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The rapid advancement of the Internet of Vehicles (IoV) has led to a massive growth in data received from IoV networks. The cloud storage has been a timely service that provides a vast range of data storage for IoV networks. However, existing data storage and access models used to manage and protect data in IoV networks have proven to be insufficient. They are centralized and usually accompanied by a lack of trust, transparency, security, immutability, and provenance. In this paper, we propose VBlock, a blockchain-based system that addresses the issues of illegal modification of outsourced vehicular data for smart city management and improvement. We introduce a novel collusion-resistant model for outsourcing data to cloud storage that ensures the network remains tamper-proof, has good data provenance and auditing, and solves the centralized problems prone to the single point of failure. We introduced a key revocation mechanism to secure the network from malicious nodes. We formally define the system model of VBlock in the setting of a consortium blockchain. Our simulation results and security analysis show that the proposed model provides a strong security guarantee with high efficiency and is practicable in the IoV environment.
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This study focuses on the evaluation of the green procurement practices among 7 mining hospitals in Ghana via qualitative analysis techniques. Thus, in this study, based on a 5-year case study, the practices of procurement officers in 7 hospitals belonging to mining companies in Ghana are explored. Within this period, interviews were conducted with key persons with recognizable responsibilities within the supply chain and procurement setup of the facilities. Details of their procurement practices, procedures, and policies were analyzed. A qualitative approach to organizational learning and practice is used to appreciate the existence of these differences observed and also to give a meaning to new perspectives on the challenges in establishing green procurement in the 7 mining companies' hospitals. The results of the analysis demonstrated that adjustments in the buyers' practices are not as much dependent on whether they understand, for instance, policies, tools, and procedures, but rather a matter of whether the buyers actually put their knowledge into practice.
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This research seeks to confirm the achievement of sustainable development in Sub-Sahara Africa. In view of this, a panel of 35 Sub-Saharan Africa countries divided into two sub-panels based on their income groupings, namely low-income, and middle-income countries, from 2000 to 2014 with a cross-sectional dependence among the series was used as a prerequisite for the analysis. We used the Pooled Mean Group estimators of the Autoregressive Distributed Lag model to ascertain the long-run mechanism between variables and analyse the Environmental Kuznets Curve hypothesis. The key results are: (1) income per capita significantly increases environmental pollution where environmental entrepreneurship decreases pollution of the environment across all panels of SSA countries; (2) in the low-income SSA economies, trade openness enhance environmental quality but increase environmental pollution in both the aggregated panel and middle-income SSA nations; (3) with the exception of low-income countries, human development palpably decreases environmental pollution in middle-income countries and in the aggregated panel a reduction is observed; (4) from financial development perspective, it produces positive and significant effect in the aggregated panel of SSA countries and middle-income SSA nations; (5) the environmental Kuznets curve conjuncture is supported for the selected panels in SSA region. Consequently, governments and policymakers should reinforce policies for the reduction of environmental pollution, more importantly, green financing policies, encourage aspiring environmental entrepreneurs to set environmentally-driven businesses, promote the use of environmental products to mitigate environmental problems and achieve sustainable development.
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Trade openness is one of the main channels of globalization and technological transfers. In environmental economic literature, the implications of trade openness remain controversial and still could be potential drivers of carbon dioxide emissions. This study therefore explores the effect of trade openness in developed countries using EU-18 economies. We employed an econometric approach that accounts for cross-section dependence among study variables. The panel CIPS and CADF unit root show that the variables are stationary and the long-run relationship was confirmed in Westerlund cointegration tests. The mean group (MG) and augmented mean group (AMG) results show that trade openness increases CO2-emissions in EU-18. Again, energy consumption and urbanization escalate emissions. The study confirmed the environmental Kuznets curve. Finally, pollution halo and pollution haven hypothesis were confirmed at both estimation methods. The Dumetriscu-Hurlin Granger causality test results confirmed bidirectional causality between trade openness and energy consumption and between trade openness and economic growth. Again, unidirectional Granger causality is running from trade openness and CO2 emissions. Policy recommendations are further proposed.
Assuntos
Desenvolvimento Econômico , Poluição Ambiental/análise , Dióxido de Carbono/análise , Internacionalidade , UrbanizaçãoRESUMO
The main aim of this current study is to empirically scrutinize the determinants of energy consumption for 24 African countries sub-grouped into three panels based on income levels: low-, lower-middle-, and upper-middle-income countries, from 1990 to 2015. Due to the presence of heterogeneity and cross-sectional reliance among country groups, recently developed econometric approaches, which include cross-sectional Im, Pesaran, and Shin together with cross-sectional Augmented Dickey-Fuller stationarity tests, Pedroni and Westerlund-Edgerton cointegration assessment, dynamic common correlated effect estimation approach and Dumitrescu-Hurlin Granger causality test are employed. Empirically, our findings depict analyzed variables are stationary and characterized by long-term stability affiliations for all panels. Economic growth, urbanization, population growth, and oil price with labor and capital stock as intermittent variables had palpable significant positive sway on energy consumption for all panels though their respective weight of contribution differed from one country group to another. The granger test of causation unveiled that (i) among all panels, urbanization and energy consumption are connected bidirectionally, whereas population growth causes energy consumption; (ii) a one-way causal link from economic growth to energy use is evidenced in low-income African countries, whereas a two-sided connection is confirmed in both lower-middle- and upper-middle-income economies; (iii) a bilateral causal association in low-income African nations is observed amid oil price and energy use, while a uni-lateral relationship extends from oil price to energy consumption in both lower-middle- and upper-middle-income nations in Africa. Such new methodologies and findings reveal that the long-term estimated effects as well as causal affiliations amid variables are skewed by different income levels of African countries in an attempt to conserve energy. Policy recommendations are further propose.