Search results for "database."
showing 10 items of 2119 documents
Complex objects modeling: An entity-relationship approach
1989
Facilities for complex object modeling are nowadays needed in several areas of database applications (CAD/CAM, office automation, robotics, ...). Consequently, either new models are developed, or existing ones are extended to better respond to this requirement. Current proposals in the latter category are mainly based on the relational approach (with, as major outcome, the NF2 family of models) or on functional models like DAPLEX. This paper intends to show that the entity-relationship approach may secure an equivalent result, preserving the well known advantages inherent to this approach : increased readability and graphical display of the database schema.
Combinatorial Identification of Hydrides in a Ligated Ag40 Nanocluster with Noncompact Metal Core
2019
No formation of bulk silver hydride has been reported. Until very recently, only a few silver nanoclusters containing hydrides have been successfully prepared. However, due to the lack of effective techniques and also poor stability of hydride-containing Ag nanoclusters, the identification of hydrides' location within Ag nanoclusters is challenging and not yet achieved, although some successes have been reported on clusters of several Ag atoms. In this work, we report a detailed structural and spectroscopic characterization of the [Ag40(DMBT)24(PPh3)8H12]2+ (Ag40H12) cluster (DMBT = 2,4-dimethylbenzenethiol). The metal framework consists of three concentric shells of Ag8@Ag24@Ag8, which can…
Structural characterization of β-2′-pyridylaminocrotonoyl-2-pyridylamide by ESI-MS, NMR, single crystal X-ray analysis and ab initio methods
2003
Abstract In contradiction with earlier reports 1H, 13C and 15N NMR spectra show that β-2′-pyridylaminocrotonoyl-2-pyridylamide is the only form present in chloroform solution. According to the X-ray data the same tautomer exists also in the crystal state. The studied amide has a dimeric form where the monomer molecules are held together by two intermolecular hydrogen bonds. The NMR spectral data show that there is also an intramolecular hydrogen bond in each monomer subunit. The dilution experiments and variable-temperature 1H NMR runs show that β-2′-pyridylaminocrotonoyl-2-pyridylamide tends to form the dimers also in chloroform solution at higher concentrations. The ESI-TOF MS measurement…
15N NMR: Substituent effect analysis inpara-andmeta-substituted phenylhydrazines
1994
15N NMR spectra of phenylhydrazine and of 14 para- and meta-substituted phenylhydrazines were measured at natural isotope abundance in DMSO-d6 solution. The substituent present exerts a larger influence on the chemical shift of the nitrogen atom directly bound to the aromatic ring (N-1) than on the second one (N-2), which shows an attenuated and inverted trend. The chemical shifts of N-1 and N-2 give a good cross correlation in both series of compounds if p-NO2 and m-F derivatives are excluded from the correlations of para- and meta-substituted phenylhydrazines, respectively. Moreover, N-1 SCS values show good linear correlations with Hammett substituent constants, with SCSs of directly bou…
Current neuroscientific research database findings of brain activity changes after hypnosis.
2021
Using multi-modal brain imaging techniques we found pronounced changes in neuronal activity after hypnotic trance induction whereby state changes seem to occur synchronously with the specific induction instructions. In clinical patients, hypnosis proved to be a powerful method in inhibiting the reaction of the fear circuitry structures. The aim of the present paper is to critically discuss the limitations of the current neuroscientific research database in the light of a debate in defining relevant hypnotic constructs and to suggest ideas for future research projects. We discuss the role of hypnotic suggestibility (HS), the impact of hypnotic inductions and the importance of the depth of hy…
Standard Vs Uniform Binary Search and Their Variants in Learned Static Indexing: The Case of the Searching on Sorted Data Benchmarking Software Platf…
2023
Learned Indexes are a novel approach to search in a sorted table. A model is used to predict an interval in which to search into and a Binary Search routine is used to finalize the search. They are quite effective. For the final stage, usually, the lower_bound routine of the Standard C++ library is used, although this is more of a natural choice rather than a requirement. However, recent studies, that do not use Machine Learning predictions, indicate that other implementations of Binary Search or variants, namely k-ary Search, are better suited to take advantage of the features offered by modern computer architectures. With the use of the Searching on Sorted Sets SOSD Learned Indexing bench…
Wireless Internet. 8th International Conference, WICON 2014, Lisbon, Portugal, November 13-14, 2014, Revised Selected Papers
2015
In this paper, the influence and improvement of the localization accuracy achieved using a fingerprint database with information coming from different channels and radio signal strength levels is evaluated. This study uses IEEE 802.15.4 networks with different power levels and carrier frequency channels in the 2.4 GHz band. Experimental results show that selecting part of this information with a cleverer data processing can provide similar or better localization accuracy than using the whole database.
Data management and concurrency control in broadcast based asymmetric environments
2006
Masteroppgave i informasjons- og kommunikasjonsteknologi 2006 - Høgskolen i Agder, Grimstad Tens of millions of users have personal handheld devices with several network interfaces built-in, and the number of users and of network interfaces included are only increasing. This growth suggests a need for new methods to disseminate data to multiple clients, and cyclic broadcast is one approach. We do a survey on the various data management protocols that describe how to broadcast the data, and the concurrency control protocols that make sure all access to the database is consistent. The various data management and concurrency control techniques deals with the restrictions in asymmetric broadcas…
Ontological Modelling of FEST with support for DDI Reasoning
2017
Master's thesis Information- and communication technology IKT590 - University of Agder 2017 FEST is a Norwegian database and information service aimed towards providing all the required pharmaceutical data to different stakeholders such as hospitals, pharmaceutical companies, and practitioners. FEST being a complete pharmaceutical database, ensures every information related to drugs such as dosage, form of drug, interactions, and brand. FEST database is represented as an XML and schema files. In this master thesis, we propose an open and linked data representation approach of FEST database by modelling it as an Ontology. We propose the integration of FEST ontology with other systems and ont…
Buffering principles for mobile multimedia over IP
2001
Masteroppgave i informasjons- og kommunikasjonsteknologi 2001 - Høgskolen i Agder, Grimstad This thesis suggests a test-bed for reviewing queue algorithms suitable for IP based mobile multimedia services. Subjective performance quality obtained in the test-bed was analysed using a network performance monitor tool. In order to evaluate possible services for use in the test-bed, a comprehensive survey was conducted. The survey revealed that a variety of categorization methods for electronic services exist. However, none of them were targeted at mobile multimedia services. Based on the different methods a framework of six service classes were proposed. Together, these classes provide a useful …