This study aimed (a) to understand the actual state of reference relations in RDA guidelines and instructions, expressed as RDF data, and (b) to grasp its characteristics at a global level by applying network analysis to those reference relations. The reference relations were examined and extracted from four datasets - RDA guidelines, instructions on entities, and those on Manifestation and Work elements. Furthermore, they were aggregated by source and destinations. The characteristics of the four graphs formed by the reference relations were analyzed using measures such as centrality.
Among metadata-related standards, data content standards like metadata guidelines and instructions for creating metadata still remain in legacy forms. This study investigates a way to transform data content standards to linked data (LD) through conversion from other formats, while referring to the proposed layered framework. Under the basic policies for making LD on which this study is based, several principal matters were examined: (a) defining units to be assigned with Universal Resource Identifiers (URIs), (b) defining relationships among the instructions with URIs and (c) expressing instructed content in instructions properly with certain Resource Description Framework (RDF) properties. With the proper choice(s) for each matter, some actual standards were converted to LD: Resource Description and Access (RDA) and Dublin Core User Guide. The results showed that the adopted way of transforming data content standards to LD is valid and proper, and the resultant LD would be expected to be utilised in various manners.
Purpose: The purpose of this study is to confirm the feasibility of RDF data conversion by presenting necessary considerations and options and then identifying appropriate options, with the intention of converting NCR2018 descriptive rules into RDF data. Method: In order to be suitable for effective utilization as linked data (1) we considered possible options for expressing individual rules as an RDF class and expressing various relationships between the classes; (2) based on the choices adopted. the conversion to RDF data was performed for the rules in the three chapters; and (3) mutual references between the RDF-expressed NCR rules and metadata in line with the rules were examined. Results: (1) In addition to the RDF class being determined based on the rule numbers of NCR2018, it was appropriate to adopt a division unit corresponding to each instruction applied independently under a given rule. Each rule and division unit was given a URI as an RDF class, and various relationships between them were properly expressed including hierarchical relationships, reference relationships, those between a rule and its alternatives, etc. (2) RDF data from the three chapters of NCR2018 were prepared by performing mechanical conversion to RDF data with manual correction. It was confirmed that RDF data can be converted without major barriers using the adopted policy and choices. (3) It was shown that mutual references between the NCR rules and metadata created under the NCR rules can be implemented, leading to a possible utilization of RDF-expressed NCR rules.
Gas chromatographic separations of the stereoisomers of menthol derivatives, important intermediates in the synthesis of physiologically active natural products, were carried out on several substituted beta-cyclodextrin (CD) columns, including per-O-methyl-beta-cyclodextrin (PME-beta-CD), heptakis(2,3-di-O-acetyl-6-tert-butyldimethylsilyl)-beta-CD (DIAC-6-TBDS-beta-CD), and heptakis(2,3-di-O-methyl-6-tert-butyldimethylsilyl)-beta-CD (DIME-6-TBDS-beta-CD) as chiral stationary phases (CSPs). With the DIME-6-TBDS-beta-CD column, a separation of the Z- and E-isomers of methylidenementhol was accomplished; no separation was achieved with the other columns. The stereoisomers of methylidenementhol and the corresponding tert-butyldimethylsilyl (TBS) ether were separated on both the beta-CD and the heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TME-beta-CD) columns by high-performance liquid chromatography (HPLC) with a mobile phase involving acetonitrile and H(2)O. For the separation of the Z- and E-isomers of methylidenementhol, the TME-beta-CD column was superior. In contrast, the beta-CD column was preferable in the case of the corresponding TBS ether.
