Sharif Digital Repository

Context. The extrasolar planet WASP-67 b is the first hot Jupiter definitively known to undergo only partial eclipses. The lack of the second and third contact points in this planetary system makes it difficult to obtain accurate measurements of its physical parameters  

The earned value technique is an essential technique in analyzing and controlling the performance of a project by providing a more accurate measurement of both project performance and project progress. This paper presents an approach to deal with fuzzy earned value indices. This includes developing new indices under fuzzy circumstances and evaluating them using alpha cut method. The model improves the applicability of the earned value techniques under real-life and uncertain conditions. A small example illustrates how the new model can be implemented in reality  

Proper operation of an engine requires accurate measurement or estimation of the engine's air charge provided to the control unit which reduces both the engine's fuel consumption and the emissions. The volumetric efficiency of the engine is a key variable in computations using the engine control unit to estimate the air charge using the speed-density equation. This paper presents a new approach for real-time estimation of the volumetric efficiency using the sliding-mode methodology. An adaptive sliding-mode observer is proposed which relies on measurements from the engine's conventional sensors. The observer is shown to estimate asymptotically the volumetric efficiency of the engine for... 

Optical tweezers provide an accurate measurement technique for evaluating mechanical properties of the living cells and many experimental studies have been done to understand the behavior of cells due to external forces. Numerical studies such as finite element methods have been used in order to simulate mechanical behavior of the Red Blood Cells (RBCs). Recent studies have shown that the particle methods are useful tools to simulate the mechanical behavior of living cells. Since in microscopic scales, using discrete models are preferred than continuum methods, a particle-based method is used to simulate the deformation of RBC which is stretched by optical tweezers. The cytoplasm of RBC is... 

Due to the lack of data in active distribution networks, employing new accurate measurement devices like phasor measurement units (PMUs) and micro-PMUs with a high reporting rate becomes an inevitable choice for the future vision of distribution systems. As a result, different algorithms have been presented to optimally place PMUs cost-effectively based on the estimation errors of the distribution state estimation (DSE) results. However, any component failure in measurement devices or communication links between sending ends and monitoring system of the distribution management system can significantly affect the DSE results. In response, this study introduces the reliability of satisfying... 

Context. Not only is gravitational microlensing a successful tool for discovering distant exoplanets, but it also enables characterization of the lens and source stars involved in the lensing event. Aims. In high-magnification events, the lens caustic may cross over the source disk, which allows determination of the angular size of the source and measurement of its limb darkening. Methods. When such extended-source effects appear close to maximum magnification, the resulting light curve differs from the characteristic Paczyński point-source curve. The exact shape of the light curve close to the peak depends on the limb darkening of the source. Dense photometric coverage permits measurement... 

In this paper, we propose a novel algorithm for rate allocation in multiple-source media streaming peer to peer networks. Our algorithm is based on ant-colony optimization and capable of handling network changes which occur quite often in unstructured P2P networks. The suggested algorithm does not need any information about the topology of the network. Moreover, it could get over uncertainties in network state information, particularly the rate of media provider nodes that could happen due to lack of accurate measurements. We show that our algorithm will reach the maximum achievable rate of the network quite fast and with relatively little overhead. In our simulations, we have demonstrated... 

Capacitors are one of the most critical components in power electronic converters, yet they are notoriously susceptible to failure. Avoiding unforeseen outages caused by capacitor failures is one of the most effective approaches to increase system availability. Therefore, a variety of methods have been proposed to monitor a capacitor health condition based on different degradation indicators. This paper proposes a new approach based on the accurate measurement of an electrolytic capacitor dissipation factor to detect its end-of-life. Since the dissipation factor is affected by both the capacitor resistance and capacitance simultaneously, it can provide more information about the health...