Sharif Digital Repository

In the Fourier domain optical coherence tomography, a picture of the optical thickness (multiplication of the refractive index n in physical thickness d) is obtained; e.g. for the retinal layers, it is used to diagnose many diseases throughout the hospitals in the country. In this work, we introduce a method for a discrete and simultaneous measurement of the refractive index and the physical thickness of multiple layers using Fourier domain optical coherence tomography, without additional information regarding the structure of the sample under investigation. In this method, the only input data are the spectrum of the FD-OCT system and the optical thickness of the sample layers (OPLs),... 

A table-based implementation of an application specific data prefetching approach is presented in this paper. This approach is proposed to improve the performance of the application specific instruction-set processors (ASIP) we develop customized to an object-oriented application. In this approach, the cache controller prefetches all data fields of an object required by a class method, when the class method is invoked. In the proposed table-based implementation, the cache controller monitors the class method calls and records the index of object data members that each method accessed. This information is used to prefetch the data items needed by a class method on next invocations of that... 

In this paper, we present results of our experiments in implementation of a widely used DSP primitive on a programmable SoC (System-on-a-Chip) Device. The DSP primitive is a 16-bit digital FIR filter which we implemented on Triscend E5 CSoC® family. Experimental results show that by properly breaking the DSP task into hardware and software parts, one can achieve higher throughput compared to DSP processor implementations, while having more flexibility and less time-to-design compared to full-hardware realizations. Programmable SoC device facilitates rapid design-space exploration, which we employed to optimize our mixed hardware-software architecture. We compared our filter throughput to... 

Engines that extract energy from low-grade heat sources, e.g., from other processes, have received considerable attention recently. The use of Fluidyne, which is a liquid piston Stirling engine, is quite popular. Herein, we explore the use of liquid-to-vapor phase change in a Fluidyne. This provides two considerable differentiators; (1) exploitation of very low temperature difference ΔT≈30 K, and (2) relatively low temperature ΔT≈330 K heat sources, for producing mechanical work, and thus electrical energy. The influence of three operating parameters, i.e., input heat flux, working fluid, and filling ratio, on the performance of the engine was characterized. Their optimum values, which yield... 

Signal compression is an important element encountered in data storage applications. Over the years various techniques for data reductions have been proposed. In this paper we introduce an effective method for compressing semi-periodic signals. Although the approach is applicable to any semi-periodic signal, our attention is focused on the compression of electrocardiogram (ECG) signals. An ECG signal is composed of many similar beats which makes it to behave semi-periodic This paper deals with beat variation periods and exploits the correlation between cycles (inter-beat) and correlation within each cycle (intra-beat) for compression. For efficient compression a 2-dimensional array is... 

The square of a graph G denoted by G2, is the graph with the same vertex set as G and edges linking pairs of vertices at distance at most 2 in G. The chromatic number of the square of the Cartesian product of two cycles was previously determined for some cases. In this paper, we determine the precise value of χ((Cm□Cn)2) for all the remaining cases. We show that for all ordered pairs (m,n) except for (7,11) we have χ(Cm□Cn)2)=γV((Cm□Cn)2)|α((Cm□Cn)2), where α(G) denotes the independent number of G. This settles a conjecture of Sopena and Wu (2010). We also show that the smallest integer k such that χ(Cm□Cn2)≤6 for every m,≥k is 10. This answers a question of Shao and Vesel (2013)  

The main purpose of this study is to evaluate the effect of intravenous irradiation of different low-level laser wavelengths on the activity of lecithin-cholesterol acyltransferase (LCAT), paraoxonase (PON1), catalase, and ferric reducing ability of plasma (FRAP) in diabetic rats. First, diabetes was induced in rats using streptozotocin (STZ). Enzymes’ activity was measured in the blood samples and compared before and after intravenous laser blood irradiation. We used four continuous-wave lasers—IR (λ = 808 nm), Red (λ = 638 nm), Green (λ = 532 nm), and Blue (λ = 450 nm)—to compare the wavelength’s effect on different enzymes’ activity. Laser power was fixed at 0.01 mW and laser energy was... 

In real soccer goal keeper has a completely different behavior that the players. Thus we designed our goal keeper with some basic ideas taken from real soccer, which is moving mainly in goal area and using arms to take the balls. Our goal keeper has a moving mechanism based on 8 motors which enables it to move forward/backward, straight left/right and rotate around its geometrical center, and a sliding arm which moves toward the direction of ball faster than the robot body. Using 3 CCD cameras in front and rear left and right provides the goal keeper with a view of about 210 degrees. © 2001 Springer-Verlag Berlin Heidelberg