Sharif Digital Repository

The Emergency Medical Services (EMS) have a major role in decreasing the mortality rate and reducing the non-reversible effects of injuries by on time care to patients and transporting them to hospitals if it is needed. Since there is an important goal directly related to the human life, any research or study to improve the performance of EMS is highly recommended. One of the most important parameters in evaluation of EMS is to measure the coverage time of a demand. The locations of EMS play substantial role to decrease the response time. So the locations of EMS stations are very important especially in large and populated cities. Mainly, there are three problems that EMS managers should... 

Biodiesel has drawn the attention of many researches to itself as a replacing source for crude oil, recently. Transesterification is one of the most popular methods used for biodiesel production. Enzyme transesterification is a more simple method in comparison with acidic or basic transesterification. However, the high price and low yield of enzyme transesterification has caused many obstacles in its application. Enzyme engineering has gained much attention as a way to improve enzyme performance. In this thesis, biodiesel production by a native enzyme named Bacillus thermocatenulatus, and two engineered-enzymes is studied. First, effective parameters and variables in biodiesel production by... 

Conical nanochannels have desirable electrokinetic properties due to asymmetry,including ionic current rectification and ion selectivity. The present study numerically addressed the effect of slip length on the ionic current rectification and ion selectivity in conical-shaped electrolyte-loaded nanochannels with and without a coated polyelectrolyte layer. The electrolyte was considered a salted incompressible Newtonian fluid. The polyelectrolyte layer was also modeled as a rigid and charged porous solid saturated with a salted Newtonian fluid. The electrolyte-polyelectrolyte layer interface was modeled as a surface, considering ion partitioning with distinct physical properties across the... 

Laser-assisted machining is nowadays considered as an alternative to conventional machining processes including ceramics grinding, which has provided the basis for extensive experimental and numerical studies in this field. Since the main difference between laser-assisted machining and conventional machining is in the presence of lasers, the main purpose of this study was to investigate the effects of laser on the laser assisted machining process. In this regard, in the first step the process of laser heating to the ceramic workpiece has been studied experimentally and numerically by finite element method. The material used in this research is a slip cast fused silica ceramic. The... 

In smart grids, energy data such as electricity and gas consumption are recorded via smart sensors installed in buildings. Analyzing energy consumption patterns and classifying users based on their consumption behavior can assist policymakers in supply management and urban-scale energy control. This study proposes an unsupervised approach to classify energy consumers according to their monthly consumption patterns. The primary objective of the clustering is to group households with similar usage behaviors, facilitating a more effective analysis of electricity consumption at an urban scale. The K-means clustering algorithm is employed to classify households into K clusters based on their... 

This thesis deals with the development of a hypothetical micronized powder factory and trying to test and engage in this hypothetical development of the following plant, it considers following factors:
1-Domestic & International market
2-Plant location
3-Plant design & development
a.machinery
b.technology & equipment
c.human resource
d.environment
e.packing
4-raw material
5-shipping & transport
To evaluate above factors the UNIDO methodology is used in this research work. The UNIDO methods are using a process by which feasibility studies of production facilities or plant are base on. After reviewing a variety of factors, ranging from financial... 

In this research ,lean and agile indexes in S.G.S Co. are evaluated. This company is the first company in engineering and supplying automotive parts as well as the first supply chain management and organization of Saipa Group. In the part of evaluating the lean management level it is the developed model of the suggested approach by Jackson “implementing a lean management system” (Jackson, 1996). As S.G.S is engaged in servicing activities not in production, we have changed some factors in Jackson's methodology. Different with the last model, we got the results and used AHP method for getting the level in each key. Finally by using another AHP the lean index of the S.G.S Co. was identified.... 

Our problem is to evaluation state and form of a tracer passing through the vessel. Using this method, we can identify the effect of during used in some defected parts of body. This evaluation leads to in solving a Laplace equation with mixed boundary condition. Separating that problem, we reach to a collection of algebraic and linear equations. Solving this system, we approximate coefficients of the solution with a series the existence and uniqueness of and analytic solution has been proved using the Eigen functions finally, using numerical algorithms, we have interpreted the analytical solutions.
 

In this thesis , we consider nonnegative (continuous) weak solutions of the porous medium equation with source , u_t-∆u^m=u^p, and p>m>1 .
Assume that, m>1 and 1< p/m u_t-∆u^m=u^p,xϵR^n ,tϵR
has no nontrivial, bounded radial solutions u≥0 .
In one space-dimensional, the conclusion of the result mentioned above remains true without the assumption of the radial symmetry. The proof is based on the intersection-comparison arguments , zero number argum- ents and a key step is to show the... 

ISO 10303 Standard also known as STEP, is an standard in the domain of mechanical manufacturing that describes data relating to drawings, design, machining, process planning, engineering and other aspects of product which all together can describe the entire life cycle of products. However, as this standard is newly born and developing these data models are expensive and time consuming, so far, no data model for description of cutting tools is developed. In this project we study the STEP parts and protocols to understand how data is stored. We study EXPRESS Modeling language, the language developed as part of the STEP standard which is the official language of data modeling in STEP. And use... 

Decision making is one of the most critical issues in engineering field. The Axiomatic Design is recently known as one of the most robust tools for decision making task. Axiomatic design is a engineering theory that provides a systematic framework for decision making using two axioms. These two axioms called Independence and Information axioms are both used to do the task.In this thesis, the information axiom is used to select the best machine (operation) for manufacturing cylindrical parts. To do that, three criteria including surface roughness, dimensional accuracy and cost have been chosen.Finally a comparison to the result of this methodology and the result of Analytical Hierarchy... 

Nowadays, because of high volume and growth of data in industrial organizations and productive factories, registration and storing of data have forgotten manual and tradition styles for which using automation and mechanized machinery and systems has been a necessary task. In order to reach to this revolution, need to some tools, facilities and methods which can fulfill this requirement is felt strongly. Therefore, high volume of data is considered as an advantage because based on precise analysis it is possible to make logical management decisions with less risk. During last years, statistical and numerical methods and simulation were used to discover knowledge and information when one of... 

This thesis is based on articles [18,15]. Zhao [18] has studied a free boundary problem modeling the growth of tumors with drug application. In this model live cells are two kindes: proliferative cells and quiescent cells. This model consists of two nonlinear second-order parabolic equations describing the diffusion of nutrient and drug concentration, and three nonlinear first-order hyperbolic equations describing the evolution of proliferative cells, quiescent cells and dead cells. He has proved that this free boundary problem has a unique global solution. Tao and Chen [15] have studied another free boundary problem modelling the growth of an avascular tumour with drug application. The... 

In competitive environment of quick market changes, developing an interoperable manufacturing system is a necessity. Process planning as a connection link between design and manufacturing, has never been able to integrate these up/down stream activities and in spite of employing computer systems, CAPP’s information has been managed in an isolated manner. To realize interoperability, the exchange of part and product data must be independent of their platforms. There are two basic approaches for this purpose: i) Utilizing interface and ii) Utilizing neutral formats. STEP (Standard for the Exchange of Product data) plays a significant role as a neutral data model to integrate design,... 

Nowdays, many of communication systems working together. The fist part of each communication system is related to separating a desired part of system input signal. This is called channelisation. Channelization is a process where single, few, or all channels from a certain frequency band are separated for further processing. The separation of single channel is usually done by down-conversion followed by filtering and optional sample-rate conversion. A straightforward implementation for multi channel sepration, which is also the traditional implementation of wideband channelizer, is to simply use a single-channel channelizer for each channel. A few applications require that an input signal be...