4,636 research outputs found

    A review of hypertext in a NASA project management context

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    The principles of data storage, the comparative strengths of data bases, and the evolution of hypertext within this context are discussed. A classification schema of indexing and of hypertext document structures is provided. Issues associated with hypertext implementation are also discussed and potential areas for further research are indicated

    Anomalies, Chern-Simons Terms and Chiral Delocalization in Extra Dimensions

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    Gauge invariant topological interactions, such as the D=5 Chern-Simons terms, are required in models in extra dimensions that split anomaly free representations. The Chern-Simons term is necessary to maintain the overall anomaly cancellations of the theory, but it can have significant, observable, physical effects. The CS-term locks the KK-mode parity to the parity of space-time, leaving a single parity symmetry. It leads to new processes amongst KK-modes, eg, the decay of a KK-mode to a 2-body final state of KK-modes. A formalism for the effective interaction amongst KK-modes is constructed, and the decay of a KK-mode to KK-mode plus zero mode is analyzed as an example. We elaborate the general KK-mode current and anomaly structure of these theories. This includes a detailed study of the triangle diagrams and the associated ``consistent anomalies'' for Weyl spinors on the boundary branes. We also develop the non-abelian formalism. We illustrate this by showing in a simple way how a D=5 Yang-Mills ``quark flavor'' symmetry leads to the D=4 chiral lagrangian of mesons and the quantized Wess-Zumino-Witten term.Comment: 51 pages, 3 figures; Corrected typos, amplified discussio

    The State of the Art in Performance Management: Learnings from Discussions with Leading Organizations

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    Performance management is one of the fundamental HR tools that has been part of organizational life for decades and has long been the backbone of other activities of the HR system (e.g., pay decisions, development plans). Despite the importance of performance management, it has historically been rated by employees, managers, and the HR function itself as one of the least effective and understood HR practices. Given the stagnation in academic research on the topic and discontent on the part of organizational stakeholders, we decided it was an opportune time to meet with leading companies to understand the state of the art in performance management. Specifically, we held two working group meetings with a total of 32 HR executives from 20 companies to discuss current challenges and best practices in the area of performance management. The discussions provided us with a deeper understanding of the dilemmas and challenges associated with performance management in large, multinational companies. We were also able to extract a handful of promising directions for enhancing the effectiveness of the performance management process

    Topological Physics of Little Higgs Bosons

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    Topological interactions will generally occur in composite Higgs or Little Higgs theories, extra-dimensional gauge theories in which A_5 plays the role of a Higgs boson, and amongst the pNGB's of technicolor. This phenomena arises from the chiral and anomaly structure of the underlying UV completion theory, and/or through chiral delocalization in higher dimensions. These effects are described by a full Wess-Zumino-Witten term involving gauge fields and pNGB's. We give a general discussion of these interactions, some of which may have novel signatures at future colliders, such as the LHC and ILC.Comment: 22 page

    Exact Equivalence of the D=4 Gauged Wess-Zumino-Witten Term and the D=5 Yang-Mills Chern-Simons Term

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    We derive the full Wess-Zumino-Witten term of a gauged chiral lagrangian in D=4 by starting from a pure Yang-Mills theory of gauged quark flavor in a flat, compactified D=5. The theory is compactified such that there exists a B_5 zero mode, and supplemented with quarks that are ``chirally delocalized'' with q_L (q_R) on the left (right) boundary (brane). The theory then necessarily contains a Chern-Simons term (anomaly flux) to cancel the fermionic anomalies on the boundaries. The constituent quark mass represents chiral symmetry breaking and is a bilocal operator in D=5 of the form: \bar{q}_LWq_R+h.c, where W is the Wilson line spanning the bulk, 0\leq x^5 \leq R and is interpreted as a chiral meson field, W=\exp(2i\tilde{\pi}/f_\pi), where f_\pi \sim 1/R. The quarks are integrated out, yielding a Dirac determinant which takes the form of a ``boundary term'' (anomaly flux return), and is equivalent to Bardeen's counterterm that connects consistent and covariant anomalies. The Wess-Zumino-Witten term then emerges straightforwardly, from the Yang-Mills Chern-Simons term, plus boundary term. The method is systematic and allows generalization of the Wess-Zumino-Witten term to theories of extra dimensions, and to express it in alternative and more compact forms. We give a novel form appropriate to the case of (unintegrated) massless fermions.Comment: 25 pages, 1 figure; minor errors fixe

    Changing an Unfavorable Employment Reputation: A Longitudinal Examination

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    Although a favorable employment reputation plays an important role in generating a large and qualified pool of job applicants for an organization (Rynes & Cable, 2003), little research has investigated whether organizations can improve applicants’ existing unfavorable employment reputation perceptions. Results from a four-week longitudinal experiment using 222 student job seekers revealed that participants’ employment reputation perceptions improved after exposure to recruitment practices and followed diminishing returns trajectories over time. High information recruitment practices (e.g., personal communication from a recruiter) from both single and multiple sources were more effective for changing unfavorable employment reputation perceptions than repeated mere exposure to the organization (i.e., exposure to only the company logo), and high information practices from multiple sources were the most effective overall. Finally, participants reporting less familiarity with the organization experienced greater reputation change across the four weeks, but only for participants in the mere exposure condition

    T-Parity Violation by Anomalies

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    Little Higgs theories often rely on an internal parity ("T-parity'') to suppress non-standard electroweak effects or to provide a dark matter candidate. We show that such a symmetry is generally broken by anomalies, as described by the Wess-Zumino-Witten term. We study a simple SU(3) x SU(3)/SU(3) Little Higgs scheme where we obtain a minimal form for the topological interactions of a single Higgs field. The results apply to more general models, including [SU(3) x SU(3)/SU(3)]^4, SU(5)/SO(5), and SU(6)/Sp(6).Comment: 17 page

    Forecasting eruptions from long-quiescent volcanoes

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    Forecasts of eruption are uncertain. The uncertainty is amplified when volcanoes reawaken after several generations in repose, because direct evidence of previous behaviour is rarely available. It fosters scepticism about warnings of volcanic activity and may compromise the success of emergency procedures. The quality of forecasts has improved over the past 50 years, owing mainly to a growing sophistication in statistical analyses of unrest. Physics-based analyses have yet to achieve the same level of maturity. Their application has been delayed by a view that volcanoes are too complex to share patterns of behaviour that can be described in a deterministic manner. This view is being increasingly challenged and an emerging line of inquiry is to understand how forecasts can be further improved by integrating statistical approaches with new constraints on possible outcomes from physics-based criteria. The introduction of deterministic reasoning yields rational explanations of why forecasts are not perfect and, as a result, offers new opportunities for increasing public confidence in warnings of eruption

    A Labor Lawyer\u27s Guide to the Americans with Disabilities Act of 1990*

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    On July 26, 1990, in a joyous ceremony on the south lawn of the White House, President George Bush signed the Americans with Disabilities Act of 1990 lx into la

    Anomaly mediated neutrino-photon interactions at finite baryon density

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    We propose new physical processes based on the axial vector anomaly and described by the Wess-Zumino-Witten term that couples the photon, Z-boson, and the omega-meson. The interaction takes the form of a pseudo-Chern-Simons term, ϵμνρσωμZνFρσ\sim \epsilon_{\mu\nu\rho\sigma}\omega^\mu Z^\nu F^{\rho\sigma}. This term induces neutrino-photon interactions at finite baryon density via the coupling of the Z-boson to neutrinos. These interactions may be detectable in various laboratory and astrophysical arenas. The new interactions may account for the MiniBooNE excess. They also produce a competitive contribution to neutron star cooling at temperatures >10^9 K. These processes and related axion--photon interactions at finite baryon density appear to be relevant in many astrophysical regimes.Comment: 4 pages, 2 figures; references adde
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