://www.v8supercars.com.au/content/tech/v8_ supercar_operations_manual/.
[3] Dixon, J.C., The Shock Absorber Handbook, John Wiley and Sons, West Sussex 2007.
[4] Karnopp, D., "Active and Semi-Active Vibration Isolation", Journal of Mechanical Design, 117, 177-185 (1995)
[5] Nowlan, D., "Finding the Sweet Spot", International Journal of Motorsport Engineering, 18(2), 52-58 (2008).
The study under investigation discovers the sorption conduct of resin used as an adsorbent toward metal ions and specified the percent sorption for the metal that reduced with rise in pH, above pH 6.The degree of uptake for resin initially was fast (88-90 %), creating equilibrium within sixty minutes for Copper. The resin exhibit the extreme percent sorption (86 - 88 %) for Nickel ranging contact time between sixty minutes; further than the described range the surge in % sorption was not recognized. The flow rate, isotherms and thermodynamic parameters were also examined for both the metal ions. PMBMNen effectively eradicated heavy amounts of metals from the real water samples.
Keywords: - Adsorbent, column method, isotherms, Metal ion uptake, resin
Aerodynamic forces are time varying forces experienced by objects undergoing air flow. The effect of these forces depends upon the shape and size of the objects. The aerodynamic force acting on a bluff body like bridge deck is different from that acting on a stream line body like an aircraft.This paper focus on the study and comparison of aerodynamic forces acting on an air craft and a bridge deck.
Keywords: - Aerodynamic coefficients, Aerodynamic forces, Bluff body, Self-excited forces, Streamlined body.
The conventional method allows testing of only one chip at a time (single-site testing). However, due to advancements in testing procedures, current test technologies are able to conduct dual-sites testing, quad-sites testing, octal-sites testing, 16-sites testing, 32-sites testing, and so on. In line with this, the multi-site testing approach is a method that increases the number of chips that can be tested in a single touch-up. This method allows more chips to be tested per hour, thus improving the testing throughput. In this research the author take the initiative to develop a multi-sites throughput model to investigate the effectiveness of multi-site testing approach on improving the testing throughput. In the case study, five multi-site configurations were applied. These configurations were single-site, quad-sites, octal-sites, ×16-sites, and ×32-sites. A hypothesis was analyzed by using one-way ANOVA and Post Hoc Test.
Keywords: - multi-site, test handler, semiconductor testing, multi-sites testing model
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