Sharif Digital Repository

This article presents an overview of the mechanical design features, fabrication and control of a Rescue Robot (CEDRA) for operation in unstructured environments. As a preliminary step, the essential characteristics of a robot in damaged and unstable situations have been established. According to these features and kinematical equations of the robot, design parameters are optimized by means of Genetic Algorithm. Optimum parameters are then utilized in construction. Upon fabrication, this unit has been tested in clean laboratory environment, as well as, ill-conditioned arenas similar to earthquake zones. The obtained results have been satisfactory in all aspects, and improvements are... 

In transition from concept design to detail design, designers and engineers need to find specific materials to optimize performance of the systems. The large number of materials and the wide range of manufacturing processes cause engineers always to seek new materials selection methods. In this research work a new method so called QFD method, which employs materials indices, is introduced. The method enjoys a combination of Ashby's materials selection concepts with the Quality Function Deployment (QFD) tool. The QFD method, which is modified here to fit the materials selection field, provides the designer with the required weighting factors for the material indices. Incorporation of House of... 

In engineering practice, the space occupied by high conductivity materials together with the cost are the two elements of major concern. Therefore, seeking for more efficient designs of high conductivity pathways ('inserts'), embedded into a heat generating body constitutes a formidable challenge. The main idea of this paper is to introduce new patterns for the highly conductive pathways, called 'fork-shaped' configurations. Essentially, two types of fork-shaped pathways, 'F1' and 'F2' are introduced. Numerical results demonstrate that, these two configurations of highly conductive pathways, remarkably surpass the latest configurations reported in the literature, with the same amount of high... 

Traumatic brain injury (TBI) has long been known as one of the most anonymous reasons for death around the world. This phenomenon has been under study for many years and yet it remains a question due to physiological, geometrical and computational complexity. Although the modeling facilities for soft tissue have improved, the precise CT-imaging of human head has revealed novel details of the brain, skull and meninges. In this study a 3D human head including the brain, skull, and meninges is modeled using CT-scan and MRI data of a 30-year old human. This model is named "Sharif University of Technology Head Trauma Model (SUTHTM)". By validating SUTHTM, the model is then used to study the... 

The reduction of long bone fractures is traditionally an invasive procedure with drawbacks of intense force, soft tissue damage, and, both, rotational and longitudinal malalignment. To combat these drawbacks, we applied a novel, wide open, threelegged, 6-DOF parallel robot, to the current surgical procedure. This platform will balance the accuracy, payload, and workspace for the surgeon, resulting in more efficient, successful surgeries. The experimental tests on a phantom reveal that the mechanism is well capable of applying the desired reduction steps against the large muscular payloads with high accuracy. © 2017 ASME  

In this article, a new method for the seismic resistant design is introduced. At first some formulation necessary for the introduction of the proposed method is carried out. This new procedure directly deals with ductility and takes into account the amount of ultimate displacement and required strength interactively. This design procedure is verified by extensive numerical examples using some actual earthquake records. The procedure is shown to be completely safe and to reduce the amount of inherent conservatism. Moreover, it has been tried to introduce some applicable correction factors. Copyright © (2006) by Earthquake Engineering Research Institute  

Reduction of cold start hydrocarbon (HC) emissions requires a proper compromise between low engine-out HC emission and fast light-off of the three way catalytic converter (TWC). In this paper, a hybrid switching system is designed and optimized for reducing HC emissions of a mid-sized passenger car during the cold start phase of FTP-75 (Federal Test Procedure). This hybrid system has the benefit of increasing TWC temperature during the early stages of the driving cycle by switching between different operational modes. The switching times are optimized to reduce the cumulative tailpipe HC of an experimentally validated automotive emission model. The designed hybrid system is tested in... 

Predicting the hydrodynamic coefficients of an autonomous underwater vehicle (AUV) is important during vehicle design. SUT-2 is an AUV. being developed by the Marine Engineering Research Center of Sharif University of Technology in Iran (MERC). Model tests are done in the marine engineering laboratory towing tank. In tins research, hydrodynamic coefficients are calculated using model test results of an autonomous underwater vehicle. Hydrodynamic forces are also analyzed. These coefficients are used for dynamic modeling and autonomous controller design  

Side weirs are frequently used in many water projects. Due to their position with respect to the flow direction, side weirs are categorized as plain, oblique and labyrinth. One of the advantages of an oblique side weir is the increase in the effective length of the weir for overflowing and, therefore, diverting more discharge with the same channel opening, weir height and flow properties (i.e., upstream discharge, upstream Froude number and so on). In this paper, an experimental set-up of a new design of an oblique side weir with asymmetric geometry has been studied. The hydraulic behavior of this kind of oblique side weir, with a constant opening length, different weir heights and... 

Today's information technology capabilities enable the enterprises to increase the manufacturing collaboration and interoperability among their different departments. These departments are engaged in different product development processes from design to manufacturing. INFELT STEP is a three-layered platform. These layers have functions and structures that enable the INFELT STEP platform to manage the product development collaboration among different CAD/CAM application software with an integrated product data structure. INFELT STEP has structures and functions in its interoperability layer that enable different CAD/CAM application software and CNC post processors to use their own data... 

Purpose - This paper aims to address the capability of reliability-centered maintenance (RCM), which is a preventive maintenance design tool. Design/methodology/approach - A model named Plant Function Deployment (PFD) is developed, in which the methodology of quality function deployment (QFD) is added to RCM to improve RCM capability in preserving the functions of the plants. Findings - The objective of preserving the plant functions with least resources, in RCM, is attained more efficiently if the methodology of QFD is added to RCM. Practical implications - PFD is a model for designing a preventive maintenance program which uses RCM and QFD methodologies. PFD organizes all the important... 

Waveform design for target identification and classification in multiple-input multiple-output (MIMO) radar systems has been studied in several recent works. In previous works, optimal signals for an estimation algorithm are found assuming that only signal- independent noise exists. This work extends previous research by studying the case where clutter is also present. We develop a procedure to design the optimal waveform which minimizes estimation error at the output of the minimum mean squared error (MMSE) estimators in two scenarios. In the first one different transmit antennas see uncorrelated aspects of the target, and we consider the correlated target aspects in the second one....