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Fast Access (fast + access)

Distribution by Scientific Domains
Chemistry25%

Selected Abstracts

A Fast Access to Non-Symmetrically Substituted 1,3-Alternate Conformers of Calix[4]arenes

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2004
Arjan W. Kleij
Abstract A simple and direct protocol is reported for the synthesis of the first non-symmetrically substituted 1,3-alternate conformers of calix[4]arenes by selective mono-deacylation of a tribenzoyl precursor under basic conditions, followed by dialkylation. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

ChemInform Abstract: Acid-Catalyzed Skeletal Rearrangement of Epoxy Alkynes: A Fast Access to Highly Functionalized Allenes.

CHEMINFORM, Issue 48 2009
Zhao-Jing Zheng
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Multiversion concurrency control for the generalized search tree

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 12 2009
Walter Binder
Abstract Many read-intensive systems where fast access to data is more important than the rate at which data can change make use of multidimensional index structures, like the generalized search tree (GiST). Although in these systems the indexed data are rarely updated and read access is highly concurrent, the existing concurrency control mechanisms for multidimensional index structures are based on locking techniques, which cause significant overhead. In this article we present the multiversion-GiST (MVGiST), an in-memory mechanism that extends the GiST with multiversion concurrency control. The MVGiST enables lock-free read access and ensures a consistent view of the index structure throughout a reader's series of queries, by creating lightweight, read-only versions of the GiST that share unchanging nodes among themselves. An example of a system with high read to write ratio, where providing wait-free queries is of utmost importance, is a large-scale directory that indexes web services according to their input and output parameters. A performance evaluation shows that for low update rates, the MVGiST significantly improves scalability w.r.t. the number of concurrent read accesses when compared with a traditional, locking-based concurrency control mechanism. We propose a technique to control memory consumption and confirm through our evaluation that the MVGiST efficiently manages memory. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Wireless provision of true VoD services and fast access to Internet

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2002
E. Pallis
Abstract The evolution of digital compression techniques has made possible the provision of full-motion video services through networking infrastructures of sufficient bandwidth. This paper presents a wireless broadband network, which is capable of providing true interactive VoD services (with full VCR functions) and fast access to Internet to a number of simultaneous clients. The network is based on frequency hopping spread spectrum (FHSS) technology operating in the 2.4 GHz frequency band. The paper describes the system architecture and configuration adopted in a real environment trial and elaborates on the provided picture quality in a multi-client environment. Copyright © 2002 John Wiley & Sons, Ltd. [source]

World Vision case study of Sigma, an analysis tool based on the Alterian database engine

INTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 4 2001
Scott Logie
One of the major issues charities have been concerned with for many years is the inability to access donor records for marketing analysis purposes,donor information has literally been locked up. Charity database tools such as Raiser's Edge and Alms have been built to provide donor details on a record-by-record basis rather than to provide summary information across the entire base. These tools carry out this function very well and have the added benefit of providing data to call centre staff as they make or receive calls from donors. As each charity has to compete more intensely for their share of donor value, however, more detailed behavioural analysis of donor bases is required. To do this, access to the entire donor data is essential, not one record at a time, but structured in a way that allows ad hoc querying. This paper discusses the various technologies that can be used to access donor data for analytical purposes and explains the merits of a new database engine developed by Alterian that allows easy and fast access to many records across multiple data tables. It also shows how one organisation has used the engine to develop a bespoke analysis tool for the charity sector and how a leading relief and development agency, World Vision, is using this tool. Copyright © 2001 Henry Stewart Publications [source]

Telemedicine and teledermatology: Past, present and future

JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 2 2008
Elisabeth M.T. Wurm
Summary Telemedicine is an emerging field within medicine with potential to revolutionize the delivery of health care. It is defined as the use of telecommunication technologies to transfer medical information.Teledermatology is a category of telemedicine. Early experiments were already made at the beginning of the 20th century, the breakthrough happened in the nineties because of the rapid progress of telecommunication technology. The latest advance is mobile telemedicine which is characterized by the use of mobile devices such as mobile phone and PDA (personal digital assistant).Advantages of telemedicine are the possibility of remote patient-care as well as the easy and fast access to expert opinions and education. This can either happen through exchange of previously stored data/images (store-and-forward method) or in real time. Since our society is increasingly becoming interconnected via technical advances, it is essential that medicine also has an objective understanding of the topic. [source]

The possible functions of involuntary autobiographical memories

APPLIED COGNITIVE PSYCHOLOGY, Issue 8 2009
Anne S. Rasmussen
Involuntary autobiographical memories are memories of personal experiences that come to mind spontaneously,that is with no preceding attempt at retrieval. We propose that such memories form a basic mode of remembering that is as frequent, common and functional as voluntary remembering but presumably evolutionarily earlier than the latter. In contrast to voluntary recall, the activation of involuntary memories involves little executive control. It typically depends on a distinct feature-overlap between the remembered and current situation, which favours the activation of specific episodic information. Involuntary remembering may serve the overarching function of providing a sense of continuity across time, thereby automatically updating our personal sense of existence. Furthermore, since involuntary memories yield fast access to memories of specific events with a distinctive content-overlap to the current situation, they may serve important directive functions in novel situations. Copyright © 2009 John Wiley & Sons, Ltd. [source]