Exact Mean Computation in Dynamic Time Warping Spaces

Dynamic time warping constitutes a major tool for analyzing time series. In particular, computing a mean series of a given sample of series in dynamic time warping spaces (by minimizing the Fr\'echet function) is a challenging computational problem, so far solved by several heuristic and inexact strategies. We spot some inaccuracies in the literature on exact mean computation in dynamic time warping spaces. Our contributions comprise an exact dynamic program computing a mean (useful for benchmarking and evaluating known heuristics). Based on this dynamic program, we empirically study properties like uniqueness and length of a mean. Moreover, experimental evaluations reveal substantial deficits of state-of-the-art heuristics in terms of their output quality. We also give an exact polynomial-time algorithm for the special case of binary time series

Developing And Implementing A Measure Of Sustainability For Workforce And Economic Development Projects In Northeast Pennsylvania

As part of a Wall Street West (WSW) grant, a project team was assembled to investigate the effectiveness of other WSW grantees working on various projects to impact the long term economic development of the financial services sector of the Northeast Pennsylvania (NEPA) corridor.  Because sustainability of grant work was deemed critical by project leaders, a literature search was undertaken to identify factors that contribute to sustainability.  Twelve factors were culled from the literature, reviewed with WSW executives and project grantees, and ultimately combined (using a BARS assessment methodology) to form an economic or workforce development Sustainability Index.  This paper reviews the logic and the steps taken to develop the Sustainability Index, discusses the validity and reliability of the instrument, and shows how it was used to measure and report the relative importance of sustainability factors in economic development activities.  The authors issue a call to action to further develop and refine the instrument across a variety of application venues

Deducing linguistic structure from the statistics of large corpora

Within the last two years, approaches using both stochastic and symbolic techniques have proved adequate to deduce lexical ambiguity resolution rules with less than 3-4 % error rate, when trained on moderat

Exploring Predictability Of Instructor Ratings Using A Quantitative Tool For Evaluating Soft Skills Among MBA Students

Academic researchers have often touted the growing importance of “soft skills” for modern day business leaders, especially leadership and communication skills.  Despite this growing interest and attention, relatively little work has been done to develop and validate tools to assess soft skills.  Forty graduate students from nine MBA courses completed the McCann Soft Skills Assessment Tool - a paper-pencil test designed to measure leadership, teamwork, critical thinking, logical reasoning, communication, and holistic thinking.  These students were also rated by their instructors on the same six dimensions in an attempt to validate the soft skills instrument.  Results showed significant correlations between leadership and communication assessment scores and faculty ratings of students on the same dimensions; however none of the other four soft skill dimensions were empirically validated.  Data also indicated moderate test – retest reliability for the assessment tool.  While some limitations are acknowledged in the current study, findings suggest that further refinement and empirical validation of the McCann Soft Skills Assessment Tool can better aid practitioners in understanding and developing these important dimensions of business competency

Physiological Limits to Inshore Invasion of Indo-Pacific Lionfish (Pterois Spp.): Insights from the Functional Characteristics of Their Visual System and Hypoxia Tolerance

Indo-Pacific lionfish (Pterois spp.) have become established throughout the Caribbean and the coastal regions of the Gulf of Mexico and western Atlantic Ocean from North Carolina to central Brazil. Lionfish may also invade estuaries, as they tolerate salinities down to 4‰. We hypothesize that the functional characteristics of their visual system (which evolved in the clear tropical waters of the Indo-Pacific) or their inability to tolerate hypoxia will limit the capacity of lionfish to occupy these areas. We assessed the former with corneal electroretinography and the latter with intermittent-flow respirometry. The luminous sensitivity, temporal resolution (quantified as flicker fusion frequency), and spectral sensitivity of the lionfish visual system are like those of native piscivores, indicating that their visual system will be functional under estuarine photic conditions and allow lionfish to be effective piscivores. In contrast, acute exposure to reduced oxygen levels (equivalent to those commonly occurring in mid-Atlantic and Gulf of Mexico estuaries) exceeded the physiological tolerances of lionfish. We therefore conclude that hypoxia will control or limit estuarine invasion

Testing cosmic censorship with black hole collisions

There exists an upper limit on the mass of black holes when the cosmological constant Λ is positive. We study the collision of two black holes whose total mass exceeds this limit. Our investigation is based on a recently discovered exact solution describing the collision of Q=M black holes with Λ\u3e0. The global structure of this solution is analyzed. We find that if the total mass is less than the extremal limit, then the black holes coalesce. If it is greater, then a naked singularity forms to the future of a Cauchy horizon. However, the horizon is not smooth. Generically, there is a mild curvature singularity, which still allows geodesics to be extended. The implications of these results for cosmic censorship are discussed