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Abstract
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Abstract
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Diagrams are ubiquitous in economics and are uncontestably among the most used, if not the most important workhorses of economists, though they come in many forms. This essay…
Abstract
Diagrams are ubiquitous in economics and are uncontestably among the most used, if not the most important workhorses of economists, though they come in many forms. This essay examines the different uses of graphs and diagrams in the pioneering work of two Victorian economists, Stanley Jevons and Alfred Marshall. We stress the difference between their use as representations and as visual reasoning tools, a difference that became obscured in the twentieth century with the rise of econometrics.
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Patrícia Dockhorn Costa, Luís Ferreira Pires and Marten J. van Sinderen
Context‐aware services platforms aim at supporting the handling of contextual information in order to provide better user‐tailored services. This paper proposes a novel services…
Abstract
Context‐aware services platforms aim at supporting the handling of contextual information in order to provide better user‐tailored services. This paper proposes a novel services platform architecture to support mobile context‐aware applications, giving emphasis to the configurability of the platforms generic functionality. The paper introduces concepts and a language to cope with configurability aspects. The paper also reports on the implementation of a prototype, which implements a Web services‐based context‐aware services platform that runs on top of 3G networks.
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Yushuo Yang and Patrick S. McCarthy
This paper analyzes the impacts of COVID-19 and related policies on airport short-run costs and decomposes the percentage changes in total and average variable costs between…
Abstract
This paper analyzes the impacts of COVID-19 and related policies on airport short-run costs and decomposes the percentage changes in total and average variable costs between pre-COVID-19 and COVID-19 periods. Data for the analysis are a panel of 50 medium and large US airports from 2012 to 2021. COVID-19 measures include COVID-19 cases and deaths. COVID-19-related policies include state-level face mask and COVID-19 vaccine mandates. Based upon a short-term multi-output translog cost function with three positive outputs (departures, non-aeronautical revenue, and workload), three associated negative attributes (delay, congestion, and air pollution), COVID-19 measures and policies, the analysis has three main conclusions: (1) A 1% increase in COVID-19 cases leads to a 0.077% increase in total operating costs. State-level face mask and COVID-19 vaccine mandates increase total operating costs by 15.9% and 16.8%, respectively; (2) COVID-19 and related policies increase airport total operating costs through contractual services costs; and (3) the cost decomposition finds that a 1 million increase in COVID-19 cases results in a 109% increase in average variable costs, while the time/technological progress effect leads to a decrease of 87% compared to the pre-COVID-19 period. Face mask and vaccine mandates increase the average variable costs by 8.91% and 4.19%, respectively. The positive output total effects range from 3.46% to 7.99%. The effects of input prices and negative attributes are relatively small.
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Bruno C.N. Oliveira, Alexis Huf, Ivan Luiz Salvadori and Frank Siqueira
This paper describes a software architecture that automatically adds semantic capabilities to data services. The proposed architecture, called OntoGenesis, is able to semantically…
Abstract
Purpose
This paper describes a software architecture that automatically adds semantic capabilities to data services. The proposed architecture, called OntoGenesis, is able to semantically enrich data services, so that they can dynamically provide both semantic descriptions and data representations.
Design/methodology/approach
The enrichment approach is designed to intercept the requests from data services. Therefore, a domain ontology is constructed and evolved in accordance with the syntactic representations provided by such services in order to define the data concepts. In addition, a property matching mechanism is proposed to exploit the potential data intersection observed in data service representations and external data sources so as to enhance the domain ontology with new equivalences triples. Finally, the enrichment approach is capable of deriving on demand a semantic description and data representations that link to the domain ontology concepts.
Findings
Experiments were performed using real-world datasets, such as DBpedia, GeoNames as well as open government data. The obtained results show the applicability of the proposed architecture and that it can boost the development of semantic data services. Moreover, the matching approach achieved better performance when compared with other existing approaches found in the literature.
Research limitations/implications
This work only considers services designed as data providers, i.e., services that provide an interface for accessing data sources. In addition, our approach assumes that both data services and external sources – used to enhance the domain ontology – have some potential of data intersection. Such assumption only requires that services and external sources share particular property values.
Originality/value
Unlike most of the approaches found in the literature, the architecture proposed in this paper is meant to semantically enrich data services in such way that human intervention is minimal. Furthermore, an automata-based index is also presented as a novel method that significantly improves the performance of the property matching mechanism.
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It is a well known fact that bacteria play a large part in the success or failure of the satisfactory production of dairy products, but the role of yeasts and moulds should not be…
Abstract
It is a well known fact that bacteria play a large part in the success or failure of the satisfactory production of dairy products, but the role of yeasts and moulds should not be overlooked. These living organisms, commonly known as fungi, are the next higher form of life in the vegetable world after the bacteria stage. Their form of growth resembles the growth of plants in that they reproduce by budding, and their spores, analogous to the seeds of plants, are the means whereby many species propagate further generations. The yeast cell is much larger than the ordinary bacterium, so that it is possible to study them with the aid of much lower magnifications. When grown on solid media the yeasts give colonies not unlike those of bacteria except that the edges of the colonies are less defined, the colonies themselves project well above the surface of the media, and their surfaces are usually of a rough appearance. A good example of mould growth is that of the ordinary “green mould.”—Yeasts usually prefer to grow on the surface of liquids, and moulds are found to grow most vigourously on solid or semi‐solid media, such as meat, cheese, butter, etc. The growth of bacteria in the media hinders the simultaneous growth of the fungi, so that it is only after the media has become too acid for the growth of bacteria that yeasts and moulds are able to grow. In support of this theory it has been found that fungi will grow on the surface of sterile milk, but ordinary fresh milk containing bacteria is not a suitable media as the fungi cannot compete with the bacteria. It is found, therefore, that only bacteria proliferate in fresh milk. However, when milk has become sour bacterial growth is arrested, and it is then that mould growth becomes perceptible. The fungi tolerate a relatively large amount of acid. Media used for their cultivation is generally standardised to a ph of about 4.5. The optimum temperature for their growth is in the region of 75°–90° F. Some species will grow at 32° F., others even below this temperature. Low temperatures are not lethal to the fungi, so that when infected products are removed from cold storage growth may occur. The temperatures required to kill them and their spores generally falls between 130°–180° F. Most yeasts are killed at temperatures above 120° F., while their spores may have to be exposed to higher temperatures.
Ian Fillis and Kim Lehman
The authors provide an understanding of how the hero identity is culturally constructed and evolving. The authors focus on heroism within an arts marketing framework through an…
Abstract
Purpose
The authors provide an understanding of how the hero identity is culturally constructed and evolving. The authors focus on heroism within an arts marketing framework through an interrogation of Northern Ireland murals. In this paper, the authors elaborate on the links between arts marketing thought and the notion of hero and draw conclusions around what the authors see as a fruitful area for arts marketing theory.
Design/methodology/approach
The authors have adopted a narrative approach, incorporating biographical method, visual analysis and ethnography in interpreting cultural murals. The authors assess representative examples in Northern Ireland using a thematic framework.
Findings
The murals the authors assessed have evolved from having a specific community focus to increasing numbers which now represent a “shared”, and therefore more modern version of the hero.
Research limitations/implications
The authors identify an emerging, aesthetically balanced portrayal of cultural murals, with a different set of heroic priorities compared to the past, which should encourage further related research elsewhere.
Practical implications
Northern Ireland murals are no longer the preserve of specific communities and are now also shared spaces which appeal to both the local population and cultural tourists.
Originality/value
Although analysis and evaluation of political murals has been carried out in other disciplines, the authors add to the limited insight from an arts marketing perspective.
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Reports on a conference held in 1989 in Wisconsin, which focused onthe topic of providing better access to information for people withdisabilities. According to the author, the…
Abstract
Reports on a conference held in 1989 in Wisconsin, which focused on the topic of providing better access to information for people with disabilities. According to the author, the conference concentrated mainly on those with vision‐related difficulties. Summarizes two of the speeches made at the conference and examines some of the technology on display. Stresses the need for adaptive technology to enable people with a disability to access the increasing amounts of computer technology in everyday life.