Sharif Digital Repository

In this paper we seek to find the contribution of groundwater in irrigation agriculture in Iran. We use nationwide panel data of agricultural production in the period of 1993-2013. The results show us differences in productivity of agricultural outputs due to availability of groundwater. Panel data allows us to control regional factors like soil fertility affecting the productivity. We are looking for the main contributors to groundwater usage. Population growth in demand side and groundwater availability in supply side seem to be the most important factors  

The formation of gas hydrates in oil and gas industries has been the subject of long-standing problems. For example, the hydrate formation may occur and block gas pipelines which can lead to safety hazards. All of these will result in catastrophic economic losses and ecological risks. Therefore, various methods were developed to mitigate the formation of gas hydrate. In many cases, the hydrate inhibition by adding kinetic and thermodynamic inhibitors to the system is the only viable option. But recently using ionic liquids as novel hydrate inhibitors and the discovery of dual function thermo-kinetic inhibitors have been studied. In this project the performance of six imidazolium-based ionic... 

In recent years, frequent involvements in claims have been inevitable due to unpredictable economic changes and increasing complexities in construction industry. Therefore, even appropriately made contracts are not exempted from claims. On the other hand, construction contract claims are time-consuming, expense-involving and most likely leading to unsatisfactory results. However, there may be some positive outcomes, such as time extension or compensation of damages. To launch investigationson claim management, a list of important and frequent claims in oil and gas industry projects of Iran was extracted after a succinct documents review. Further, the most important claim causes were... 

Think of an Alpine hiker who because of avalanche and a blinding blizzard, is stranded on a desolate, mountain path facing a chasm. The hiker cannot return the way he came because of the avalanche, yet, if he stays where he is, he will freeze as the temperature plummets. The hiker’s only real hope is to jump the chasm. Knowing that exertion generally follows belief, the hiker realizes that his attempt will be half-hearted, diminishing his chance of survival, unless he brings himself to the belief that he can make the jump. In circumstances like these, one is clearly justified both in forming beliefs motivated by pragmatic reasons, and in suppressing beliefs (I cannot make the jump) motivated... 

The thesis at hand provides a comparative study of Kantian and Fichtean ethics. In the course of this study, the ethical theory of these philosophers will be analyzed through three stages of “Foundation of Ethics,” “System of Ethics,” and “Application of Ethics”: Foundation of Ethics seeks out human will as the sole possible ground for ethical theory of both Kant and Fichte; System of Ethics follows the endeavors of the two thinkers in deducing concept of ethics from this sole ground; and lastly, Application of Ethics introduces the ethical thoughts resulting from a Fichtean account of ethics. This thesis is mostly based upon studies of Allen W. Wood of the ethical thoughts of Kant and... 

In this dissertation, we are considering the following question: can the Rigidity Thesis (RT) be reduced to the Wide Scope Thesis (WT). According to the RT, proper names of natural language are rigid designators and most of the definite descriptions of natural language are not rigid designators. Thus, the Descriptive Theory of Proper Names (DTPN), according to which the semantic content of a proper name is a (set of) definite description(s), is false. According to WT, the semantic content of a sentence containing a proper name is given by a (set of) definite description(s) with wide scope (over intensional operators, modal operators included). Such a semantic content can explain the... 

In this thesis a smart anticorrosive pH-responsive coat was developed with layer by layer (LbL) technique in the assembly of SiO2/CTAB/PSS/HMTA/PSS/PEI/PSS. SiO2 nanoparticles were prepared from Matland Company (Iran) with average size of 24 nm. At first, the corrosion inhibition of HMTA for API 5L Grade B steel in 3.5 wt.% NaCl solution was investigated. Tafel polarization technique showed the optimum concentration of HMTA was 0.08 M with 92% corrosion inhibition efficiency as the morphology of coverage and adsorption on the steel surface was confirmed by SEM and EDS. AFM results showed the roughness of the surface decreased from 241 nm to 56 nm that is attributed to HMTA adsorption on the... 

Arising from the intersection of two modern ideas in logic and mathematics, namely Type Theory - specifically Martin-Löf’s intuitionistic type theory, and Homotopy Theory, Homotopy Type Theory has introduced a novel formalism that formalizes every mathematical object - including constructions, definitions, and proofs - in a specific and fundamentally different way from other interpretive frameworks (such as set theory), bringing forth new results - both philosophically and mathematically. The first goal of this research is to understand the meaning of Homotopy Type Theory as a foundation for mathematics through exploring this new formalism. The second goal of this research is to understand... 

In recent years, sparse representation has had a variety of applications in computer vision such as noise reduction, image reconstruction, classification and dimension reduction. In this project, we aim to provide a method of matching the keypoints obtained from the Scale Invariant feature Transform (SIFT) algorithm. In this algorithm is used descriptor instead of intensity . The proposed method, first, extracts the salient points from the images and learns a dictionary-based descriptors corresponding to the points. Then, using the dictionary, it obtains the sparse coefficients for each salient point by which, it determines the correspondence of the salient points in the two images using SVD... 

This study investigates the possibility of knowledge transfer from military industries, with a focus on the missile industry, to other sectors in the country, particularly the automotive industry, from the perspective of technological capabilities. The objective of this research is to conduct a comparative analysis of the technological capabilities of these two industries and to evaluate the potential and challenges associated with the process of knowledge and technology transfer. The research methodology involves qualitative analysis through interviews with experts and the review of relevant documents and records. The conceptual framework has been developed based on existing models of... 

The direct reference theory about proper names considers the references of proper names as their contents. This view is persuasive for many philosophers. However, it encounter with some difficulties. Some of these difficulties are related to nonrefering names, called empty names sometimes. If natural language contains such names, the direct refernce theory shall propose some solutions to solve mistakes raised by them. In this project, in chapter one, I will assess the direct reference theory. In chapter two, I will argue that at least some names from natural language are empty. And finally, in chapter three and four, I will put forward some ways to take out of difficulties raised by empty... 

One of the crucial matters in the area of Supply Chain Management is the ability of a supply chain to act and react under different circumstances. A helpful tool to understand the supply chain is simulation modeling. With the help of simulation modeling, we can provide the opportunity for the agents in a model to perform based on the defined environment.In the current research, a complete literature review is performed on the topics of supply chain planning and various distribution models and algorithms. With the focus on the vaccine as a critical item, we propose a model to distribute vaccines based on the degree of agents, and we realize that vaccine distribution, while facing huge demand... 

In this paper, we introduce a novel decision making strategy on how to assign markets to a multi-item newsvendor’s problem. We present a new formulation method based on the integration of news-vendor problem and dynamic programming approach alongside an efficient solution method. Suppose there are n distinct products and corresponding time intervals for selling them in different markets. These products will be worthless (perishable) at the end of each interval. Our proposed framework represents a trade-off between costs associated with staying in a market for further periods and costs of relocating the business in a new market. The objective is to maximize the total profit of our decisions... 

The search for an empirically proven quantum theory of gravity is one of the greatest open problems of fundamental physics. Obstacles are formal and conceptual in nature. Our goal is to find a theory that somehow unites general relativity (Einstein's classical field gravity theory) and quantum field theory. In this research work, the problem of quantum gravity and the reason for its importance are investigated, as well as the proposed solutions; and what philosophical issues do these approaches and the issue itself create. Research has been carefully selected to remain managed in terms of size and content, however, some basic formalism is introduced to enter physics and the philosophy of... 

Nowadays, with the increasing number of polyethylene terephthalate wastes, the issue of its recycling has become very important. Among the problems of polyethylene terephthalate recycling are its loss of crystallinity and mechanical properties. Recycled polyethylene terephthalate does not have the properties of new polyethylene terephthalate and using its mixture with other materials is an effective way to remove its waste from nature and return it to the production cycle. The aim of this study is to produce a mixture of recycled polyethylene terephthalate with polycarbonate and glass fibers with mechanical properties such as good impact strength, which ultimately leads to the production of... 

In the current digital era, the large number of mobile developers and android applications has led to intense competition. Users can easily access many android applications to meet their needs. This abundance of available software makes it difficult for developers to attract and retain users, as they can easily switch from one application to another. This switch can happen if the current application does not meet the user’s needs, has issues, or if a better alternative is available. Therefore, developers must focus on keeping their users satisfied. To ensure user satisfaction, developers need to address user needs effectively. This includes fixing reported issues, adding new features, and... 

This research attempts to develop the optimal solution for an inventory problem consisting of a single machine which produces items some of which may be defective. We assume that no shortages are allowed and all defective items are to be reworked. Setup cost for rework and waiting time of defectives are considered. This research consists of two different parts. In the first part we consider two different policies where in the first policy in each cycle after the regular production the machine is setup for the rework of defectives of the same cycle. In the second policy several cycles constitute a period. All the defectives produced in the period are reworked in the last cycle of that period.... 

In this dissertation, we investigate the problem of the existence of finite geodetic sequences from point to point (0, n). This has not been proven in the general case. In this dissertation, we present an article that illustrates this question in a particular case of z ^ 2 subspaces whose self and complement are infinite and connected (e.g., slit planes, half-planes, and sectors). Writing x_n for the sequence of boundary vertices, we show that the sequence of geodesics from any point to x_n has an almost sure limit assuming only existence of finite geodesics. For all passage-time configurations, we show existence of a limiting Busemann function. Specializing to the case of the half-plane, we...