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1 – 10 of over 9000Wei Meng, Qian Li, Bo Zeng and Yingjie Yang
The purpose of this paper is to unify the expression of fractional grey accumulating generation operator and the reducing generation operator, and build the FDGM(1,1) model with…
Abstract
Purpose
The purpose of this paper is to unify the expression of fractional grey accumulating generation operator and the reducing generation operator, and build the FDGM(1,1) model with the unified fractional grey generation operator.
Design/methodology/approach
By systematically studying the properties of the fractional accumulating operator and the reducing operator, and analyzing the sensitivity of the order value, a unified expression of the fractional operators is given. The FDGM(1,1) model with the unified fractional grey generation operator is established. The relationship between the order value and the modeling error distribution is studied.
Findings
The expression of the fractional accumulating generation operator and the reducing generation operator can be unified to a simple expression. For −1<r < 1, the fractional grey generation operator satisfies the principle of new information priority. The DGM(1,1) model is a special case of the FDGM(1,1) model with r = 1.
Research limitations/implications
The sensitivity of the unified operator is verified through random numerical simulation method, and the theoretical proof was not yet possible.
Practical implications
The FDGM(1,1) model has a higher modeling accuracy and modeling adaptability than the DGM(1,1) by optimizing the order.
Originality/value
The expression of the fractional accumulating generation operator and the reducing generation operator is firstly unified. The FDGM(1,1) model with the unified fractional grey generation operator is firstly established. The unification of the fractional accumulating operator and the reducing operator improved the theoretical basis of grey generation operator.
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Shuliang Li, Ke Gong, Bo Zeng, Wenhao Zhou, Zhouyi Zhang, Aixing Li and Li Zhang
The purpose of this paper is to overcome the weakness of the traditional model, in which the grey action quantity is a real number and thus leads to a “unique solution” and to…
Abstract
Purpose
The purpose of this paper is to overcome the weakness of the traditional model, in which the grey action quantity is a real number and thus leads to a “unique solution” and to build the model with a trapezoidal possibility degree function.
Design/methodology/approach
Using the system input and output block diagram of the model, the interval grey action quantity is restored under the condition of insufficient system influencing factors, and the trapezoidal possibility degree function is formed. Based on that, a new model able to output non-unique solutions is constructed.
Findings
The model satisfies the non-unique solution principle of the grey theory under the condition of insufficient information. The model is compatible with the traditional model in structure and modelling results. The validity and practicability of the new model are verified by applying it in simulating the ecological environment water consumption in the Yangtze River basin.
Practical implications
In this study, the interval grey number form of grey action quantity is restored under the condition of insufficient system influencing factors, and the unique solution to the problem of the traditional model is solved. It is of great value in enriching the theoretical system of grey prediction models.
Social implications
Taking power consumption as an example, the accurate prediction of the future power consumption level is related to the utilization efficiency of the power infrastructure investment. If the prediction of the power consumption level is too low, it will lead to the insufficient construction of the power infrastructure and the frequent occurrence of “power shortage” in the power industry. If the prediction is too high, it will lead to excessive investment in the power infrastructure. As a result, the overall surplus of power supply will lead to relatively low operation efficiency. Therefore, building an appropriate model for the correct interval prediction is a better way to solve such problems. The model proposed in this study is an effective one to solve such problems.
Originality/value
A new grey prediction model with its interval grey action quantity based on the trapezoidal possibility degree function is proposed for the first time.
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We examined the dynamic volatility connectedness and diversification strategies among US real estate investment trusts (REITs) and green finance indices.
Abstract
Purpose
We examined the dynamic volatility connectedness and diversification strategies among US real estate investment trusts (REITs) and green finance indices.
Design/methodology/approach
The DCC-GARCH dynamic connectedness framework and he DCC-GARCH t-copula model were employed in this study.
Findings
Using daily data from 2,206 observations spanning from 2 January 2015 to 31 January 2023 this paper presents the following findings: (1) cross-market spillovers exhibited a high correlation and significant fluctuations, particularly during extreme events; (2) our analysis confirmed that REIT acted as net receivers from other green indices, with the S&P North America Large-MidCap Carbon Efficient Index dominating the in-network volatility spillover; (3) this observation suggests asymmetric spillovers between the two markets and (4) a portfolio analysis was conducted using the DCC-GARCH t-copula framework to estimate hedging ratios and portfolio weights for these indices. When REIT and the Dow Jones US Select ESG REIT Index were simultaneously added to a risk-hedged portfolio, our findings indicated that no risk-hedging effect could be achieved. Moreover, the cost and performance of hedging green assets using REIT were found to be comparable.
Originality/value
We first examined the dynamic volatility connectedness and diversification strategies among US REITs and green finance indices. The outcomes of this study carry practical implications for market participants.
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Getaneh Alemu, Brett Stevens and Penny Ross
With the aim of developing a conceptual framework which aims to facilitate semantic metadata interoperability, this paper explores overarching conceptual issues on how traditional…
Abstract
Purpose
With the aim of developing a conceptual framework which aims to facilitate semantic metadata interoperability, this paper explores overarching conceptual issues on how traditional library information organisation schemes such as online public access catalogues (OPACs), taxonomies, thesauri, and ontologies on the one hand versus Web 2.0 technologies such as social tagging (folksonomies) can be harnessed to provide users with satisfying experiences.
Design/methodology/approach
This paper reviews works in relation to current metadata creation, utilisation and interoperability approaches, focusing on how a social constructivist philosophical perspective can be employed to underpin metadata decisions in digital libraries. Articles are retrieved from databases such as EBSCO host and Emerald and online magazines such as D‐Lib and Ariadne. Books, news articles and blog posts that are deemed relevant are also used to support the arguments put forward in this paper.
Findings
Current metadata approaches are deeply authoritative and metadata deployments in digital libraries tend to favour an objectivist approach with focus on metadata simplicity. It is argued that unless information objects are enriched with metadata generated through a collaborative and user‐driven approach, achieving semantic metadata interoperability in digital libraries will remain difficult.
Practical implications
In this paper, it is indicated that the number of metadata elements (fields) constituting a standard has a direct bearing on metadata richness, which in turn directly affects semantic interoperability. It is expected that this paper will contribute towards a better understanding of harnessing user‐driven metadata.
Originality/value
As suggested in this paper, a conceptual metadata framework underpinned by a social constructivist approach substantially contributes to semantic interoperability in digital libraries.
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This chapter covers the significant developments in subject access embodied in the Functional Requirements (FR) family of models, particularly the Functional Requirements for…
Abstract
Purpose
This chapter covers the significant developments in subject access embodied in the Functional Requirements (FR) family of models, particularly the Functional Requirements for Subject Authority Data (FRSAD) model.
Design/methodology/approach
A structured literature review was used to track the genesis of FRSAD. It builds on work by Pino Buizza and Mauro Guerrini who outlined a potential subject access model for FRBR. Tom Delsey, the author of Resource Description and Access (RDA), also examined the problem of adding subject access.
Findings
FRSAD seemed to generate little comment when it appeared in 2009, despite its subject model which departed from that in previous FR standards. FRSAD proposed a subject model based on “thema” and “nomen,” whereby the former, defined as “any entity used as the subject of a work,” was represented by the latter, defined as “any sign or sequence of signs.” It is suggested in this chapter that the linguistic classification theory underlying the PRECIS Indexing System might provide an alternative model for developing generic subject entities in FRSAD.
Originality/value
The FR family of models underpin RDA, the new cataloguing code intended to replace AACR2.Thus issues with FRSAD, which are still unresolved, continue to affect the new generation of cataloguing rules and their supporting models.
Pino G. Audia and Fiona Kun Yao
We study the spatial diffusion of stock backdating, an instance of corporate misconduct about which public information was virtually absent until 2005. Contrary to the findings of…
Abstract
We study the spatial diffusion of stock backdating, an instance of corporate misconduct about which public information was virtually absent until 2005. Contrary to the findings of Bizjack, Lemmon, and Whitby (2009), our results reveal that this “invisible” practice did not diffuse through board interlocks. Rather, stock backdating spread through geographic proximity: firms were more likely to backdate stock options to the extent that other firms located geographically close to them had done so. Lending support to the importance of localized interactions among members of the local business elite, the effect of geographical proximity was conditional on high levels of local board interlocks. Our findings regarding the differential impact of geographic proximity and board interlocks on the diffusion of this invisible practice are analogous to the diffusion pattern of controversial practices proposed by Davis and Greve (1997).
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Through examination of the Library Reference Model (LRM) specifications for nomen and the potential challenges visual nomen might present for their description and use in…
Abstract
Purpose
Through examination of the Library Reference Model (LRM) specifications for nomen and the potential challenges visual nomen might present for their description and use in information systems, the purpose of this study was to investigate two questions: (1) how do nonlinguistic or nonalphanumeric signs or symbols act as nomen to identify entities? and (2) what details or attributes are relevant to describe and classify such nomen to integrate them into information systems?
Design/methodology/approach
This research was built on an exploratory, qualitative instrumental case study design using multiple (or comparative) cases. Using the International Federation of Library Associations and Institutions LRM conceptualization of nomen as the basis, this research explored the similarities and differences between the LRM definition, its attributes and the use of nonlinguistic and nonalphanumeric “strings” for visual nomen to represent a res, moving iteratively between the LRM documentation, visual nomen identified in previous research and additional examples. This study used a constant comparative method to conduct a structured, focused comparison across different cases found in the source survey.
Findings
A close review of the history of the development of the nomen entity was made to understand the semiotic relationship between entities and their symbolic representation, how those symbols are then reified to be further classified and described and how such definitions in the LRM offer a path forward for better understanding the role and function of visual nomen. Based on the foundation of the nomen entity and its attributes established in the LRM, this research then looked at visual representations of concepts and entities to suggest a nascent framework for describing aspects of visual nomen which may be relevant to their use and application
Originality/value
This exploratory study of the use of supralinguistic ways of referencing entities delineates novel insights into a potential framework for describing and using visual nomen as a way of labeling or naming entities represented in information systems. By examining the specifications of the nomen entity and its attributes as delineated by the LRM, this study reinforces the applicability of LRM-defined attributes in the use of visual nomen in addition to offering other attributes or dimensions.
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The purpose of this paper is to present an up-to-date survey on the non-orthogonal multiple access (NOMA) technique with co-operative strategy, a fast-evolving fifth-generation…
Abstract
Purpose
The purpose of this paper is to present an up-to-date survey on the non-orthogonal multiple access (NOMA) technique with co-operative strategy, a fast-evolving fifth-generation (5 G) technology. NOMA is used for serving many mobile users, both in power and code domains. This paper considers the power-domain NOMA, which is now discussed as NOMA.
Design/methodology/approach
The first part of the paper discusses NOMA-based cooperative relay systems using different relay strategies over different channel models. In various research works, the analytical expressions of many performance metrics were derived, measured and simulated for better performance of the NOMA systems. In the second part, a brief introduction to diversity techniques is discussed. The multiple input and multiple output system merged with cooperative NOMA technology, and its future challenges were also presented in this part. In the third part, the paper surveys some new conceptions such as cognitive radio, index modulation multiple access, space-shift keying and reconfigurable intelligent surface that can be combined with NOMA systems for better performance.
Findings
The paper presents a brief survey of diverse research projects being carried out in the field of NOMA. The paper also surveyed two different relaying strategies that were implemented in cooperative NOMA over different channels and compared several performance parameters that were evaluated and derived in these implementations.
Originality/value
The paper provides a scope for recognizable future work and presents a brief idea of the new techniques that can be united with NOMA for better performance in wireless systems.
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The proposed model can emphasize the priority of new information and can extract messages from the first pair of original data. The comparison results show that the proposed model…
Abstract
Purpose
The proposed model can emphasize the priority of new information and can extract messages from the first pair of original data. The comparison results show that the proposed model can improve the traditional grey model.
Design/methodology/approach
The grey multivariate model with fractional Hausdorff derivative is firstly put forward to enhance the forecasting accuracy of traditional grey model.
Findings
The proposed model is used to predict the air quality composite index (AQCI) in ten cities respectively.
Originality/value
The effect of population density on AQCI in cities with poor air quality is not as significant as that of the cities with better air quality.
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Ceri Binding, Claudio Gnoli and Douglas Tudhope
The Integrative Levels Classification (ILC) is a comprehensive “freely faceted” knowledge organization system not previously expressed as SKOS (Simple Knowledge Organization…
Abstract
Purpose
The Integrative Levels Classification (ILC) is a comprehensive “freely faceted” knowledge organization system not previously expressed as SKOS (Simple Knowledge Organization System). This paper reports and reflects on work converting the ILC to SKOS representation.
Design/methodology/approach
The design of the ILC representation and the various steps in the conversion to SKOS are described and located within the context of previous work considering the representation of complex classification schemes in SKOS. Various issues and trade-offs emerging from the conversion are discussed. The conversion implementation employed the STELETO transformation tool.
Findings
The ILC conversion captures some of the ILC facet structure by a limited extension beyond the SKOS standard. SPARQL examples illustrate how this extension could be used to create faceted, compound descriptors when indexing or cataloguing. Basic query patterns are provided that might underpin search systems. Possible routes for reducing complexity are discussed.
Originality/value
Complex classification schemes, such as the ILC, have features which are not straight forward to represent in SKOS and which extend beyond the functionality of the SKOS standard. The ILC's facet indicators are modelled as rdf:Property sub-hierarchies that accompany the SKOS RDF statements. The ILC's top-level fundamental facet relationships are modelled by extensions of the associative relationship – specialised sub-properties of skos:related. An approach for representing faceted compound descriptions in ILC and other faceted classification schemes is proposed.
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