A Supervisor for Control of Mode-switch Process

Many processes operate only around a limited number of operation points. In order to have adequate control around each operation point, and adaptive controller could be used. When the operation point changes often, a large number of parameters would have to be adapted over and over again. This makes application of conventional adaptive control unattractive, which is more suited for processes with slowly changing parameters. Furthermore, continuous adaptation is not always needed or desired. An extension of adaptive control is presented, in which for each operation point the process behaviour can be stored in a memory, retrieved from it and evaluated. These functions are co-ordinated by a ¿supervisor¿. This concept is referred to as a supervisor for control of mode-switch processes. It leads to an adaptive control structure which quickly adjusts the controller parameters based on retrieval of old information, without the need to fully relearn each time. This approach has been tested on experimental set-ups of a flexible beam and of a flexible two-link robot arm, but it is directly applicable to other processes, for instance, in the (petro) chemical industry

Supervisory Control of Mode-switch Processes; Application to a flexible beam

Many processes operate only around a limited number of operation points. In order to have adequate control around each operation point, an adaptive controller could be used. Then, if the operation point changes often, a large number of parameters would have to be adapted over and over again. This prohibits application of conventional adaptive control, which is more suited for processes with slowly changing parameters. Furthermore, continuous adaptation is not always needed or desired. An extension of adaptive control is presented, in which for each operation point the process behaviour can be stored in a memory, retrieved from it and evaluated. These functions are coordinated by a “supervisor”. This concept is referred to as supervisory control. It leads to an adaptive control structure which, after a learning phase, quickly adjusts the controller parameters based on retrieval of old information, without the need to fully releam each time. This approach has been tested on an experimental set-up of a flexible beam, but it is directly applicable to processes in e.g. the (petro)chemical industry as well

The (im)possibilities of disaster risk reduction in the context of high-intensity conflict: the case of Afghanistan

ABSTRACT Conflict aggravates disaster risk and impact through increased vulnerability and weakened response capacities. Disaster risk reduction (DRR) and disaster governance are needed – but often deemed unfeasible – in conflict-affected areas. In Afghanistan, despite the high-intensity conflict (HIC), there is a growing body of practice on DRR. To provide insight on DRR in HIC contexts, this study used document analysis, stakeholder interviews, and participant observation to analyse the promotion, implementation, and challenges of DRR in Afghanistan. The findings show that DRR was promoted after international recognition of Afghanistan’s high disaster risk, which coincided with expanding opportunities for development. Early Afghan DRR projects were hazard-oriented and focused on mitigation infrastructure, but some have shifted towards an integrated approach. DRR is challenging in HIC contexts because of complex logistical and funding needs required to overcome access and security issues. The Afghan experience shows that DRR is possible in HIC countries, provided that different levels of conflict are acknowledged, sufficient time and funding are available, and disaster governance arrangements are in place. Expectations regarding the possibilities for DRR in HIC areas should be tempered by the realities of limitations in terms of geographical coverage, real impact, and capacities to reduce vulnerability in an integrated way. KEYWORDS: Disaster risk reduction (DRR), high-intensity conflict settings, disaster governance, Afghanistan, resilience humanitarianis

Rijpheidskenmerken van appels van het ras Golden Delicious

In 1983 werden tussen januari en juni op 4 veilingen in Nederland elke maand 20-25 monsters Golden Delicious appelen uit de aanvoer genomen en werden een aantal basisgegevens genoteerd als maat, klasse, vorm en bewaarmethode. Op de veilingen werden vervolgens enkele subjektieve kenmerken bepaald als een oordeel over slijtage door de keurmeester en een schatting van de kleur. Tenslotte werden een aantal objektieve kenmerken aan dezelfde monsters bepaald, met name de hardheid, het zuurgehalte en de refraktie. Het onderzoek had tot doel: zoeken naar kriteria, waarmee afleving gekarakteriseerd kan worde

Security guidelines for field research in complex, remote and hazardous places

These guidelines assist researchers in conducting their field-based research or fieldwork in hazardous, remote or complex environments as safely and securely as possible. Fieldwork comes with risks, ranging from the mundane risks of car accidents to more exceptional risks of encountering violence. These risks may affect the security of the researcher and the research outcomes, as well as the security of the respondents, local assistants and interpreters, the home and host organizations, and research sponsors. Taking into account the risk environment should be