Effective One-Dimensional Models from Matrix Product States

In this paper we present a method for deriving effective one-dimensional models based on the matrix product state formalism. It exploits translational invariance to work directly in the thermodynamic limit. We show, how a representation of the creation operator of single quasi-particles in both real and momentum space can be extracted from the dispersion calculation. The method is tested for the analytically solvable Ising model in a transverse magnetic field. Properties of the matrix product representation of the creation operator are discussed and validated by calculating the one-particle contribution to the spectral weight. Results are also given for the ground state energy and the dispersion.Comment: 17 pages, 8 figure

The significance of Martin Buber\u27s I-thou philosophy for communication theory

In a review of literature, it is clear that the significance of Martin Buber’s philosophy of dialogue, or I-Thou philosophy, has been recognized by scholars in related disciplines. It also appears that no in-depth study has been done to discover the significance of Martin Buber’s I-Thou philosophy for communication theory. In order to determine this significance the author proposes to: (1) Examine the efforts of communication scholars as they have attempted to establish the significance of Martin Bubder’s I-Thou philosophy for communication theory.; (2) Present an analysis of Martin Buber’s concept of relation.; (3) Present an analysis of Martin buber’s concept of dialogue.; and (4) Propose a definition of interpersonal communication based upon Martin Buber’s I-Thou philosophy of dialogical relation. Communication scholars are greatly hindered in their research of the I-Thou philosophy by the limited scholarship that has been done on Buber’s writings. To this point in time, research continues without an in-depth guide to the relationship of this philosophy to communication theory

The NSABB Recommendations: Rationale, Impact, and Implications

The National Science Advisory Board for Biosecurity (NSABB) has recommended that two scientific papers concerning the laboratory adaptation of avian H5N1 influenza virus to mammal-to-mammal respiratory transmission restrict their content to prevent others from replicating their work. After hearing from experts in the field of influenza research and public health, the benefits of the research were deemed less important than the potential negative consequences. The evaluation followed established NSABB procedures and prior policy recommendations for identifying dual use research of concern (DURC). This recommendation was received by the United States Government, endorsed and forwarded to the research teams and scientific journals involved with the publications

Do Engineering Students Learn Ethics From an Ethics Course?

The goal of the present research is to develop machine-assisted methods that can assist in the analysis of students’ written compositions in ethics courses. As part of this research, we analyzed Social Impact Assessment (SIA) papers submitted by engineering undergraduates in a course on engineering ethics. The SIA papers required students to identify and discuss a contemporary engineering technology (e.g., autonomous tractor trailers) and to explicitly discuss the ethical issues involved in that technology. Here we describe the ability of three machine tools to discriminate differences in the technical compared to ethical portions of the SIA papers. First, using LIWC (Language Inquiry and Word Count) we quantified differences in analytical thinking, expertise and self-confidence, disclosure, and affect, in the technical and ethical portions of the papers. Next, we applied MEH (Meaning Extraction Helper) to examine differences in critical concepts in the technical and ethical portions of the papers. Finally, we used LDA (Latent Dirichlet Allocation) to examine differences in the topics in the technical and ethical portions of the papers. The results of these three tests demonstrate the ability of machine-based tools to discriminate conceptual, affective, and motivational differences in the texts that students compose that relate to engineering technology and to engineering ethics. We discuss the utility and future directions for this research.Cockrell School of Engineerin

Exploratory topic modeling with distributional semantics

As we continue to collect and store textual data in a multitude of domains, we are regularly confronted with material whose largely unknown thematic structure we want to uncover. With unsupervised, exploratory analysis, no prior knowledge about the content is required and highly open-ended tasks can be supported. In the past few years, probabilistic topic modeling has emerged as a popular approach to this problem. Nevertheless, the representation of the latent topics as aggregations of semi-coherent terms limits their interpretability and level of detail. This paper presents an alternative approach to topic modeling that maps topics as a network for exploration, based on distributional semantics using learned word vectors. From the granular level of terms and their semantic similarity relations global topic structures emerge as clustered regions and gradients of concepts. Moreover, the paper discusses the visual interactive representation of the topic map, which plays an important role in supporting its exploration.Comment: Conference: The Fourteenth International Symposium on Intelligent Data Analysis (IDA 2015

Simplifying Choices in Defined Contribution Retirement Plan Design

In view of the growth and popularity of defined contribution pensions, along with the government’s growing attention to retirement plan costs and investment choices provided, it is important to evaluate how people select their plan investments. This paper tracks how employees in a large firm altered their fund allocations when the employer streamlined its pension fund menu, tiering options in an easier-to-understand format. Using administrative data, we examine what investment choices the plan participants elected prior to and after the streamlining, and how they altered their equity share, risk exposure, fees paid, and turnover patterns as a result of the change. We also discuss what difference the changes might make for participants’ eventual retirement wellbeing. Specifically, we show that streamlined participants’ new allocations exhibited significantly lower turnover rates and expense ratios; based on reasonable assumptions, this could lead to additional aggregate savings for these participants over a 20-year period of $20.2M, or in excess of$9,400 per participant. Moreover, after the reform, streamlined participants’ portfolios held significantly less equity and exhibited significantly lower risks by way of reduced exposures to most systematic risk factors, compared to their non-streamlined counterpart

The 2010 cholera outbreak in Haiti: How science solved a controversy

The article focuses on the genetic basis of the spread of cholera in Haiti which clarifies both the climatic and human transmission hypotheses explaining the origin of the disease after the January 12, 2010 earthquake. Topics include the role of the nonpathogenic Vibrio cholerae in cholera, studies supporting the human transmission hypothesis, and molecular study on the origin of Vibrio cholerae in the country. The use of genome sequencing as a tool for molecular epidemiology is considered

Global Trends in Space Access and Utilization

In the not-so-distant past, space access and air/space technology superiority were within the purview of the U.S. and former Soviet Union's respective space agencies, both vying for global leadership in space exploitation. In more recent years, with the emergence of the European Space Agency (ESA) member countries and Asian countries joining the family of space-faring nations, it is truer now more than ever that space access and utilization has become a truly global enterprise. In fact, according to the Space Report 2007, this enterprise is a $251-billion economy. It is possible to gauge the vitality of worldwide efforts from open sources in today's transparent, media-based society. In particular, print and web broadcasters regularly report and catalog global space activities for defense and civil purposes. For the purposes of this paper, a representative catalog of missions is used to illustrate the nature of the emerging "globalization." This paper highlights global trends in terms of not only the providers of space access, but also the end-users for the various recently accomplished missions. With well over 50 launches per year, in recent years, the launch-log reveals a surprising percentage of "cooperative or co-dependent missions" where different agencies, countries, and/or commercial entities are so engaged presumably to the benefit of all who participate. Statistics are cited and used to show that recently over d0% of the 50-plus missions involved multiple nations working collectively to deliver payloads to orbit. Observers, space policy professionals, and space agency leaders have eloquently proposed that it might require the combined resources and talents of multiple nations to advance human exploration goals beyond low earth orbit. This paper does not intend to offer new information with respect to whether international collaboration is necessary but to observe that, in continuing to monitor global trends, the results seem to support the thesis that a global interdependent effort with all its likely complexities is an increasingly viable and pragmatic option. The discussion includes a breakdown of space missions into those of civil (scientific), military, and strictly commercial nature. It concludes that all three are robust components of a globally diversified portfolio of activities relying, essentially, on a common space industrial base and space infrastructure. As in other industries, the distribution of space industry assets and knowledge across countries and continents enables a diverse suite of options and arrangements, particularly in the areas of civil and commercial space utilization. A survey of several ongoing bilateral and multilateral space collaboration examples are provided to augment the observations regarding multinational work in space

Physician Perceptions of ADHD Stimulant Diversion and Misuse

© The Author(s) 2016. Objective: The recent rise in ADHD has prompted concerns about adolescents with ADHD diverting and/or misusing stimulants. This is the first study to assess physician perceptions of the pervasiveness of these issues. Method: Questionnaires were mailed to a national sample of pediatric subspecialists. Responses were analyzed (n = 826; 18% response rate) using descriptive statistics and regression analyses. Results: In the past year, 59% of physicians suspected ≥1 patient(s) with ADHD diverted stimulants. Seventy-four percent believed ≥1 patient(s) feigned symptoms to obtain an initial ADHD diagnosis; 66% believed ≥1 patient(s) wanted stimulants to improve academic performance. Child and adolescent psychiatrists were most likely to suspect diversion and feigning symptoms. Thirty-nine percent of physicians believed diversion was at least “common.” Conclusion: Although many physicians suspected stimulant diversion and misuse, a substantial number were unaware of these issues, and subspecialist perceptions varied. These findings support the potential pervasiveness of these issues and the need for increased physician awareness

Assessing Face Validity of a Physical Activity Questionnaire for Spanish-Speaking Women in California

To create a culturally appropriate assessment, the study reported here developed and evaluated the face validity of a visually enhanced Spanish-language physical activity questionnaire. A professional translated the English version of the International Physical Activity Questionnaire (IPAQ), and an expert panel subsequently reviewed it. Photos of individuals engaged in physical activity behaviors were added. Cognitive interviews were completed with low-income Spanish-speaking women in California (n=20). Questionnaire text was modified and then reviewed by translation experts (n=7). With a high readability score of 98, the questionnaire demonstrates adequate face validity and is ready for further validation