Sharif Digital Repository

Hough transform based object detectors divide an object into a number of patches and combine them using a shape model. For efficient combination of patches into the shape model, the individual patches are assumed to be independent of one another. Although this independence assumption is key for fast inference, it requires the individual patches to have a high discriminative power in predicting the class and location of objects. In this paper, we argue that the sparsity of the appearance of a patch in its neighborhood can be a very powerful measure to increase the discriminative power of a local patch and incorporate it as a sparsity potential for object detection. Further, we show that this... 

This study investigates an ethanol liquid jet subjected to combination of an air crossflow and a normal electric field. The results on the liquid jet trajectory and subsequent droplets flight paths are presented. The liquid jet trajectory was found as a function of two non-dimensional quantities; the liquid jet to the crossflow momentum ratio and the electroinertial number. The electroinertial number is defined as the ratio between the liquid jet specific momentum and the electric force. A correlation is introduced for the jet trajectory in low crossflow speeds and electric field intensities. The same two quantities control the detached droplets flight paths. Satellite droplets flight angles... 

Adult cardiomyocytes are terminally differentiated cells that result in minimal intrinsic potential for the heart to self-regenerate. The introduction of novel approaches in cardiac tissue engineering aims to repair damages from cardiovascular diseases. Recently, conductive biomaterials such as carbon- and gold-based nanomaterials, conductive polymers, and ceramics that have outstanding electrical conductivity, acceptable mechanical properties, and promoted cell-cell signaling transduction have attracted attention for use in cardiac tissue engineering. Nevertheless, comprehensive classification of conductive biomaterials from the perspective of cardiac cell function is a subject for... 

Creating laser texture on dental implants is a novel method for accelerating osseointegration and prolongation of lifespan. The purpose of this research was twofold: (1) Creating intersecting lines pattern with different angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°) on the surface of Ti6Al4V, using pulse Nd:YAG laser with a wavelength of 1064 nm and a pulse length of 170 ns and (2) comparing optical and SEM images, EDS analyses, contact angles (CAs), and surface free energies (FEs) for different intersecting lines angles. CA and FE depended on the intersecting lines angle according to Y = Y 0 + A sin (x B + C), where Y is the CA or FE; x is the intersecting lines angle; and Y0, A, B, and C... 

Systematic delivery of therapeutic agents to specific sites, with a stimulus-responsive drug release profile is currently a rapidly growing area. Mesoporous silica nanoparticles (MSNs) are the useful platforms as drug/gene delivery systems due to their unique properties including the ability to control the pore size, high porosity, and morphology, which can directly affect the mechanism and profile of drug release. The appropriate fabrication strategy can tailor the particle shape and size, leading to enhanced delivery and release mechanisms. The MSN surface can be modified by using either organic or inorganic molecules to induce smart and site-specific drug delivery and release.... 

Wireless body area networks (WBANs) are characterized by short-range wireless communication between inherently resource-limited sensors that operate in the vicinity of the human body for recording certain physiological signals. One of the main limitations of WBANs is in terms of their available power. Since the nodes are typically battery-driven, an efficient power transmission is essential to guarantee long-lasting communications among nodes without the need for frequent battery replacement or charging. In this study, aiming to improve the WBAN performance, we first investigate the power allocation problem by choosing the ergodic capacity and the outage probability as the desired metrics.... 

Wireless Body Area Networks (WBANs) are one of the emerging technological trends that have gained a lot of attention both from academic and industrial domains. WBAN, as standardized by IEEE 802.15.6, is a network composed of intelligent, miniaturized, low power nodes that are implanted in, placed on or in close proximity of human body for certain healthcare applications. Sensors send their acquired data to a central hub wirelessly for further processing. In this paper, based on a publicly available channel data set, we investigate the applicable channel models in a typical WBAN. Considering various scenarios with different carrier frequencies, bandwidths, body movements, and transceiver... 

Wireless communication networks may be categorized based on the extent of the geographical area that they cover. The latest trend in this assortment is wireless body area network (WBAN), which is standardized by IEEE 802.15.6 and is defined as a network composed of intelligent, miniaturized, low-power nodes that are implanted in, placed on, or in close proximity to the human body for certain healthcare applications. In this paper, we will start with some assessments on applicable channel models for a typical WBAN. Considering various scenarios with different carrier frequencies, bandwidths, body movements, and transceiver locations, the well-known Bayesian Information Criterion is used to... 

Wireless body area network (WBAN) is composed of miniaturised sensors that operate in the vicinity of the human body for recording the vital physiological signals and wirelessly transmitting them to a central hub for further processing. In this study, a statistical approach is applied to an experimental channel data set to extract the models for the squared channel gain that best describe the characteristics of the transmission medium between the sensors and the central hub. The derived models are then utilised to investigate the error rate performance of WBAN sensors. On the basis thereof, an optimisation problem is formed for which the cost function is the symbol error rate (SER) metric.... 

Wireless body area networks (WBANs) are characterized by short-range wireless communication between inherently resource-limited sensors that operate in the vicinity of the human body for recording certain physiological signals. One of the main limitations of WBANs is in terms of their available power. Since the nodes are typically battery-driven, an efficient power transmission is essential to guarantee long-lasting communications among nodes without the need for frequent battery replacement or charging. In this study, aiming to improve the WBAN performance, we first investigate the power allocation problem by choosing the ergodic capacity and the outage probability as the desired metrics.... 

In this paper, a new topology for multicomputer interconnection networks, based on triangular mesh, is proposed. The new network, referred to as the triangular pyramid (or tripy for short), has L levels of triangular mesh. We study some basic important properties of the proposed network as well as introduce a routing algorithm for the tripy network based on the routing of triangular meshes. We prove that this form of pyramidal network is Hamiltonian, Hamiltonian-connected, and pancyclic. We also prove that the proposed network is 6-colorable and conduct a brief comparison of the tripy and its traditional pyramid counterpart. Our results show that the proposed network has higher scalability,... 

In this paper we study the statistical properties of the Signal to Noise Ratio (SNR) of the dual-hop relaying link in a cooperative wireless communication system in the presence of channel estimation errors for Decode and Forward (DF) relaying protocol. Then for assessment of the system performance the Symbol Error Rate (SER) is considered. Two approaches are introduced for SER calculation from which the second one results in a closed form solution. Finally the second approach is used to find an optimum power allocation scheme for transmission of pilot and data symbols at the source and the relay terminals that results in minimizing the SER and considerable amount of power saving. Also Monte... 

In this paper, a new topology for multicomputer interconnection networks, based on triangular mesh, is proposed. The new network, referred to as the triangular pyramid (or tripy for short), has L levels of triangular mesh. We study some basic important properties of the proposed network as well as introduce a routing algorithm for the tripy network based on the routing of triangular meshes. We prove that this form of pyramidal network is Hamiltonian, Hamiltonian-connected, and pancyclic. We also prove that the proposed network is 6-colorable and conduct a brief comparison of the tripy and its traditional pyramid counterpart. Our results show that the proposed network has higher scalability,... 

A communication system incorporating a bit rate limiter (BRL) device is analyzed using recently proposed statistical models for power splitters and combiners. We also consider the possible optical attenuation and amplification before and after BRL device. We obtain the total output moment generating function (MGF) of the number of photoelectrons at the receiver end for two possible synchronization procedures. Furthermore, we use saddle-point approximation method to evaluate the system performance considering the effects of shot-noise, thermal noise, and source extinction ratio  

In this paper, we present a thorough analysis based on photon-counting techniques on temporal/spatial fiber-optic code-division multiple-access systems incorporating both post- and pre-optical amplifiers. In this analysis, we consider the effect of shot noise, thermal noise, and source extinction on system bit-error rate. Our results can be used to estimate the maximum tolerable amount of quantum fluctuations in the received signal