Sharif Digital Repository

A qualitative study has been conducted in order to identify evidence of bounded rationality in software engineers' career decision making. Tversky and Kahneman's heuristics and biases approach has been used as a theoretical framework of the study. The theoretical framework comprised four decision-making and judgment heuristics, i.e. availability, representativeness, anchoring and adjustment, and affect heuristic. The data were gathered through semi-structured interviews and analyzed using thematic analysis method. The final results revealed that software engineers did make use of heuristics in making career decisions. Several incidents of the use of availability, representativeness, and... 

According to the development of communication, cryptography has become a vital issue. Several algorithms have been introduced for cryptography applications. Stream ciphers are such algorithms with high speed and appropriate efficiency. Lots of attacks have been applied to stream ciphers. We concentrate on two kinds of attacks in this thesis. Distinguishing attack is a general attack in which the attacker tries to distinguish the observed output sequence from random. Designers apply this kind of attack to test the statistical probabilities of the output sequence. We applied this attack on Grain family and Trivium family. In the proposed attack, nonlinear parts are replaced with linear ones.... 

Image Registration is spatially alignment of two images in a wide range of applications such as remote sensing, computer assisted surgery, and medical image analysis and processing. In general, registration algorithms can be categorized as either intensity based or feature based. The feature based methods use the alignment between the extracted features in two images. The simplest feature is images intensity which is directly used in the intensity based method via similarity measure. This similarity measure quantifies the matching of two images.Similarity measure is main core of image registration algorithms. Spatially varying intensity dis-tortion is an important challenge in a wide range... 

Modern sensors consist of arrays of detectors specially arranged to enhance precision, capabilities, and field of view (FOV). Sensor arrays can have multiple functionalities such as the simultaneous detection of position and motion. We use a linear sensor model and develop an optimization method to design an array of photodiodes. Our objective function minimizes bias and variance estimations. We introduce a maximum likelihood technique to approximate and determine the bias caused by measurement errors, and verify our theory by statistically complete simulations. We apply our theory to design an optimal sun sensor. The sensor has a predefined conical FOV, and its accuracy is controlled by a... 

Today with respect to the particle physics experiments and astrophysical observations we know that Neutrinos are massive. Free streaming of light Neutrinos supresses the density field of matter and opposes gravitational growth, so that clusters formed at fixed mass are fewer and hence more biased than for a pure CDM density field. One way to study the effects of Neutrinos on the formation of large-scale structures is to examine the matter power-spectrum and corellation function in the presence of massive Neutrinos.In the presence of massive Neutrinos, the matter power-spectrum is suppressed in small scales and also correlation function and clustering bias are changed in comparison to the CDM... 

A bolometer is a device for measuring electromagnetic waves, which uses the heating of a material with variable resistance to temperature. Due to the existing limitations and quality improvement, superconducting materials are used in the manufacture of these devices. In this dissertation, the construction and improvement of the components of a high temperature transient edge superconducting radiometer with terahertz detection capability is discussed. In the construction of these detectors, the superconducting material YBa2Cu3O7-x is used as a thermal sensor with a transition temperature of 93.5K. In order to characterize these detectors, an automatic system for measuring the voltage response... 

Visual Question Answering (VQA) deep-learning systems tend to capture superficial statistical correlations in the training data because of strong language priors and fail to generalize to test data with a significantly different question-answer(QA) distribution. To address this issue, we introduce a Visually Directed Question Encoder to replace the commonly used RNNs in base models. our method uses visual features alongside word embeddings of question words to encode each word. As a result, the model is forced to look at the visual information relevant to each word and it no longer produces answers based on just the question itself. We evaluate our approach on the VQA generalization task...