ABSTRACT
Climate change has become mankind's main challenge. Greenhouse gas (GHG) emissions from shipping are not totally irresponsible for this representing, roughly, 3% of the global total;an amount equal to that of Germany's total GHG emissions. The Fourth Greenhouse Gas Study 2020 of the International Maritime Organization (IMO) predicts that the share of GHG emissions from shipping will increase further, as international trade recovers and continues to grow, alongside with the economic development of India, China, and Africa. China and the European Union have proposed to include shipping in their carbon emissions trading systems (ETS). As a result, the study of the relationship between the carbon finance market and the shipping industry, attempted here for the first time, is both important and timely, both for policymakers and shipowners. We use wavelet analysis and the spillover index methods to explore the dynamic dependence and information spillovers between the carbon finance market and shipping. We discover a long-term dependence and information linkages between the two markets, with the carbon finance market being the dominant one. Major events, such as the 2009 global financial crisis;Brexit in 2016;the 2018 China-US trade frictions;and COVID-19 are shown to strengthen the dependence of carbon finance and shipping. We find that the dependence is strongest between the EU carbon finance market and dry bulk shipping, while the link is weaker in the case of tanker shipping. Nonetheless, carbon finance and tanker shipping showed a relatively stronger dependence when OPEC refused to cut production in 2014, and when the China-US trade disputes led to the collapse of oil prices after 2018. We show that information spillovers between carbon finance and shipping are bidirectional and asymmetric, with the carbon finance market being the principal transmitter of information. Our results and their interpretation provide guidance to governments on whether (and how) to include shipping in emissions trading schemes, supporting at the same time the environmental sustainability decisions of shipping companies. © 2023 The Authors
ABSTRACT
This paper reflects on the work that was done to establish a national wastewater pathogen surveillance system in New Zealand in response to the COVID-19 pandemic. After a short review of the wastewater literature, a timeline of SARS-CoV-2 is described to situate the work in a country that effectively eliminated COVID-19 from the community, but at the time of writing had a population that was more exposed than in other countries. The paper then turns to describe three broad categories of research needed to establish the COVID-19 wastewater surveillance system: monitoring, data analysis and ethics. Some of the work covers familiar ground for those trained in science, technology, engineering and mathematics, such as the spatial location and temporal frequency of field sampling. Other work sits more comfortably with those trained in the humanities and social science, such as population mobility and the ethics of surveillance. The message that comes from our experience is the need to work together, which takes courage, empathy and patience as we learn to accept each other's epistemological foundations and modus operandi.
ABSTRACT
We propose a novel approach to determine the respiration rate of a moving subject, in terms of the velocity change, by using a frequency-modulated continuous-wave radar. In conventional methods, the respiration rate is determined by considering the variation in the distance between the targets and radar;however, these methods are vulnerable to the subject’s movements. The proposed approach estimates the respiration rate by considering the velocity, instead of the distance. An experiment was conducted to measure respiration in several subjects performing various movements. The experimental results demonstrate that the proposed method is more robust to the subject’s movements compared to conventional research methods, and can more accurately estimate the respiration rate.
ABSTRACT
This paper presents a heterogeneous configuration of the multirotor unmanned aerial system (UAS) that features the combined characteristics of the helicopter and quadrotor in a single multirotor design, featuring the endurance and energy efficiency similar to a helicopter, while keeping the mechanical simplicity, control, and manoeuvrability of the standard quadrotor. Power needed for a rotorcraft to hover has the inverse relation with the rotor disc. Therefore, multiple small rotors of the quadrotor are energetically outperformed by a large rotor of the helicopter, for a similar size. Designing the stable control system for such a dynamically complex multirotor configuration remains the main challenge as the studies previously carried out on these designs have successfully demonstrated energy efficiency but at the cost of degraded attitude control. Advancements in the energetics of the multirotor results in enhanced endurance and range that could be highly effective in remote operation applications. However, a stable control system is required for accurate positioning. In this paper, a cascaded PID control approach is proposed to provide the control solution for this heterogeneous multirotor. Automatic tuning is proposed to design the PID controller for each loop of the cascade structure. A relay feedback experiment is conducted in a controlled environment, followed by identification of the open-loop frequency response and estimation of dynamics. Subsequently, PID controllers are tuned through approximated models with the help of tuning rules. A custom-designed flight controller is used to experimentally implement the proposed control structure. Presented experimental results demonstrate the efficacy of the proposed control strategy for heterogeneous multirotor UAS.