Sharif Digital Repository

Wearable human activity recognition systems (HAR) using inertial measurement units (IMU) play a key role in the development of smart rehabilitation systems. Training of a HAR system with patient data is costly, time-consuming, and difficult for the patients. This study proposes a new scheme for the optimal design of HARs with minimal involvement of the patients. It uses healthy subject data for optimal design for a set of activities used in the rehabilitation of PD1 patients. It maintains its performance for individual PD subjects using a single session data collection and an adaptation procedure. In the optimal design, several classifiers (i.e. NM, k-NN, MLP with RBF as a hidden layer, and... 

An efficient method to automatically recognize basic human actions is proposed to improve the communication between a human and a computer. Human actions are considered as patterns generated by complex non-linear dynamical models. A non-linear dynamical model is used to represent human actions. Gaussian process dynamical models are used to capture the spatial and temporal behaviors of actions. To make the process more efficient a 7-dimensional feature is extracted for each action. Although the extracted feature vector is compact compared to a high-dimensional temporal pattern, it can efficiently discriminate among different actions. The tests run on CMU MoCap database with SVM show promising... 

CAPTCHA (Completely Automatic Public Turing Test to Tell Computer and Human Apart) systems are used to distinguish human users from computer programs automatically. The goal of them is to ask questions which human users can easily answer, but current computers cannot. Most current CAPTCHA methods are based on the weak points of OCR (Optical Character Recognition) systems. In this paper, a new CAPTCHA method is presented on the basis of object categorization. In this method, a number of objects are chosen randomly and the pictures of these objects are searched in the Internet and downloaded. The pictures are then shown to the user and the user is asked to mark the objects which belong to a... 

Nowadays, a great amount of information is circulated through the Internet. Some of them exclusively belong to a special group of users and require protection and safeguarding against unauthorized access. To this end, a category of systems called HIP (Human Interactive Proof) are designed to distinguish between various groups of users. An important task on the Internet websites is registration. Some hackers write programs to make fake registration that waste the resources of the web sites or even stop them from providing services. Therefore, human users should be distinguished from computer programs. CAPTCHA (Completely Automatic Public Turing Test to Tell Computer and Human Apart) methods... 

Design for Human Safety (DfHS) is an approach to integrate knowledge of human safety in the design process. DfHS is multi-disciplinary in its nature, requiring many kinds of information and knowledge. Number of DfHS studies tried to apply Axiomatic Design (AD) to achieve their aims. The purpose of this paper is to review the literature on application of AD in DfHS in manufacturing systems and to propose a roadmap for future DfHS works. This paper examines the number and type of publications dealing with this context. The review covers papers published between 1990 (when AD was introduced first) and 2017. It is based on a range of combinations of the following keywords: "Axiomatic design" and... 

Multiple human 3D pose estimation is a challenging task. It is mainly because of large variations in the scale and pose of humans, fast motions, multiple persons in the scene, and arbitrary number of visible body parts due to occlusion or truncation. Some of these ambiguities can be resolved by using multiview images. This is due to the fact that more evidences of body parts would be available in multiple views. In this work, a novel method for multiple human 3D pose estimation using evidences in multiview images is proposed. The proposed method utilizes a fully connected pairwise conditional random field that contains two types of pairwise terms. The first pairwise term encodes the spatial... 

Facial expression imitation with applications in the design of human robot interaction (HRI) systems is an active area of research. In this study, we propose an approach for real-time imitation of human facial expression by a humanoid social robot 'Alice'. Artificial neural network (ANN) and Kinect sensor are used for recognition and classifying of the facial expressions like happiness, sadness, fear, anger and surprise; with the Alice humanoid robot imitating the comprehended expressions. Results and experiments demonstrate the effectiveness of the approach. © 2016 IEEE  

Background: The early repolarization pattern (ERP) has been considered a normal variant in electrocardiography (ECG) for a long time. Nevertheless, increasing evidence has demonstrated its association with adverse outcomes. Objectives: The present study aimed to evaluate the prevalence of ERP in the Iranian general population and demonstrate its clinical and ECG correlates. Methods: A cross sectional study, comprising 1424 consecutive healthy adult individuals, was conducted at two university based hospitals in Tehran, Iran in 2012-2013. The ERP prevalence, clinical characteristics and ECG morphology were investigated in volunteers. Results: ERP was present in 136 out of 1,424 people (9.6%).... 

Availability of low-cost range sensors and the development of relatively robust algorithms for the extraction of skeleton joint locations have inspired many researchers to develop human activity recognition methods using 3-D data. In this paper, an effective method for the recognition of human activities from the normalized joint trajectories is proposed. We represent the actions as multidimensional signals and introduce a novel method for generating action templates by averaging the samples in a “dynamic time” sense. Then, in order to deal with the variations in speed and style of performing actions, we warp the samples with action templates by an efficient algorithm and employ wavelet... 

Multiple human 3D pose estimation is a challenging task. It is mainly because of large variations in the scale and pose of humans, fast motions, multiple persons in the scene, and arbitrary number of visible body parts due to occlusion or truncation. Some of these ambiguities can be resolved by using multiview images. This is due to the fact that more evidences of body parts would be available in multiple views. In this work, a novel method for multiple human 3D pose estimation using evidences in multiview images is proposed. The proposed method utilizes a fully connected pairwise conditional random field that contains two types of pairwise terms. The first pairwise term encodes the spatial... 

Nowadays, a great amount of information is circulated through the Internet. Some of them exclusively belongs to a special group of users and requires protection and safeguarding against unauthorized access. To this end, a category of systems called HIP (Human Interactive Proof) have been introduced to distinguish between various groups of users. CAPTCHA (Completely Automatic Public Turing Test to Tell Computer and Human Apart) methods are one of the important branches of HIP systems which are used to distinguish between human users and computer programs automatically. These methods are based on Artificial Intelligence (AI) topics. The goal of these systems is to ask questions which human... 

Many websites on the Internet offer services to people. They usually ask the users to fill the registration forms for using their services. Unfortunately, some vandalistic persons write programs which make automatic fake registration. For solving this problem, CAPTCHA (Completely Automated Public Turing test to tell Computers and Human Apart) systems are invented. These systems distinguish human users from computer programs. One of the CAPTCHA methods which is designed for Persian and Arabic users is Nastaliq CAPTCHA. In this method, the image of a Persian or Arabic word which is written in Nastaliq font is chosen from a dictionary, and it is shown to the users, then they are asked to type... 

Nowadays a great deal of information is circulated through the Internet. Some of it exclusively belongs to a special group of people and requires protection and safeguarding against unauthorized access. To this end some systems called HIP (Human Interactive Proofs) have been introduced to tell humans and computers apart or various groups of people apart. In this paper, a new method for telling users apart by help of showing picture of a multiplechoice question has been presented. This multiple-choice question is related to some protected information in the field of user's profession. Since picture of question is viewed the computer cannot answer it. On the other hand, only experts and... 

Robotic blimps have a wide range of applications, such as monitoring activities in their surroundings, advertising, and performing on stages. They also have remarkable capacities to be used as a social robot. In this research, a manually operated social robotic blimp has been developed intending to interact with children as a social agent and attract adults’ attention as an entertainer in indoor public environments. Since the appearance of a social robot has a significant impact on its acceptance, first, we acquired opinions of several participants on the shape of a desired floating robot. The results revealed that a simple spherical structure adequately draws people’s attention. After... 

A hybrid scaffold of gelatin-glycosaminoglycan matrix and fibrin (FGG) has been synthesized to improve the mechanical properties, degradation time and cell response of fibrin-like scaffolds. The FGG scaffold was fabricated by optimizing some properties of fibrin-only gel and gelatin-glycosaminoglycan (GG) scaffolds. Mechanical analysis of optimized fibrin-only gel showed the Young module and tensile strength of up to 72 and 121 KPa, respectively. Significantly, the nine-fold increase in the Young modulus and a seven-fold increase in tensile strength was observed when fibrin reinforced with GG scaffold. Additionally, the results demonstrated that the degradation time of fibrin was enhanced... 

Objectives: Ankylosing spondylitis (AS) is a rheumatic disorder that is mostly determined by genetic and environmental factors. Given the known importance of macrophage in AS pathogenesis, we investigated the transcriptional profile of macrophage cells in the disease. Methods and Results: Two approaches of differential expression and subsequently, weighted gene co-expression network analysis was utilized to analyze a publicly available microarray dataset of macrophages. Integral membrane protein 2A (ITM2A) was among the most significant genes with a decreased trend in the common results of both methods. In order to confirm the finding, the expression of ITM2A was evaluated in... 

Recent studies have demonstrated that high-level semantics in data can be captured using sparse representation. In this paper, we propose an approach to human body pose estimation in static images based on sparse representation. Given a visual input, the objective is to estimate 3D human body pose using feature space information and geometrical information of the pose space. On the assumption that each data point and its neighbors are likely to reside on a locally linear patch of the underlying manifold, our method learns the sparse representation of the new input using both feature and pose space information and then estimates the corresponding 3D pose by a linear combination of the bases... 

Motivation: The interactions among proteins and the resulting networks of such interactions have a central role in cell biology. Aligning these networks gives us important information, such as conserved complexes and evolutionary relationships. Although there have been several publications on the global alignment of protein networks; however, none of proposed methods are able to produce a highly conserved and meaningful alignment. Moreover, time complexity of current algorithms makes them impossible to use for multiple alignment of several large networks together.Results: We present a novel algorithm for the global alignment of protein-protein interaction networks. It uses a greedy method,... 

This paper is concerned with global analysis of an SAIS epidemiological model in a population of varying size introduced by Busenberg and van den Driessche. In this model the population is divided into three subgroups of susceptible, asymptomatic and infective individuals. It has been shown that this system has no periodic solutions and all its trajectories tend to the equilibria of the system. We use the Poincaré Index theorem to determine the number of the equilibria and their stability properties. We have shown that bistability occurs for suitable values of parameters and found a set of examples of all possible dynamics of the system