Sharif Digital Repository

This paper presents some approaches based on data mining techniques to solve the prediction task of Computational Intelligence and Learning (CoIL) Challenge 2000. The prediction task of the contest is a direct mailing problem and the goal is to improve its response rate. The main issue in this competition is the incompatibility of the dataset in which the distribution of the classes of the target attribute is highly unbalanced. This in turn causes high error rate in identifying the minority class samples. Three different level methods including data-level, algorithm-level, and hybrid method are used to overcome this issue. The specificity and sensitivity criteria are employed to compare the... 

One of the most important criteria in travel analysis is the vehicle kilometer traveled (VKT). The distance which personal cars, vans or other automobiles travel is measured through this criterion. In addition, the VKT is used in transportation planning, accident analysis, transportation budgets assignment, and estimation of automobile pollutions. In this work we process origin-destination data gathered in Shiraz, Iran to estimate the VKT. To this end, we incorporate the linear regression and geographically weighted regression (GWR) methods. Through this research, data from origin-destination statistics of Shiraz, gathered by the transportation institute of Sharif University of Technology in... 

In recent years, numerous companies in various industries apply supply-chain management to improve their market competitiveness. Advances in information technology bring new approaches for managing supply chain activities. Consequently, emphasis on supply-chain coordination has increased in recent years. Vendor managed inventory (VMI) is an important coordination initiative. In VMI, the vendor assumes responsibility for managing inventories at retailers using advanced online messaging and data-retrieval systems. In this dissertation we investigate the effect of VMI on supply chain performance under make-to-order and make-to-stock environment. By using renewal reward theorem, we derive the... 

In this thesis, we study monadic second order logic and the languages of graphs. We introduce the notion of ∆- regular graph automaton. Then we designed this finite automaton for processing on labeled graphs. Definability of graph languages which are recognizable by this automaton is shown. To do this, we first briefly introduced monadic second order logic, and then we studied definability of regular string and tree languages in monadic second order logic. In the last section of thesis, ∆- regular graph automaton is introduced  

Performance based design was first introduced in order to evaluate seismic vulnerability of structures in retrofitting topic and was rapidly implemented in new design codes. The main cause conducting widely developing of performance based design methods, has been accurate estimation of seismic demand parameters. Since seismic structural members displacement during earthquake has a direct effect on the amount of sustained damages, displacement index has always been a key concept in performance based design. The main goal followed by this research is comparing the results obtained from the standard pushover method (with two theorems of distributed plasticity and plastic hinges) and the... 

Polymeric film for packaging applications are commonly made from a variety of polyethylenes using a blown film process. Nowadays high density polyethylene with bimodal molecular weight distributions are used to improve the performance and the final properties. In the present study samples with different bimodal molecular weight distribution in a similar film preparation are developed. The EX5 sample from the Jam Petrochemical showed microstructure with heavily oriented stack of lamellae in the machine direction. In contrast, the 7000F sample from the Mehr Petrochemical presented a microstructure with a lower degree of lamellae, containing lamella twist and more link between the crystalline... 

Aqueous environment with vegetation in coastal areas plays important role in ecologic systems. The plants in aqueous environment caused to vertical and lateral changes of flow velocity profile. When sunlight penetrates the water, it will turns into heat energy. The plants caused to blocking the light path, to make a difference in temperature and thus the density differences on the horizon. This density gradient will lead to the gravity flow. Due to the observations, in coastal wetlands, beside the plants the emerged from the water, there are some completely submerged plants that their root in the soil and shallow layer of fluid covered on them. This study to approaching the conditions, is... 

There are different kinds of ownership structures. In every economy special kinds of these structures are common. These structures include Pyramidal ownership, cross-ownership, etc. These structures empower shareholders to make a gap between their cash flow right and ownership right in a special firm so they could control more firms with the same capital. These structures have their pros and cons, like the internal capital market and tunneling. Of important factors affecting these structures are Legal protection of minor shareholders, shareholder concentration, and largest shareholder. In this research, we find that, unlike most countries, there is a negative relationship between a firm's... 

The soil-water retention curves (SWRC) is an unsaturated soil mechanics hydro chemical state surface, which expresses the relationship between the soil suction and water content. The soil-water retention curve could describe the water adsorption and desorption process that happened in soils. The difference between the desorption or drying retention curve and the adsorption or wetting retention curves in a specific soil specimen indicates the hydraulic hysteresis phenomenon. Generally, the amount of water remaining in the drying process is greater than the amount of water adsorbed in the wetting process at a certain amount of suction. Suction due to the combined effects of capillary and... 

The classical economic batch quantity (EBQ) model assumes that all produced items have a perfect quality. But in real-life production systems, generation of defective items is inevitable. A portion of these defective items is considered to be scrap , while the other is assumed to be reworkable and reworking them can reduce costs and increase productivity. In this thesis we have studied the economic batch quantity for a single stage production system with rework and scrapping . We want to satisfy the customer demand and minimize total costs of the system like set up costs , production costs , rework costs , holding costs , shortage costs and scrapping costs . In the first chapter of this... 

Based on the latest statistical figures, more than 50 billion Rials worth of medical equipment exists in Iran’s medical centers. In spite of this, Breakdown maintenance is used in all hospitals, which means that the equipment is utilized as long as it is not out of order and only in such a situation, i.e. a breakdown, the necessary repair operation is conducted on the equipment. In fact, no maintenance is carried out to prevent a breakdown, while the “prevention from breakdown” concept has long been introduced in the majority of industries in many countries including Iran and its positive impacts are undisputable. This thesis aims at proposing a solution for the implementation of a “planned... 

Access control, which is the process of mediating every request to resources and data maintained by a system and determining whether the request should be granted or denied, plays an important role in the system security. The existing of non-monotonicity property in a deduction and decision making process means that some of the previous deductions or decisions may be retracted by adding new information and premises. Based on the definition, in a non-monotonic access control system, adding new information or access control rules may invalidate some of the previous conclusions (permissions/prohibitions). The requirements such as decision making based on the imperfect information, supporting... 

Hub and Spoke networks come into play when considering direct link between all origins and destinations is either impossible or expensive in a transportation system. In this kind of problems, some nodes are chosen as hub from all origin and destination nodes to collect flows and then distribute them. Implementing hub network leads to minimizing transportation cost, sorting flows and conveying them in economies of scale. Otherwise, shipping flows directly may cause decreasing the travelling distance and the delivery time consequently. In this dissertation, combination of hub network and direct shipment is investigated. To obtain the optimal hub locations and direct links between non-hub nodes... 

In real life, we can not always expect agents and authorities to have the same desires. Also when it comes to conflicts, agents always tend to break the authorities’ norms to follow their own strategies. Hence we can not expect strict norms to model an actual real life situation.In this article we introduce punishment normative systems, based on multi-agent Marokov chain processes (MMDPs). We try to extend the punishment idea to be also applicable on long-run and infinite strategies. We consider a version of the multi-agent model that is widely used in different situations and then provide an algorithm to find a fair normative system that distributes obligations equally on the agents, while... 

This research deals with a supply chain consisting of one vendor and several retailers. Every retailer orders a fixed discrete quantity in fixed discrete time intervals. Order quantity and order cycle of each retailer could be different from the others. The vendor orders the required quantity to a supplier to fulfill the received demands. Also the vendor orders a discrete quantity, which will be immediately received at the vendor’s warehouse. In this supply chain system, the lead-time is assumed to be zero and shortage is allowed for vendor. The aim is to find minimum vendor’s inventory cost. We proposed a backward Dynamic Programming algorithm for the model. The algorithm creates vendor’s...