A new and novel Au-catalyzed cycloisomerization of ynals bearing a pendant unsaturated bond leading to synthetically valuable [6.7.n]tricyclic compounds were developed. This study strongly supports the intermediacy of [3 + 2] cycloaddition proposed by DFT calculation and provides an easy access to key skeletons found in a variety of natural products.

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At first glance, multi-element forearm mounted vibrotactile displays would appear to have considerable potential as an output device for mobile computing. The devices are small, robust and discrete, and the body site both easily accessible and socially acceptable for such a purpose. However, due to the absence of a thorough account of vibrotactile perception, it is hard to determine their feasibility, or even what might form an appropriate arrangement of vibrating elements or tactors. We describe two studies intended to shed light on these issues. The first extends the localization literature relating to the forearm, and its results indicate that different spatial arrangements of tactors can result in substantially different levels of performance. The second study examines the influence of adjusting the size of the area of the skin experiencing a vibration with its perceived intensity. The results indicate a positive relationship between increased size and increased perceived intensity. Finally, the implications of these studies for the design of vibrotactile arrays are discussed.CR INTRODUCTIONIt has long been accepted that the skin, the largest organ in the body, has considerable potential as a conduit for information. Correspondingly, there is a substantial history of research investigating how it might be effectively utilized. This effort has led to the development of a wide variety of skin stimulation technologies, ranging from electrical to vibratory to pneumatic. Of these technologies, large scale vibrotactile displays, utilizing motor or transducer based vibrating elements, and considered either individually or in groups, have arguably been the most popular. The reasons for this are straightforward and easy to enumerate: they are simple to construct, small, cheap, robust, reliable, and consume modest amounts of power. Initial investigations with these displays during the 60's and 70's focused on sensory substitution, where the intention was that tactile stimuli could be used to represent otherwise absent visual or auditory cues to impaired users. To highlight one example from this era, rigorous empirical work on topics ranging from character recognition to the display of patterns representing the spatial aspects of visual scenes were conducted using various versions of TVSS [9], a system most typically incarnated as a 20 by 20 back mounted array of vibrating elements (or tactors). Beyond research with this laudable aim, more recent attention has begun to focus on the potential of vibrotactile stimuli in mobile computing scenarios. This is no doubt due to the dramatic rise of this domain during the last decade, in conjunction with a general recognition that non-visual cues have an important role to play in the interfaces to handheld or wearable computing devices [4], and, when compared to other types of haptic or tactile device, the practical suitability of vibrotactile displays to mobile environments.Tan [21] provides one of the earliest discussions of vibrotactile displays for mobile computing....

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At first glance, multi-element forearm mounted vibrotactile displays would appear to have considerable potential as an output device for mobile computing. The devices are small, robust and discrete, and the body site both easily accessible and socially acceptable for such a purpose. However, due to the absence of a thorough account of vibrotactile perception, it is hard to determine their feasibility, or even what might form an appropriate arrangement of vibrating elements or tactors. We describe two studies intended to shed light on these issues. The first extends the localization literature relating to the forearm, and its results indicate that different spatial arrangements of tactors can result in substantially different levels of performance. The second study examines the influence of adjusting the size of the area of the skin experiencing a vibration with its perceived intensity. The results indicate a positive relationship between increased size and increased perceived intensity. Finally, the implications of these studies for the design of vibrotactile arrays are discussed.

The white cane is a widely used mobility aid that helps visually impaired people navigate the surroundings. While it reliably and intuitively extends the detection range of ground-level obstacles and drop-offs to about 1.2 m, it lacks the ability to detect trunk and head-level obstacles. Electronic Travel Aids (ETAs) have been proposed to overcome these limitations, but have found minimal adoption due to limitations such as low information content and low reliability thereof. Although existing ETAs extend the sensing range beyond that of the conventional white cane, most of them do not detect head-level obstacles and drop-offs, nor can they identify the vertical extent of obstacles. Furthermore, some ETAs work independent of the white cane, and thus reliable detection of surface textures and drop-offs is not provided. This paper introduces a novel ETA, the Advanced Augmented White Cane, which detects obstacles at four vertical levels and provides multi-sensory feedback. We evaluated the device in five blindfolded subjects through reaction time measurements following the detection of an obstacle, as well as through the reliability of dropoff detection. The results showed that our aid could help the user successfully detect an obstacle and identify its height, with an average reaction time of 410 msec. Drop-offs were reliably detected with an intraclass correlation > 0.95. This work is a first step towards a low-cost ETA to complement the functionality of the conventional white cane.

Delivering distance information of nearby obstacles from sensors embedded in a white cane-in addition to the intrinsic mechanical feedback from the cane-can aid the visually impaired in ambulating independently. Haptics is a common modality for conveying such information to cane users, typically in the form of vibrotactile signals. In this context, we investigated the effect of tactile rendering methods, tactile feedback configurations and directions of tactile flow on the identification of obstacle distance. Three tactile rendering methods with temporal variation only, spatio-temporal variation and spatial/temporal/intensity variation were investigated for two vibration feedback configurations. Results showed a significant interaction between tactile rendering method and feedback configuration. Spatio-temporal variation generally resulted in high correct identification rates for both feedback configurations. In the case of the four-finger vibration, tactile rendering with spatial/temporal/intensity variation also resulted in high distance identification rate. Further, participants expressed their preference for the four-finger vibration over the single-finger vibration in a survey. Both preferred rendering methods with spatio-temporal variation and spatial/temporal/intensity variation for the four-finger vibration could convey obstacle distance information with low workload. Overall, the presented findings provide valuable insights and guidance for the design of haptic displays for electronic travel aids for the visually impaired.

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