SUMMARYA large part of the computational effort in shape optimization problems is expended in the numerical computation of the gradients for sensitivity information. This effort increases dramatically with an increase in the number of variables used to represent the shape. An adaptation of the gradient projection algorithm for shape optimization problems is described here along with a method to reduce the intermediate size of the optimization problem by allowing adaptive refinement of the shape. The method is demonstrated with a simple representative test case.

Light based systems are frequently used in the field of medicine for diagnostic and surgical procedures, medical photography, phototherapy, etc. Phototherapy involves the use of light energy for the treatment of physical or mental illnesses. Illumination parameters such as wavelength and dose of therapy can be varied to have distinct effects on cells and tissues. This has necessitated the need to design a system which is programmable for various parameters related to therapy and can also be used by people at large for biomedical applications. The paper presents the design and implementation of a portable, hand-held and programmable Light Emitting Diode (LED) based phototherapy system using embedded technology. The system is designed around the ARM based TM4C123GH6PM microcontroller processor. The microcontroller has been programmed to allow for selection of various parameters such as frequency, duty cycle, and time of exposure. The matrix keypad interface and liquid crystal display (LCD) offer the ease of human interface. An LED driver circuit has been efficiently designed to modulate the output power of LED. Further, Super Bright LED (SLED) of wavelength ~633 nm has been successfully tested and results of optical characterization including spectral and spatial response have been presented in the results section. The designed system successfully achieves the programmable parameters required for dose optimisation required for enhancing the therapeutic effects of a phototherapy system.

A finite array of arbitrarily spaced parallel rods is considered. It is assumed that momentum deficit may be superposed locally. The momentum deficit is computed behind each cylinder—considering it as a single cylinder—using one of the accepted theories. Then the momentum deficits at each point due to all the cylinders are superposed. From this an overall velocity distribution is calculated. Experiments with various rod diameters and spacings were conducted. The results were within 3 percent of the theoretically predicted local velocity, and under 10 percent of the predicted local velocity defect (at locations of significant velocity deficits).

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