Using ontologies to support customisation and maintain interoperability in distributed information systems with application to the Domain Name System

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Global distributed systems must be standards-based to allow interoperability between all of their components. While this guarantees interoperability, it often causes local inflexibility and an inability to adapt to specialised local requirements. We show how local flexibility and global consistency can coexist by changing the way that we represent these systems. The proven technologies already in use in the Semantic Web, to support and interpret metadata annotation, provide a well-tested starting point. We can use OWL ontologies and RDF to describe distributed systems using a knowledge-based approach. This allows us to maintain separate local and global operational spaces which, in turn, gives us local flexibility and global consistency. The annotated and well-defined data is better structured, more easily maintained and less prone to errors since its purpose can be clearly determined prior to use. To illustrate the application of our approach in distributed systems, we present our implementation of an ontologically-based Domain Name System (DNS) server and client. We also present performance figures to demonstrate that the use of this approach does not add significant overhead to system performance.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

Bridging the gap between the semantic web and existing network services

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.This paper presents an overview of a mechanism for bridging the gaps between the Semantic Web data and services, and existing network-based services that are not semantically-annotated or do not meet the requirements of Semantic Web-based applications. The Semantic Web is a relatively new set of technologies that mutually interoperate well but often require mediation, translation or wrapping to interoperate with existing network-based services. Seen as an extension of network-based services and the WWW, the Semantic Web constitutes an expanding system that can require significant effort to integrate and develop services while still providing seamless service to users. New components in a system must interoperate with the existing components and their use of protocols and shared data must be structurally and semantically equivalent. The new system must continue to meet the original system requirements as well as providing the new features or facilities. We propose a new model of network services using a knowledge-based approach that defines services and their data in terms of an ontology that can be shared with other components.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

Optimising performance in network-based information systems: Virtual organisations and customised views

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Network-based information systems use well-defined standards to ensure interoperability and also have a tightly coupled relationship between their internal data representation and the external network representation. Virtual organisations (VOs), where members share a problem-solving purpose rather than a location-based or formal organisation, constitute an environment where user requirements may not be met by these standards. A virtual organisation has no formal body to manage change requests for these standards so the user requirements cannot be met. We show how the decoupling of the internal and external representations, through the use of ontologies, can enhance the operation of these systems by enabling flexibility and extensibility. We illustrate this by demonstrating a system that implements and enhances the Domain Name System, a global network-based information system. Migrating an existing system to a decoupled, knowledge-driven system is neither simple nor effortless but can provide significant benefits.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

Developing an ontology for the domain name system

©2005 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Ontologies provide a means of modelling and representing a knowledge domain. Such representation, already used in purpose-built distributed information systems, can also be of great value when applied to existing distributed information systems. The domain name system (DNS) provides a wide-area distributed name resolution system which is used extensively across the Internet. Changing the type and nature of resource records stored in the DNS currently requires an extensive request for comment procedure which takes a substantial amount of time, as the change has to be made globally. We propose an ontology for a DNS zone file, to provide a machine readable codification of the DNS and a mechanism for allowing local changes to the stored and represented structure of DNS records, using the extensible nature of OWL to allow local variations without having to go through the manual RFC procedure. This ontologically based system replaces a slow manual procedure with a rapid, machine-realisable procedure based on a uniform ontological representation of significant DNS knowledge. This paper discusses the application of ontologies to the DNS and how such an application can be built using OWL, the Web ontology language.Nickolas J. G. Falkner, Paul D. Coddington, Andrew L. Wendelbor

S. P. Walker to W. C. Falkner (27 April 1861)

Reply to Falkner concerning his disappointment at Governor Pettus\u27 arrangementshttps://egrove.olemiss.edu/ciwar_corresp/1570/thumbnail.jp

Multiple cyclotron line-forming regions in GX 301-2

We present two observations of the high-mass X-ray binary GX 301-2 with NuSTAR, taken at different orbital phases and different luminosities. We find that the continuum is well described by typical phenomenological models, like a very strongly absorbed NPEX model. However, for a statistically acceptable description of the hard X-ray spectrum we require two cyclotron resonant scattering features (CRSF), one at ~35 keV and the other at ~50 keV. Even though both features strongly overlap, the good resolution and sensitivity of NuSTAR allows us to disentangle them at >=99.9% significance. This is the first time that two CRSFs are seen in GX 301-2. We find that the CRSFs are very likely independently formed, as their energies are not harmonically related and, if it were a single line, the deviation from a Gaussian shape would be very large. We compare our results to archival Suzaku data and find that our model also provides a good fit to those data. We study the behavior of the continuum as well as the CRSF parameters as function of pulse phase in seven phase bins. We find that the energy of the 35 keV CRSF varies smoothly as function of phase, between 30-38 keV. To explain this variation, we apply a simple model of the accretion column, taking the altitude of the line-forming region, the velocity of the in-falling material, and the resulting relativistic effects into account. We find that in this model the observed energy variation can be explained simply due to a variation of the projected velocity and beaming factor of the line forming region towards us.Comment: 18 pages, 10 figures, accepted for publication in A&

Letter From Roland P. Falkner to Francis Mairs Huntington-Wilson, November 21, 1909

The document is a handwritten letter from Roland P. Falkner to Francis Mairs Huntington-Wilson concerning a paper on increased restriction of immigration.https://digitalcommons.ursinus.edu/fmhw_immigration/1003/thumbnail.jp

A Probabilistic Analysis of Kademlia Networks

Kademlia is currently the most widely used searching algorithm in P2P (peer-to-peer) networks. This work studies an essential question about Kademlia from a mathematical perspective: how long does it take to locate a node in the network? To answer it, we introduce a random graph K and study how many steps are needed to locate a given vertex in K using Kademlia's algorithm, which we call the routing time. Two slightly different versions of K are studied. In the first one, vertices of K are labelled with fixed IDs. In the second one, vertices are assumed to have randomly selected IDs. In both cases, we show that the routing time is about c*log(n), where n is the number of nodes in the network and c is an explicitly described constant.Comment: ISAAC 201

Relationship of adipokines with insulin sensitivity in African Americans.

INTRODUCTION: Cytokines produced by adipose tissue, including adiponectin, have been associated with metabolic abnormalities. The purpose of this study was to examine the relationship of insulin sensitivity measured by euglycemic hyperinsulinemic insulin clamp with plasma adiponectin and other adipokines in young adult African Americans. METHODS: Participants were healthy African Americans. Anthropometric measures, blood pressure, an oral glucose tolerance test and an euglycemic hyperinsulinemic insulin clamp were performed. Insulin sensitivity measurements were adjusted for percentage of fat mass. Plasma concentrations of adiponectin, plasminogen activator inhibitor-1 (PAI-1) and interleukin-6 (IL-6) were assayed on plasma from fasting blood samples. Pearson correlation coefficients and multiple regression models were fitted to assess the association between glucose sensitivity and cytokines. RESULTS: In univariate analysis, there were statistically significant correlations of plasma adiponectin level (r = 0.19, P = 0.004), PAI-1 (r = -0.19, P = 0.020) and IL-6 (r = -0.24, P \u3c 0.001) with measures of insulin sensitivity after adjustment for both fat mass and insulin clamp concentration. In multivariate analysis, adiponectin [geometric mean ratios (GMR) 1.15, P = 0.007], PAI-1 (GMR 0.998, P = 0.021) and body mass index (GMR 0.95, P \u3c 0.001) were each independently associated with insulin sensitivity. For IL-6, there was no significant association with insulin sensitivity independent of obesity. CONCLUSION: These data show a significant and independent positive correlation of adiponectin with insulin sensitivity. The relationship of IL-6 with insulin sensitivity seems to be dependent on adiposity