Search (31 results, page 1 of 2)

0.018883549 = product of:
  0.06609242 = sum of:
    0.04489393 = weight(_text_:interactions in 1262) [ClassicSimilarity], result of:
      0.04489393 = score(doc=1262,freq=2.0), product of:
        0.22965278 = queryWeight, product of:
          5.8977947 = idf(docFreq=329, maxDocs=44218)
          0.038938753 = queryNorm
        0.19548613 = fieldWeight in 1262, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.8977947 = idf(docFreq=329, maxDocs=44218)
          0.0234375 = fieldNorm(doc=1262)
    0.021198487 = weight(_text_:with in 1262) [ClassicSimilarity], result of:
      0.021198487 = score(doc=1262,freq=16.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.22591603 = fieldWeight in 1262, product of:
          4.0 = tf(freq=16.0), with freq of:
            16.0 = termFreq=16.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0234375 = fieldNorm(doc=1262)
  0.2857143 = coord(2/7)

Abstract

The Z39.50 standard for information retrieval is important from a number of perspectives. While still not widely known within the computer networking community, it is a mature standard that represents the culmination of two decades of thinking and debate about how information retrieval functions can be modeled, standardized, and implemented in a distributed systems environment. And - importantly -- it has been tested through substantial deployment experience. Z39.50 is one of the few examples we have to date of a protocol that actually goes beyond codifying mechanism and moves into the area of standardizing shared semantic knowledge. The extent to which this should be a goal of the protocol has been an ongoing source of controversy and tension within the developer community, and differing views on this issue can be seen both in the standard itself and the way that it is used in practice. Given the growing emphasis on issues such as "semantic interoperability" as part of the research agenda for digital libraries (see Clifford A. Lynch and Hector Garcia-Molina. Interoperability, Scaling, and the Digital Libraries Research Agenda, Report on the May 18-19, 1995 IITA Libraries Workshop, <http://www- diglib.stanford.edu/diglib/pub/reports/iita-dlw/main.html>), the insights gained by the Z39.50 community into the complex interactions among various definitions of semantics and interoperability are particularly relevant. The development process for the Z39.50 standard is also of interest in its own right. Its history, dating back to the 1970s, spans a period that saw the eclipse of formal standards-making agencies by groups such as the Internet Engineering Task Force (IETF) and informal standards development consortia. Moreover, in order to achieve meaningful implementation, Z39.50 had to move beyond its origins in the OSI debacle of the 1980s. Z39.50 has also been, to some extent, a victim of its own success -- or at least promise. Recent versions of the standard are highly extensible, and the consensus process of standards development has made it hospitable to an ever-growing set of new communities and requirements. As this process of extension has proceeded, it has become ever less clear what the appropriate scope and boundaries of the protocol should be, and what expectations one should have of practical interoperability among implementations of the standard. Z39.50 thus offers an excellent case study of the problems involved in managing the evolution of a standard over time. It may well offer useful lessons for the future of other standards such as HTTP and HTML, which seem to be facing some of the same issues.
This paper, which will appear in two parts, starting with this issue of D-Lib, looks at several strategic issues surrounding Z39.50. After a relatively brief overview of the function and history of the protocol, I will examine some of the competing visions of the protocol's role, with emphasis on issues of interoperability and the incorporation of semantics. The second installment of the paper will look at questions related to the management of the standard and the standards development process, with emphasis on the scope of the protocol and how that relates back again to interoperability questions. The paper concludes with a discussion of the adoption and deployment of the standard, its relationship to other standards, and some speculations on future directions for the protocol. This paper is not intended to be a tutorial on the details of how current or past versions of Z39.50 work. These technical details are covered not only in the standard itself (which can admittedly be rather difficult reading) but also in an array of tutorial and review papers (see <http://lcweb.loc.gov/z3950/agency> for bibliographies and pointers to on-line information on Z39.50). Instead, the paper's focus is on how and why Z39.50 developed the way it did, and the conceptual debates that have influenced its evolution and use. While a detailed technical knowledge of the operation of Z39.50 is certainly helpful, it should not be necessary in order to follow most of the material here. Some disclaimers are in order. I have been actively involved in the development of Z39.50 since the early 1980s and have been a participant -- and on occasion, even an instigator -- of some of the activities described here. This paper is an attempt to make a critical assessment of the current state of Z39.50 and a review of its development with the full benefit of hindsight. It recounts a number of debates that occurred within the developer community over the past years. In many of these, I advocated specific positions or approaches, sometimes successfully and sometimes unsuccessfully. What is presented here is one person's perspective - mine --, which is sometimes at odds with the current consensus with the developer community; I've tried to represent opposing views fairly, and to differentiate my opinions from fact or consensus. However, others will undoubtedly disagree with many of the comments here.

0.010272195 = product of:
  0.03595268 = sum of:
    0.017487857 = weight(_text_:with in 3696) [ClassicSimilarity], result of:
      0.017487857 = score(doc=3696,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.1863712 = fieldWeight in 3696, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0546875 = fieldNorm(doc=3696)
    0.018464822 = product of:
      0.036929645 = sum of:
        0.036929645 = weight(_text_:22 in 3696) [ClassicSimilarity], result of:
          0.036929645 = score(doc=3696,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.2708308 = fieldWeight in 3696, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0546875 = fieldNorm(doc=3696)
      0.5 = coord(1/2)
  0.2857143 = coord(2/7)

Abstract

Provides examples to illustrate the growing use and acceptance of remote access to OPACs. Examines the differences between offering in-house public access and remote access to users and offers suggestions to help address some of the requirements of remote users. Discusses the shortcomings of the bibliographic record, what can be done to enhance the OPAC record, remote access to periodical indexes, access to the physical items represented by the bibliographic records, and the importance of establishing lines of communication with remote users

Date

8. 1.2007 17:22:42

0.0060293297 = product of:
  0.042205308 = sum of:
    0.042205308 = product of:
      0.084410615 = sum of:
        0.084410615 = weight(_text_:22 in 4147) [ClassicSimilarity], result of:
          0.084410615 = score(doc=4147,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.61904186 = fieldWeight in 4147, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.125 = fieldNorm(doc=4147)
      0.5 = coord(1/2)
  0.14285715 = coord(1/7)

Source

Cogito. 9(1993) H.2, S.18-22

0.005275664 = product of:
  0.036929645 = sum of:
    0.036929645 = product of:
      0.07385929 = sum of:
        0.07385929 = weight(_text_:22 in 8109) [ClassicSimilarity], result of:
          0.07385929 = score(doc=8109,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.5416616 = fieldWeight in 8109, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.109375 = fieldNorm(doc=8109)
      0.5 = coord(1/2)
  0.14285715 = coord(1/7)

Source

Cogito. 10(1994) H.4, S.17-22

0.005275664 = product of:
  0.036929645 = sum of:
    0.036929645 = product of:
      0.07385929 = sum of:
        0.07385929 = weight(_text_:22 in 2656) [ClassicSimilarity], result of:
          0.07385929 = score(doc=2656,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.5416616 = fieldWeight in 2656, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.109375 = fieldNorm(doc=2656)
      0.5 = coord(1/2)
  0.14285715 = coord(1/7)

Date

30.11.1995 20:53:22

0.004521997 = product of:
  0.031653978 = sum of:
    0.031653978 = product of:
      0.063307956 = sum of:
        0.063307956 = weight(_text_:22 in 354) [ClassicSimilarity], result of:
          0.063307956 = score(doc=354,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.46428138 = fieldWeight in 354, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.09375 = fieldNorm(doc=354)
      0.5 = coord(1/2)
  0.14285715 = coord(1/7)

Source

Com!. 1997, H.8, S.22-24

0.004521997 = product of:
  0.031653978 = sum of:
    0.031653978 = product of:
      0.063307956 = sum of:
        0.063307956 = weight(_text_:22 in 5935) [ClassicSimilarity], result of:
          0.063307956 = score(doc=5935,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.46428138 = fieldWeight in 5935, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.09375 = fieldNorm(doc=5935)
      0.5 = coord(1/2)
  0.14285715 = coord(1/7)

Footnote

Rez. in: Internet Professionell 2000, H.2, S.22

0.004282741 = product of:
  0.029979186 = sum of:
    0.029979186 = weight(_text_:with in 3099) [ClassicSimilarity], result of:
      0.029979186 = score(doc=3099,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.3194935 = fieldWeight in 3099, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.09375 = fieldNorm(doc=3099)
  0.14285715 = coord(1/7)

Abstract

Reviews the pros and cons of providing library clients with access to remote OPACs and comments on the use of electronic communications as an alternative to the traditional conference

0.004282741 = product of:
  0.029979186 = sum of:
    0.029979186 = weight(_text_:with in 3162) [ClassicSimilarity], result of:
      0.029979186 = score(doc=3162,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.3194935 = fieldWeight in 3162, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.09375 = fieldNorm(doc=3162)
  0.14285715 = coord(1/7)

Abstract

A special issue devoted to articles dealing with the ISO Reference Model for Open Distributed Processing

0.004037807 = product of:
  0.02826465 = sum of:
    0.02826465 = weight(_text_:with in 6436) [ClassicSimilarity], result of:
      0.02826465 = score(doc=6436,freq=4.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.30122137 = fieldWeight in 6436, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0625 = fieldNorm(doc=6436)
  0.14285715 = coord(1/7)

Abstract

Networks allow different users from outside the library to have remote access to library catalogues. These remote users may face problems that differ from the OPAC users' in the library. They may not be comfortable with the computer technology and may not be familiar with the OPAC of the library. Libraries should offer different support services from those provided to on-site users. These users need technical advice as well as special instruction aids and guides to lead them to the information they want to retrieve

0.0037683311 = product of:
  0.026378317 = sum of:
    0.026378317 = product of:
      0.052756634 = sum of:
        0.052756634 = weight(_text_:22 in 877) [ClassicSimilarity], result of:
          0.052756634 = score(doc=877,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.38690117 = fieldWeight in 877, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.078125 = fieldNorm(doc=877)
      0.5 = coord(1/2)
  0.14285715 = coord(1/7)

Pages

S.22-31

0.0037683311 = product of:
  0.026378317 = sum of:
    0.026378317 = product of:
      0.052756634 = sum of:
        0.052756634 = weight(_text_:22 in 2955) [ClassicSimilarity], result of:
          0.052756634 = score(doc=2955,freq=2.0), product of:
            0.13635688 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.038938753 = queryNorm
            0.38690117 = fieldWeight in 2955, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.078125 = fieldNorm(doc=2955)
      0.5 = coord(1/2)
  0.14285715 = coord(1/7)

Date

19. 2.1999 20:21:22

0.003568951 = product of:
  0.024982655 = sum of:
    0.024982655 = weight(_text_:with in 6770) [ClassicSimilarity], result of:
      0.024982655 = score(doc=6770,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.2662446 = fieldWeight in 6770, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.078125 = fieldNorm(doc=6770)
  0.14285715 = coord(1/7)

Abstract

Describes the asynchronous transfer mode (ATM) protocol, technology and architecture, as well as the issues which it is designed to solve. Traces the evolution of ATM and examines the applications for which ATM is likely to be used. Describes comparisons made with alternative networking technologies and matters which require further solution

0.003568951 = product of:
  0.024982655 = sum of:
    0.024982655 = weight(_text_:with in 809) [ClassicSimilarity], result of:
      0.024982655 = score(doc=809,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.2662446 = fieldWeight in 809, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.078125 = fieldNorm(doc=809)
  0.14285715 = coord(1/7)

0.003568951 = product of:
  0.024982655 = sum of:
    0.024982655 = weight(_text_:with in 5155) [ClassicSimilarity], result of:
      0.024982655 = score(doc=5155,freq=8.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.2662446 = fieldWeight in 5155, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0390625 = fieldNorm(doc=5155)
  0.14285715 = coord(1/7)

Abstract

Hinich and Molyneux review the literature of internet measurement and note three results consistently to be found in network traffic studies. These are "self-similarity," "long-range dependence," by which is meant that events in one time are correlated with events in a previous time and remain so through longer time periods than expected, and "heavy tails" by which they mean many small connections with low byte counts and a few long connections with large byte counts. The literature also suggests that conventional time series analysis is not helpful for network analysis. Using a single day's traffic at the Berkeley National Labs web server, cumulated TCP flows were collected, log transforms were used with the adding of .01 to all values allowing log transforms of the zero values, and providing a distribution that overcomes the heavy tail problem. However, Hinich's bicorrelation test for nonlinearity using overlapping moving windows found strong evidence of nonlinear structures. Time series analysis assumes linear systems theory and thus additivity and scalability. Spectral analysis should provide large peaks at the lowest frequencies if long range dependence is present since the power spectrum would go to infinity if the frequency goes to zero. This does not occur and so long range dependence must be questioned, at least until it is determined what effect other OSI layers may have on the TCP data.

0.0035330812 = product of:
  0.024731567 = sum of:
    0.024731567 = weight(_text_:with in 4216) [ClassicSimilarity], result of:
      0.024731567 = score(doc=4216,freq=4.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.2635687 = fieldWeight in 4216, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0546875 = fieldNorm(doc=4216)
  0.14285715 = coord(1/7)

Abstract

Hartford University mounted a DRA Atlas Integrated library system in 1991, using a DECnet/Ethernet network and a VAX 6310 mainframe computer. As VAX VT320 terminals were available in many campus buildings, the library's catalogue could be searched from many locations and could be dialed up by remote users. Commercial databases in MARC format could be mounted on the system and searched with the same commands that users employed for the OPAC. Explains the use of Periodical Abstracts from UMI on the online catalogue. Discusses searching strategies and compares the Periodical Abstracts Ondisc CD-ROM with the tape loaded product

0.0028551605 = product of:
  0.019986123 = sum of:
    0.019986123 = weight(_text_:with in 3102) [ClassicSimilarity], result of:
      0.019986123 = score(doc=3102,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.21299566 = fieldWeight in 3102, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0625 = fieldNorm(doc=3102)
  0.14285715 = coord(1/7)

Abstract

This report presents the results of a survey of users who access the University of California's online union catalog, the MELVYL library system, via microcomputers with modems or connections carried through local or wide area networks. The report includes descriptive statistics on user location, status, subject interest, affiliation, in-library versus out-of-library usage patterns, need for assistance, and desire for new features

0.0028551605 = product of:
  0.019986123 = sum of:
    0.019986123 = weight(_text_:with in 3103) [ClassicSimilarity], result of:
      0.019986123 = score(doc=3103,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.21299566 = fieldWeight in 3103, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0625 = fieldNorm(doc=3103)
  0.14285715 = coord(1/7)

Abstract

Describes the design of a front end enabling users to access a library's OPAC from locations remote from the physical libraries themselves. Current technological developments are renewed with reference to 10 years' experience of remote public access at the National Technical Library, Denmark

0.0028551605 = product of:
  0.019986123 = sum of:
    0.019986123 = weight(_text_:with in 1589) [ClassicSimilarity], result of:
      0.019986123 = score(doc=1589,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.21299566 = fieldWeight in 1589, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0625 = fieldNorm(doc=1589)
  0.14285715 = coord(1/7)

Abstract

Computer and communications technology is having a profound impact on libraries and the way in which they serve their users. Discusses online catalogues in libraries, the development of the Internet and OSI, and the development of search and retrieve (SR) protocols to allow standardized access to library catalogues across communications networks. Considers the deployment of SR protocols, problems with interoperability of clients and servers, interlibrary loan possibilities of SR protocols, and the feasibility of electronic document delivery

0.0028551605 = product of:
  0.019986123 = sum of:
    0.019986123 = weight(_text_:with in 2604) [ClassicSimilarity], result of:
      0.019986123 = score(doc=2604,freq=2.0), product of:
        0.09383348 = queryWeight, product of:
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.038938753 = queryNorm
        0.21299566 = fieldWeight in 2604, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.409771 = idf(docFreq=10797, maxDocs=44218)
          0.0625 = fieldNorm(doc=2604)
  0.14285715 = coord(1/7)