Sharif Digital Repository

In this research, the nonlinear elastic behavior of human extensor apparatus was investigated. To this goal, firstly the best material parameters of hyperelastic strain energy density functions consisting of the Mooney–Rivlin, Ogden, invariants, and general exponential models were derived for the simple tension experimental data. Due to the significance of stress response in other deformation modes of nonlinear models, the calculated parameters were used to study the pure shear and balance biaxial tension behavior of the extensor apparatus. The results indicated that the Mooney–Rivlin model predicts an unstable behavior in the balance biaxial deformation of the extensor apparatus, while the... 

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... 

We present a novel deep convolutional neural network (DCNN) model for predicting human behavior in repeated games. The model is the first deep neural network presented on repeated games that is able to be trained on games with arbitrary size of payoff matrices. Our neural network takes the players’ payoff matrices and the history of the play as input, and outputs the predicted action picked by the first player in the next round. To evaluate the model’s performance, we apply it to some experimental games played by humans and measure the rate of correctly predicted actions. The results show that our model obtains an average prediction accuracy of about 63% across all the studied games, which... 

Dynamic analyses are necessary problems in offshore jacket structures design and assessment. These analyses have various applications in recognition of dynamic behavior, fatigue analysis, damage detection, etc. Natural frequencies and mode shapes, as inherent vibrational features of a structure, are key parameters in referred analyses. These parameters are mainly affected by mass and stiffness matrices and slightly by damping. Therefore, it is more important to estimate the stiffness matrix of a structure accurately, especially in stiff structures such as offshore jacket platforms. In many cases, the stiffness of levels is required. For example, it can be useful in the construction of an... 

Dynamic analyses are necessary problems in offshore jacket structures design and assessment. These analyses have various applications in recognition of dynamic behavior, fatigue analysis, damage detection, etc. Natural frequencies and mode shapes, as inherent vibrational features of a structure, are key parameters in referred analyses. These parameters are mainly affected by mass and stiffness matrices and slightly by damping. Therefore, it is more important to estimate the stiffness matrix of a structure accurately, especially in stiff structures such as offshore jacket platforms. In many cases, the stiffness of levels is required. For example, it can be useful in the construction of an... 

Driving behavior recognition is a notable topic in travel safety, as transportation and insurance companies could adopt effective tools to detect unsafe driving and internalize the associated costs. Different driving events and the related severity must be detected to distinguish abnormal behaviors. The global positioning system (GPS) provides useful information regarding the location of the vehicle at any time and is vastly used in various devices such as smartphones and GPS trackers. Other sensors, on the other hand, provide complementary valuable information but their implementation requires extra costs and more complex and intensive algorithms. We developed a threshold-based algorithm to... 

Driving simulators can provide safe real-world driving conditions that may help researchers study driving behavior; however, driving simulator sickness (DSS) has been recognized as one of the most frequent challenges associated with using driving simulators. The DSS issue may affect the validity and reliability of results obtained during the driving simulator experience. Therefore, it is necessary to understand the potential consequences of DSS in the virtual environment of a driving simulator. The goal of this study is to analyze DSS symptoms among participants of a driving simulator by their demographics. The samples of four simulator studies were combined, including a total of 259... 

Wind turbine blade life prediction is the most important parameter to estimate the power generation cost. Due to the price and importance of wind blade, many experimental and theoretical methods were developed to estimate damages and blade life. A novel multiaxial fatigue damage model is suggested for the life prediction of a wind turbine blade. Fatigue reduction of fiber and interfiber characteristics are separately treated and simulated in this research. Damage behavior is considered in lamina level and then extended to laminate; hence, this model can be used for multidirectional laminated composites. The procedure of fatigue-induced degradation is implemented in an ABAQUS user material... 

Wind turbine blade life prediction is the most important parameter to estimate the power generation cost. Due to the price and importance of wind blade, many experimental and theoretical methods were developed to estimate damages and blade life. A novel multiaxial fatigue damage model is suggested for the life prediction of a wind turbine blade. Fatigue reduction of fiber and interfiber characteristics are separately treated and simulated in this research. Damage behavior is considered in lamina level and then extended to laminate; hence, this model can be used for multidirectional laminated composites. The procedure of fatigue-induced degradation is implemented in an ABAQUS user material... 

Objective: Spine kinematics, kinetics, and trunk muscle activities were evaluated during different stages of a fatigue-induced symmetric lifting task over time. Background: Due to neuromuscular adaptations, postural behaviors of workers during lifting tasks are affected by fatigue. Comprehensive aspects of these adaptations remain to be investigated. Method: Eighteen volunteers repeatedly lifted a box until perceived exhaustion. Body center of mass (CoM), trunk and box kinematics, and feet center of pressure (CoP) were estimated by a motion capture system and force-plate. Electromyographic (EMG) signals of trunk/abdominal muscles were assessed using linear and nonlinear approaches. The L5-S1... 

Transitions is today’s debate in almost all topics both in academia and practice. Energy transitions among others, have received relatively more attention, due to the global demand for increasing energy efficiency and lowering environmental impacts. In recent decades, energy management systems, through implementing energy management programs and related practices within industrial companies, have played a vital role in enhancing industrial energy efficiency performance levels. However, still there are problems at very first step of energy management program installation, which is decision-making. Despite market and non-market failures, lack of information, inadequate knowledge, the... 

The researches on environmental and sustainability are an active topic, especially in the waste management. As such, the hazardous waste optimization is an active research topic in developing countries which may be integrated with carbon emissions and green subjects. This grand challenge motivates the current research to contribute a new multi-objective optimization model to address the green hazardous waste location-routing problem. The proposed multi-objective optimization model establishes four objectives simultaneously for the first time. In addition to the total cost and the greenhouse gas emissions of the transportation systems as the two main objectives, another objective function... 

The planning and operation problems of parking lots of plug-in electric vehicles (PEVs) are studied in this paper. Herein, each distribution company (DISCO) allocates the parking lots to the electrical feeders to minimize the power loss and expected energy not supplied of the system, and consequently minimize the total cost of the planning problem over the given time horizon. In addition, the generation company (GENCO) manages the charging time of PEVs parked in the parking lots to defer the more expensive and pollutant generation units, and as a result maximize its daily profit. In both planning and operation problems, the behavioral model of PEVs' drivers are modeled with respect to the... 

In this paper, we investigate the problem of detecting and monitoring changes (abnormality) in molecular communication (MC), using the quickest change detection (QCD) schemes. The objective is to watch an environment using a sensor network and make decisions on the time and location of changes based on the received signals from sensors in the fusion center (FC). Such assumptions call for considering spatial and temporal correlations among sensors' transmitting signals. We use the framework of Partially Observable Markov Decision Processes (POMDPs) based on non-homogeneous Markov models. The metric in detection (stopping-time) scenario is to minimize the delay of announcing an abnormality... 

The planning and operation problems of parking lots of plug-in electric vehicles (PEVs) are studied in this paper. Herein, each distribution company (DISCO) allocates the parking lots to the electrical feeders to minimize the power loss and expected energy not supplied of the system, and consequently minimize the total cost of the planning problem over the given time horizon. In addition, the generation company (GENCO) manages the charging time of PEVs parked in the parking lots to defer the more expensive and pollutant generation units, and as a result maximize its daily profit. In both planning and operation problems, the behavioral model of PEVs' drivers are modeled with respect to the... 

Nowadays, Distributed Denial of Service (DDoS) attacks are among the most prevailing and costly attacks across the networks which challenge a variety of services. While many defense mechanisms are presented to detect and mitigate DDoS attacks, attackers constantly explore alternative approaches for orchestrating novel DDoS attacks. Distribution of the mechanism and its deployment into different zones can improve the accuracy and coverage of DDoS attack varieties. In this paper, we propose a 3-phase DDoS attack countermeasure, named RAD, based on a statistical model for scoring users in order to detect DDoS attacks. In the first phase, users are classified into either suspicious or benign... 

Person authentication based on only the name, password or person identification number is not secured enough. In recent years researchers have focused on human physiological and behavioral parameters, because these parameters are more unique and human-specific than traditional ones. This approach of person authentication is usually called biometric authentication. Signature is the most commonly used behavioral biometric which is investigated in two ways of online and offline by researchers. In online procedure, the temporal indices of signature such as signing velocity, and acceleration are involved to increase the accuracy relative to offline methods and to recognize counterfeit signatures.... 

Traffic collisions are one of the most important challenges threatening the general health of the world. Iran's crash statistics demonstrate that approximately 16,500 people lose their lives every year due to road collisions. According to the traffic police of Iran, heavy vehicles (including trailers, trucks, and panel trucks) contributed to 20.5% of the fatal road traffic collisions in the year 2013. This highlights the need for devoting special attention to heavy vehicle drivers to further explore their driving characteristics. In this research, the effect of heavy vehicle drivers' behavior on at-fault collisions over three years has been investigated with an innovative approach of... 

Road traffic crashes have become an important public health problem. By studying the statistics of heavy vehicle crashes in the world, it becomes obvious that although heavy vehicle drivers experience fewer crashes than private car drivers, a large percentage of heavy vehicle crashes leads to death. So, it is important to identify the driving characteristics of heavy vehicle drivers. In this study, 474 Iranian truck drivers were interviewed face to face. Response rate of the survey was 80%, the participants who answered the questions on two behavioral questionnaires: Driver Behavior Questionnaire (DBQ) and Attention-Related Driving Error Scale (ARDES). Also, two sleep assessing... 

There are relatively few comprehensive studies on driving errors and violations in Iran, a non-Western country with a high traffic fatality rate. In this study, 712 drivers completed a questionnaire at technical inspection centres and carwashes in Tehran, Iran. Respondents were asked about their demographic characteristics, accident involvement, traffic fines, and driving aberrations in the form of the Driver Behaviour Questionnaire (DBQ). The results of a principal component analysis of the DBQ showed a distinction between errors and two types of violations: speeding and non-speeding violations. Correlation analyses showed that DBQ violations were associated with a higher driving mileage, a...