Sharif Digital Repository

In many real-world applications, data contain multiple input channels (e.g., web pages include text, images and etc). In these cases, supervisory information may also be available in the form of distance constraints such as similar and dissimilar pairs from user feedbacks. Distance metric learning in these environments can be used for different goals such as retrieval and recommendation. In this research, we used from dual-wing harmoniums to combining text and image modals to a unified latent space when similar-dissimilar pairs are available. Euclidean distance of data represented in this latent space used as a distance metric. In this thesis, we extend the dual-wing harmoniums for... 

Recent advances in data recording has lead to different modalities like text, image, audio and video. Images are annotated and audio accompanies video. Because of distinct modality statistical properties, shallow methods have been unsuccessful in finding a shared representation which maintains the most information about different modalities. Recently, deep networks have been used for extracting high-level representations for multimodal data. In previous methods, for each modality, one modality-specific network was learned. Thus, high-level representations for different modalities were extracted. Since these high-level representations have less difference than raw modalities, a shared... 

Traffic congestion is one of the most important issues facing modern societies that causes many impacts such as environmental pollutions and waste of physical and spiritual energies. One of the traffic congestion mitigation strategies is network management, which encompasses a diverse range of tools. Efficient management of urban transportation network requires the transportation network information. Traffic equilibrium in the transportation network is one of the fundamental information that is required for most of network management tools. In this study, a multi-modal traffic assignment model with complementarity structure is proposed that can determine the multi-modal traffic equilibrium... 

Due to the recent advances in the learning of multimodal data, humans tend to use computer systems in order to solve more complex problems. One of them is Visual Question Answering (VQA), where the goal is finding the answer of a question asked about the visual contents of a given image. This is an interdisciplinary problem between the areas of Computer Vision, Natural Language Processing and Reasoning. Because of recent achievements of Deep Neural Networks in these areas, recent works used them to address the VQA task. In this thesis, three different methods have been proposed which adding each of them to existing solutions to the VQA problem can improve their results. First method tries to... 

Governments are concurrently faced with two problems in Network Development Problem (NDP): limited resources to invest, and the economic justification of the candidate projects. Public- Private Participation (PPP) is a solution for the first problem, in which Build- Operate- Transfer (BOT) is a scheme to implement this partnership.This study formulates a NDP, in which two sources of funds back projects’ construction: that of the private investor and the public budget for this purpose. The problem is seen as bi-level optimization, with the upper level dealing with the government decisions on the level of participation (from 0 to 100 percent of the project costs), and the lower level being a... 

Blind Source Separation (BSS) is a challenging task in signal processing which aims to separate sources from their mixtures when no information is available about the sources or the mixing system. Different approaches have already been proposed for source separation.However, during the last decade, new approaches based on multimodal nature of phenomena have been proposed for source separation. Different aspects of a multimodal phenomenon can be measured by means of different instruments where each of the measured signals is called a modality of that phenomenon. Although the modalities are different signals with different features, due to the same physical origin, they usually have some...