Sharif Digital Repository

According to the rise of turnover and pace of trading, accelerating of analysis and making decision is unavoidable. Humans are unable to analyze big data quickly without behavioral biases so, using machines to analyze big data seems critical. Hence, financial markets tend to apply algorithmic trading in which some techniques like data mining and machine learning are notable. OLPS which sequentially allocates capital among a set of assets aiming to maximize the final return of investment in the long run, is the core problem in algorithmic trading. This article presents an online portfolio selection algorithm. The online portfolio selection sequentially selects a portfolio over a set of assets... 

The purpose of this study is to model the long-term effects of taxes on different aspects of private cars upon auto ownership and use, and thereby auto industries in producing more fit cars, so as to minimize auto emission. It involves used car market, different car demands and auto industry production. The study follows some previous studies in this area and tries to enhance the various aspects of the model by directing it toward a more real situation. In order to visualize the effects of the model, it has been applied on the case of Shiraz in 1378. It has been shown that the model was able to reduce air pollution and fuel consumption by 90% and 50%, respectively, as compared to the “Do... 

Electrospray is an interesting method to produce spray. This study has an insight on electrospraying phenomenon and its effective parameters. All modes, the forces and the situation to establish has been investigated for ethanol. Suitable configuration is introduced and for different flow rates and voltages the phenomenon is studied. Images are captured by two camera (high speed camera and high resolution camera) by using two method (shadowgraphy and light scattering). In the respect of producing fine and monodisperse droplets in cone-jet mode the stability of this mode is imported to enlarge. The special nozzle is design to increase stability of cone-jet mode even 70 times of using... 

The Darcy’ law is valid for low velocity or low Reynolds number where merely viscous force is responsible for pressure loss in the porous media. At higher velocity, because of inertial forces and turbulency, the pressure loss would be higher than Darcy’ law estimates; therefore at these flow regimes the Darcy’ law is no longer valid. Hence, consideration of Non-Darcy flow effect is necessary to sufficiently model high gas velocity effects. The velocity is high in gas reservoirs especially those ones that are considered for underground gas storage. In this study, the effects of Non-Darcy flow on several parameters such as; estimation of differential pressure, flowing bottom hole pressure,... 

Author identification using statistical methods is a branch of authorship attribution which is one of important problems in natural language processing. Using different statistical methods, an anonymous text is attributed to an author. One of the primary parts of the task is to choose the appropriate stylistic features of the text in order to study the significances of style. These features must be quantitatively studied and could be extracted in lexical level, character level, and syntactic or semantic levels. The next step is text classification in which different machine learning methods such as decision tree, Artificial Neural Networks, Naïve Bayes and other methods could be used.... 

Big-data server workloads have vast datasets, and hence, frequently access off-chip memory for data. Consequently, server workloads lose significant performance potential due to off-chip latency and bandwidth walls. Recent research advocates using 3D stacked DRAM to break the walls. As 3D stacked DRAM cannot accommodate the whole datasets of server workloads, most proposals use 3D DRAM as a large cache. Unfortunately, a large DRAM cache imposes latency overhead due to (1) the need for tag lookup and (2) inefficient utilization of on-chip and off-chip bandwidth, and as a result, lowers the benefits of 3D stacked DRAM. Moreover, storing the tags of a multi-gigabyte DRAM cache requires changes... 

Incidence of brain metastases (BM) from any tumor varies according to the method of data collection and date reported, ranging from 8 to 14 per 100,000 people per year. According to current population, about 6400 to 11000 BM Patients per year is expected. Without treatment, prognosis is dismal with survival of only 1–2 months. However, survival can be extended to 3–6 months with whole-brain radiotherapy (WBRT) and to 11 months with either surgery followed by adjuvant WBRT or surgery plus adjuvant stereotactic radiosurgery (SRS). Intravascular brachytherapy (generally iodine-125 (125I)) into the surgical cavity is another treatment strategy. 125I has been shown to confer local control... 

L1 instruction cache misses creates a crucial performance bottleneck for server applications. Server applications extensively use operating system services, and as such, have large instruction footprint that dwarfs instruction cache size. Meanwhile, fast access requirements preclude enlarging instruction cache that can hold the whole instruction footprint of current server workloads. Prior works proposed using hardware prefetching schemes to eliminate or reduce the effect of instruction cache misses. They use the fact that server application instruction sequences are repetitive. So by recording and prefetching based on such sequesnces, L1 insruction misses could be reduced. While they... 

Server workloads operate on large volumes of data. As a result, processors executing these workloads encounter frequent L1-D misses. An L1-D miss causes a request packet to be sent to an LLC slice and a response packet to be sent back to the L1-D, which results in high overhead. While prior work targeted response packets, this work focuses on accelerating the request packets through a simple-yet-effective predictor. Upon the occurrence of an L1-D miss, the predictor identifies the LLC slice that will serve the next L1-D miss and a circuit will be set up for the upcoming miss request to accelerate its transmission. When the upcoming miss occurs, the resulting request can use the already... 

Air pollution is a prevalent and pressing issue in Tehran, with significant impacts on both the environment and human health. this study uses statistical techniques, such as Pearson correlation, to determine the direction of influence of meteorological parameters on air pollutant concentrations, and Convergent Cross Mapping to quantify the causal relationship between meteorological parameters and ambient air pollutant concentrations, as well as feedback effects. Additionally, the research delves into the correlation between consumption of fossil fuels and air pollutants, as well as the relationship between lung cancer incidence and mortality by histological subtype and long-term exposure to... 

Air pollution in major cities has been a concern for over half a century, but its impact on public health has grown significantly in recent years, causing severe physical, mental, and financial harm. This project aims to propose effective policies to mitigate air pollution by focusing on the transportation sector. Transportation demand is analyzed through four scenarios, each addressing changes in public transportation usage, the promotion of cycling and walking culture, the penetration of digital solutions, and flexible working hours. The project, using the Huvaal model, forecasts transportation demand in 2050 under various population and climate conditions, based on artificial population...