I.V. Sergienko, V.M. Yanenko, O.V. Gaiduk, N.I. Proskura and N.V. Yanenko
The computer technology (CT) for modelling of the ecology‐economic situation in the alienation zone (AZ) of Chenobyl is developed. It includes the databases of potentially…
Abstract
The computer technology (CT) for modelling of the ecology‐economic situation in the alienation zone (AZ) of Chenobyl is developed. It includes the databases of potentially dangerous objects and program modules (PM) for modelling of the ecology‐economic situation in the AZ. The optimal redistribution of means, directed at resource restoration, liquidation of technogenic pollution, the restoration of basis capital, prevention of pollution migration for bounds of the AZ is determined by use of this model. A distinctive feature of the accounts carried out in this work is that they allow the estimation not only of risk value, but also of levels of reserve possiblities of various objects of the AZ. The critical values of measured parameters, at which achievement the emergencies can occur, are also determined. The CT includes the following program modules: geo‐information system; PM for risk assessment of emergency occurences in the AZ; PM for dynamic optimisation tasks.
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Vyacheslav Kushakov, Vira Dvoriak, Olga Morozova, Lyu Azbel and Galyna Sergienko
To the best of the authors’ knowledge, no study has previously examined the use of psychoactive substances (PASs) at electronic dance music (EDM) events in Ukraine. Addressing…
Abstract
Purpose
To the best of the authors’ knowledge, no study has previously examined the use of psychoactive substances (PASs) at electronic dance music (EDM) events in Ukraine. Addressing this gap in the research literature, this study aims to: describe the recreational drug scene associated with Ukrainian EDM culture; identify clusters of EDM participants who use PAS, based on their drug use patterns; and assess the uptake of drug checking and investigate associations between drug checking and subsequent drug-related behaviour.
Design/methodology/approach
A series of cross-sectional surveys were conducted in 2021 (N = 1,307) among EDM festival participants in Ukraine. The authors performed cluster analysis to identify distinct profiles of PAS users. Trends in drug checking were analysed based on cross-sectional surveys conducted at one recurring festival in 2018 (N = 99), 2019 (N = 195) and 2021 (N = 237).
Findings
The substances most often used at EDM events were 3,4-Methylenedioxymethamphetamine (37%), amphetamine (16%), lysergic acid diethylamide (11%) and cocaine (9%). Between 2018 and 2021, the proportion of participants who reported to have ever tested their drugs has increased from 2% to 26% (p < 0.001). Unexpected or inconclusive test results led to a significantly lower chances of drug consumption (p = 0.003). The authors identified three distinct clusters of PAS users among the EDM festival attendees in Ukraine.
Originality/value
This study will inform the development of harm reduction interventions tailored to various subgroups of recreational PAS users taking into account gender-specific patterns of use suggested by the authors’ cluster analysis. Increased availability of drug checking is crucial to reduce the risks of drug-related harm associated with the consumption of mis-sold, mislabeled and/or adulterated substances.
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Lyudmila Y. Bogachkova, Lidiya S. Guryanova and Shamam G. Khurshudyan
The energy efficiency policy is a priority component of the overall economic policy of different countries striving to ensure the competitiveness and sustainability of national…
Abstract
The energy efficiency policy is a priority component of the overall economic policy of different countries striving to ensure the competitiveness and sustainability of national economic development. The improvement of energy efficiency represents an important economic task for the post-Soviet countries, characterized by excessive energy intensity of the economy, and the solution of this task requires proper information and analytical support: a system for accounting and analyzing energy consumption indicators. The present research is aimed at developing the tools to support decision-making in the sphere of evaluation and estimation of performance of the State energy efficiency policy of territories and testing these tools on the example of Russian regions. The study has been carried out using the methods of statistics, economic, mathematical and econometric modeling, structural, dynamic and comparative analyses. The following tools have been proposed: the method for differentiated accounting of various factors’ influence on the dynamics of energy consumption in the regions and for estimating the index of technological efficiency of electricity consumption; the method for the empirical classification of territories by types of their energy and economic development. We’ve revealed the general trend and typological features in the dynamics of electricity consumption efficiency indicators in the constituent entities of the Russian Federation and carried out the decomposition factor and comparative analysis of energy consumption patterns of the Volgograd region over 2005–2014 on the basis of the proposed tools.
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Sarah E. Scales and Jennifer A. Horney
Prior to the onset of the COVID-19 pandemic, women did nearly three-quarters of the world’s unpaid work. As institutional supports, including in-person school and community-based…
Abstract
Prior to the onset of the COVID-19 pandemic, women did nearly three-quarters of the world’s unpaid work. As institutional supports, including in-person school and community-based care for children, the elderly, and the disabled vanished early in the pandemic, many women’s caregiving responsibilities increased. In some cases, opportunities for paid employment disappeared due to layoffs and furloughs, while in others, paid work was no longer possible without access to the missing institutional supports. Either way, access to needed supports – financial, practical, and social – was diminished. The lapse of needed supports also had severe impacts on subgroups of women, including pregnant and post-partum women. A range of considerations – vaccine safety, social interaction and infection risk, disease severity – have posed serious challenges for pregnant and post-partum women. Across the board, women’s need for continuous access to better social, financial, and practical supports at home, in the community, and in the workplace was made even more evident by the COVID-19 pandemic.
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Shrawan Kumar Trivedi and Shubhamoy Dey
Email is a rapid and cheapest medium of sharing information, whereas unsolicited email (spam) is constant trouble in the email communication. The rapid growth of the spam creates…
Abstract
Purpose
Email is a rapid and cheapest medium of sharing information, whereas unsolicited email (spam) is constant trouble in the email communication. The rapid growth of the spam creates a necessity to build a reliable and robust spam classifier. This paper aims to presents a study of evolutionary classifiers (genetic algorithm [GA] and genetic programming [GP]) without/with the help of an ensemble of classifiers method. In this research, the classifiers ensemble has been developed with adaptive boosting technique.
Design/methodology/approach
Text mining methods are applied for classifying spam emails and legitimate emails. Two data sets (Enron and SpamAssassin) are taken to test the concerned classifiers. Initially, pre-processing is performed to extract the features/words from email files. Informative feature subset is selected from greedy stepwise feature subset search method. With the help of informative features, a comparative study is performed initially within the evolutionary classifiers and then with other popular machine learning classifiers (Bayesian, naive Bayes and support vector machine).
Findings
This study reveals the fact that evolutionary algorithms are promising in classification and prediction applications where genetic programing with adaptive boosting is turned out not only an accurate classifier but also a sensitive classifier. Results show that initially GA performs better than GP but after an ensemble of classifiers (a large number of iterations), GP overshoots GA with significantly higher accuracy. Amongst all classifiers, boosted GP turns out to be not only good regarding classification accuracy but also low false positive (FP) rates, which is considered to be the important criteria in email spam classification. Also, greedy stepwise feature search is found to be an effective method for feature selection in this application domain.
Research limitations/implications
The research implication of this research consists of the reduction in cost incurred because of spam/unsolicited bulk email. Email is a fundamental necessity to share information within a number of units of the organizations to be competitive with the business rivals. In addition, it is continually a hurdle for internet service providers to provide the best emailing services to their customers. Although, the organizations and the internet service providers are continuously adopting novel spam filtering approaches to reduce the number of unwanted emails, the desired effect could not be significantly seen because of the cost of installation, customizable ability and the threat of misclassification of important emails. This research deals with all the issues and challenges faced by internet service providers and organizations.
Practical implications
In this research, the proposed models have not only provided excellent performance accuracy, sensitivity with low FP rate, customizable capability but also worked on reducing the cost of spam. The same models may be used for other applications of text mining also such as sentiment analysis, blog mining, news mining or other text mining research.
Originality/value
A comparison between GP and GAs has been shown with/without ensemble in spam classification application domain.
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Shrawan Kumar Trivedi and Prabin Kumar Panigrahi
Email spam classification is now becoming a challenging area in the domain of text classification. Precise and robust classifiers are not only judged by classification accuracy…
Abstract
Purpose
Email spam classification is now becoming a challenging area in the domain of text classification. Precise and robust classifiers are not only judged by classification accuracy but also by sensitivity (correctly classified legitimate emails) and specificity (correctly classified unsolicited emails) towards the accurate classification, captured by both false positive and false negative rates. This paper aims to present a comparative study between various decision tree classifiers (such as AD tree, decision stump and REP tree) with/without different boosting algorithms (bagging, boosting with re-sample and AdaBoost).
Design/methodology/approach
Artificial intelligence and text mining approaches have been incorporated in this study. Each decision tree classifier in this study is tested on informative words/features selected from the two publically available data sets (SpamAssassin and LingSpam) using a greedy step-wise feature search method.
Findings
Outcomes of this study show that without boosting, the REP tree provides high performance accuracy with the AD tree ranking as the second-best performer. Decision stump is found to be the under-performing classifier of this study. However, with boosting, the combination of REP tree and AdaBoost compares favourably with other classification models. If the metrics false positive rate and performance accuracy are taken together, AD tree and REP tree with AdaBoost were both found to carry out an effective classification task. Greedy stepwise has proven its worth in this study by selecting a subset of valuable features to identify the correct class of emails.
Research limitations/implications
This research is focussed on the classification of those email spams that are written in the English language only. The proposed models work with content (words/features) of email data that is mostly found in the body of the mail. Image spam has not been included in this study. Other messages such as short message service or multi-media messaging service were not included in this study.
Practical implications
In this research, a boosted decision tree approach has been proposed and used to classify email spam and ham files; this is found to be a highly effective approach in comparison with other state-of-the-art modes used in other studies. This classifier may be tested for different applications and may provide new insights for developers and researchers.
Originality/value
A comparison of decision tree classifiers with/without ensemble has been presented for spam classification.
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Kadir Bilisik and Bekir Yildirim
– The aim of this study was to understand the stick-slip properties of single and multiple yarn pull-out in dry and treated polyester satin woven fabric in boundary regions.
Abstract
Purpose
The aim of this study was to understand the stick-slip properties of single and multiple yarn pull-out in dry and treated polyester satin woven fabric in boundary regions.
Design/methodology/approach
Polyester satin pattern woven fabric was used to conduct the pull-out tests in order to examining the kinetic region of the force-displacement curve. Data generated from this research help the authors to obtain stick-slip force and accumulative retraction force.
Findings
It was found that stick-slip force and accumulative retraction force depend on the number of pulled ends in the fabric, fabric sample dimensions and softening treatments. Stick-slip forces of polyester satin fabric in the multiple yarn pull-out test were higher than those of the single yarn pull-out test. Stick-slip force in single and multiple yarn pull-out tests in the dry polyester satin fabric was generally higher than those of the softening treated polyester satin fabric. In addition, the warp directional single and multiple yarn stick-slip and accumulative retraction forces in the dry and softening treated polyester fabrics were generally higher than those in the weft direction in the fabric edges due to fabric density. On the other hand, the amount of stick-slip force was related to the number of interlacement points in the fabric, whereas the amount of accumulative retraction force was related to fabric structural response.
Originality/value
The mechanism of stick-slip and accumulative retraction force of dry-treated polyester satin pattern woven fabrics were explained. This research could be valuable for development of multifunctional fabrics in technical textiles and ballistic.
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The purpose of this paper is to design a double parabolic nozzle and to compare the performance with conventional nozzle designs.
Abstract
Purpose
The purpose of this paper is to design a double parabolic nozzle and to compare the performance with conventional nozzle designs.
Design/methodology/approach
The throat diameter and divergent length for Conical, Bell and Double Parabolic nozzles were kept same for the sake of comparison. The double parabolic nozzle has been designed in such a way that the maximum slope of the divergent curve is taken as one-third of the Prandtl Meyer (PM) angle. The studies were carried out at Nozzle Pressure Ratio (NPR) of 5 and also at design conditions (NPR = 3.7). Experimental measurements were carried out for all the three nozzle configurations and the performance parameters compared. Numerical simulations were also carried out in a two-dimensional computational domain incorporating density-based solver with RANS equations and SST k-ω turbulence model.
Findings
The numerical predictions were found to be in reasonable agreement with the measured experimental values. An enhancement in thrust was observed for double parabolic nozzle when compared with that of conical and bell nozzles.
Research limitations/implications
Even though the present numerical simulations were capable of predicting shock cell parameters reasonably well, shock oscillations were not captured.
Practical implications
The double parabolic nozzle design has enormous practical importance as a small increase in thrust can result in a significant gain in pay load.
Social implications
The thrust developed by the double parabolic nozzle is seen to be on the higher side than that of conventional nozzles with better fuel economy.
Originality/value
The overall performance of the double parabolic nozzle is better than conical and bell nozzles for the same throat diameter and length.
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Vincenzo Corvello, Monica De Carolis, Saverino Verteramo and Annika Steiber
This paper explores digital transformation's impact on the work of owners in entrepreneurial firms. The interplay between working practices and technology is analyzed, taking into…
Abstract
Purpose
This paper explores digital transformation's impact on the work of owners in entrepreneurial firms. The interplay between working practices and technology is analyzed, taking into account the organizations' specific contexts.
Design/methodology/approach
A multiple case study design was applied. Eight cases of entrepreneurial firms, defined as companies that bring new products and services to the market by creating and seizing opportunities, were selected, with the goal to maximize the diversity of cases. The sample includes both small- and medium-sized firms, as well as high- tech and low- tech companies in equal number. Interviews have been used to collect both quantitative and qualitative data, which was analyzed in a structured way.
Findings
The digital transformation of entrepreneurial work, that is the daily work of entrepreneurs, is an evolutionary, practice-based phenomenon, rather than the result of rational design. The use of different digital tools is interrelated and depends on the characteristics, and dynamics of the surrounding environment.
Practical implications
The findings of this study are relevant to entrepreneurs interested in understanding the dynamics of their working practice, to software development firms interested in entrepreneurs as customers and to institutions interested in the education of entrepreneurs.
Originality/value
To the best of the authors' knowledge this is the first study which considers the interplay between digital technology and the daily activities of entrepreneurs, considered as a whole. It provides insights on how these interconnected dimensions evolve, thus contributing to understanding the work of entrepreneurs, and as a consequence the dynamics of entrepreneurial firms in the context of digital transformation of organizations.
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Bojan Matkovski, Stanislav Zekić, Žana Jurjević and Danilo Đokić
The purpose of this paper is to determine if the agribusiness sector can be an initiator of export on the emerging markets. For this aim, we analyzed export opportunities for the…
Abstract
Purpose
The purpose of this paper is to determine if the agribusiness sector can be an initiator of export on the emerging markets. For this aim, we analyzed export opportunities for the region of Vojvodina, the region in Serbia with the most potential for agribusiness.
Design/methodology/approach
This paper uses the Comparative Advantage Index and the Index of Intra-industrial Integration to determine the region's level of comparative advantage and the market's level of integration on the main emerging markets.
Findings
The results show that this region has the most competitive advantages in crop production – primarily in cereals and industrial plants – but the situation is not favorable for livestock production. Because of this, comparative advantage should be used as a factor for the growth of competitiveness in the sectors for which crop products are the raw material base. At the same time, agricultural policy measures should encourage more intensive agricultural production, which could create a better foundation for progress in the food industry.
Research limitations/implications
Data collected on foreign trade at the level of statistical regions is not always reliable. Also, regional and local characteristics are specific to each country, so the ability to generalize conclusions is limited.
Practical implications
This paper provides a useful review of the agri-food sector's competitiveness and determines which agri-food segments have competitive advantages. It is essential for policymakers to identify what determinants improve or degrade the competitiveness of the region's agri-food sector.
Originality/value
Since there are a limited number of studies analyzing trends of competitiveness for the region's agri-food sector, the paper will contribute to filling this gap. Furthermore, the framework is conceptually innovative in identifying the determinants that create export opportunities for the region on the international market.