Böcker av Carlos Castillo

A story of a Mexican child named Carlos, separated from his grandmother, and brought across the US border by a determined mother. Carlos is raised in the mean Chicago streets of the late 80s and early 90s, where he joins a gang and ends up in prison after killing a rival. In an underground super-max prison, Carlos finds the path of redemption as he obtains his college education and becomes a model inmate, but then is brutally attacked by his own gang. Carlos's path takes a surprising twist when he is given the choice to stay in prison in the US or be deported much sooner to his country of birth. Carlos chooses deportation and soon finds himself in a foreign land where he uses his higher learning skills and life's lessons to not just survive, but to achieve success. Over the course of a decade, Carlos becomes a successful, law-abiding businessman. The story ends with Carlos's heartfelt letters to the victim of his crime, his mentors, and the reader, offering a message of hope and determination to those carrying the burden of society's dismissimve and disparaging labels. It is a gripping story of redemption and a sobering message of empowerment that advocates the use of education to rise above poverty, violence, ignorance, and the mistakes and circumstances of one's past.

Research on social networks has exploded over the last decade. To a large extent, this has been fueled by the spectacular growth of social media and online social networking sites, which continue growing at a very fast pace, as well as by the increasing availability of very large social network datasets for purposes of research. A rich body of this research has been devoted to the analysis of the propagation of information, influence, innovations, infections, practices and customs through networks. Can we build models to explain the way these propagations occur? How can we validate our models against any available real datasets consisting of a social network and propagation traces that occurred in the past? These are just some questions studied by researchers in this area. Information propagation models find applications in viral marketing, outbreak detection, finding key blog posts to read in order to catch important stories, finding leaders or trendsetters, information feed ranking, etc. A number of algorithmic problems arising in these applications have been abstracted and studied extensively by researchers under the garb of influence maximization. This book starts with a detailed description of well-established diffusion models, including the independent cascade model and the linear threshold model, that have been successful at explaining propagation phenomena. We describe their properties as well as numerous extensions to them, introducing aspects such as competition, budget, and time-criticality, among many others. We delve deep into the key problem of influence maximization, which selects key individuals to activate in order to influence a large fraction of a network. Influence maximization in classic diffusion models including both the independent cascade and the linear threshold models is computationally intractable, more precisely #P-hard, and we describe several approximation algorithms and scalable heuristics that have been proposed in the literature. Finally, we also deal with key issues that need to be tackled in order to turn this research into practice, such as learning the strength with which individuals in a network influence each other, as well as the practical aspects of this research including the availability of datasets and software tools for facilitating research. We conclude with a discussion of various research problems that remain open, both from a technical perspective and from the viewpoint of transferring the results of research into industry strength applications.

Social media is an invaluable source of time-critical information during a crisis. However, emergency response and humanitarian relief organizations that would like to use this information struggle with an avalanche of social media messages that exceeds human capacity to process. Emergency managers, decision makers, and affected communities can make sense of social media through a combination of machine computation and human compassion - expressed by thousands of digital volunteers who publish, process, and summarize potentially life-saving information. This book brings together computational methods from many disciplines: natural language processing, semantic technologies, data mining, machine learning, network analysis, human-computer interaction, and information visualization, focusing on methods that are commonly used for processing social media messages under time-critical constraints, and offering more than 500 references to in-depth information.