Survey of Advanced Nonlinear Control Strategies for UAVs: Integration of Sensors and Hybrid Techniques.

This survey paper explores advanced nonlinear control strategies for Unmanned Aerial Vehicles (UAVs), including systems such as the Twin Rotor MIMO system (TRMS) and quadrotors. UAVs, with their high nonlinearity and significant coupling effects, serve as crucial benchmarks for testing control algorithms. Integration of sophisticated sensors enhances UAV versatility, making traditional linear control techniques less effective. Advanced nonlinear strategies, including sensor-based adaptive controls and AI, are increasingly essential. Recent years have seen the development of diverse sliding surface-based, sensor-driven, and hybrid control strategies for UAVs, offering superior performance over linear methods. This paper reviews the significance of these strategies, emphasizing their role in addressing UAV complexities and outlining future research directions.

The aesthetic appeal of assistive technology and the economic value baby boomers place on it: A pilot study.

BACKGROUND: This pilot study aimed to understand the importance of assistive technology (AT) aesthetics on the intention to purchase, using grab rails as the example. Furthermore, the study explored the economic value consumers placed on aesthetic appeal. METHOD: Structured interviews were conducted with 25 participants, nine female, mean age 59; where seven grab rails were presented and feedback obtained on the level of appeal and 'willingness to pay'. Responses to open-ended and fixed response questions were transcribed by the interviewer during the interview and a qualitative content analysis conducted. RESULTS: Positive and negative terms in relation to aesthetics were used to describe appealing and unappealing grab rails; however, all grab rails were felt to have negative aesthetic aspects by at least five participants. Physical design and finish emerged as the two main themes regarding the appeal of the grab rail designs. Participants' 'willingness-to-pay' for appealing options was mixed, with both over and under valuations. The most likely grab rails to be purchased were considered both appealing and cost effective by participants. CONCLUSION: Aesthetic appeal plays an important role in acceptance and uptake of AT. Designers and manufacturers should be encouraged to provide appealing options as the study has shown consumers prefer aesthetically appealing grab rails. However, the challenge is creating more appealing designs, without increasing cost as consumers seem to not want to pay more for them. Furthermore, clinicians need to acknowledge the importance of aesthetics when recommending interventions and be familiar with a range of options to provide clients with more choice.

Pap test discrepancies and follow-up histology.

Papanicolaou (Pap) test discrepancy rates between cytotechnologists (CTs) and cytopathologists (CPs) are often kept to evaluate the performance of individual CTs. This is based on the unproven assumption that the CP's diagnoses are more likely to be correct. We investigated this assumption using data from our discrepancy files and comparing them to follow-up histology. All Pap test discrepancies were noted between January 1, 2001-December 31, 2001. Surgical pathology files were then searched for follow-up histology within 9 mo of the Pap test. Histologic diagnoses were compared with the previous CT and CP diagnoses, and then judged regarding accuracy. In total, 63,376 Pap tests were evaluated between January 1, 2001-December 31, 2001. There were 795 discrepancies throughout this period (1.25%). One hundred and sixty-six cases with discrepancies had follow-up histology within 9 mo of the Pap test (20.9%). Of downgraded cases (103), CPs were more correct in 51 cases (49.5%), whereas CTs were more correct in 52 cases (50.5%). Of upgraded cases (63), CPs were more correct in 19 cases (30.2%), whereas CTs were more correct in 44 cases (69.8%). Our results suggest that CPs are not more likely to be correct than CTs when there is a discrepancy with the diagnosis of a Pap test, especially when CPs upgrade CT diagnoses. This suggests that discrepancy data may be helpful for evaluating the performance of both CPs and CTs. It may also be of educational use for both CPs and CTs to know the follow-up histology in these cases.