共查询到20条相似文献，搜索用时 15 毫秒
1.
L. Egghe 《Journal of Informetrics》2011,5(3):439-445
We define the generalized Wu- and Kosmulski-indices, allowing for general parameters of multiplication or exponentiation. We then present formulae for these generalized indices in a Lotkaian framework.Next we characterise these indices in terms of their dependence on the quotient of the average number of items per source in the m-core divided by the overall average (m is any generalized Wu- or Kosmulski-index).As a consequence of these results we show that the fraction of used items (used in the definition of m) in the m-core is independent of the parameter and equals one divided by the overall average. 相似文献
2.
《Journal of Informetrics》2007,1(1):59-67
Statistical distributions in the production of information are most often studied in the framework of Lotkaian informetrics. In this paper, we recall some results of basic theory of Lotkaian informetrics, then we transpose methods (Theorem 1) applied to Lotkaian distributions by Leo Egghe (Theorem 2) to the exponential distributions (Theorem 3, Theorem 4). We give examples and compare the results (Theorem 5). Finally, we propose to widen the problem using the concept of exponential informetric process (Theorem 6). 相似文献
3.
《Journal of Informetrics》2014,8(3):491-492
We clarify the content of the article “Impact coverage of the success-index” by Leo Egghe and show that its real contribution is showing that for a Lotkaian system it is possible to determine a threshold value as a function of the system's parameters such that the value of the success-index corresponding to this threshold value is equal to the h-index and similar indices. It is observed that these results do not strictly hold in discrete systems. 相似文献
4.
陈昭锋 《中国科技资源导刊 (中国信息导报)》2011,(1):9-17
从自主创新源建设视角来研究区域科技资源配置是研究自主创新的新思路。科技资源集聚型配置是自主创
新源能力建设的重要机制。自主创新源建设既是我国创新型国家的重要战略目标,也是促进我国经济社会转型和产业升
级的重要基础。利用经济社会转型和产业升级的契机、利用改革开放率先一步的条件,让长三角先进城市成为世界自主
创新源,是本课题研究的重要出发点。 相似文献
5.
Giovanna F. Miranda Luisa Vercellesi Edoardo Pozzi Flavia Bruno 《Health information and libraries journal》2009,26(1):39-46
Background: Health authorities, hospitals, commercial enterprises, and mass media all deliver health and medical communication in different forms. With such a vast amount of biomedical and clinical information available, any action to ensure the spread of clinically relevant news items is welcome. Objectives: This paper tries to define a new role for health science librarians in improving medical communication and reporting. Methods: Literature relating to the health and medical reporting is analysed to identify major difficulties encountered by health communicators. Results: There are two areas where health science librarians can develop new roles in health communication: (i) supporting journalists and health communicators in selecting sources and understanding scientific papers, and (ii) directly translating scientific information into news items, supplying a list of products in this direction (i.e. targeted newsletters, media releases, news items). New skills and competencies needed to cope with the new roles are described in detail in a suggested academic curriculum for health communicators. Conclusions: A better understanding of the mass media's needs can provide much needed support in the field of health communication. 相似文献
6.
Daniel Torres-Salinas Rosa Rodríguez-Sánchez Nicolás Robinson-García J. Fdez-Valdivia J.A. García 《Journal of Informetrics》2013,7(2):412-424
In this paper we provide the reader with a visual representation of relationships among the impact of book chapters indexed in the Book Citation Index using information gain values and published by different academic publishers in specific disciplines. The impact of book chapters can be characterized statistically by citations histograms. For instance, we can compute the probability of occurrence of book chapters with a number of citations in different intervals for each academic publisher. We predict the similarity between two citation histograms based on the amount of relative information between such characterizations. We observe that the citation patterns of book chapters follow a Lotkaian distribution. This paper describes the structure of the Book Citation Index using ‘heliocentric clockwise maps’ which allow the reader not only to determine the grade of similarity of a given academic publisher indexed in the Book Citation Index with a specific discipline according to their citation distribution, but also to easily observe the general structure of a discipline, identifying the publishers with higher impact and output. 相似文献
7.
This paper demonstrates the application of module arithmetic for controlling the level of information security by a new technique referred as integer splitting. The basic definitions and concepts of the method are provided. The mathematical function of arising transformation is described in detail; its properties were studied and the basic theorems were proven that justify the use of splitting in practical applications. An active system was designed and characteristic cases of its operation are considered. 相似文献
8.
The explosion of content in distributed information retrieval (IR) systems requires new mechanisms in order to attain timely and accurate retrieval of unstructured text. This paper shows how to exploit locality by building, using, and searching partial replicas of text collections in a distributed IR system. In this work, a partial replica includes a subset of the documents from larger collection(s) and the corresponding inference network search mechanism. For each query, the distributed system determines if partial replica is a good match and then searches it, or it searches the original collection. We demonstrate the scenarios where partial replication performs better than systems that use caches which only store previous query and answer pairs. We first use logs from THOMAS and Excite to examine query locality using query similarity versus exact match. We show that searching replicas can improve locality (from 3 to 19%) over the exact match required by caching. Replicas increase locality because they satisfy queries which are distinct but return the same or very similar answers. We then present a novel inference network replica selection function. We vary its parameters and compare it to previous collection selection functions, demonstrating a configuration that directs most of the appropriate queries to replicas in a replica hierarchy. We then explore the performance of partial replication in a distributed IR system. We compare it with caching and partitioning. Our validated simulator shows that the increases in locality due to replication make it preferable to caching alone, and that even a small increase of 4% in locality translates into a performance advantage. We also show a hybrid system with caches and replicas that performs better than each on their own. 相似文献
9.
Philip Calvert 《Public Library Quarterly》2018,37(2):222-228
ABSTRACTAfter books and other items are deselected from the library, there remains the problem of what to do with them. Traditional means of disposal such as taking books to the tip can mean a public relations disaster is lying in wait. As alternatives, libraries have given away books to organizations that will value them, or they can sell discarded items to generate revenue. Book sales have changed significantly with the widespread adoption of the Web because this creates a much larger potential market than could be reached with sales in the library. There are many companies that take and onsell discarded library books; some are for profit and some are social businesses. Another option is to sell books to recycling companies because paper recycling is becoming much more widespread. The last, newest, and most innovative option is ‘upcycling’, which means using an old discarded library book to make something new, such as a desk, shoes, or even a chandelier. 相似文献
10.
11.
《Communication monographs》2012,79(3):245-268
Infante and Wigley's (1986) Verbal Aggressiveness Scale (VAS) is a widely accepted and frequently used measure of trait verbal aggression. Although the scale is almost always scored as if it were unidimensional, previous factor analytic studies provide evidence that it is multidimensional with two distinct factors. The present studies (N = 194 and 177) used confirmatory factor analysis to replicate the two‐factor solution. The two‐factor model was consistent with the data, and provides a better fit to the data than the unidimensional solution. The first factor, comprised of all aggressively worded, nonreflected items, appears to measure verbal aggressiveness as intended whereas the second factor, comprised of all reverse‐scored items (benevolently worded), appears to measure a communication style related to other‐esteem confirmation and supportiveness. Given this interpretation, it is recommended that only the 10 aggressively worded items be scored. Hamilton, Buck, and Chory‐Assad, in an adversarial collaborative discussion, agree that the VAS is bidimensional, but offer an alternative conceptual model. They hold that the two factors reflect selfish individualism and prosocial cooperation. 相似文献
12.
《Microprocessing and Microprogramming》1995,41(5-6):359-372
Most of the proposed VLSI dictionary machines appearing in the literature were designed to fit in one chip only. If the number of acquired elements is larger than that of VLSI cells, another chip has to be designed and manufactured to take a larger dictionary into account. In this paper, we propose a new design for dictionary machines that assembles blocks of standard existing dictionary machines. Our machine is as efficient as the best machines described in the literature, with the enormous advantage of scaling up quite easily, with no degradation of its performance, by simply adding more and more standard blocks. 相似文献
13.
Abstract Even though e‐commerce almost disappeared from public discussion, it still assumes a vital role in the strategic management of most enterprises. New entry in e‐commerce, whether as a new business segment of an established company or as a new enterprise, is likely to deal with the liabilities of size and newness. The aim of this paper it to discuss if those factors have an impact on the implementation and success of B2C e‐commerce. We chose the online book market as our reference market and drew a random sample of retailers and publishers with an online shop. The quality of the web presence, indirect success (number of links to a particular site) and direct success (turnover of the web shop) were compared in subsamples constructed by the use of median splits according to age and size. Younger companies and larger companies were found to have a web presence of higher quality and were more successful than older or smaller companies. We conclude that the liabilities of newness do not seem to have an adverse performance impact in e‐commerce. However, when a market entry is considered, new players must ensure that they can commit enough resources to build a high quality web presence. 相似文献
14.
《College & Undergraduate Libraries》2013,20(2):99-106
Abstract To determine if research findings from large academic, research libraries on the number of public access terminals needed apply to smaller libraries, the author compared results of a study done at a large research institution to one done at a mid-sized university. The data were different. This is important because the active automation market is currently thriving at smaller libraries, not larger ones, and because environment/size does seem to be critical to the consideration of automation parameters. Thus, smaller libraries should establish their own parameters and employ models generated at large institutions only as a general recipe. 相似文献
15.
《Journal of Informetrics》2007,1(3):185-192
In this paper, we propose two methods for scoring scientific output based on statistical quantile plotting. First, a rescaling of journal impact factors for scoring scientific output on a macro level is proposed. It is based on normal quantile plotting which allows to transform impact data over several subject categories to a standardized distribution. This can be used in comparing scientific output of larger entities such as departments working in quite different areas of research. Next, as an alternative to the Hirsch index [Hirsch, J.E. (2005). An index to quantify an individuals scientific research output. Proceedings of the National Academy of Sciences of the United States of America, 102(46), 16569–16572], the extreme value index is proposed as an indicator for assessment of the research performance of individual scientists. In case of Lotkaian–Zipf–Pareto behaviour of citation counts of an individual, the extreme value index can be interpreted as the slope in a Pareto–Zipf quantile plot. This index, in contrast to the Hirsch index, is not influenced by the number of publications but stresses the decay of the statistical tail of citation counts. It appears to be much less sensitive to the science field than the Hirsch index. 相似文献
16.
17.
Robert Waller 《文物保护研究》2018,63(5):288-292
ABSTRACTThe Royal British Columbia Museum (RBCM), Canada, houses a collection of almost 7 million artifacts, archival records, and natural history specimens. Three comprehensive collection risk assessments over the past decade have resulted in improvements to the physical environments of the collections as well as new policies and procedures to reduce risk. However, there remain ongoing risks that can only be mitigated through major facility renewal. The last collection risk assessment, completed in 2016, was revisited to review the data and build a defensible case for funding to replace the RBCM's on-site collection storage facilities. Changes to overall collections risk is a complex function of collection development and use trends, evolving risk factors both internal and external to the museum, a growing understanding of the relationship between risks and preservation, in addition to reduction due to risk mitigation projects and building systems aging and wearing out. A defensible method for illustrating the facilities-related risks over time involves estimating the expected loss of individual collection items or loss in value of a group of items that may occur if a major facility upgrade or redevelopment is not realized in the near future. Risk assessment data for representative collection units were reviewed to differentiate risk due to permanent facility characteristics versus more active controls, operations budget controlled risk versus capital budget controlled risk, and collection management-controlled risk versus facility management-controlled risk. This enabled the risk model to isolate risks that could only be mitigated through major facility upgrades. Change in collection value was expressed as Object Equivalents Lost (OEL) and its compliment Object Equivalents Remaining (OER). Projections into the future indicating the effect of varying facility renewal dates could then be clearly shown. Losses, when presented as numbers of items expected to be lost from the collection, become emotionally salient to persons in senior management and governance roles. 相似文献
18.
One function of a call number is to organize the library collection to promote browsability either on the shelf or in an online catalog. This study, based on research done at the Ohio State University Libraries, examines the impact on library collection organization if call numbers are not changed to fit into the shelf list sequence. The browsability of items were tracked by assessing how many screens away titles appear from like items in the online public access catalog, if call numbers by a bibliographic utility were not changed. The study assesses whether not reviewing the call numbers affects patrons’ ability to find the items. 相似文献
19.
《资料收集管理》2013,38(1-2):41-57
Librarians must make selection decisions for their libraries based on the actual and perceived needs of their clientele. Scholars in any discipline will most likely become aware of new books in their field through the extensive reviews published in scholarly journals. Reviews in ten journals indexed by the MLA Bibliography were examined for content, timeliness, and evaluation of the reviewer, in order to determine if scholarly reviews in literature journals are useful collection development sources. The findings of the study suggest that collection development librarians at large academic libraries should use scholarly journals on a regular basis for collection development purposes, while librarians at smaller academic libraries should use them to supplement traditional trade reviewing sources, such as Choice. 相似文献
20.
《Library & information science research》2001,23(3):257-276
The information-seeking behavior of lawyers has not been fully investigated empirically. Prior work has tended to focus on legal research as the central task performed by lawyers in their information-seeking activities. This analysis of more than 150 interviews of practicing lawyers showed that legal research should not be considered information-seeking. The lawyers interviewed identified other tasks, such as administration of their law practices, as constituting problem-solving, information-seeking activities. In solving their problems, the lawyers overwhelmingly preferred informal sources when seeking information. In addition, they preferred sources of information internal to their organizations rather than external sources, although this was less true for lawyers from smaller firms. Neither the lawyer’s gender nor the size of the center in which the practice was located influenced the type of information sources chosen. The model for the information-seeking behavior of professionals advanced by another author group is discussed and modifications are suggested that create a new model offering a fuller picture of the behavior of lawyers. 相似文献