Sharif Digital Repository

Increasing complexity of modern embedded systems has caused tasks with different criticality levels to run on a shared hardware platform, called mixed-criticality systems. In these systems, it is important to use fault tolerant techniques to achieve reliability targets. Moreover, the limited battery life in many applications and real-time requirements make energy-aware reliability management and guaranteeing deadline constraints a major challenge. Checkpointing with rollback recovery is a good option to ensure reliability of these sys- terns because of its low cost and relatively low time overhead. However, improper use of this technique can impose high energy overhead and cause deadline... 

Rehabilitation science has been proved that, in most cases, manipulation of injured body part, repeatedly, can help in returning the performance of that part. So robots can be useful for rehabilitation applications. Rehabilitation robots can record physical parameters such as position, velocity and force, so can play important role in developmentof making decisions on exercise types. Among the existing robots, cable-driven robots have specifications such as vast workspace, low cost, flexibility and light weight which make them suitable for rehabilitation applications.
The purpose of this research is kinematic design of a multi-link cable-driven robot for arm rehabilitation.In the most of... 

Dynamic positioning system is a controller system used to maintain the position and heading of a vessel with no use of anchors, jack ups but only using the propellers installed on the vessel. A vessel has six degrees of freedom, including three rotations and three transfer. In dynamic positioning systems, the vessel is controlled only on the horizontal plane such that its position and heading are controlled according to predetermined values. To achieve this, position and heading of the vessel is determined and the controller system computes the direction and required power of each propeller. Preliminary systems utilized PID controllers. As the control science has advanced, model based... 

Traffic accidents around the world kill a large number of people every year, and their lightest consequences are temporary disabilities for citizens. According to the statistics, the number and severity of accidents have been growing, due to the expansion of cities and the human population there, and this increases the need to pay attention to traffic safety. One of the substantial subcategories of traffic safety research is public transportation. However, limited studies have been done in this field. One of the main modes of public transportation are buses, which bring more risk of accidents to passengers, due to their size and higher passenger capacity compared to passenger vehicles.... 

Among motorized vehicles, motorcycles are recognized as a common mode of transportation in countries with low to moderate income. Iran is also one of the countries where motorcycles are considered a primary means of transportation. However, in recent years, motorcycle accidents have sharply increased, with 30 percent of accidents in Iran involving motorcycles. This highlights the importance and necessity of taking measures to enhance safety and reduce motorcycle accidents in Iran. In this study, data on intercity motorcycle accidents in the provinces of Khorasan Razavi, Isfahan, Qom, Mazandaran, Gilan, Hamedan, Hormozgan, and Ilam were used. The main objective was to identify and compare the... 

Because of severe weather events (such as floods and storms), transportation infrastructures are directly and indirectly damaged, which may cause many undesirable economic and social losses for people and cities. Among various severe events, flood is known as an important factor in the breakdown (closure of roads and bridges) of the components of the transportation network. Evaluating the performance of the city's road transport network against flood events leads to a better understanding of the network's condition and allows decision-makers to identify the weaknesses in the system and reduce potential damages as much as possible. In this research, with the aim of investigating the... 

This thesis examines the accessibility gap between different modes of transportation in Tehran Province, with a particular focus on public transportation and cycling. The main objective of this research is to calculate and analyze accessibility indicators to various land uses (such as commercial, service, and recreational) around metro stations using two modes of travel: cycling and bus-walking. The study utilizes simulations in Python and geographic libraries to compare these two modes of travel based on four key accessibility indicators: 1) nearest Opportunity, 2) cumulative opportunity, 3) average distance, and 4) gravity-based accessibility to measure the accessibility gap between the... 

Politicians and urban planners aim to improve citizens' overall life satisfaction. Researchers have offered various definitions of life satisfaction, making it difficult to provide a specific definition. However, life satisfaction can be seen as an assessment of different aspects of life. The method of travel and transportation factors undoubtedly play a crucial role in this assessment. Due to personal and social constraints, users' behavior in transportation can either may or may not align with their attitudes. This behavior leads to the categorization of users into two groups: consonant and dissonant users. Consequently, planning and policy-making to increase life satisfaction will differ... 

Freight transportation by trucks plays a critical role in economic development and shaping human life. A significant portion of the total and operational costs of countries is accounted for by transportation, and efforts to optimize it have always been considered of utmost importance. One of the emerging technologies aimed at transforming traditional transportation is vehicle automation. Due to its more uniform nature compared to urban transportation, road freight transportation has greater potential for adopting this technology. Numerous studies have addressed this issue; however, the assumption of fixed variables and the lack of an optimal program for the gradual transition from... 

In this research, a dashboard has been developed to support decision-making in the integration of freight companies. Freight companies usually consist of a limited number of vehicles due to the high cost of vehicles, while the fixed costs of a freight company constitute a significant part of that company's total cost. Therefore, if these companies are merged, their total cost will be substantially decreased. Moreover, under particular demand levels, the integration of freight companies reduces the mileage, travel time, and the number of required cars. Therefore, the integration of freight companies not only reduces fixed costs but also reduces other costs including greenhouse gas costs by... 

Various public transportation types, e.g., Trains, Buses, and Airplanes, are susceptible to damages made by the impacts of the external objects, which are typically classified as low to medium velocity impacts. This problem reveals the significance of investigating the effects of impact on thin-walled structures, which are the main components of these vehicles' bodies. Owing to the controllable rheological properties of the Magnetorheological fluid with respect to the magnetic field, it can be utilized to control the structure exposed to impact adaptively and minimize the damages. Due to this purpose, sandwich structures such as sandwich beams and plates, thanks to their extended response... 

In recent years, energy storage systems have received widespread attention from researchers to increase the reliability of the power grid. These systems have different types that compressed air system is of special importance due to its high stored energy and long life. In this system, the surplus of electricity generated from renewable energy sources or grid electricity at low power consumption is compressed and stored in a tank. When there is a need for power consumption or peak power consumption, compressed air will generate electricity by passing through the turbine and will help the network. Large-scale type of the system requires special geographical location for air storage; for this... 

Pulse compression techniques such as linear frequency modulation (LFM) and phase-coded pulse are an active research topic in radar systems, spread spectrum communication applications, etc. Pulse compression technique is employed to achieve high range resolution with enough low average power. A problem in pulse compression is masking of small targets by the range sidelobes of large nearby targets. Furthermore, the range sidelobes may be detected as separate targets and thus increase the false alarm. The most popular waveform among pulse compression techniques is the LFM (also known as chirp). However, the LFM waveform is susceptible to electronic warfare; hence using the biphase coded... 

Rehabilitation usually involves physical therapy, occupational therapy and counseling for the patient's morale to help to restore his power and performance. Considering the economic outlook and the costs of rehabilitation methods and due to the increasing prevalence of stroke and the need to recover the patients in a short period, only the use of robotic systems opens the door to the medical community. Since a large rehabilitation robots designed and built and each been used according to their advantages and shortcomings. In this project, the major shortcomings examined and exoskeleton designed on two major features including portability and covering shoulder workspace. Shoulder movement was... 

The control approaches in Exoskeletons are different from Autonomous robot. Because the Exoskeletons are in connection and interaction with the user. On the other hand they can use the wearer’s abilities such as intelligence, sensory organs, self-control and etc. Therefore, one of the most important parts of exoskeletons control algorithms is its interaction with the user. This part should recognize the goal and purpose of the wearer such as stopping, walking start, change in stepping and direction and etc. properly. Utilizing these algorithms properly, one can reduce the muscle activities and energy consumption up to 20 percent [1]. This investigations demonstrate the importance of the... 

Intelligent design theory is based on this idea that Darwinian theory of evolution can not explain Irreducibly complexities in organisms. Intelligent design theory in explaining these complexities conclude the existence of an intelligent designer. It is claimed that by remaining officially agnostic about the nature of the designer, intelligent design theory can be offered as a scientific claim, rather than a religious one, which could make it a viable alternative to Darwinism. In this thesis we study sober's point of view on intelligent design. Sober believes that, initially, we shoud present the strongest formulation of intelligent design theory and then evaluating whether this theory is a... 

Since the advent of online real estate database companies like Zillow, Trulia and Redfin, the problem of automatic estimation of market values for houses has received considerable attention. Several real estate websites provide such estimates using a proprietary formula. Although these estimates are often close to the actual sale prices, in some cases they are highly inaccurate. One of the key factors that affects the value of a house is its interior and exterior appearance, which is not considered in calculating automatic value estimates. In this work, we evaluated the impact of visual characteristics of a house the buyer's proposed price. Using deep convolutional neural networks on a large... 

In this thesis we investigate the consept of supreme Pfister forms developed by K. J. Becher. Let F be a field of characteristic different from 2. Several properties of F with respect to an anisotropic form ϕ over F are introduced and their relations are studied. A form ϕ is called supreme if it is anisotropic and every anisotropic form over F is a subform of ϕ. It can be easily shown that if F has a supreme form then F is nonreal and ϕ is a Pfister form. We see how examples of such fields may be obtained. Also we compare fields having a supreme Pfister form with n-local fields (i.e., fields which up to isometry have exactly two n-fold Pfister forms). Finally, we apply our results to the... 

Control of line of sight (LOS) orientation is a fundamental prerequisite for virtually all dynamic applications in which an optical sensor is used to obtain images. In this research, a 3 DOF parallel mechanism is utilized to build a stable platform for high precision satellite photography. The platform may be designed based on the Stewart platform concept. The stability is obtained by controlling the roll, pitch and yaw of the mechanism. To apply linear control techniques and to use roll-pitch and yaw rates and also their absolute values, an active stable platform is designed. Line Of Sight (LOS) is a position vector from origin of a topocentric-horizontal system to the satellite of... 

Over the last years, terrorist attacks and accidental explosions have brought on a need for research in the field of structural engineering to study the response of a building subjected to blast loading conditions. An explosion within or surrounding a building, not only can have disastrous effects causing both structural damage or failure, but may also lead to the death of human beings.In order to prevent these catastrophes and gain a better understanding of responses of the buildings and lateral resisting systems with different characteristics, the study of the behavior of the lateral resisting systems under blast loading conditions is essential. This research will also aid in the...