Sharif Digital Repository

In this thesis the sequent calculi for intuitionistic logic have been studied and compared with these calculi in classical logic, moreover soundness and completeness theorems for these calculi have been proved. Also an algorithmic method is presented to construct the proof-search with this feature that proof-search terminates and the subformula property preserved. In particular the analysis and comparison of two calculi IG and SIC provided by Tassi and Corsi have been done. Finally, we consider the calculus SJC, stack-based Jankov calculus which is similar to SIC and describes proof-search procedure for weak excluded middle logic. If the proof-search is successful in each calculus SIC or... 

One of the most elusive problems in quantum mechanics is the transition between classical and quantum physics. This problem can be traced back to the Schrodinger's cat. A key element that lies at the center of this problem is the lack of a clear understanding and characterization of macroscopic quantum states. Our understanding of Macroscopic Quantumness relies on states such as the Greenberger-Horne-Zeilinger(GHZ) or the NOON state. Here we take a first principle approach to this problem. We start from coherence as the key quantity that captures the notion of quantumness and demand the quantumness to be collective and macroscopic. To this end, we introduce macroscopic coherence which is the... 

The fuel consumption of displacement ships is one of the vital and sensitive issues in the marine transportation industry, which affects all economic and environmental aspects. There are few important parameters for displacement ships that can be changed and optimized to reduce fuel consumption and the resulting pollutants. In this study, extreme trim has been selected as one of these important parameters and it has been studied numerically using Star CCM+ software. It should be noted that the extreme trim approach is used when returning from a trip (when there is no load). The results obtained in the extreme trim mode showed a decrease of 26.76% in the resistance of the KVLCC2 tanker-ship... 

This work presents a modification of deep neural networks for time series analysis. We used kernel layer(s), as a novel approach, at the beginning of the common deep neural networks. These kernels learn based on dynamic time warping (DTW). In each kernel, DTW is calculated between the kernel value and a part of input time series or a part of last layer output (if the kernel is not in the first layer). DTW also gives an alignment path for the input series. This alignment path is used to defining a loss function with the goal of getting better alignment (lower DTW distance) between the kernel and the other input. Besides getting better accuracy on the examined datasets, the other achievement... 

Entanglement is one of the key resources of quantum information science which makes identification of entangled states essential to a wide range of quantum technologies and phenomena.This problem is however both computationally and experimentally challenging.Here we use autoencoder neural networks to find semi-optimal measurements for detection of entangled states. We show that it is possible to find high-performance entanglement detectors with as few as three measurements. Also, with the complete information of the state, we develop a neural network that can identify all two-qubits entangled states almost perfectly.This result paves the way for automatic development of efficient... 

Increase in electricity demands and expansion cost of the power system as well as raising more concerns on environmental issues have led to increasing attraction towards Distributed Generation (DG) application in power systems. DG is generally defined as small generation units, ranging from several KW to several MW, that are installed on the distribution network. In Iran, the energy generated by DG units is purchased by Tavanir or distribution companies through guaranteed fixed-price purchase contract. The contract price imposes substantial effects on the cost and benefit of DG owners as well as those of the distribution company (DisCo). A logical and fair pricing model can provide more... 

In this study, different metal oxides were impregnated on the surface of ZSM-5 employed as photocatalysis for degradation of methylene blue dye used in the presence of ultraviolet light. The final products were characterized by powder X-ray diffraction (XRD) and fourier transform infrared (FT-IR) method. According to the proposed mechanism for the photocatalytic degradation of methylene blue based on these results, it was found that the reaction followed from the first-order mechanism. The results indicated that rate constant for pure ZSM-5 was 9.3〖 ₓ10〗^(-3) (min-1). Furthermore the impregnated ZSM-5 having 12% zinc oxide demonstrated the highest photocatalytic activity with rate constant... 

Quantum Information Processing (QIP) is one of the active areas of research in both theoretical and experimental physics. Any experimental technique that is used for a scalable implementation of QIP must satisfy DiVincenzo’s criteria [17]. Nuclear Magnetic Resonance (NMR) satisfies many of these conditions, but it is not scalable and cannot initialize the qubits to pure state [28]. NMR can be a great platform for studying the fundamentals of QIP. In this project, for a two­qubit system, we prepare pseudo pure states from the initial mixed states by using unitary operations and implement CNOT gates. According to the results of our experiments, we can apply all the gates with high fidelity.... 

Ensuring the security and trustworthiness of industrial equipment is a major concern for manufacturers and users across various industries. Industrial control systems include all equipment, networks, and input-output devices that control and automate the process of collecting data, processing it, and generating commands for actuators. As these systems are widely used and play a crucial role in optimizing the use of industrial tools, this research focuses on them. Our research focuses on presenting a comprehensive and precise method that can test industrial control devices communicating with other devices via the IEC 104 protocol. We use a firmware fuzzing approach to assess system weaknesses... 

The Cu-Cr10% ingots were prepared in induction furnace and these ingots were used to prepare CuCr25% in VAR. The percentages of elements were checked by chemical analysis. The ingots were divided to slices with 20gr mass and these slices were put in quartz tubes. The quartz tubes were assembled in melt spinning machine and the ribbons were quenched onto a rotating copper wheel. Three different wheel speeds, 8, 16, 36 m/s were chosen. The microstructure of the ribbons was examined using a scanning electron microscopy (SEM). The relationship between wheel speed and thickness of the ribbons were compared with mathematical modeling. The disk of ribbons with thickness of 0.5mm and radius of 5mm... 

The importance of using a fast and automatic method to classify variable stars for large amounts of data is undeniable. There have been many attempts for classifying variable stars by traditional algorithms, which require long pre-processing time. In recent years, neural networks as classifiers have come to notice. This thesis proposes the Hierarchical Classification technique, which contains several models with the same network structure. Our pre-processing method produces input data by using light curves and the period. We use OGLE-IV variable stars database to train and test the performance of Convolutional Neural Networks based on the Hierarchical Classification technique. We see that...