James M McCracken – författare

A Key. A Medal. A Warning. For young Charlie MacCready, life is one mystery after another. Left at his grandparents' home in the middle of the night when he was two, Charlie's mother said she would return for him. Ten years later, sent to Saint Michael's Abbey & Home for Boys by his uncle, Charlie finds himself in the center of another mystery.Awakened in the middle of the night, he hears a sound coming form the attic above his dorm. Together with his new friends Howard, Gus, and Rick, they set out to findThe Ghost in the Attic.

Life for young Charlie MacCready is one mystery after another. Haunted by nightmares, Charlie sees someone following him,lurking in the shadows. Is it real or just his imagination? When his friends are attacked, the finger of blame begins topoint at Charlie. He must act fast to prove his innocence. Alone, he must find theShadows in the Dark.

A Map. A Butte. A Warning. As Charlie's third summer begins,there is another mystery in the air.Where there's smoke . . . Someone is setting fires.Can Saint Michael's Abbey & Home for Boysescape its past or are they doomed to repeat it? Join Charlie and Howard as they set out tofind the real pyromaniac and silence theSirens in the Night.

A Locket. A Promise. A Murder.Fifteen years ago, two-year-old Charlie MacCready was left at his grandmother's home. His mother promised to return for him. Now, as his final year at Saint Michael's Abbey and Seminary begins, Charlie should be planning for his future, but how can he when he is still troubled by the mystery of his lost parents? What happened to them? Why haven't they returned for him? Disappointment. Confusion. Anger.Nothing Charlie has experienced has prepared him for what he finds when it comes to the Lost and Found.

Many scientific disciplines rely on observational data of systems for which it is difficult (or impossible) to implement controlled experiments. Data analysis techniques are required for identifying causal information and relationships directly from such observational data. This need has led to the development of many different time series causality approaches and tools including transfer entropy, convergent cross-mapping (CCM), and Granger causality statistics. A practicing analyst can explore the literature to find many proposals for identifying drivers and causal connections in time series data sets. Exploratory causal analysis (ECA) provides a framework for exploring potential causal structures in time series data sets and is characterized by a myopic goal to determine which data series from a given set of series might be seen as the primary driver. In this work, ECA is used on several synthetic and empirical data sets, and it is found that all of the tested time series causality tools agree with each other (and intuitive notions of causality) for many simple systems but can provide conflicting causal inferences for more complicated systems. It is proposed that such disagreements between different time series causality tools during ECA might provide deeper insight into the data than could be found otherwise.

This book is a brief introduction to negative quantum channels, i.e., linear, trace-preserving (and consistent) quantum maps that are not completely positive. The flat and sharp operators are introduced and explained. Complete positivity is presented as a mathematical property, but it is argued that complete positivity is not a physical requirement of all quantum operations. Negativity, a measure of the lack of complete positivity, is proposed as a tool for empirically testing complete positivity assumptions.Table of Contents: Preface / Acknowledgments / Introduction and Definition of Terms / Tomography / Non-Positive Reduced Dynamics / Complete Positivity / Physical Motivation of Complete Positivity / Measures of Complete Positivity / Negative Channels / Negative Climates with Diagonal Composite Dynamics / Rabi Channels / Physical Motivations for Sharp Operations / Negative Qubit Channel Examples with Multi-Qubit Baths / Proposed Experimental Demonstration of Negativity / Implications of Negative Channels / Uses for Negative Channels / Conclusions / Bibliography / Author's Biography

Many scientific disciplines rely on observational data of systems for which it is difficult (or impossible) to implement controlled experiments. Data analysis techniques are required for identifying causal information and relationships directly from such observational data. This need has led to the development of many different time series causality approaches and tools including transfer entropy, convergent cross-mapping (CCM), and Granger causality statistics. A practicing analyst can explore the literature to find many proposals for identifying drivers and causal connections in time series data sets. Exploratory causal analysis (ECA) provides a framework for exploring potential causal structures in time series data sets and is characterized by a myopic goal to determine which data series from a given set of series might be seen as the primary driver. In this work, ECA is used on several synthetic and empirical data sets, and it is found that all of the tested time series causality tools agree with each other (and intuitive notions of causality) for many simple systems but can provide conflicting causal inferences for more complicated systems. It is proposed that such disagreements between different time series causality tools during ECA might provide deeper insight into the data than could be found otherwise.

This book is a brief introduction to negative quantum channels, i.e., linear, trace-preserving (and consistent) quantum maps that are not completely positive. The flat and sharp operators are introduced and explained. Complete positivity is presented as a mathematical property, but it is argued that complete positivity is not a physical requirement of all quantum operations. Negativity, a measure of the lack of complete positivity, is proposed as a tool for empirically testing complete positivity assumptions.Table of Contents: Preface / Acknowledgments / Introduction and Definition of Terms / Tomography / Non-Positive Reduced Dynamics / Complete Positivity / Physical Motivation of Complete Positivity / Measures of Complete Positivity / Negative Channels / Negative Climates with Diagonal Composite Dynamics / Rabi Channels / Physical Motivations for Sharp Operations / Negative Qubit Channel Examples with Multi-Qubit Baths / Proposed Experimental Demonstration of Negativity / Implications of Negative Channels / Uses for Negative Channels / Conclusions / Bibliography / Author''s Biography