1,720,960 research outputs found
A methodology for determining optimal durations for the use of contaminated crops as fodder following a nuclear accident using a dynamic food-chain model
No full textA methodology for determining optimal durations for the use of contaminated crops as fodder was designed based on cost-benefit analysis. Illustrative results of the application of this methodology to pigs are presented for the hypothetical deposition of radionuclides on August 15 when a number of crops are fully developed in Korean agricultural conditions. For investigating the appropriateness of the use of contaminated crops as fodder, the net benefit from this action was compared with the imposition of a ban on human consumption of contaminated crops without alternative use. The time-dependent radionuclide concentrations in crops and pork after the deposition event were predicted from a dynamic food-chain model DYNACON. The net benefit from the actions was quantitatively evaluated in terms of cost equivalent of the doses incurred or averted and the monetary costs needed to implement the action. The optimal duration for the use of contaminated crops as fodder depended on a number of factors such as radionuclide, variety of crops fed as fodder and duration of the action. Such action was more cost effective for Cs-137 deposition than for Sr-90 or I-131 deposition. The use of contaminated crops as fodder can be an effective response to a public reluctance to consume contaminated crops. (C) 2000 Elsevier Science Ltd. All rights reserved
Development of a dynamic food chain model DYNACON and its application to Korean agricultural conditions
No full textA dynamic food chain model DYNACON was developed to simulate the radionuclide transfer on agricultural ecosystems. DYNACON estimates the radioactivity in each compartment of food chains for three radionuclides, nine plant species and five animal products as a function of the deposition date. A number of the parameter values used in this study are representative of Korean agricultural conditions. The model was expressed by coupled differential equations and the radioactivity in each compartment was solved as a function of time following an acute deposition. Although DYNACON is structurally based on existing models, it was designed in order to simulate more realistic radionuclide behavior in Korean agricultural conditions and to save computation time. It was found that the radioactivity in foodstuffs depends strongly on the date of deposition. A comparative study between DYNACON and an equilibrium model showed good agreement for depositions that occur during the growing season of plants. DYNACON is going to be implemented in a Korean rear-time dose assessment system FADAS
A methodology for optimisation of countermeasures for animal products after a nuclear accident and its application
No full textA methodology for the optimisation of the countermeasures associated with the contamination of animal products was designed based on cost-benefit analysis. Results are discussed for the hypothetical deposition of radionuclides on 15 August, when pastures are fully developed in Korean agricultural conditions. A dynamic food chain model, DYNACON, was used to evaluate the effectiveness of the countermeasures for reducing the ingestion dose. The countermeasures considered were: (1) a ban on food consumption; and (2) the substitution of clean fodder. These are effective in reducing the ingestion dose as well as simple and easy to carry out in the first year after deposition. The net benefit of the countermeasures was quantitatively estimated in terms of avertable doses and monetary costs. The benefit depends on a variety of factors, such as radionuclide concentrations on the ground, starting time and duration of the countermeasures. It is obvious that a fast reaction after deposition is important in maximising the cost effectiveness of the countermeasures. In most cases, the substitution of clean fodder is more cost effective than a ban on food consumption. The methodology used in this study may serve as a basis for rapid decision-making on the introduction of countermeasures relating to the contamination of animal products after a nuclear accident. (C) 1999 Elsevier Science Ltd. All rights reserved
Seasonal influence of countermeasures for milk after a nuclear accident
No full textThe seasonal influence of countermeasures for milk after a nuclear accident was investigated using a quantitative decision-aiding technique, cost-benefit analysis. The 15th day of April and July was selected as a typical deposition date of radionuclide for growing season and non-growing season of pastures, respectively. A dynamic food chain model, DYNACON, was used to evaluate the effectiveness of countermeasures for reducing the ingestion dose. The countermeasures considered are (1) a ban on milk consumption and (2) the substitution of clean fodder. The net benefit from the countermeasures was quantitatively evaluated in terms of cost equivalent of avertable doses and monetary costs of implementing the action. It showed a distinct difference for the different deposition seasons of radionuclides. Obviously, the rapid introduction of a countermeasure after a deposition was important in maximizing the cost effectiveness. In most cases, the substitution of clean fodder was more cost effective than a ban on milk consumption
A Study on the Application of Countermeasure for the Reduction of the Ingestion Dose After Nuclear Accident
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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