Sharif Digital Repository

Entanglement spectrum is the set of eigenvalues of reduced density matrix for a definite state. It contains more information than the entanglement entropy. This spectrum can show entanglement measure, quantum phase transition and topological order in a system. In recent years, the entanglement spectrum for several models has been studied. The entanglement spectrum shows a correspondence to the energy spectrum within some specific regions, which are related to the edge state of the system; It has been verified for the Heisenberg ladder [1] and fractional quantum Hall effect [3]. Moreover, the topological order can be seen in the entanglement spectrum. There exists an acceptable adaption... 

Gesture and motion evaluation are needed for a variety of applications. The use of human hand motions as a natural interface tool has motivated researchers to conduct research in the modeling, analysis and evaluation of various hand movements. In particular, human-computer intelligent interaction has been a focus of research in vision-based gesture recognition. In this work, we introduce a 3-D hand model evaluation method that offers flexible and elaborate representation of hand motion. We used landmarked points on tips and joints of the fingers and calculated the 3-D coordinates of these points through a stereo vision system followed by an HMM (Hidden Markov Model) to recognize hand... 

International Data Company (IDC) has reported, at the end of 2020, the total amount of digital data stored in the entire world will reach 40 thousand Exabytes. The idea of accessing this volume of data, anywhere at any time by exploiting commodity hardware, led into the introduction of cloud storage. The abounded rate and variety of failures in the equipment used in cloud storage systems, placed fault tolerance, at top of the challenges in these systems. HDFS layer in Hadoop has provided cloud with reliable storage. Replication is the conventional method to protect data against failures in HDFS. But the storage overhead is a big deal and therefore designers are tending towards erasure codes.... 

Internet of Things (IoT) is a communicative infrastructure, which establishes IP-based connections between many smart devices with limited energy supplies. The gathering of such an enormous number of connected devices would impose many challenges, with routing the most important issue. Standardization of the IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) was a major step towards fulfilling the IoT routing requirements. The key element in determining the routing policies and creation of the topology in RPL is the objective function. According to our studies, more than 97% of the consumed energy of a node in wireless networks is due to transceiver activities. On the other hand,... 

One of the most important concerns in food industry is decreasing the contamination of food and increasing their shelf life. Antimicrobial/antioxidant packaging, an active packaging concept, can be considered an extremely challenging technology that could have a significant impact on shelf-life extension and food safety of meat and meat products. Due to harmfulness of chemical preservatives, their use has been limited and therefore natural antimicrobial/antioxidant agents have become more popular. Propolis is a natural resinous substance, with a high polyphenol content, produced by honeybees and characterized by antimicrobial, anti-inflammatory and antioxidant properties, which make it... 

According to current researches, graphene oxide (GO) membranes show promising desalination properties due to ease of synthesis, low production cost, and high efficiency. There are several experimental works to study ionic sieving properties of GO membranes. However, it is difficult to characterize atomistic mechanism of water permeation and ion rejection by experimental approaches. On the other hand, there exist a few reports in which the atomistic picture of water permeation across GO membranes is investigated by means of molecular dynamics (MD) simulation. In the present work, in addition to water desalination, the atomic scale mechanism of ion rejection is studied using large scale MD...