Term Structure of Volatility and Price Jumps in Agricultural Markets - Evidence from Option Data

Empirical evidence suggests that agricultural futures price movements have fat-tailed distributions and exhibit sudden and unexpected price jumps. There is also evidence that the volatility of futures prices contains a term structure depending on both calendar-time and time to maturity. This paper extends Bates (1991) jump-diffusion option pricing model by including both seasonal and maturity effects in volatility. An in-sample fit to market option prices on wheat futures shows that our model outperforms previous models considered in the literature. A numerical example illustrates the economic significance of our results for option valuation.Option pricing, Futures, Term structure of volatility, Jump-diffusion, Agricultural markets, Demand and Price Analysis,

Her må vi bare gjøre det beste vi kan for barna ...

I mars 2020 endret barnehagehverdagen seg drastisk som en konsekvens av koronapandemien. Barnehagene stengte ned for ordinær drift fra 13.mars og holdt stengt frem til 20. april (Os, et al., 2021). Tidligere forskning viser til endringer for organiseringen i barnehagen der kohortinndeling, større voksentetthet og et forbud mot foreldre i barnehagen ble poengtert (Pramling Samuelsson et, al., 2020). Restriksjoner og tiltak som en konsekvens av koronapandemien har påvirket en rekke faktorer innenfor det spesialpedagogiske arbeidet i barnehagen. Statistikken viser til at flere barn med vedtak om spesialpedagogisk hjelp, ikke har fått opprettholdt dette vedtaket under nedstengingen av barnehagene (Utdanningsdirektoratet, 2020). Tidligere forskning peker også på konsekvenser for manglende støtte for foreldre av barn med spesielle behov under pandemien (Paulauskaite et, al., 2021). Denne studien tar sikte på å belyse hvordan spesialpedagoger opplevde innvirkningen av koronapandemien på det spesialpedagogiske arbeid i barnehagen. Formålet med masteroppgaven var å få en dypere forståelse og innsikt i hvilke utfordringer og muligheter koronapandemien skapte for spesialpedagoger i barnehagen. Studien har følgende problemstilling: Hvordan opplever spesialpedagoger innvirkningen av koronapandemien på det spesialpedagogiske arbeidet i barnehagen? Problemstillingen ble også supplert med tre forskningsspørsmål som bidrar til å spesifisere retningen på forskningen. Disse omhandler opprettholdelse av vedtak om spesialpedagogisk hjelp, organisering av det spesialpedagogiske arbeidet i barnehagen og foreldresamarbeid under korona omstendighetene. For å belyse problemstillingen og forskningsspørsmålene er det valgt en kvalitativ metode. Studiens empiri er innsamlet ved bruk av semistrukturerte intervjuer med fem spesialpedagoger som arbeider i barnehagen. Analyseringen av dataene ble gjennomført ved bruk av Braun og Clarke (2006) sin tematiske analysemodell. Funnene i studien indikerer at spesialpedagogene delvis opprettholde vedtak om spesialpedagogisk hjelp ved nedstengingen av barnehagen. Enkelte barn fikk opprettholdt vedtak med bakgrunn i individuelle vurdering gjort av spesialpedagogene. Da barnehagen åpnet var det likevel ikke en optimal måte å gjennomføre spesialpedagogisk arbeid da barnehagen hadde en rekke restriksjoner og tiltak. Informantene opplever likevel hensiktsmessige sider ved organiseringen som økt voksentetthet og nærhet med barna. Videre tyder funnene på at det var utfordrende å opprettholde et godt foreldresamarbeid i nedstengingen. Kommunikasjonen ble utfordret da det var mangel på de «uformelle samtalene». Funnene indikerer at veiledning av foreldrene ble vurdert ut ifra barnets utfordringer og opplevelsen av hjemmemiljøe

Physics-guided neural networks for inversion-based feedforward control applied to hybrid stepper motors

Rotary motors, such as hybrid stepper motors (HSMs), are widely used in industries varying from printing applications to robotics. The increasing need for productivity and efficiency without increasing the manufacturing costs calls for innovative control design. Feedforward control is typically used in tracking control problems, where the desired reference is known in advance. In most applications, this is the case for HSMs, which need to track a periodic angular velocity and angular position reference. Performance achieved by feedforward control is limited by the accuracy of the available model describing the inverse system dynamics. In this work, we develop a physics-guided neural network (PGNN) feedforward controller for HSMs, which can learn the effect of parasitic forces from data and compensate for it, resulting in improved accuracy. Indeed, experimental results on an HSM used in printing industry show that the PGNN outperforms conventional benchmarks in terms of the mean-absolute tracking error

Knowledge Management towards a digitalization era: systematic review of past research and future directions

This paper presents a systematic analysis of knowledge management (KM) research spanning the last four decades. The analysis is tracing the research paradigms, the theoretical premises and the objects of study of extant research building on the accomplishments of the past to map the key dimensions of KM as a research domain. Furthermore, a number of directions for future research are identified. The review provides a conceptual basis for synthesizing and extending KM research. During the past four decades, KM matured as a domain and its popularity increased for both academics and practitioners. The interest in KM is fueled by digitalization and the turn to a knowledge economy. The systematic analysis of research output over the years reveals the sociotechnical character of KM as shifts in the study of technology and organizations that are closely related to the domain´s evolution. A systematic analysis of overarching review papers was chosen as a method that allows to thoroughly delve in the content without compromising coverage. Specifically, the findings reveal the plurality of research paradigms in extant KM research and the diversity of theoretical conceptualizations. Overall, there is a shift from the individual‐knowledge focus towards a group‐knowledge focus, which is more compatible with networking rather than repository approaches to KM. The objects of study also vary significantly covering technologies, the interplay between technologies and organizations and knowledge trajectories including creation, elicitation, codification, conversion, accumulation, transfer, application, valorization and obsolescence. Future research can be developed to cover underexplored areas and underrepresented theoretical and methodological approaches in extant research and to respond to needs for research on emerging topics related to digitalization. However, returning to the roots of the KM field when practitioners made substantial contributions to KM research may be useful, especially because of the opportunities that new KM technologies offer.acceptedVersio

Physics-guided neural networks for feedforward control with input-to-state stability guarantees

Currently, there is an increasing interest in merging physics-based methods and artificial intelligence to push performance of feedforward controllers for high-precision mechatronics beyond what is achievable with linear feedforward control. In this paper, we develop a systematic design procedure for feedforward control using physics-guided neural networks (PGNNs) that can handle nonlinear and unknown dynamics. PGNNs effectively merge physics-based and NN-based models, and thereby result in nonlinear feedforward controllers with higher performance and the same reliability as classical, linear feedforward controllers. In particular, conditions are presented to validate (after training) and impose (before training) input-to-state stability (ISS) of PGNN feedforward controllers. The developed PGNN feedforward control framework is validated on a real-life, high-precision industrial linear motor used in lithography machines, where it reaches a factor 2 improvement with respect to conventional mass-friction feedforward

Awareness of dementia risk reduction among current and future healthcare professionals: A survey study

Background: The total number of people affected by dementia worldwide is increasing rapidly. Recent studies provided evidence for the contribution of modifiable risk and protective factors to dementia risk. Although healthcare professionals could play an essential role in informing the general public about the relationship between lifestyle and dementia, it is unclear what they know about this relationship. Therefore, this study assesses the awareness of dementia risk reduction among current and future healthcare professionals.Design and methods: An online survey was carried out among 182 healthcare students from Maastricht University and 20 general practitioners (GPs) and practice nurses in Limburg, The Netherlands. The survey assessed the knowledge about risk and protective factors of dementia and identified needs, wishes and barriers concerning dementia risk reduction strategies.Results: The majority of current (75.0%) and future (81.9%) healthcare professionals indicated that dementia risk reduction is possible. Among students, awareness of cardiovascular risk factors of dementia (e.g., coronary heart disease (44.5%), hypertension (53.8%)) was low. Most participants (>70.0%) would like to receive more information about dementia risk reduction.Conclusions: The majority of current and future healthcare professionals were aware of the relationship between lifestyle and dementia risk. However, there are still substantial gaps in knowledge regarding individual dementia risk factors. Given the essential role of healthcare professionals in providing lifestyle advice, there is a need to increase awareness by providing educational programs focused on dementia risk reduction

Income Uncertainty and the Decision to Invest in Bulk Shipping

We develop a coherent framework for the valuation of real assets and determination of the optimal time to invest. To this end, we model the stochastic nature of income and develop methodologies for valuing traded derivatives to facilitate model calibration and for assessing real investment projects. A valuation paradigm for freight-linked assets is presented and the effects of uncertainty in the key parameters are examined by means of a sensitivity analysis. Using a real option approach, we demonstrate its usefulness in investment appraisal and optimal timing of entry. We accompany our theoretical results with illustrative examples from the shipping industry