Two-center resonant photo ionization

Photoionization of an atom $A$, in the presence of a neighboring atom $B$, can proceed via resonant excitation of $B$ with subsequent energy transfer to $A$ through two-center electron-electron correlation. We demonstrate that this two-center mechanism can strongly outperform direct photoionization at nanometer internuclear distances and possesses characteristic features in its time development and the spectrum of emitted electrons.Comment: 4 pages, 3 figure

Assessment and Comparison of Liquefied Energy Gas Terminal Risk

This report has two main goals: (1) To present and compare the various procedures of risk assessment as they have been applied to liquefied energy gas (LEG) terminal siting, and in doing so to clarify the limits of knowledge and understanding of LEG risks. (2) To quantify and compare the risks at four LEG terminal sites, namely Eemshaven (Netherlands--NL), Mossmorran (United Kingdom-UK), Point Conception (USA), and Wilhelmshaven (Federal Republic of Germany--D). The major findings of this report can be summarized as follows: 1. There is no unique concept of risk that is used throughout all the risk assessment reports examined in this study. Many of the important differences between the reports stem from the different risk concepts used. Some reports do not even define their underlying risk concepts. However, there is a concept of risk that involves several measures, each based on both probabilities of failures and consequences of failures, that is judged to be superior to other less comprehensive risk concepts. 2. The possible failures of the system, the probability of those failures and the estimation of their consequences to life and limb differ between the reports. Not all the differences can be explained by differences between the terminals and sites; some must be viewed as resulting from the limited knowledge and understanding of LEG risks. In this respect too little reference is made to remaining uncertainties in the estimation of risk in most reports. 3. Given the differences between the reports there is no relative tendency for each report individually to over- or underestimate the risk. Rather each report is more conservative on certain topics and less so on other topics as compared to the other reports. Thus no report can be singled out as producing a more conservative estimate of the risk (with respect to all parts of the total risk) than all the other reports. 4. On a relative risk scale it can be said that among the four sites Point Conception is the terminal with the lowest risk (because of very low population density), Mossmorran and Wilhelmshaven are the two terminals with the highest relative risk (because of high population density and more vessel traffic) and Eemshaven is in between. However, this does not imply anything at all about absolute risk. 5. Although risk is an important dimension of the decision to import LXG and to choose a specific site for the terminal, it should not be forgotten that other dimensions, like reliability, are important too. Any decision regarding LEG importation and terminal siting should involve comparisons with alternative options. As part of that process the risk of LEG should be compared with the risk of other options. 6. Whatever flaws the LEG risk assessments may have, they are clearly superior to less systematic ways to identify possible system weaknesses and inform the decision making process on the topic of risk. This paper is the first part of a research report. The second part will specifically address the problem of giving guidelines to evaluate LEG terminal risk assessment reports and in particular to evaluate the risk assessment reports for the four terminal sites under study

NDKNDK, KˉDN\bar{K} DN and NDDˉND\bar{D} molecules

We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one D meson, and in addition another meson, $\bar{D}, K$ or $\bar{K}$. The systems are studied using the Fixed Center Approximation to the Faddeev equations. The study is made assuming scattering of a $K$ or a $\bar{K}$ on a $DN$ cluster, which is known to generate the $\Lambda_c(2595)$, or the scattering of a nucleon on the $D\bar{D}$ cluster, which has been shown to generate a hidden charm resonance named X(3700). We also investigate the configuration of scattering of $N$ on the $KD$ cluster, which is known to generate the $D_{s0}^*(2317)$. In all cases we find bound states, with the $NDK$ system, of exotic nature, more bound than the $\bar{K} DN$.Comment: 9 figure

Liquefied Energy Gas Terminal Risk: A Comparison and Evaluation

For some years, IIASA has promoted and undertaken studies of the analytical, institutional, and sociological aspects of the risks associated with new technologies. Since 1979, with the encouragement and generous financial support of the Bundesministerium fuer Forschung und Technologie of the Federal Republic of Germany, IIASA has made particular studies of the issues associated with siting terminals for shipping, storage, and processing of liquefied energy gases (LEG). From the beginning, comparative analyses of issues and ways of handling them in different places and various conditions were judged of capital importance. Dr. Christoph Mandl, an Austrian operational researcher, and Dr. John Lathrop, an American decision analyst, directed their attention to this aspect of the studies. This report presents their results

An evaluation resource for geographic information retrieval

In this paper we present an evaluation resource for geographic information retrieval developed within the Cross Language Evaluation Forum (CLEF). The GeoCLEF track is dedicated to the evaluation of geographic information retrieval systems. The resource encompasses more than 600,000 documents, 75 topics so far, and more than 100,000 relevance judgments for these topics. Geographic information retrieval requires an evaluation resource which represents realistic information needs and which is geographically challenging. Some experimental results and analysis are reported

Entanglement in bosonic systems

We present a technique to resolve a Gaussian density matrix and its time evolution through known expectation values in position and momentum. Further we find the full spectrum of this density matrix and apply the technique to a chain of harmonic oscillators to find agreement with conformal field theory in this domain. We also observe that a non-conformal state has a divergent entanglement entropy.Comment: 7 pages, 6 figure

Density operators that extremize Tsallis entropy and thermal stability effects

Quite general, analytical (both exact and approximate) forms for discrete probability distributions (PD's) that maximize Tsallis entropy for a fixed variance are here investigated. They apply, for instance, in a wide variety of scenarios in which the system is characterized by a series of discrete eigenstates of the Hamiltonian. Using these discrete PD's as "weights" leads to density operators of a rather general character. The present study allows one to vividly exhibit the effects of non-extensivity. Varying Tsallis' non-extensivity index $q$ one is seen to pass from unstable to stable systems and even to unphysical situations of infinite energy.Comment: 22 page

US primary care in 2029: A Delphi survey on the impact of machine learning

ObjectiveTo solicit leading health informaticians' predictions about the impact of AI/ML on primary care in the US in 2029.DesignA three-round online modified Delphi poll.ParticipantsTwenty-nine leading health informaticians.MethodsIn September 2019, health informatics experts were selected by the research team, and invited to participate the Delphi poll. Participation in each round was anonymous, and panelists were given between 4-8 weeks to respond to each round. In Round 1 open-ended questions solicited forecasts on the impact of AI/ML on: (1) patient care, (2) access to care, (3) the primary care workforce, (4) technological breakthroughs, and (5) the long-future for primary care physicians. Responses were coded to produce itemized statements. In Round 2, participants were invited to rate their agreement with each item along 7-point Likert scales. Responses were analyzed for consensus which was set at a predetermined interquartile range of ≤ 1. In Round 3 items that did not reach consensus were redistributed.ResultsA total of 16 experts participated in Round 1 (16/29, 55%). Of these experts 13/16 (response rate, 81%), and 13/13 (response rate, 100%), responded to Rounds 2 and 3, respectively. As a result of developments in AI/ML by 2029 experts anticipated workplace changes including incursions into the disintermediation of physician expertise, and increased AI/ML training requirements for medical students. Informaticians also forecast that by 2029 AI/ML will increase diagnostic accuracy especially among those with limited access to experts, minorities and those with rare diseases. Expert panelists also predicted that AI/ML-tools would improve access to expert doctor knowledge.ConclusionsThis study presents timely information on informaticians' consensus views about the impact of AI/ML on US primary care in 2029. Preparation for the near-future of primary care will require improved levels of digital health literacy among patients and physicians

GeoCLEF 2007: the CLEF 2007 cross-language geographic information retrieval track overview

GeoCLEF ran as a regular track for the second time within the Cross Language Evaluation Forum (CLEF) 2007. The purpose of GeoCLEF is to test and evaluate cross-language geographic information retrieval (GIR): retrieval for topics with a geographic specification. GeoCLEF 2007 consisted of two sub tasks. A search task ran for the third time and a query classification task was organized for the first. For the GeoCLEF 2007 search task, twenty-five search topics were defined by the organizing groups for searching English, German, Portuguese and Spanish document collections. All topics were translated into English, Indonesian, Portuguese, Spanish and German. Several topics in 2007 were geographically challenging. Thirteen groups submitted 108 runs. The groups used a variety of approaches. For the classification task, a query log from a search engine was provided and the groups needed to identify the queries with a geographic scope and the geographic components within the local queries