In the present paper, we describe a method for recording the coordinates of a fish in an aquarium in a three-dimensional space, using a single video camera and a mirror. We use photogrammetic equations for this, considering the image obtained in the mirror as a virtual image obtained by a second camera. A transformation of the coordinate system is required to express the obtained coordinates in anx,y,z system defined by the edges of the aquarium. The accuracy of the proposed method was estimated, and errors in extreme conditions were found to be 0.8% to 1.2 %, compared with the dimensions of the aquarium used in the test. 相似文献
Two experiments tested whether a dogmatic alcohol prevention message may, by arousing psychological reactance (the motivation to reassert a threatened freedom) result in more subsequent alcohol consumption, compared to a neutral message. In Study 1, 535 college students received either a high-threat (dogmatic) or low-threat (neutral) message recommending either abstinence or controlled drinking. Results indicated that high-threat messages were rated more negatively and resulted in more drinking intentions compared to low threat. The negative effect of high threat on message ratings was most pronounced for habitually heavy drinkers and an abstinence-espousing message. In Study 2, under the guise of a “memory study,” 74 college students received either a high- or low-threat message recommending abstinence from alcohol. Then, under the guise of a “perception study,” all subjects participated in a taste-rating task in which their beer consumption was unobtrusively measured. Results indicated that the effect of high threat was most negative for male heavy drinkers, who drank significantly more beer compared to low-threat controls. These results suggest that the persuasive ability of alcohol prevention efforts depend to a considerable extent on the reactance-arousing properties of the materials and that dogmatic alcohol prevention materials may have counterproductive effects for some college students. 相似文献