68,311 research outputs found
Introducing Microcells into Macrocellular Networks: A Case Study
No full textAbstract?The performance in terms of signal-to-interference ratio (SIR), teletraffic, and spectral efficiency of a combined macrocellular and microcellular network is investigated when either both types of cells share the same channel set, or when the channel set is partitioned between the macrocells and the microcells. The analysis is for time-division multiple access (TDMA) with frequency hopping, power control, and discontinuous transmission, and the radio channel is composed of an inverse fourth-power path loss law with log-normal fading. We commence by introducing a single microcell into a hexagonal cluster of macrocells before considering clustered microcells. Both omni-directional and sectorized cells are examined. We find that high reuse factors are required when channel sharing is employed. When channel partitioning is used, no co-channel interference occurs between the microcells and the macrocells allowing them to be planned independently. The reuse factors in the microcells and macrocells therefore do not need to be increased beyond conventional values. The outcome is that by opting for channel partitioning, the improvement in spectral efficiency compared to channel sharing is two to three times greater. Index Terms?Co-channel interference, land mobile radio cel-lular systems, time division multiaccess
Coombs L. C. et Freedman R. — Pre-marital Pregnancy, Childspacing and later Economic Achievement
No full textHo J. Coombs L. C. et Freedman R. — Pre-marital Pregnancy, Childspacing and later Economic Achievement. In: Population, 26ᵉ année, n°2, 1971. p. 236
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Molecular structure of highly excited resonant states in Mg-24 and the corresponding Be-8+O-16 and C-12+C-12 decays
No full textExotic Be-8 and C-12 decays from high-lying resonances in Mg-24 are analyzed in terms of a cluster model. The calculated quantities agree well with the corresponding experimental data. It is found that the calculated decay widths are very sensitive to the angular momentum carried by the outgoing cluster. It is shown that this property makes cluster decay a powerful tool to determine the spin as well as the molecular structures of the resonances.Physics, NuclearSCI(E)7ARTICLE5null8
Letter from J. R. Eakin to Arthur G. Ringland
No full textLetter (copy) from J. R. Eakin to Arthur C. Ringland about the alignment of 40 acres near the Buggeln ranch
Letter from Joseph R. Goodman to Claude C. Cornwall, Central Utah Relocation Center, January 13, 1943
No full textLetter from Joseph R. Goodman to Claude C. Cornwall, containing a reference letter regarding William Shiro Hoshiyama. Goodman writes that Hoshiyama and his brother John operated a grocery store before forced removal.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
Chronic hepatitis C associated with Coombs-positive hemolytic anemia
No full textHepatitis C virus (HCV) is a recognized cause of significant extrahepatic disease. Induction of autoimmune hemolytic anemia (AIHA) has been reported, either during or after interferon (IFN) treatment of HCV infection. We herein report a 56-year-old patient with HCV infection who developed severe Coombs-positive AIHA in the absence of treatment with IFN. Prednisone therapy was initiated, but intravenous immunoglobulins were added because of persistent hemolysis. Clinical course was complicated by rapid deterioration and the development of Creutzfeldt-Jakob disease. Having discarded other possible causes of AIHA, we suggest a possible association between AIHA and infection by HCV. © 2004 The European Hematology Association All right reserved.BARBOLLA L, 1993, VOX SANG, V65, P156; BJORKHOLM M, 1993, J INTERN MED, V234, P119; Chao TC, 2001, J CLIN GASTROENTEROL, V33, P232, DOI 10.1097-00004836-200109000-00014; de-la-Serna-Higuera C, 1999, J CLIN GASTROENTEROL, V28, P358, DOI 10.1097-00004836-199906000-00017; FLORES G, 1993, AM J HEMATOL, V44, P237, DOI 10.1002-ajh.2830440404; HYMAN GA, 1956, AM J MED SCI, V221, P448; JEFFERIES LC, 1994, HEMATOL ONCOL CLIN N, V8, P1087; PANUSH RS, 1973, GASTROENTEROLOGY, V64, P1015; PORTELL A, 1982, REV CLIN ESP, V64, P101; Ramos-Casals M, 2003, MEDICINE, V82, P87, DOI 10.1097-00005792-200303000-00003; Sandler SG, 2002, CURR OPIN HEMATOL, V9, P509, DOI 10.1097-01.MOH.0000034927.52450.9A; Srinivasan R, 2001, J CLIN GASTROENTEROL, V32, P245, DOI 10.1097-00004836-200103000-00015; TAKASE K, 1995, J GASTROENTEROL, V30, P795, DOI 10.1007-BF02349651; Zignego AL, 1999, J HEPATOL, V31, P369, DOI 10.1016-S0168-8278(99)80239-675
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Oblate stability of A approximate to 110 nuclei near the r-process path
No full textEven-even A approximate to 110 nuclei approaching the astrophysical r-process path have been investigated using both the cranked and the configuration-constrained shell models. The calculations show that, with increasing neutron number in the Zgreater than or equal to40 nuclides, nuclear shapes evolve from prolate, through triaxial to oblate deformations. In contrast to other regions of the nuclear chart, pronounced oblate shapes dominate the collective rotation from ground states to very high spins (Isimilar to40), when Ngreater than or equal to70. The stability of the oblate shapes is due to the simultaneous upper-shell neutron and proton Fermi surfaces, reinforced by the rotation alignment behavior of both nucleon types. Configuration-constrained calculations predict the coexistence of well-deformed prolate and oblate multiquasiparticle (isomeric) states.Physics, NuclearSCI(E)49ARTICLE2null6
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