Learning Word Representations with Hierarchical Sparse Coding

We propose a new method for learning word representations using hierarchical regularization in sparse coding inspired by the linguistic study of word meanings. We show an efficient learning algorithm based on stochastic proximal methods that is significantly faster than previous approaches, making it possible to perform hierarchical sparse coding on a corpus of billions of word tokens. Experiments on various benchmark tasks---word similarity ranking, analogies, sentence completion, and sentiment analysis---demonstrate that the method outperforms or is competitive with state-of-the-art methods. Our word representations are available at \url{http://www.ark.cs.cmu.edu/dyogatam/wordvecs/}

Study of Some Interesting Topics in the Theory of Graphs

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Investigating the link between transaction and computational costs in a blockchain environment

The research and thinking pertaining to blockchain have thus far focused on cryptocurrency and Bitcoin. However, there is increased interest in using the technology to solve operational challenges in manufacturing and service supply chains. In this study, we introduce a new implication of using blockchain technology and propose two unique contributions. First, we introduce the notion of computational costs (measured in units of gas) as an essential mechanism for completing operational transactions in the blockchain environment. Second, we discuss the use of smart contracts and their influence on operational transactions. To investigate the link between blockchain transaction and computational costs, this study uses an experimental methodology. We develop and implement a fully functional virtual public blockchain to store, validate, and maintain transactions. The methodology provides a process to measure the computational costs, frequency, and intensity of transactions. This research contributes to conceptual research on the blockchain implementation paradigm. Its novelty stems from the identification of computational costs for operational transactions and use of an experimental methodology. This research provides managers an insight into the design of smart contract transactions in a supply chain from a cost perspective

Respiratory challenge MRI: practical aspects

Respiratory challenge MRI is the modification of arterial oxygen (PaO2) and/or carbon dioxide (PaCO2) concentration to induce a change in cerebral function or metabolism which is then measured by MRI. Alterations in arterial gas concentrations can lead to profound changes in cerebral haemodynamics which can be studied using a variety of MRI sequences. Whilst such experiments may provide a wealth of information, conducting them can be complex and challenging. In this paper we review the rationale for respiratory challenge MRI including the effects of oxygen and carbon dioxide on the cerebral circulation. We also discuss the planning, equipment, monitoring and techniques that have been used to undertake these experiments. We finally propose some recommendations in this evolving area for conducting these experiments to enhance data quality and comparison between techniques

The theory of recttification in biological systems

The theory of biological rectification originated from the study of physiological processes of the human body. Biological processes are defined by certain structures; biological rectification is achieved by biological structures too. These rectifying biological structures are the biological rectifying valves, a definition adopted from physics. An extension of this notion leads to a generalization of the rectification phenomena in biological systems. The practical value of this theoretical concept is widely presumed. Here we show that the loss of rectification may result in dysfunction or even destruction of the biological system, the rectification implies the simplification of biological processes, reduce the utilization of energy in biological systhems and in general can help in understanding the processes in the human body and biology better. We hope that experts of different scientific fields will probably confirm or disprove this hypothesis.

Five minutes with Dani Rodrik: “The West has made a serious mistake in failing to see the wide range of abuses that the Turkish regime has been engaged in”

Around 300 officers in the Turkish military were jailed in 2010-2011 over an alleged coup to overthrow the Turkish government. The controversy over the arrests is still on-going, with all officers still in jail released earlier this month pending a retrial. In an interview with EUROPP’s editor Stuart Brown, Dani Rodrik discusses the case, the impact it has had on Turkish politics, and why it would be a mistake to interpret the removal of the military from politics in this way as a process of democratisation