Abstract: A collision avoidance system for a mobile unit includes an image capturing unit for capturing an image of an environment surrounding a mobile unit. Motion vector is calculated based on the captured image. Collision probability is calculated based on the motion vectors of the image. The system includes a plurality of receptive field units that are modeled on the optic lobe cells of the flies. Each of the receptive field units includes a filter producing an excitatory response to the motion vector diverging from the center of the receptive field in the central area of the receptive field and producing an inhibitory response to the motion vector converging toward the center of the receptive field in the areas around the central area. The outputs of the receptive field units are compared to determine a direction in which the obstacle approaches the mobile unit. The mobile unit moves in a direction to avoid collision.

Abstract: A system for accurately detecting approach to an object by performing simple processing. The system comprises an optical flow calculating section for calculating an optical flow based on at least two time-series images; a first adding section for calculating an added value for detecting approach, by adding values corresponding to data of the optical flow assigned to a first predetermined area defined on the images, where a predetermined filter function is used in the adding calculation; a second adding section for calculating an added value for detecting vibration, by adding values corresponding to data of the optical flow assigned to a second predetermined area defined on the images, where said filter function is used in the adding calculation; and, a situation determining section for determining that approach to the object has occurred when a difference between the added values for detecting approach and vibration exceeds a predetermined threshold value.

Abstract: A system for accurately detecting approach to an object by performing simple processing. The system comprises an optical flow calculating section for calculating an optical flow based on at least two time-series images; a first adding section for calculating an added value for detecting approach, by adding values corresponding to data of the optical flow assigned to a first predetermined area defined on the images, where a predetermined filter function is used in the adding calculation; a second adding section for calculating an added value for detecting vibration, by adding values corresponding to data of the optical flow assigned to a second predetermined area defined on the images, where said filter function is used in the adding calculation; and, a situation determining section for determining that approach to the object has occurred when a difference between the added values for detecting approach and vibration exceeds a predetermined threshold value.

Abstract: An electric double-layer capacitor includes a casing, a pair of porous electrodes disposed within the casing, a permeable separator sandwiched between both the porous electrodes, and an electrolytic liquid formed of an organic solvent, injected into the casing and permeating the porous electrodes and the separator. The separator is formed from an aggregate of cellulose fiber having a surface modified by an organic solvent thereby. A method of making a separator for an electric double-layer capacitor includes producing a cellulose fiber aggregate, forming a sheet of the cellulose fiber aggregate, modifying a surface of the cellulose fiber aggregate sheet by immersing the sheet in an organic solvent for a predetermined time period, drying the modified sheet, and cutting the dried sheets to form the separator of a desired size and shape. The cellulose fiber aggregate sheet may also be pretreated by immersing the sheet in an amphipathic solvent.

Abstract: An electric double-layer capacitor includes a casing, a pair of porous electrodes disposed within the casing, a permeable separator sandwiched between both the porous electrodes, and an electrolytic liquid formed of an organic solvent, injected into the casing and permeating the porous electrodes and the separator. The separator is formed from an aggregate of cellulose fiber having a surface modified by an organic solvent thereby.