Alarm systems comprises an eye gaze direction detecting part, an obstacle detecting device and an alarm controlling part. These core-shell nanocrystals are highly stable and provide quantum yields and stability suitable for applications such as flow cytometry, cellular imaging, and protein blotting, medical imaging, and other applications where cadmium toxicity is an issue. A correlation determination unit determines a degree of correlation between the antennas based on the variation trend of the value in relation to the reception quality of each of the antennas recognized. Accordingly, the thermal conductive sheet with conductive foil of the present invention improves thermal conduction from the thermal conductive layer to the conductive foil, eliminating the unfavorable effects of the skin layer and the primer layer, and thus improves heat radiation of the thermal conductive sheet with conductive foil. Accordingly, the waterproof sock enables a wearer to keep his feet warm and dry and in a cold and wet environment such as a ski lodge.