Sharif Digital Repository

Memories today expose an all-or-nothing correctness model thatincurs significant costs in performance, energy, area, and designcomplexity. But not all applications need high-precision storagefor all of their data structures all of the time. This these proposesmechan-isms that enable applications to store data approximately in a phase change memory main memoryand shows that doing so can improve the performance and reduce the power consumption by proposing two mechanisms. The First allows errors in multi-level cells by reducing the number ofprogramming pulses used to write them. The second mechanism reduces the number of error-prone patterns in the content of data block through a lightweith... 

In this dissertation, after analyzing the disadvantages of the offer cost minimization mechanism, it will be shown that it is necessary to find new auction mechanisms to be applied along with the fair, practical, and justifiable marginal pricing mechanism. Alternatively, the payment cost minimization mechanism has been proposed in the recent years. Different aspects of this mechanism have not been analyzed yet. There are many practical and economical considerations that yet need to be modeled in this mechanism and the problem formulation needs some improvements. As the first step, this mechanism will be compared with the traditionally offer cost minimization in a very simple market model.... 

The present study proposes a pricing model for manufacturing and customer support companies which is carried out in the form of multi-level programming. In this model, the manufacturer is considered as the leader and supporting companies as followers. In fact, manufacturer sets up the price level for its customer support first and then according to this price level, customer support companies choose their products and specify the level of after-sales services and the prices. The purpose of this study is to provide insight into the analysis of the after-sales services in a supply chain. The results can be notable for managers in order to demonstrate the impact of different strategies of... 

In recent years, having an efficient supply chain has become an important element in the success of organizations. Attention to different aspects of the supply chain can have a significant impact on gaining a competitive advantage in the market. With the development of global markets, designing resilient supply chains has become a critical issue among businesses. The importance of this topic has prompted researchers and decision-makers to develop quantitative and qualitative models to reduce the damages caused by disruptions to supply chain systems. Various factors, including human and natural elements, can jeopardize the efficiency of supply chain systems. Therefore, supply chain systems... 

In this thesis, a simplified method was introduced to model the wave scattering by the metallic objects in a microcell, in order to determine the coverage pattern. First, the equivalent images method was introduced, which models the building walls effect. This method is fast, memory saving and accurate enough to estimate the scattered fields. Two-ray incidence model accuracy was investigated and confirmed in modeling the scattering from the metallic objects. This method also enhances saving in time and memory. The accuracy of single scattering assumption was investigated and confirmed in a scenario of multiple metallic scatterers. Based on this assumption, we can superimpose the scattered... 

Using an efficient method to manage inventory systems is always a challenging issue in supply chain optimization. In supply chains including perishable goods, it is possible to reduce waste and other costs by identifying uncertain demand patterns and managing inventory levels at different stages of the supply chain. Considering the uncertainty and complex conditions of supply chains in the real world, in order to create a suitable model to express these conditions, various uncertain factors must be considered, each of which affects the supply chain inventory level in some way. In this research, a multi-level perishable supply chain model with uncertain demand, lead time and deterioration... 

With increasing number of cores and developing sophisticated applications in today’s computer systems, larger main memory capacity is increasingly demanded. Unfortunately, DRAM cannot satisfy the increasing demand for larger main memory capacity due to its power and scalability limits that makes further scaling of DRAM infeasible. Phase Change Memory (PCM) is one of the most promising candidates to be used at main memory level of the memory hierarchy because it is more scalable, denser, and consumes less standby power compared to DRAM. PCM is a new resistive memory which is capable of storing data based on resistance values. The wide resistance range of PCM allows for storing multiple bits... 

This research deals with the joint problem of reopening the roads closed after a disastrous natural event and the damaged area relief programming. While these two problems are connected to each other by the joint resources of ruins and debris removal, they are usually treated separately in the literature, and their solutions are sought in practice by the art of experienced authorities. This study formulates a dynamic tri-level integer programming problem to represent the two problems of Road Reopening and Relief, in which the crisis manager has the objective of minimizing the death tolls over a planning time interval. It identifies the roads for reopening at the first level; and the second... 

Nowadays, ultra-wideband (UWB) communication systems are in focus because of their attractive features such as high capacity, low power consumption and robustness against fading. On the other hand, spectrally-encoded spread-time (SE/ST) systems with superior ability on interference suppression provide proper multiuser efficiency over UWB channels. Coherent SE/ST code division multiple access (CDMA) systems are widely addressed in the literature requiring accurate channel estimation and high implementation complexity. In this paper we propose multi-level SE/ST CDMA system with non-coherent detection by considering two different scenarios: i) Known :only channel gain components of desired user... 

Today convolutional neural networks (CNN) are very popular due to their high accuracy and robustness. As the size and complexity of CNNs grow, the demand for larger on-chip memories also increases. Given that off-chip access memory has a high cost, one solution is to enlarge on-chip caches by employing emerging multi-level Cell (MLC) STT-RAMs. This memory provides higher capacity at the cost of lower reliability. The root cause of low reliability of MLC STT-RAM is failure of read and write operations. However, MLC STT-RAM and CNNs are perfect matches in the sense that in one hand MLC STT-RAM provides higher capacity, on the other hand CNN can tolerates moderate level of inaccuracy and low... 

Ever increasing number of on-chip processors coupled with the trend towards rising memory footprints of the programs increases the demand for larger cache and main memory to hide the long latency of disk system. During the last three decades, SRAM- and DRAM-based memory successfully kept pace with this capacity demand by exponential reduction in cost per bit. Feedbacks from industry also confirms that entering sub-20nm technology era with dominant role of leakage power, however, SRAM and DRAM memories are confronting serious scalability and power limitations. To this end, researchers always pursuit some circuit-level and architectural proposals for incorporating non-volatile technologies in... 

Distribution is a necessary part of a supply chain. Location-routing problem is a problem that decide about location of facility , allocation and routing for vehicle. This research focus on modeling for multi-level and multi-product for perishable foods that include five suppliers, three plants, two depots and ten costumers. costumers and products classify according to their importance for the company and their quality into three batch. In order to decreasing of cost return orders and damaged products, a special system are Designed that products can be sent again. In real world we do not have any certain data for model’ parameters, then we consider uncertainty and use robust for showing...