Integrated approaches to handle UAV actuator fault

Unmanned AerialVehicles (UAV) has historically shown to be unreliable when compared to their manned counterparts. Part of the reason is they may not be able to a ord the redundancies required to handle faults from system or cost constraints. This research explores instances when actuator fault handling may be improved with integrated approaches for small UAVs which have limited actuator redundancy. The research started with examining the possibility of handling the case where no actuator redundancy remains post fault. Two fault recovery schemes, combing control allocation and hardware means, for a Quad Rotor UAV with no redundancy upon fault event are developed to enable safe emergency landing. Inspired by the integrated approach, a proposed integrated actuator control scheme is developed, and shown to reduce the magnitude of the error dynamics when input saturation faults occur. Geometrical insights to the proposed actuator scheme are obtained. Simulations using an Aerosonde UAV model with the proposed scheme showed significant improvements to the fault tolerant stuck fault range and improved guidance tracking performance. While much research literature has previously been focused on the controller to handle actuator faults, fault tolerant guidance schemes may also be utilized to accommodate the fault. One possible advantage of using fault tolerant guidance is that it may consider the fault degradation e ects on the overall mission. A fault tolerant guidance reconfiguration method is developed for a path following mission. The method provides an additional degree of freedom in design, which allows more flexibility to the designer to meet mission requirements. This research has provided fresh insights into the handling UAV extremal actuator faults through integrated approaches. The impact of this work is to expand on the possibilities a practitioner may have for improving the fault handling capabilities of a UAV

Values to Be Added to an Eastphalia Order by the Emerging China

Eastphalia Emerging?: Asia, International Law, and Global Governance, Symposium. Indiana University Maurer School of Law, Bloomington, Indiana, 200

Integrated Open Source Design for Architecture in High Density Housing Practice

High-density housing can be interpreted as collections of individual units, which inevitably results in the dilemma between the global standardization designed by architects and local customization implemented by users. However, it is impossible to reflect the users’ various needs in the conceptual design stage for high-density housing because of the economic, industrial and time constrains. In response to this challenge, this research paper outlines a different high-density housing design approach that can adopt users’ individual customization in the conceptual design stage during the housing design practice. Hence, the design process would be an open-ended evolutionary and transparent process rather than deterministic executions as we have now in most high-density cities, such as Hong Kong. In order to overcome the deficiency in addressing future uncertainties of different users and address the issues of one-off developments without iterating users’ feedback in the housing practice, this essay proposes IOSDA (integrated open source design for architecture) for the design practice of high-density housing, through collective data and parametric connectivity between users and architects. IOSDA reflects a different design attitude towards the future, i.e., to shift from architects’ heroic prediction of the future to collective engagement of the present with more robust capacities for new possibilities.published_or_final_versio

The topological glass in ring polymers

We study the dynamics of concentrated, long, semi-flexible, unknotted and unlinked ring polymers embedded in a gel by Monte Carlo simulation of a coarse-grained model. This involves the ansatz that the rings compactify into a duplex structure where they can be modelled as linear polymers. The classical polymer glass transition involves a rapid loss of microscopic freedom within the polymer molecule as the temperature is reduced toward Tg. Here we are interested in temperatures well above Tg where the polymers retain high microscopic mobility. We analyse the slowing of stress relaxation originating from inter-ring penetrations (threadings). For long polymers an extended network of quasi-topological penetrations forms. The longest relaxation time appears to depend exponentially on the ring polymer contour length, reminiscent of the usual exponential slowing (e.g., with temperature) in classical glasses. Finally, we discuss how this represents a universality class for glassy dynamics

Mining the FX electronic inter-dealer market

This paper examines the feasibility of applying data mining techniques to testing market efficiency hypothesis using a high frequency, up to one thousand of a second, electronic brokerage data. Results suggest the existence of a pattern of negative autocorrelation in returns of DEM/USD over relative short lags (less than 40 seconds). However, this pattern is not feasible by two reasons: (1) the structure of autocorrelation pattern is inconsistent and changes too rapidly (2) the largest potential speculative profit is smaller than the regulated tick size. These results indicate that dealers have engaged in any potential profitable speculations based on past price information

Exploring Concurrent Relationships between Economic Factors and Student Mobility in Expanding Higher Education Achieving 2030

Student mobility is one of the most important indicators to reflect institutional internationalization in a sustainable higher education system. Student mobility issues have been addressed in previous studies, and the phenomenon was discussed in association with related factors persistently. Since higher education sustainable development has received much scholarly attention, monitoring student mobility flows to adjust international strategies is necessary. This study explored practical approaches to detect student mobility flows in the process of higher education expansion. Targeting Taiwan’s higher education system as an example, we addressed the topic of system expansion and the core issues of student mobility. Target series data were collected from 1950 to 2021, including the economic growth ratio, GDP per capita, higher education enrollment, gross enrollment ratio (GER), and the number of inbound and outbound students. The data were transformed with index formats, for example, the economic growth ratio, enrollment increasing ratio (IR), and net flow ratio. The cross-correlation function (CCF) and autoregressive integrated moving average (ARIMA) were used to determine the correlations of the series data and their future trends. The findings suggested that the system expansion, with GER and IR, might reflect fluctuated student mobility in economic growth. This study confirmed that the time series approaches work well in detecting the phenomena of higher education expansion and their effects on student mobility flow in the future