This paper presents a multi-layer scheme to control a formation of three mobile robots. Each layer works as an independent module, dealing with a specific part of the problem of formation control, thus giving to the system more flexibility. In order to reduce formation errors, the proposed architecture includes a layer which performs an adaptive dynamic compensation, using a robust updating law, which compensates for each robot dynamics. The controller is able to guide the robots to the desired formation, including the possibility of time-varying position and/or shape. Stability analysis is performed for the closed-loop system, and the result is that the formation errors are ultimately bounded. Finally, simulation results for a group of three unicycle-like mobile robots are presented, which show that system performance is improved when the adaptive dynamic compensation layer is included in the formation control scheme. © 2009 IEEE.
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Abstract Long-haul travel does not constitute an obstacle for tourists to travel and is fast gaining the attention of tourists in new and unique experiences. This study was conducted to identify the long-haul travel motivation by international tourists to Penang. A total of 400 respondents participated in this survey, conducted around the tourist attractions in Penang, using cluster random sampling. However, only 370 questionnaires were only used for this research. Data were analysed using SPSS software 22 version. The findings, ‘knowledge and novelty seeking’ were the main push factors that drove long-haul travel by international tourists to Penang. Meanwhile, the main pull factor that attracts long- haul travel by international tourists to Penang was its ‘culture and history’. Additionally, there were partly direct and significant relationships between socio-demographic, trip characteristics and travel motivation (push factors and pull factors). Overall, this study identified the long-haul travel motivations by international tourists to Penang based on socio-demographic, trip characteristics and travel motivation and has indirectly helped in understanding the long-haul travel market particularly for Penang and Southeast Asia. This research also suggested for an effective marketing and promotion strategy in pro- viding useful information that is the key to attract international tourists to travel long distances. Keywords:
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