179,226 research outputs found
Oldeman, R. A. A. — Forests : Elements of Silvology. Springer-Verlag, Berlin, Heidelberg, New York, 1990
No full textHladik Annette. Oldeman, R. A. A. — Forests : Elements of Silvology. Springer-Verlag, Berlin, Heidelberg, New York, 1990. In: Revue d'Écologie (La Terre et La Vie), tome 46, n°4, 1991. pp. 391-392
Status of the CHORUS structure function measurement
No full textThe CHORUS detector, designed to search for neutrino oscillations, was used to record a high-statistics sample of neutrino and anti- neutrino interactions during the extension of the experiment in 1998, using the lead calorimeter as a target. The measurement of the structure functions F/sub 2/(x, Q/sup 2/) and xF/sub 3/(x, Q/sup 2/) is underway. (6 refs)
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"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.
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
Bifurcations of global reinjection orbits near a saddle-node Hopf bifurcation
No full textThe saddle-node Hopf bifurcation (SNH) is a generic codimension-two bifurcation of equilibria of vector fields in dimension at least three. It has been identified as an organizing centre in numerous vector field models arising in applications. We consider here the case that there is a global reinjection mechanism, because the centre manifold of the zero eigenvalue returns to a neighbourhood of the equilibrium. Such a SNH bifurcation with global reinjection occurs naturally in applications, most notably in models of semiconductor lasers. We construct a three-dimensional model vector field that allows us to study the possible dynamics near a SNH bifurcation with global reinjection. This model follows on from our earlier results on a planar (averaged) vector field model, and it allows us to find periodic and homoclinic orbits with global excursions out of and back into a neighbourhood of the SNH point. Specifically, we use numerical continuation techniques to find a two-parameter bifurcation diagram for a well known and complicated case of a SNH bifurcation that involves the break-up of an invariant sphere. As a particular feature we find a concrete example of a phenomena that was studied theoretically by Rademacher: a curve of homoclinic orbits that accumulates on a segment in parameter space while the homoclinic orbit itself approaches a saddle periodic orbit
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.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
Five thousand years of sustainability? : a case study on Gedeo land use (Southern Ethiopia)
No full textKey words : Ethiopia, Gedeo, ensete , pacemaker , spacemaker , placemaker, agroforest, agro-ecosystem, sustainability, biodiversity.The present volume is a study of an ancient way of land use, over five thousand years old, by the Gedeo in Ethiopia. The densely populated Gedeo country (500 persons per km 2) covers highlands (range 1200 to 3000m asl) between 5 oand 7 oNorth and 38 oand 40 oEast, in the escarpment of the Rift Valley facing Lake Abaya. Based on perennial cropping, emphasis on trees in particular lends the "agroforests" a forest-like appearance. Ensete ( Ensete ventricosum (Welw.) Cheesman Musaceae) and Yirga-Chaffee, one of the world's renowned cultivars of Coffea arabica L. Rubiaceae, is grown under these trees. Largely due to their unique cropping system, the Gedeo are immune to soil erosion and famines, ravaging the Ethiopian highlands at intervals. The central theme of the present ecological study is to understand theoretical and practical aspects of the holistic Gedeo land use better, and to contribute to the design capability of the farmers. Theoretically, farm design is examined from the perspective of forest ecology. The concepts of eco-unit and agro/silvatic mosaic , at the lowest and highest levels, respectively, provide more insight in agroforests as blocks of forests, with humans assuming the roles performed by some natural forces in forests. Therefore, these agroforests remain multivalent resources. Empirically, the design is examined as farmers' day-to-day management of these resources. The study provides a strong theoretical basis in favor of Gedeo land use with its complex mix of elements to represent a multiple purpose land use from which modern day agriculture and forestry emerged as overspecialized offshoots. Gedeo land use harmonises aspects of production and protection. Agroforest components are divided into core and subsidiary components. The first type has a pacemaker role (regulation of agro-ecosystem rhythm), a spacemaker role (provision of biotope space for other crops) and/or a placemaker role (provision of living space, or niches for other organisms). Ensete and various multipurpose tree species fulfil the latter function. Annual crops, the coffee or farm animals are regarded as "fillers". Ensete , with its anatomical water-stocking and storage mechanisms and with its fibrous root system forming a mat-like structure 30 to 60 cm deep which on decomposition yields organic matter for soil maintenance, is more than a mere crop. The higher carrying capacity of Gedeo "agroforests" is traced back to the high productivity of ensete (over 5.6 tons ha -1year -1) and judicious use of accompanying crops. It has been found that six mature ensete plants ( gantticho type) feed an adult during a year. A farm household of seven persons then needs an area of no more than 0.2 hectare for a sustainable yearly supply of 42 ensete plants, gantticho type. Management is based on either single or multiple rotations. The latter is explained, using ensete as an example. Analyses revealed that the soils are clay-loam, their pH (H 2 O) ranging between 5 and 6. The limiting factor is available phosphorus (range 1.0 to 4.0 ppm). Organic matter (%) ranged between 4 and 5, total nitrogen (%) between 0.3 to 0.5, and cation exchange capacity (meq/100g soil) from 21.0 to 25.0. Gedeo soil management is organic, using as inputs crop by-products, leaf litter from multipurpose trees and "weeds", domestic wastes, rotation of dwelling sites and farmyard manure. In achieving sustained products and services from "agroforest" components, farmers' effort is mainly directed at optimisation of the interrelationships among diverse components. Number and/or mass of "agroforest" components to be harvested and planted are balanced. This fully corresponds to the Central-European concept of sustained yield forestry. No organism is intrinsically harmful to the farmers. The weedy flora, for instance, is used to protect future yield, first by providing physical cover to the soil, second by conserving soil nutrients in its biomass, later to be released to "crop" plants by mulching the weedy biomass.Gedeo land use contains elements of shifting cultivation, the basis of farmers' management at the level of an agro/silvatic-mosaic . Like in shifting cultivation, vegetation is used to regenerate exhausted land. However, unlike in shifting cultivation, this enables production and regeneration, simultaneously. Whereas shifting cultivators burn and convert mature forest plots, the Gedeo synchronize harvest and replanting. In this way, continuous use of the same plot of land is ensured indefinitely. It is concluded that this way of land use is best suited to the mountainous terrain of the Gedeo country. It is argued that through the judicious use of high-yielding and environment-friendly ensete , subsistence agriculture can stave off the recurring famine and drought-ridden image of Ethiopia. The level of employment provided by Gedeo "agroforests" is declining as a result of growing population. Therefore, there is an urgent need for assistance. The present productivity of these systems can be enhanced by carefully redesigning existing composting processes. Finding better marketing channels for the produce of the "agroforests" is a priority in the short term. Thus, organically grown arabica coffee from the Gedeo "agroforests" should be certified and processed in situ . Unused biotopes for integrating components in the system still exist or can be opened up in Gedeo "agroforests", e.g., for a multipurpose tree species such as Morinaga sp. (locally called shiferaw ), a leguminous timber tree, the leaves of which are eaten as a vegetable. Diverse species of wild mushrooms can be domesticated. Generally, ways and means should be found for cultivation of miniature crops of high value in the soil and the canopy, particularly tiny organisms such as nitrogen-processing bacteria, mycorrhizal and edible fungi (diverse mushrooms) or medicinal lichens. The Rift Valley and its inhabitants were a source of civilized human development for millennia. The present study demonstrates that principles of sustainability were successfully woven in at least some of their societies. This book therefore advocates building on this basis by studying and teaching these principles as a base for new, sustainable land use design in the Twenty First Century
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Liftings for noncomplete probability spaces
No full textThe current state of knowledge concerning liftings for noncomplete probability spaces is discussed. This is a somewhat expanded version of the author's talk given at the 1991 Summer Conference on General Topology and Applications in Honor of Mary Ellen Rudin and Her Work.PT: S; CR: BURKE MR, IN PRESS P AM MATH S BURKE MR, 1991, ISRAEL J MATH, V73, P33 BURKE MR, 1992, ISRAEL J MATH, V79, P289 CARLSON T, THEOREM LIFTING CHRISTENSEN JPR, 1974, TOPOLOGY BOREL STRUC FREMLIN DH, 1989, HDB BOOLEAN ALGEBRAS, P877 INOESCUTULCEA A, 1966, 5TH P BERK S MATH ST, V2 IONESCUTULCEA A, 1967, CONTRIBUTIONS PROB 1, P63 IONESCUTULCEA A, 1969, TOPICS THEORY LIFTIN JECH TJ, 1978, SET THEORY JOHNSON RA, 1980, P AM MATH SOC, V80, P234 JUST W, IN PRESS T AM MATH S KUPKA J, 1983, INDIANA U MATH J, V32, P717 LOSERT V, 1983, LNM, V1080, P95 MAHARAM D, 1958, P AM MATH SOC, V9, P987 SHELAH S, 1983, ISRAEL J MATH, V45, P90 TALAGRAND M, 1982, P AM MATH SOC, V84, P379 VONNEUMANN J, 1931, CRELLES J MATH, V165, P109; NR: 18; TC: 0; J9: ANN N Y ACAD SCI; PG: 4; GA: BZ86BSource type: Electronic(1
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