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Smart houses for elderly or physically challenged people need a method to understand residents' intentions during their daily-living behaviors. To explore a new possibility, we here developed a novel brain-machine interface (BMI) system integrated with an experimental smart house, based on a prototype of a wearable near-infrared spectroscopy (NIRS) device, and verified the system in a specific task of controlling of the house's equipments with BMI. We recorded NIRS signals of three participants during typical daily-living actions (DLAs), and classified them by linear support vector machine. In our off-line analysis, four DLAs were classified at about 70% mean accuracy, significantly above the chance level of 25%, in every participant. In an online demonstration in the real smart house, one participant successfully controlled three target appliances by BMI at 81.3% accuracy. Thus we successfully demonstrated the feasibility of using NIRS-BMI in real smart houses, which will possibly enhance new assistive smart-home technologies.

We investigate the quantum radiation emitted by a uniformly accelerated Unruh-DeWitt detector in de Sitter spacetime. We find that there exists a non-vanishing quantum radiation at late times in the radiation zone of the conformally flat coordinates, which cover the region behind the cosmological horizon for the accelerated detector. The theoretical structure of producing the late-time quantum radiation is similar to that of the same model in Minkowski spacetime: it comes from a nonlocal correlation of the quantum field in the Bunch-Davies vacuum state, which can be traced back to the entanglement between the field modes defined in different regions in de Sitter spacetime.PACS numbers: 04.62.+v * Electronic address: sylin@cc.ncue.edu.tw † Electronic address: kazuhiro@hiroshima-u.ac.jp 1 The laser field is never static, and the acceleration of the driven charge is not uniform. In such non-equilibrium conditions the quantum radiation of an Unruh-DeWitt detector is indeed non-zero [11,12]. However, non-equilibrium conditions are not the main point of this paper, see below.

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