Sharif Digital Repository

The set of human arm, forearm, and wrist has the ability of performing very miscellaneous movements which has led to human inspiration for designing sorts of robots for various tasks. The aim of the present study is the design and simulation of a robot, similar to the human hand and arm. In the beginning, a shape-adaptive 2 DOF under-actuated mechanism which is actuated by one motor, is selected as the second and third phalanges of the human finger. Also the first phalanx of the finger moves independently by another motor. By adding a ratchet to the second joint of the finger, with the help of only two actuators, the feasibility of exerting isotropic force to the object in three phalanges... 

Solid-State Disks (SSDs) offer advantages such as no mechanical parts, low power consumption, and constant read latency. SSDs, however, suffer from shortcomings such as erase-before-update requirement and limited endurance.Redundant Array of Independent Disks (RAID) are commonly used in storage servers to enhance performance and reliability. To further enhance system performance, one can employ efficient Input/Output (I/O) scheduling algorithms suitedto the disk structure in RAID-based systems.In this thesis, we present an I/O scheduling method to improve endurance and performance of SSD-based RAID systems. In the proposed I/O scheduling algorithm, read requests are sent directly to SSDs and... 

The increasing demand for air transportation, along with air traffic limitations and environmental pollution concerns, necessitate a comprehensive study in the field of airspace-management. In this regard, one of the promising alternatives is flying smarter via “Formations”. In fact, many works have discussed the benefits of “Commercial Formation Flights”; however, none have discussed a practical way to manage such formations for long-distance cruise. This paper discusses a new approach to manage the “Geometrical Arrangement” of such flights in an efficient manner. In fact, with the help of the so called “Game Theory” and without complex computations we are able to guide each individual... 

Mixed-critical systems (MCSs) use a common hardware platform to schedule and execute tasks with multiple critical levels. Multi-core processors are commonly used by these systems, and batteries are frequently employed to provide the energy they require due to their portable nature or lack of access to large energy sources. Therefore, it is essential to use energy-management methods, such as dynamic voltage and frequency scaling (DVFS) and dynamic power management (DPM), to reduce their energy consumption. Using power/energy management methods can lead to missed deadlines due to increased execution time of tasks. In two-level mixed-critical systems, the lack of correct and timely execution of... 

Resin Transfer Molding (RTM) which is one of the categories of Liquid Composite Molding (LCM) process, is considered as one of the most important process in polymer composite manufacturing. To improve this manufacturing method and reaching higher qualities, numerous modified methods has been developed. One of these modified methods is Vaccum Assisted Resin Trasnfer Molding with Flexible Tooling which is considerably applicable in manufacturing parts with high quality, large and complex geometry. Although, this manufacturing method has variety of advantages, there are some problems such as void formation making production difficult and dependent to experimental trial and error. So numerical... 

Organizations are established and developed based on a specific existence policy. They would exist as long as they are able to do their basic mission. An organization could perform its mission through some work processes. The better processes makes higher organization’s productivity. In order words desirable quality and quantity of an organization depends on processing functions. Improved processes use minimum resources to achieve efficiency maximum. Deeds and Properties Registration Org. (DPRO) is a unit, which maintains and supports national security through arranging individual social and economic relations, the organization has an outstanding position. Following composition of 20-year... 

Land subsidence is a gradual settling or sudden sinking of the land surface from changes that take place underground. There are different causes of land subsidence; most notably, groundwater overdraft and severe weather conditions. Subsidence of the land surface due to ground water overdraft is caused by an increase in the intergranular pressure in unconsolidated aquifers, which results in a loss of buoyancy of solid particles in the zone dewatered by the falling water table and accordingly compaction of the aquifer. In this study, an experimental approach was developed to examine applicability of Microbially induced carbonate precipitation (MICP) for land subsidence control under... 

Considering the daily growth of industries in international market competition and the necessity of investment in related infrastructure development, determining the priority of industries in order to strengthen or support of these industries, seems as an inevitable issue, so for the purpose of making proper decisions in an optimum way, we must use scientific decision making methods. This study evaluates the priority of industries in Iran and comparison of them. Therefore, according to the international standard classification of economic activities (ISIC), two-digit and four-digit codes are specified for each industry. In addition, based on major economic indicators, the status of these...