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In this paper, we focus on how the qualitative vocabulary of Dynalearn, which is used for describing dynamic systems, corresponds to the mathematical equations used in quantitative modeling. Then, we demonstrate the translation of a qualitative model into a quantitative model, using the example of an object falling with air resistance.
To analyze on-water rowing performance, a valid determination of the power loss due to the generation of propulsion is required. This power los can be calculated as the dot product of the net water force vector ( ~ F w;o ) and the time derivative of the position vector of the point at the blade where ~ F w;o is applied (~r PoA = w ). In this article we presented a method that allows for accurate determination of both parameters using a closed system of three rotational equations of motion for three different locations at the oar. Additionally, the output of the method has been validated. An oar was instrumented with three pairs of strain gauges measuring local strain. Force was applied at different locations of the blade, while the oar was fixed at the oarlock and the end of the handle. Using a force transducer and kinematic registration, the force vector at the blade and the deflection of the oar were measured. These data were considered to be accurate and used to calibrate the measured strain for bending moments, the deflection of the oar and the angle of the blade relative to its unloaded position. Additionally, those data were used to validate the output values of the presented method plus the associated instantaneous power output. Good correspondence was found between the estimated perpendicular blade force and its reference (ICC = .999), while the parallel blade force could not be obtained (ICC = .000). The position of the PoA relative to the blade could be accurately obtained when the perpendicular force was 5.3 N (ICC = .927). Instantaneous power output values associated with the perpendicular force could be obtained with reasonable accuracy (ICC = .747). These results suggest that the power loss due to the perpendicular water force component can be accurately obtained, while an additional method is required to obtain the power losses due to the parallel force.
Shani and Arad (2014) claimed that tourism scholars tend to endorse the most pessimistic assessments regarding climate change, and that anthropogenic climate change was a "fashionable" and "highly controversial scientific topic". This brief rejoinder provides the balance that is missing from such climate change denial and skepticism studies on climate change and tourism. Recent research provides substantial evidence that reports on anthropogenic climate change are accurate, and that human-induced greenhouse gas emissions, including from the tourism industry, play a significant role in climate change. Some positive net effects may be experienced by some destinations in the short-term, but in the long-term all elements of the tourism system will be impacted. The expansion of tourism emissions at a rate greater than efficiency gains means that it is increasingly urgent that the tourism sector acknowledge, accept and respond to climate change. Debate on tourism-related adaptation and mitigation measures is to be encouraged and welcomed. Climate change denial is not.
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Looking at the trends in the four quarters of 2021, it is clear that (partial) lockdowns of sectors have been very bad news for business performance. Also not directly hit sectors like the care and service industry underperformed. The horeca, retail and cultural sectors were hit hardest by recurring lockdowns. Business services and technical professionals were more resilient. We have observed a strong decrease in sales, net margins, investment (willingness), solvability and entrepreneurial wages in periods of lockdown. They are (far) below the levels of the pre-Corona year 2019. Start-ups and the self-employed were the most vulnerable. The type of market in which entrepreneurs operate is of great importance. Turnover, net margins and entrepreneurial wages in the B2B markets are significantly higher than in the B2C markets. We were unable to establish any direct positive effects of the degree of digitization of businesses on net margins (Q2 special). Rather, the utilization of too many applications seems to deteriorate business performance. Entrepreneur digital skills are able to predict net margins better and positively. We will repeat this special in the near future as many businesses have only recently started to digitize. Entrepreneurs have lost their way in the forest of local, provincial, national and EU subsidies (Q3 special), halving the number of applications compared to 2015. Tax deduction programs seem far more effective than the dazzling diversity of subsidies. Owners of businesses with staff are especially willing to pay specialized advisors to detect and apply for subsidies on a “no cure, no pay” basis. There appears to be a strong link between the self-estimated sales skills of entrepreneurs and their turnover, and the short-term growth expectations (Q4 special). The more experienced and skilled in sales, the higher the quarterly turnover and the higher the growth expectation. However, 62% of entrepreneurs are unskilled or untrained in sales skills. And 30% of entrepreneurs indicate that they are not effective at selling. Overall, the lockdowns resulted in a growing number of entrepreneurs developing into marginal companies. Financial reserves, such as saved pensions and private/partner/family capital were depleted. Lockdowns also increased firm and private debts, which the majority of companies are unable to repay. Poverty is knocking at the door of many Dutch entrepreneurs and, even with the support of a partner income, only 4 out of 10 entrepreneurs earn a more than marginal living. Our main recommendations in the quarterly reports of 2021 are: 1. Strengthen the solvability of micro-businesses by converting tax debts in subordinate loans. 2. Pro-actively contact entrepreneurs to support them with support possibilities, (poverty alleviation) allowances and free coaching and sales, financial and digital training possibilities. 3. Start proactively discussing the viability of the firm and business model and possible ways to resolve debts. There is strong demand and shortages on the labor market, which makes this the perfect time to guide depleted entrepreneurs to (far) better paid jobs.
Inaugural address of Frederike Praasterink, Professor Future Food Systems 22 February 2018. Three important principles contribute to the transformation of food systems: - Redesign food systems from ‘less bad’ to ‘net positive’ - Reconnect consumers, producers, youth - Revalue food through true cost accounting and new business models
MULTIFILE
Amidst escalating environmental and social challenges, this study explores regenerative business models’ definition and characteristics. While sustainable models have made considerable strides in research, policy, and practice, the advent of regenerative business models offers a progressive leap forward. Regenerative business models aspire to contribute to ecological restoration and societal well-being. The regenerative business model concept is, however, still in its infancy and lacks a comprehensive definition. Our study aims to expand this knowledge, using a Delphi-inspired approach that builds on the knowledge of academic and business experts. Our approach includes three rounds of surveys: an open-ended survey, a survey for rating and ranking the earlier responses of all participants, and a final survey to select key characteristics. We investigate patterns and distinctions among regenerative, regenerative business, and regenerative business models, and analyze their positioning vis-a-vis circular and net-positive models. Findings underscore that organizations adopting regenerative business models focus on planetary health and societal well-being. They generate value across multiple stakeholder levels, including nature, societies, customers, suppliers, shareholders, and employees. Despite overlapping with circular and net-positive models, regenerative business models also emphasize interdependencies between humans and nature, and provide a more holistic approach, centered on restoration rather than mere mitigation.
