189,710 research outputs found
Estimates of the bistable region in metal cutting
No full textThe classical model of regenerative vibration is investigated with new kinds of nonlinear cutting force characteristics. The standard nonlinear characteristics are subjected to a critical review from the nonlinear dynamics viewpoint based on the experimental results available in the literature. The proposed nonlinear model includes finite derivatives at zero chip thickness and has an essential inflexion point. In the case of the one degree-of-freedom model of orthogonal cutting, the existence of unstable self-excited vibrations is proven along the stability limits, which is strongly related to the force characteristic at its inflexion point. An analytical estimate is given for a certain area below the stability limit where stable stationary cutting and a chaotic attractor coexist. It is shown how this domain of bistability depends on the theoretical chip thickness. The comparison of these results with the experimental observations and also with the subcritical Hopf bifurcation results obtained for standard nonlinear cutting force characteristics provides relevant information on the nature of the cutting force nonlinearit
Description Abrégée Du Pays De Kamtschatka : tirée de la traduction allemande de M. Tobie Koehler faite sur l'original Anglois de MM. Grieve & Jeffreys / par Mr. A. P.
No full textAuszug/Zusammenfassung des Werkes Opisanie Zemli Kamtschatki von Stepan KrascheninnikowVollst. Namensformen und vermutl. Verfasser anhand des Originaltitels ermitteltAutopsie nach Exemplar der ULB Sachsen-AnhaltVorlageform des Erscheinungsvermerks: A Erlang Chés Wolfgang Walther 1768
China's new type rural social insurance pension (NRSIP): transposition central government pilot guidelines into local documents
No full text<p>The list provides an overview of how the pilot guidelines issued by the central government have been transposed into local documents (provincial level).</p>
<p>Matthias Stepan has compiled the data and information in the period 2009-2013. It has been part of his dissertation project at VU University Amsterdam.</p>Matthias Stepan has compiled the data and information in the period 2009-2013. It has been part of his dissertation project at VU University Amsterdam
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
SPECIFICITY OF ZOOMORPHIC IMAGE OF WOLF AS MYTHOLOGICAL AND CULTURAL CONSTANT (ON THE BASIS OF SALISH AND SOME PALEO-SIBERIAN MYTHOLOGIC TRADITIONS)
No full text<p><span>The paper examines the semantic specificity of the image of a wolf in the mythological and folklore tradition of the indigenous peoples of North America (namely, the Salish tribes), as well as a number of speakers of Paleo-Siberian languages (Itelmen and Chukchi, in particular). It is shown that this image is marked as a salient cultural constant in the mythological, ethnocultural and linguistic-cultural traditions mentioned above. At the same time this constant has a certain duality: for example, in Salish mythology, the wolf can act both as the creator of the world, and as a trickster and jester. Various lexical units representing the semantics of a given mythological image, both of an appellative nature and proper names (place names), are explored. Such place names examples are provided. In the authors' view, they stress the significance of the wolf image for Salish mythological and linguistic tradition. In conclusion, the similarities and differences in this image semantics in the mythological traditions under consideration are established. A hypothesis is made about the causes of the semantic convergence of these images in a number of aspects.</span></p>
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
СОЦІАЛЬНО-ЕКОНОМІЧНА ПРОБЛЕМАТИКА У ПРАЦЯХ СТЕПАНА КАЧАЛИ. (SOCIAL AND ECONOMIC PERSPECTIVE IN STEPAN KACHALA'S WORKS).
No full textСтаття висвітлює роль Степана Качали у дослідженні соціальних і економічних аспектів життя селян, у становленні та розвитку кооперативного руху на території Східної Галичини в кінці ХІХ ст.
(The article lights up the role of Stepan Kachala in researches social and economic aspects of life of peasants and becoming and development the cooperative motion on territory of East Galychina in second part ofXIX century.
Contributions of Stepan V Lomov to the research and development of composite materials
No full textThis paper presents a comprehensive review of the scientific and engineering contributions of Prof. Stepan V. Lomov in a career spanning over 3 decades. Starting from his early work on the modelling of dry textiles, different aspects of composite materials have benefited from his inspiring contribution. His wide scientific curiosity drove the research on several topics, covering permeability, forming, damage, fatigue, nano-engineered composites, as well as development of analytical and numerical models at different scales. The paper presents a full spectrum of his scientific career aiming to link his achievements and the future research on composite materials
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
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