Modeling a Pre-Touch Reaction Distance around Socially Touchable Upper Body Parts of a Robot

Although before-touch situations are essential to achieve natural touch interactions between people and robots, they receive less attention than after-touch situations. This study reports pre-touch reaction distance analysis results around touchable upper body parts, i.e., shoulders, elbows, and hands, based on human–human pre-touch interaction. We also analyzed the effects of gender, approach side, speed, and acclimation in modeling the pre-touch reaction distance, and found that the distance around the hands is smaller than the distance around the shoulders and elbows, and speed and acclimation affect the distance. On the other hand, gender and approach side do not significantly affect the pre-touch reaction distance. Finally, we implemented the results in a male-looking android and confirmed that it reacted toward pre-touch based on the obtained model.

Influence of the Environment on the Reliability of Security Magnetic Contacts

Magnetic contacts are one of the basic components of an alarm system, providing access to buildings, especially windows and doors. From long-term reliability tests, it can be concluded that magnetic contacts show sufficient reliability. Due to global warming, we can measure high as well as low ambient temperatures in the vicinity of magnetic contacts, which can directly affect their reliability. As part of partial tests, research into the reliability of magnetic contacts, we created a test device with which their reaction distance was examined under extreme conditions simulated in a thermal chamber. The results of the practical tests have yielded surprising results.

Behaviour of herring (Clupea harengus L.) towards an approaching autonomous underwater vehicle

The reaction of schooling wintering herring (Clupea harengus L.) in Ofotfjord in northern Norway is studied when approached by an autonomous underwater vehicle (AUV) with electrical propulsion. The reaction of herring is recorded running the AUV in the beam of the mother vessel's 38-kHz echosounder and in more detail with an onboard 120-kHz echosounder. The results indicate an insignificant reaction of herring to the approaching AUV, although some variations were observed depending on the experimental set-up. Technical uncertainty in the recordings close to the AUV transducer creates some ambiguity in the results. No reaction could be identified from the ship's sounder when the AUV passed under the vessel. Processing of the onboard echosounder data suggests a mean avoidance distance of 8.0 m in these experiments. In a realistic autonomous survey situation it is assumed that the AUV can approach as closely as 5–10 m to herring schools without affecting the acoustic observation, which makes it a potentially useful platform for hydroacoustic research and survey. More systematic studies are needed to precisely define the threshold reaction distance to the AUV, and the work should be conducted with transducers on a more silent platform than RV “Johan Hjort”, which was used in this study.

Effects of light, prey size, and turbidity on reaction distances of lake trout (Salvelinus namaycush) to salmonid prey

Most studies on visual foraging by fish have focused on reaction distances to invertebrate prey; however, these acuity-based results considerably overestimate reaction distances of piscivores to prey fish. In laboratory experiments, we quantified reaction distance of adult lake trout (Salvelinus namaycush) to rainbow trout (Oncorhynchus mykiss) and cutthroat trout (Oncorhynchus clarki) as a function of light (0.17-261 lx), prey size (55, 75, and 139 mm), and turbidity (0.09, 3.18, and 7.40 NTU). Reaction distances increased rapidly with increasing light from <25 cm at 0.17 lx to about 100 cm at a light threshold of 17.8 lx. Reaction distance declined as a decaying power function of turbidity. By constructing equations that describe the combined effects of light and turbidity on reaction distances, we can begin to model prey detection capabilities of piscivores at any depth at any time of day in natural environments.