9,414 research outputs found

    OPTIMIZING FIRST-TERM RETENTION OF SAILORS

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    In many cases, a low retention rate of first-term sailors indicates that unsatisfactory sailors who are struggling to find guidance also cannot find a career path that fits them. Helping each sailor find their best fit can improve the retention rate in the Navy. The Navy recently developed the Job Opportunities In the Navy (JOIN) program to help sailors find their career paths on the Bureau of Naval Personnel Online. However, there are not enough data to support the effectiveness of JOIN. Based on a dataset obtained from the Navy Enlisted System, we first analyze which factors correlate to sailors’ stays in the Navy. Then using the results from the first part of the analysis, we set up a probability distribution model to maximize the retention rate of enlisted sailors in the Navy. The result from this study can be used to help first-term sailors with JOIN. First, we conduct an analysis using a binomial logistic regression model and then calculate the model’s accuracy using a confusion matrix. Second, using the variables we select in the first part of our analysis, we set up an optimization model, specifically a probability distribution model, to maximize the retention rates of enlisted sailors. Our model produces a list of rates, from the highest probability of retention rate to the lowest probability for recruits.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

    CP1CP^{1} model with Hopf term and fractional spin statistics

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    We reconsider the CP1CP^{1} model with the Hopf term by using the Batalin-Fradkin-Tyutin (BFT) scheme, which is an improved version of the Dirac quantization method. We also perform a semi-classical quantization of the topological charge Q sector by exploiting the collective coordinates to explicitly show the fractional spin statistics.Comment: 15 page

    Symmetries of SU(2) Skyrmion in Hamiltonian and Lagrangian approaches

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    We apply the Batalin-Fradkin-Tyutin (BFT) method to the SU(2) Skyrmion to study the full symmetry structure of the model at the first class Hamiltonian level. On the other hand, we also analyze the symmetry structure of the action having the WZ term, which corresponds to this Hamiltonian, in the framework of the Lagrangian approach. Furthermore, following the BFV formalism we derive the BRST invariant gauge fixed Lagrangian from the above extended action.Comment: 14 pages, final revised version, to appear in Mod. Phys. Lett.

    Flavor symmetry breaking effects on SU(3) Skyrmion

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    We study the massive SU(3) Skyrmion model to investigate the flavor symmetry breaking (FSB) effects on the static properties of the strange baryons in the framework of the rigid rotator quantization scheme combined with the improved Dirac quantization one. Both the chiral symmetry breaking pion mass and FSB kinetic terms are shown to improve cc the ratio of the strange-light to light-light interaction strengths and cˉ\bar{c} that of the strange-strange to light-light.Comment: 12 pages, latex, no figure

    Retrievals of All-Weather Daily Air Temperature Using MODIS and AMSR-E Data

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    Satellite optical-infrared remote sensing from the Moderate Resolution Imaging Spectroradiometer (MODIS) provides effective air temperature (Ta) retrieval at a spatial resolution of 5 km. However, frequent cloud cover can result in substantial signal loss and remote sensing retrieval error in MODIS Ta. We presented a simple pixel-wise empirical regression method combining synergistic information from MODIS Ta and 37 GHz frequency brightness temperature (Tb) retrievals from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) for estimating surface level Ta under both clear and cloudy sky conditions in the United States for 2006. The instantaneous Ta retrievals showed favorable agreement with in situ air temperature records from 40 AmeriFlux tower sites; mean R2 correspondence was 86.5 and 82.7 percent, while root mean square errors (RMSE) for the Ta retrievals were 4.58 K and 4.99 K for clear and cloudy sky conditions, respectively. Daily mean Ta was estimated using the instantaneous Ta retrievals from day/night overpasses, and showed favorable agreement with local tower measurements (R2 = 0.88; RMSE = 3.48 K). The results of this study indicate that the combination of MODIS and AMSR-E sensor data can produce Ta retrievals with reasonable accuracy and relatively fine spatial resolution (~5 km) for clear and cloudy sky conditions

    The Chiral Model of Sakai-Sugimoto at Finite Baryon Density

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    In the context of holographic QCD we analyze Sakai-Sugimoto's chiral model at finite baryon density and zero temperature. The baryon number density is introduced through compact D4 wrapping S^4 at the tip of D8-\bar{D8}. Each baryon acts as a chiral point-like source distributed uniformly over R^3, and leads a non-vanishing U(1)_V potential on the brane. For fixed baryon charge density n_B we analyze the bulk energy density and pressure using the canonical formalism. The baryonic matter with point like sources is always in the spontaneously broken phase of chiral symmetry, whatever the density. The point-like nature of the sources and large N_c cause the matter to be repulsive as all baryon interactions are omega mediated. Through the induced DBI action on D8-\bar{D8}, we study the effects of the fixed baryon charge density n_B on the pion and vector meson masses and couplings. Issues related to vector dominance in matter in the context of holographic QCD are also discussed.Comment: V3: 39 pages, 16 figures, minor corrections, version to appear in JHEP. V2: references added, typos correcte

    Mechanical self-confinement to enhance energy storage density of antiferroelectric capacitors

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    The energy storage density of electrical capacitors utilizing antiferroelectric compositions Pb0.99Nb0.02[(Zr0.57Sn0.43)1−yTiy]0.98O3 as dielectrics is measured at a series of temperatures in a series of dielectric compositions with and without self-confinement. Under the applied electric field of 70 kV/cm, a maximum energy density of 1.3 J/cm3 is achieved. The mechanical self-confinement was introduced by partially electroding the central portion of thedielectric ceramic disk. A phase-field model was developed and it confirms the presence of compressive stresses ∼30 MPa in the electroded portion of the dielectric disk and the contribution to the increased energy density from the mechanical confinement

    Monomeric ephrinB2 binding induces allosteric changes in Nipah virus G that precede its full activation.

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    Nipah virus is an emergent paramyxovirus that causes deadly encephalitis and respiratory infections in humans. Two glycoproteins coordinate the infection of host cells, an attachment protein (G), which binds to cell surface receptors, and a fusion (F) protein, which carries out the process of virus-cell membrane fusion. The G protein binds to ephrin B2/3 receptors, inducing G conformational changes that trigger F protein refolding. Using an optical approach based on second harmonic generation, we show that monomeric and dimeric receptors activate distinct conformational changes in G. The monomeric receptor-induced changes are not detected by conformation-sensitive monoclonal antibodies or through electron microscopy analysis of G:ephrinB2 complexes. However, hydrogen/deuterium exchange experiments confirm the second harmonic generation observations and reveal allosteric changes in the G receptor binding and F-activating stalk domains, providing insights into the pathway of receptor-activated virus entry.Nipah virus causes encephalitis in humans. Here the authors use a multidisciplinary approach to study the binding of the viral attachment protein G to its host receptor ephrinB2 and show that monomeric and dimeric receptors activate distinct conformational changes in G and discuss implications for receptor-activated virus entry

    Strong correlation effects in the doped Hubbard model in infinite dimensions

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    The density of states and the optical conductivity of the doped Hubbard model on a Bethe lattice with infinite connectivities have been studied using an analytic variant of the Lanczos continued fraction method. The spectral weight of the gap states and the position of the chemical potential upon hole or electron doping have been studied. We argue that the strong correlation effects such as gap states and midinfrared band shown in two dimensions also appear in infinite dimensions.Comment: 9 pages, revtex, 3 figures upon reques
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