7,147 research outputs found
Energy-efficient through-life smart design, manufacturing and operation of ships in an industry 4.0 environment
Energy efficiency is an important factor in the marine industry to help reduce manufacturing and operational costs as well as the impact on the environment. In the face of global competition and cost-effectiveness, ship builders and operators today require a major overhaul in the entire ship design, manufacturing and operation process to achieve these goals. This paper highlights smart design, manufacturing and operation as the way forward in an industry 4.0 (i4) era from designing for better energy efficiency to more intelligent ships and smart operation through-life. The paper (i) draws parallels between ship design, manufacturing and operation processes, (ii) identifies key challenges facing such a temporal (lifecycle) as opposed to spatial (mass) products, (iii) proposes a closed-loop ship lifecycle framework and (iv) outlines potential future directions in smart design, manufacturing and operation of ships in an industry 4.0 value chain so as to achieve more energy-efficient vessels. Through computational intelligence and cyber-physical integration, we envision that industry 4.0 can revolutionise ship design, manufacturing and operations in a smart product through-life process in the near future
Application of an expert system shell in the preliminary design of offshore supply vessels
This paper presents the application of expert system programming in preliminary ship design with particular emphasis on offshore supply vessels. Instead of using one of the conventional programming expert system languages, the system is developed using an expert system shell, Leonardo. The design program is written in such a way that it is user friendly as well as giving the user full control over the progress of the design. The algorithms developed in this system are based on extensive research on existing offshore supply vessels
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The Risk of Cancer from CT Scans and Other Sources of Low-Dose Radiation: A Critical Appraisal of Methodologic Quality
AbstractIntroduction: Concern exists that radiation exposure from computerized tomography (CT) will cause thousands of malignancies. Other experts share the same perspective regarding the risk from additional sources of low-dose ionizing radiation, such as the releases from Three Mile Island (1979; Pennsylvania USA) and Fukushima (2011; Okuma, Fukushima Prefecture, Japan) nuclear power plant disasters. If this premise is false, the fear of cancer leading patients and physicians to avoid CT scans and disaster responders to initiate forcedevacuations is unfounded.Study Objective: This investigation provides a quantitative evaluation of the methodologic quality of studies to determine the evidentiary strength supporting or refuting a causal relationshipbetween low-dose radiation and cancer. It will assess the number of higher qualitystudies that support or question the role of low-dose radiation in oncogenesis.Methods: This investigation is a systematic, methodologic review of articles published from 1975–2017 examining cancer risk from external low-dose x-ray and gamma radiation, defined as less than 200 millisievert (mSv). Following the PRISMA guidelines, the authors performed a search of the PubMed, Cochrane, Scopus, and Web of Science databases. Methodologies of selected articles were scored using the Newcastle Ottawa Scale (NOS) and a tool identifying 11 lower quality indicators. Manuscript methodologies were rankedas higher quality if they scored no lower than seven out of nine on the NOS and contained no more than two lower quality indicators. Investigators then characterized articles as supporting or not supporting a causal relationship between low-dose radiation and cancer.Results: Investigators identified 4,382 articles for initial review. A total of 62 articles met all inclusion/exclusion criteria and were evaluated in this study. Quantitative evaluation of the manuscripts’ methodologic strengths found 25 studies met higher quality criteria while 37 studies met lower quality criteria. Of the 25 studies with higher quality methods, 21 out of 25did not support cancer induction by low-dose radiation (P = .0003).Conclusions: A clear preponderance of articles with higher quality methods found no increased risk of cancer from low-dose radiation. The evidence suggests that exposure to multiple CT scans and other sources of low-dose radiation with a cumulative dose up to 100 mSv (approximately 10 scans), and possibly as high as 200 mSv (approximately 20 scans), does not increase cancer risk
Dynamic behavior of eye globes
Spherical shell equations and inertia terms for dynamic behavior of eye globe
Sea-level Rise, Storm Surges, and Extreme Precipitation in Coastal New Hampshire: Analysis Of Past And Projected Trends
Shipbuilding 4.0 Index Approaching Supply Chain
The shipbuilding industry shows a special interest in adapting to the changes proposed by
the industry 4.0. This article bets on the development of an index that indicates the current situation
considering that supply chain is a key factor in any type of change, and at the same time it serves as a
control tool in the implementation of improvements. The proposed indices provide a first definition
of the paradigm or paradigms that best fit the supply chain in order to improve its sustainability and
a second definition, regarding the key enabling technologies for Industry 4.0. The values obtained
put shipbuilding on the road to industry 4.0 while suggesting categorized planning of technologies
Marine Invaders in the Northeast: Rapid Assessment Survey of Non-native and Native Marine Species of Floating Dock Communities, August 2003
In his seminal book on The Ecology of Invasions by Animals and Plants, Elton (1958) laid the foundation for the science of biological invasions. He identified the importance of human-mediated vectors as means of transporting organisms to new locations and discussed invasions in the context of ecological impacts and evolutionary consequences. Elton even identified what needed to be done to prevent practical and ecological damages from invaders--keep them out, eradicate them, and if all else fails, manage them at acceptable levels. We have not been vigilant in applying this knowledge to marine ecosystems, although this is changing. Our ability to detect changes in numbers and rate of marine introductions depends on well-documented lists of species in time and space, appropriate identification of non-native species, and careful records that follow changes in nomenclature, distribution, potential vectors, and ecosystem alterations caused by non-native species.United States. Environmental Protection Agency (Grant X83055701
Philadelphia region input-output study working papers. Volume 3 - Final demand
Input-output coefficients for 86 final demand sectors in Philadelphia regio
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