38517 research outputs found
Sort by
A security transmission and storage solution about sensing image for blockchain in the internet of things
Get PDFWith the rapid development of the Internet of Things (IoT), the number of IoT devices has increased exponentially. Therefore, we have put forward higher security requirements for the management, transmission, and storage of massive IoT data. However, during the transmission process of IoT data, security issues, such as data theft and forgery, are prone to occur. In addition, most existing data storage solutions are centralized, i.e., data are stored and maintained by a centralized server. Once the server is maliciously attacked, the security of IoT data will be greatly threatened. In view of the above-mentioned security issues, a security transmission and storage solution is proposed about sensing image for blockchain in the IoT. Firstly, this solution intelligently senses user image information, and divides these sensed data into intelligent blocks. Secondly, different blocks of data are encrypted and transmitted securely through intelligent encryption algorithms. Finally, signature verification and storage are performed through an intelligent verification algorithm. Compared with the traditional IoT data transmission and centralized storage solution, our solution combines the IoT with the blockchain, making use of the advantages of blockchain decentralization, high reliability, and low cost to transfer and store users image information securely. Security analysis proves that the solution can resist theft attacks and ensure the security of user image information during transmission and storage
Forecasting tourism demand with an improved mixed data sampling model
Get PDFSearch query data reflect users’ intentions, preferences and interests. The interest in using such data to forecast tourism demand has increased in recent years. The mixed data sampling (MIDAS) method is often used in such forecasting, but is not effective when moving average (MA) dynamics are involved. To investigate the relevance of the MA components in MIDAS models to tourism demand forecasting, an improved MIDAS model that integrates MIDAS and the seasonal autoregressive integrated moving average process is proposed. Its performance is tested by forecasting monthly tourist arrivals in Hong Kong from mainland China with daily composite indices constructed from a large number of search queries using the generalised dynamic factor model. The forecasting results suggest that this new model significantly outperforms the benchmark model. In addition, comparing the forecasts and nowcasts shows that the latter generally outperform the former
The chemical composition and manufacturing technology of glass beads excavated from the Hetian Bizili site, Xinjiang
Get PDFThe Hetian Bizili site in Lop County, located on the southern route of the Silk Road in Xinjiang, China, was a trade and cultural hub between the East and the West in ancient times. In 2016, a large number of glass beads were unearthed from the 40 tombs excavated on this site. In this study we determined the chemical compositions and manufacturing technology of bodies and decorations of twelve glass beads from the M5 tomb of Bizili by using LA-ICP-AES, EDXRF, Raman Spectrometry, and SR-μCT. The chemical compositions of the beads were all Na2O–CaO–SiO2, with plant ash mainly used as a flux. Lead antimonate and lead stannate were used as the opacifying agents. We detected elevated levels of boron and high levels of phosphorus in some beads: this is discussed in the context of the type of flux used and the possible use of a P-rich opacifier. Some of the beads with high contents of aluminum may potentially come from Pakistan. In terms of manufacturing technology, the craftsmen made ‘eye’ beads in different ways and also trail decorated beads
Corporate power over human rights: an analytical framework
Get PDFThis paper presents an original framework designed to systemize understandings of corporate power over human rights. The framework disaggregates four sites of this power: corporations have direct power over individuals’ human rights, power over the materialities of human rights, power over institutions governing human rights, and power over knowledge around human rights. This disaggregation is derived primarily from the work of Barnett and Duvall, and focuses on effects of corporate activity, rather than the Weberian understanding of power as the ability to achieve desired outcomes. The framework captures a broad set of corporate acts based on their (potential) harm to human rights. It is argued that understanding business and human rights through the lens of power can help to advance a more comprehensive account of business impacts on human rights
Energy and the environment in Sub-Saharan Africa: Household perceptions of improved cookstoves
Get PDFEnvironmental assessment of the near-net-shape electrochemical metallisation process and the Kroll-electron beam melting process for titanium manufacture
Get PDFThe enforcement of environmental policies, in recent years, has become one of the major driving forces for industrial upgrading. Therefore, this study is focused on the evaluation of the environmental impact of a newly proposed titanium additive manufacturing process, including its in-depth comparison with the conventional method. This new method, referred to as Near-net-shape Electrochemical Metallisation, is based on the in-situ metallisation (via the FFC-Cambridge Process) of 3D-printed titanium oxide precursors (using Direct Ink Writing Process). In order to evaluate the main contributors to the environmental damage and to compare them with the conventional route for titanium manufacturing, the gate-to-gate Life Cycle Assessment has been conducted following established international standards. From this, the main contributors within the Near-net-shape Electrochemical Metallisation process were identified to be electricity and synthetic rutile, with medium impacts from argon and nickel. It was found that major impacts were challenging to be reduced without affecting the properties of the final product. However, the medium impacts can theoretically be modified, yielding potential improvements in the sustainability of the process by 10%. When compared to the conventional route (consisting of the Kroll Process, Free Fall Gas Atomisation and Electron Beam Melting), the end point results demonstrated that, by adopting the Near-net-shape Electrochemical Metallisation Process, the overall impact of titanium fabrication was dramatically reduced. Specifically, an average reduction of 68% for the ecosystem, human health and resources was observed
A hybrid combinatorial approach to a two-stage stochastic portfolio optimization model with uncertain asset prices
Get PDFPortfolio optimization is one of the most important problems in the finance field. The traditional Markowitz mean-variance model is often unrealistic since it relies on the perfect market information. In this work, we propose a two-stage stochastic portfolio optimization model with a comprehensive set of real-world trading constraints to address this issue. Our model incorporates the market uncertainty in terms of future asset price scenarios based on asset return distributions stemming from the real market data. Compared with existing models, our model is more reliable since it encompasses real-world trading constraints and it adopts CVaR as the risk measure. Furthermore, our model is more practical because it could help investors to design their future investment strategies based on their future asset price expectations. In order to solve the proposed stochastic model, we develop a hybrid combinatorial approach, which integrates a hybrid algorithm and a linear programming (LP) solver for the problem with a large number of scenarios. The comparison of the computational results obtained with three different metaheuristic algorithms and with our hybrid approach shows the effectiveness of the latter. The superiority of our model is mainly embedded in solution quality. The results demonstrate that our model is capable of solving complex portfolio optimization problems with tremendous scenarios while maintaining high solution quality in a reasonable amount of time and it has outstanding practical investment implications, such as effective portfolio constructions
Method of creating vernacular houses pictograms based on “climate – form” impact and relationship: houses’ pictograms; Part 1
Get PDFThe purpose of this paper is to present a method of creation of a pictogram system describing architectural form components of vernacular houses; those components acquire their form due to influences imposed by a particular climatic context. Many books and articles have been written on the topic but they suffer from one of the following disadvantages regarding the current goal: they are too comprehensive and specific or they are oriented towards particular philosophical or cultural thinking. The pictograms proposed in this research are on the other hand based on a global approach of many views of a specific problem such as form, scale, enveloping, openings and others.
The research method is based on the existing literature, important guidelines for creating pictograms in general, and a unique investigation of 87 vernacular houses. A template for the extracted data about their form, function, structure, composition and technology is used for this investigation. Following established methods, it is proposed to use (and respectively exclude) some of the climate influences which may or may not be relevant to certain house’s features.
A set of pictogram rules has been created and based on them ten houses’ pictograms from different climate zones and different continents were created as a test.
The pictogram method of studying vernacular houses provides an important global overview of the most essential house members generated in reaction to the climate. It allows for rough estimation and partial comparison in order to spread an indispensable foundation for future deeper research.
This research will ultimately lead to the creation of a world map of vernacular houses’ pictograms as an electronic source, which is further explored in part 2 of this study
Innovation through urban diversity and achieving comprehensive sustainable urbanism from a community-oriented approach
Get PDFIn current urban studies focused on pathways of sustainable urbanism, the main discourse is on the development of all-inclusive approaches or comprehensive methods that could encompass multiple factors of sustainability. As a result, a bigger emphasis has been given to other dimensions of “cultural” or “governance” (also known as institutional). In more recent years, more scholarly research studies refer to governance as the fourth pillar of sustainability, and more research studies analyse the multi-dimensional methods of socio-cultural, socio-economic, etc. These factors all have major impacts on the social, environmental, and economic aspects of the city. As a result, this research study aims to test the notion of “sustainable urbanism” from a behavioural perspective, which includes market development behavior and political economy (or mixed economy). This study promotes urban diversity from the multiplicity of diversity across the physical environment, social and economic systems, cultural attributes, people backgrounds, professions and sectors, etc. This then leads to discussions on innovation through urban diversity. Hence, it is important to evaluate how diversity promotes sustainable urbanism through specific economic and social systems in contemporary city development scenarios. The findings from this study feed into matters of urban diversity and urban innovation, and towards pathways of sustainable urbanism
What causes Chinese listed firms to switch bank loan provider? Evidence from a survival analysis
Get PDFThis paper analyses the duration of firm-bank relationships and examines what drives firms in China to change from one bank loan provider to another. Matched data of firm-loan-duration to bank provides a unique panel data set of relationship between China's listed firms and their lending banks consisting of 2102 firms listed on both the Shanghai Stock Exchange and Shenzhen Stock Exchange in the period of 1996–2016. The Cox proportional hazard model is used to allow for a semiparametric hazard function after parametrically controlling for firm-specific financial factors, industry factors, ownership characteristics, internal management changes, and external macroeconomic changes. In addition, we explore the impact of the 2008 financial crisis, bank-financial and ownership characteristics. The main finding of this study is that in an environment of growing commercialisation of relationships the firm-bank relationship between state-owned enterprises (SOEs) and state-owned banks (SOBs) in China remains super-stable. However, a change in the CEO of a firm even of a SOE increases the probability of the loan-provider being changed
Access Repository Dashboard
Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇