Human Safety Requirements Research Articles

On service life quantification and service life management

The service life of infrastructures is of high relevance for the provision of societal and industrial functionality and sustainability. Despite this high relevance, the service life is not explicitly considered of the design and operation procedures. Towards an efficient and sustainable service life management, this paper contains a description of approaches for service life limit quantification and service life management. The service life limit quantification is based on scenario modelling for identifying technical and economical service life limits. The technical service life limit is determined with a system reliability analysis and the comparison with target reliabilities accounting for human safety requirements. The service life management approach builds upon the service life limit quantification and further includes the probabilities, benefits, cost and consequences associated to the system states throughout the service life. In this way, technical, economic and life safety models and boundaries can be jointly analysed and optimised based on decision theory. Both the technical service life quantification and the service life management approaches are exemplified through the documentation of case studies. Furthermore, the principles and key outcomes pertaining to service life quantification are summarized.

The Conceptualization of an Unmanned Aerial System (UAS) Ship–Shore Delivery Service for the Maritime Industry of Trinidad

Human risk has further increased within the global maritime industry because of the coronavirus disease (COVID-19) pandemic. It also impacted the economic activity within the Caribbean islands, including its ship–shore delivery sector. Traditionally, this service includes human interface presenting safety and health hazards, and vessels employed operate on fossil fuels, releasing emissions that contribute to harmful GHG and air pollution. Opportunities have arisen for local maritime companies to introduce innovative strategies within the industry to rectify these challenges. Implementing unmanned aerial system (UAS) technology can reduce operational costs, human risk, environmental impact, and delivery time. This study assessed the feasibility of a UAS ship–shore delivery service to optimize near-harbor deliveries within six major ports of Trinidad. Data was gathered through field observations, a literature survey, questionnaires, and interviews with relevant stakeholders. Based on the above approach, the needs of the local ship–shore delivery sector were identified and categorized. An appropriate UAS which addressed these needs while maintaining the economic, environmental, and human safety requirements was then identified. Recommendations for overcoming the local implementation and operational challenges that were encountered are presented. This study may serve as a reference for conceptualizing a UAS ship–shore delivery service and offers resolutions for similar implementation challenges.

Safety requirements for symbiotic human–robot collaboration systems in smart factories: a pairwise comparison approach to explore requirements dependencies

Industry 4.0 is expected to deliver significant productivity gain taking advantage of Internet of things (IoT). Smart solutions, enhanced by IoT, are constantly driving revolutionary approaches in multiple domains. Smart factories are one domain where intelligent integrated robotic systems will revolutionize manufacturing, resulting in a complex ecosystem, where humans, robots and machinery are combined. In this setting, human safety requirements are of paramount importance. This paper focuses on symbiotic human–robot collaboration systems (HRC), where human safety requirements are essential. Hence, it aims to explore and prioritize human safety requirement dependencies, as well as their dependencies with other critical requirements of smart factory operation, as effectiveness and performance. Toward this end, the proposed approach is based on SysML to represent the requirements dependencies and pairwise comparisons, a fundamental decision-making method, to quantify the importance of these dependencies. This model-driven approach is used as the primary medium for conveying traceability among human safety requirements as well as traceability from safety requirements to effectiveness and performance requirements in the system model. The analysis is based on the operational requirements identified in the European project HORSE, which aims to develop a methodological/technical framework for easy adaptation of robotic solutions from small-/medium-sized enterprises. Validation of the results is also performed to further elaborate on human safety requirement dependency exploration. The outcomes of this paper may be beneficial for symbiotic HRC systems in the early design stage. As the system is being developed with an emphasis on human safety, all these requirements that have been assessed with highly prioritized dependencies should be taken into account, whereas those with negligible ones have to be ignored since they do not significantly affect the rest of the process. Since operational requirements may be conflicted and incompatible, this approach may be very useful for other systems as well during the system design phase to find the appropriate solution satisfying the majority of the requirements, giving a priority to the ones with highly ranked dependencies and hence facilitating the implementation phase and afterward the production line. The outcomes may be used as a step in developing a model-driven approach which should be able to support the manufacturing process, facilitating the integration of systems and software modeling, which is increasingly important for robotic systems in smart factories incorporating HRC.

Target reliability indices for existing quay walls derived on the basis of economic optimisation and human safety requirements

General frameworks for reliability differentiation have evolved over time and are mainly developed for buildings. However, recommendations for the safety of existing quay walls are lacking. In this study, target reliability indices for assessing existing quay walls were derived by economic optimisation and by evaluating the requirements concerning human safety. In quay-wall design, some dominant stochastic design variables are largely time-independent, such as soil and material properties. The influence of time-independent variables on the evolution of the probability of failure was taken into consideration, since this affects the present value of future failure costs and the associated target reliability indices. The target reliability indices obtained for existing quay walls depend on the consequences of failure and the remaining lifetime. If the failure modes of a quay wall are governed by time-independent design parameters and the quay wall has already survived the early service period, the residual probability of failure is lower for an existing quay wall compared to a new structure. Hence, this should be considered in the determination of target reliability indices. The method to evaluate quay-wall reliability over time can also be used to assess other civil and geotechnical structures.

Wireless Power Transfer Using Oscillating Magnets

The advancement of portable and implantable electronic devices has driven active research into wireless power transfer (WPT) methods. Current commercial WPT techniques using coil coupling have limitations, such as range, frequency, safety, line of sight, orientation, and concurrency. This paper presents a system utilizing oscillating magnets to extract power from a low-level ac magnetic field. This system enables the simultaneous powering of multiple low-power devices in an environment that meets human safety requirements. Compared with conventional WPT techniques, such as RF or acoustic power transfer, the proposed system transfers stable power to electronic nodes placed anywhere within the magnetic field under low driving frequency. Theoretical power calculations and experimental demonstrations are presented to prove the concepts and quantify performance. A custom three-dimensional printed millimeter-size oscillator loaded with two 8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> cubic permanent magnets is employed as the energy receiver to experimentally validate the proposed system. Measurements show that the raw ac electrical power and rectified dc power received by the oscillator achieve 269 and 135 μW, respectively, under 400 μT excitation magnetic field amplitude at 355 Hz.

Lightning grounding system of a tall-mast for human safety

Numerical techniques enable realistic analysis of lightning currents effects on tall structures including actual installation conditions. Characteristics such as the frequency dependence of soil parameters, inductances and capacitances due to nearby metallic elements, and the actual geometry of the structure and its grounding system are commonly neglected or simplified in lightning grounding system design. In this paper, the impact of neglecting these characteristics on a tall-mast lightning grounding system design is discussed. The effects are determined using three risk assessment approaches based on energy calculation, voltage thresholds, and current integration, which allows comparing the performance of the grounding system under different conditions. Results obtained from numerical simulations and then verified by measurements show that a metallic protecting fence not connected to the earthing mesh produces lower human safety risks to lightning currents than when it is connected. This result is in opposition to common design practices and shows the need to assess each specific grounding design under true conditions to guarantee human safety requirements.

Agricultural Chemical Safety Assessment: A Multisector Approach to the Modernization of Human Safety Requirements

Better understanding of toxicological mechanisms, enhanced testing capabilities, and demands for more sophisticated data for safety and health risk assessment have generated international interest in improving the current testing paradigm for agricultural chemicals. To address this need, the ILSI Health and Environmental Sciences Institute convened a large and diverse group of international experts to develop a credible and viable testing approach that includes scientifically appropriate studies that are necessary without being redundant, and that emphasize toxicological endpoints and exposure durations that are relevant for risk assessment. Benefits of the proposed approach include improved data for risk assessment, greater efficiency, use of fewer animals, and better use of resources. From the outset of this endeavor, it was unanimously agreed that a tiered approach should be designed to incorporate existing knowledge on the chemistry, toxicology, and actual human exposure scenarios of the compound, with integration of studies on metabolism/kinetics, life stages, and systemic toxicities. Three international task forces were charged with designing study types and endpoints on metabolism/ kinetics, life stages, and systemic toxicities to be used in the tiered approach. This tiered testing proposal departs from the current standardized list of hazard studies used by many national authorities, and represents the first comprehensive effort of its kind to scientifically redesign the testing framework for agricultural chemicals.

Attack of the Killer Tomatoes-Reply

In Reply. —The Council on Scientific Affairs' article, Biotechnology and the American Agricultural Industry, was designed to provide information on the safety of individual, genetically modified foods, not to endorse or assert the safety of any particular food or technology. The introduction of theBacillus thuringiensisvarkurstaki(Btk) transgene into plants for purposes of pest control and the effects of the toxin on herbivorous insects is clearly described. Two parameters will require continued monitoring to ensure that human safety requirements are met: (1) the concentration of the toxin in the transgenic plant; and (2) structural changes unique to the transgene-encoded toxin protein. Current studies are directed to promoting expression of the toxin gene during those stages of the plant life cycle that are most susceptible to insect damage. The goal of transgenic plant technology is not specifically to increase toxin expression in the edible fruits of plants, but to

Investigation of computer hardware failure due to corrosion

Failure analysis was conducted on two failed electronic cardsfrom the Computer Center of the Kuwait Institute for Scientific Research. The results of the elemental analysis indicated that the corrosion product film found on contact pins and soldered through holes was composed of copper and sulphur compounds. Chemical analysis of the air in the computer room indicated a high level of nitrogen oxide (up to 300 ppb), whereas other gases such as H2S and SO2 were below the detectahle limits (100 and 200 ppb respectively) of the analytical technique used. It was concluded that the initial high relative humidity ( ∼ 75%) had synergised with the strongly oxidising nitrogen oxide and H2S and/or SO2 to bring about the corrosion of copper substrate in ‘bare spots’ or gaps in the soldered contacts, causing card failure. Other factors, such as galvanic coupling of the copper substrate with nickel, silver, and gold plates, and the relatively high local temperature, may have accelerated the corrosion process. A decrease in the relative humidity to the optimum value of 45% did not obviate card failure. It was concluded that efficient air filters should be utilised in the computer environment, as electronic equipment can be damaged by levels of pollutant gases 10 times lower than those cited for human safety requirements.