3,986 research outputs found

    Whites and the Active Representation of Racial Minority Interests

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    This study explored personal and organizational factors that contribute to White public administrators actively representing the interests of racial minority minorities. Data collection comprised of 15 semi-structured interviews. The average age was 54, and the length of service was 3-33 years. Subjects were asked about their personal background, what it means to be White, and work experiences in local county government. Personal factors found were racial consciousness, major life events, and significant relationships with people of color. Organizational factors included a diverse and inclusive work environment, bureaucracy, legal and compliance issues, and supervisor support. Findings included that Whites did not have to be racially conscious to actively represent racial minority interests. Patterns of active representation were organized into three types: deliberate, partial, and conformist. Duality in organizational factors emerged as facilitative and limiting. New factors emerged: supervisor support, leadership engagement, and external factors. All subjects adopted a role to represent racial minority interests but role adoption did not mean behaviors were consistent with beliefs. Seeing solutions to address racial disparities appeared to be less possible without racial consciousness to move to deliberate action. This study is unique in the field of public administration. Findings challenged assumptions about active representation from previous research from the White majority. In particular, the assumption that role adoption means effective representation. Organizational factors previously identified only as limitations were also found to be facilitative. Primary limitations in this study included a small sample size with results unable to be generalized for all White public administrators

    Density-functional calculations of the electronic structure and lattice dynamics of superconducting LaO0.5_{0.5}F0.5_{0.5}BiS2_{2}: Evidence for an electron-phonon interaction near the charge-density-wave instability

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    We discuss the electronic structure, lattice dynamics and electron-phonon interaction of newly discovered superconductor LaO0.5_{0.5}F0.5_{0.5}BiS2_{2} using density functional based calculations. A strong Fermi surface nesting at k\mathbf{k}=(π\pi ,π\pi ,0) suggests a proximity to charge density wave instability and leads to imaginary harmonic phonons at this k\mathbf{k} point associated with in-plane displacements of S atoms. Total energy analysis resolves only a shallow double-well potential well preventing the appearance of static long-range order. Both harmonic and anharmonic contributions to electron-phonon coupling are evaluated and give a total coupling constant λ≃0.85\lambda \simeq 0.85 prompting this material to be a conventional superconductor contrary to structurally similar FeAs materials.Comment: Supplementary Materials is adde

    Wind conditions in idealized building clusters: Macroscopic simulations using a porous turbulence model

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    Simulating turbulent flows in a city of many thousands of buildings using general high-resolution microscopic simulations requires a grid number that is beyond present computer resources. We thus regard a city as porous media and divide the whole hybrid domain into a porous city region and a clear fluid region, which are represented by a macroscopic k-Δ model. Some microscopic information is neglected by the volume-averaging technique in the porous city to reduce the calculation load. A single domain approach is used to account for the interface conditions. We investigated the turbulent airflow through aligned cube arrays (with 7, 14 or 21 rows). The building height H, the street width W, and the building width B are the same (0.15 m), and the fraction of the volume occupied by fluid (i. e. the porosity) is 0.75; the approaching flow is parallel to the main streets. There are both microscopic and macroscopic simulations, with microscopic simulations being well validated by experimental data. We analysed microscopic wind conditions and the ventilation capacity in such cube arrays, and then calculated macroscopic time-averaged properties to provide a comparison for macroscopic simulations. We found that the macroscopic k-Δ turbulence model predicted the macroscopic flow reduction through porous cube clusters relatively well, but under-predicted the macroscopic turbulent kinetic energy (TKE) near the windward edge of the porous region. For a sufficiently long porous cube array, macroscopic flow quantities maintain constant conditions in a fully developed region. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

    Temperature Dependent Mean Free Path Spectra of Thermal Phonons Along the c-axis of Graphite

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    Heat conduction in graphite has been studied for decades because of its exceptionally large thermal anisotropy. While the bulk thermal conductivities along the in-plane and cross-plane directions are well known, less understood are the microscopic properties of the thermal phonons responsible for heat conduction. In particular, recent experimental and computational works indicate that the average phonon mean free path (MFP) along the c-axis is considerably larger than that estimated by kinetic theory, but the distribution of MFPs remains unknown. Here, we report the first quantitative measurements of c-axis phonon MFP spectra in graphite at a variety of temperatures using time-domain thermoreflectance measurements of graphite flakes with variable thickness. Our results indicate that c-axis phonon MFPs have values of a few hundred nanometers at room temperature and a much narrower distribution than in isotropic crystals. At low temperatures, phonon scattering is dominated by grain boundaries separating crystalline regions of different rotational orientation. Our study provides important new insights into heat transport and phonon scattering mechanisms in graphite and other anisotropic van der Waals solids

    Compressing Inertial Motion Data in Wireless Sensing Systems – An Initial Experiment

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    The use of wireless inertial motion sensors, such as accelerometers, for supporting medical care and sport’s training, has been under investigation in recent years. As the number of sensors (or their sampling rates) increases, compressing data at source(s) (i.e. at the sensors), i.e. reducing the quantity of data that needs to be transmitted between the on-body sensors and the remote repository, would be essential especially in a bandwidth-limited wireless environment. This paper presents a set of compression experiment results on a set of inertial motion data collected during running exercises. As a starting point, we selected a set of common compression algorithms to experiment with. Our results show that, conventional lossy compression algorithms would achieve a desirable compression ratio with an acceptable time delay. The results also show that the quality of the decompressed data is within acceptable range

    Does solitary wave solution persist for the long wave equation with small perturbations?

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    In this paper, persistence of solitary wave solutions of the regularized long wave equation with small perturbations are investigated by the geometric singular perturbation theory. Two different kinds of the perturbations are considered in this paper: one is the weak backward diffusion and dissipation, the other is the Marangoni effects. Indeed, the solitary wave persists under small perturbations. Furthermore, the different perturbations do affect the proper wave speed ensuring the persistence of the solitary waves. Finally, numerical simulations are utilized to confirm the theoretical results
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