Velocity-Free State Feedback Fault-Tolerant Control for Satellite with Actuator and Sensor Faults

A velocity-free state feedback fault-tolerant control approach is proposed for the rigid satellite attitude stabilization problem subject to velocity-free measurements and actuator and sensor faults. First, multiplicative faults and additive faults are considered in the actuator and the sensor. The faults and system states are extended into a new augmented vector. Then, an improved sliding mode observer based on the augmented vector is presented to estimate unknown system states and actuator and sensor faults simultaneously. Next, a velocity-free state feedback attitude controller is designed based on the information from the observer. The controller compensates for the effects of actuator and sensor faults and asymptotically stabilizes the attitude. Finally, simulation results demonstrate the effectiveness of the proposed scheme.

‘Oh, Oh Rodeo!!’: American Cowboys and Post-Independence Ireland

In 1924 Tex Austin, an American showman, brought his world travelling Rodeo to Croke Park in Dublin. Coming at a time of significant social and political upheaval in Ireland, Austin's rodeo promised an entirely new kind of spectacle which was free from imperial or British connotations. Austin's rodeo, and cowboy paraphernalia in general, seemed largely immune from cultural suspicions despite the fact that few citizens knew what a rodeo actually entailed. The purpose of the present article is twofold. First it provides a detailed examination of Tex Austin's Dublin Rodeo, and a growing proliferation of cowboy culture in interwar Ireland. Second, it uses Austin's Rodeo and its aftermath, to discuss the rise of cowboy masculinities in Ireland. Done to highlight the multiplicity of masculine identities in the Free State, the article discusses the appeal of cowboy inspired masculinity in Ireland, as well as the mediums through which it passed. Such an identity was not all encompassing but it did exist, and was sustained by the entertainment and leisure industry. Its study reiterates the need for more work on the various pressures and influences brought to bear on Irish masculinity.

Optimization of 3D controlled ELM-free state with recovered global confinement for KSTAR with n=1 resonant magnetic field perturbation

Mitigation of deleterious heat flux from edge-localized modes (ELMs) on fusion reactors is often attempted with 3D perturbations of the confining magnetic fields. However, the established technique of resonant magnetic perturbations (RMPs) also degrades plasma performance, complicating implementation on future fusion reactors. In this paper, we introduce an adaptive real-time control scheme on the KSTAR tokamak as a viable approach to achieve an ELM-free state and simultaneously recover high-confinement (βN~1.91, βp~1.53, and H98~0.9), demonstrating successful handling of a volatile complex system through adaptive measures. We show that, by exploiting a salient hysteresis process to adaptively minimize the RMP strength, stable ELM suppression can be achieved while actively encouraging confinement recovery. This is made possible by a self-organized transport response in the plasma edge which reinforces the confinement improvement through a widening of the ion temperature pedestal and promotes control stability, in contrast to the deteriorating effect on performance observed in standard RMP experiments. These results establish the real-time approach as an up-and-coming solution towards an optimized ELM-free state, which is an important step for the operation of ITER and reactor-grade tokamak plasmas.

Opportunistic avian nectarivory on flowering Aloe maculata with a review of visiting bird species

Eight bird species were recorded feeding on Aloe maculata (Soap Aloe) nectar at Biddulphsberg, Senekal, Free State, from 23–26 August 2021. Birds were mist-netted as part of a bird ringing study and aloe pollen was noticed on some birds. The flowering aloes attract mainly Malachite Nectarinia famosa and White-bellied Sunbirds Cinnyris talatala as well as Cape Zosterops virens and Orange River White-eyes Z. pallidus. Of the 108 birds ringed or collected, 34 birds (eight species) had aloe pollen on them. These species, including a first record of Black-chested Prinia Prinia flavicans, and a confirmed record of Streaky-headed Seedeaters Crithagra gularis, represent the first observations of birds probing A. maculata flowers.

The impact of emotional intelligence on behavioural factors during transition: A case of the Free State Technical and Vocational Education and Training colleges

Orientation: Numerous changes at the Technical and Vocational Education and Training (TVET) requires some degree of emotional intelligence (EI) to achieve any level of efficiency, competitiveness and success.Research purpose: The primary purpose of this research is to empirically contribute to a comprehension of how a leader’s EI can be utilised to positively influence organisational behaviours during the transitional period.Design/methodology/approach: The study adopted a positivist research approach, that is descriptive in nature. A survey was conducted by providing a structured questionnaire to a sample of 310 academics and support staff of the TVET college sector in the Free State Province of South Africa. Data analysis was based on a total of 188 questionnaires collected, giving a return rate of 61%. The structural equation modelling (SEM) analysis and interpretation was conducted using a component-based approach to establish the correlation between the items.Main Findings: The SEM findings revealed that EI of Free State TVET college managers significantly affects all the dependent variables namely, organisational work commitment, employee job satisfaction, task-oriented behaviour, teamwork except staff morale. Emotional intelligence reflects a reasonable power of predictability toward all other variables except staff morale of the respondents.Practical/managerial implications: To ensure sustained exceptional performance, recruitment strategy for managers must deliberately incorporate EI measurements at TVET colleges.Contribution/value add: The study demonstrates empirical proof of the positive impact of a leader’s EI on organisational behaviours, thereby confirming that EI is an enabler of organisational work commitment, job satisfaction, task-oriented behaviour, teamwork, but not staff morale.