Sharif Digital Repository

Despite a rather long history of bureaucratic public administration, Iranian public sector has failed to catch up with the ever developing knowledge of fighting corruption in “public procurement”, a critical field of governmental management which accounts for at least 15 percent of GDP around the world. While international organizations like TI and OECD have been broadly active in globalizing the standards of integrity and calling for improvements in the national frameworks of procurement, a reductionist agenda might take the safest path of change by following whatever prescribed by those international bodies. However, there have also been some deeper reflections on the complexities of... 

Cable-driven robots are referred to as parallel robots actuated with cables. In fact,in such robots rigid links are replaced by cables, which may be extended to desired lengths without making mechanism much heavy. This robot possesses a number of unique properties that makes it suitable for many industrial applications. The main factor which makes cable robots analysis different from other parallel robots is the incapability of cables to push objects. Hence, obtaining the workspace of a cable robot is one of the most important subjects associated with this type of robot.The goal of this thesis is to design a spatial translational cable driven robot, which may be used for object handling. For... 

Uncertain fuel prices and also global climate changes are accompanied by some state initiatives such as renewable portfolio standards (RPS). This has caused a fast growth in the amount of renewable energy installed worldwide especially wind energy over last decades. However, the intrinsic characteristics of wind farms output power, i.e. intermittency and volatility of wind speed along with being non-dispatchable in output generation of wind turbine raises many new technical and financial challenges for power system operators and planners. Up to these issues, large level of wind power penetration causes a growing concern in wind energy curtailment issue which the wind farm’s operator may be... 

In recent decades the use of FRP materials for strengthening structures has been developed extensively, thanks to their high strength, sufficient stiffness, high durablity, and ease of use. A great deal of research has been conducted on strengthening reinforced concrete beams and columns with FRP composites. By contrast, not many researches are performed on slabs, especially two-way slabs. In these few researches, the loading and boundary conditions are limited to simplest ones. Therefore, in this thesis, the focus of attention is on strengthening reinforced concrete slabs under various loads and boundary conditions using FRP composites.
In this thesis, first, FRP composites and their... 

In this research, trade and transportation trends of Asia-Europe-Africa, in the both intercontinental and intracontinental levels have been analyzed. With analyses which are done in this research, determinant factors for modeling and investigating international bilateral trade in these three continents have been recognized. The relevant time-series data were extracted from centralized and international databases. The examined database consists of 11 variables grouped in four categories: bilateral trade data, transportation, geographical and socio-economic characteristics. Transportation data is based on three different networks. The first network consisted of highway, rail and marine modes... 

Access to global memory is one of the bottlenecks in performance and energy in GPUs. Graphical processors uses multi-thread in streaming multiprocessors to reduce memory access latency. However, due to the high number of concurrent memory requests, the memory bandwidth of low level memorties and the interconnection network are quickly saturated. Recent research suggests that adjacent thread blocks share a significant amount of data blocks. If the adjacent thread blocks are assigned to specific streaming multiprocessor, shared data block can be rused by these thread blocks. However the thread block scheduler assigns adjacent thread blocks to different streaming multiprocessors that increase... 

One of the key subjects in the area of mathematical optimization is a class of problems known as combinatorial optimization. We can find the optimal solution of continuous optimization problems feasible in time. But, in combinatorial optimization, we aim to obtain the optimal solution of the problem over a finite set. These problems are NP-hard and no polynomial-time solution has been proposed for this class of problems so far. Thus, in practical scenarios, we often use heuristic methods for solving NP-hard problems. There are lots of heuristic methods and choosing the best one in different situations might be challenging. In recent years, with the advances in deep neural networks,... 

Nanolaunchers are launch vehicles capable of carring light payloads (under 50 kg) to Low Earth orbit and received much attention in the few past years. Launching the nanosatellites grown about 30 times from 2008 to 2017. Since this category of launch vehicles has fewer developing costs and lower thechnology level, they fit developing space technology in our country. Conversely, the demand of high propellant mass fraction and specific impulse may be a serious difficulty to attain this technology.The only operating nanolauncher in the world is SS-520-5 which belongs to Japan and is a three-stage solid propellant launcher. The goal of this project is also the conceptual design and feasiblity... 

The present work was aimed to account a green and eco-friendly synthesis of copper oxide nanoparticles using Salvia hispanica extracts for the first time.The synthesized copper oxide nanoparticles were fully characterized using FT-IR, XRD, FESEM, EDX, TEM and UV-Vis spectroscopy techniques. The average particle size of copper oxide nanoparticles is around 35 nm and shape of nanoparticles are spherical. Biological activity of the synthesized nanoparticles were evaluated in terms of antibacterial assessments against Staphylococcus aureus and Escherichia coli. In the following, the potential antibacterial activity against gram positive (S.aureus) and gram negative (E.coli) bacteria’s were... 

Design of complex systems requires different challenges to be met simultaneously. Yet the current methods lack a sound theoretic framework and thus designers normally rely on heuristic or empirical methods; based on available experiences. Such approaches to the system design entail both technical and business risks and subsequently increase the probability of long-term problems. In this research, along with the theoretical framework of the systems design concepts, we discuss number of important models. The main concentration of the work, however, is to; somehow, correlate Axiomatic Design Matrix (ADM) with Design Structure Matrix (DSM). Here we exploit mathematical model based on sets and by...