Abstract: A three-dimensional printing system that includes a nozzle and means for positioning the nozzle. The nozzle is configured to dispense a concrete mix. The means for positioning the nozzle may include cable and control systems. The cable system includes positioning cables that are connected to the nozzle. The control system includes control modules each connected to a different corresponding one of the positioning cables. Each of the control modules controls a distance that the corresponding positioning cable positions the nozzle from the control module. Alternatively, the means for positioning the nozzle may include first and second flying drones.

Abstract: A three-dimensional printing system that includes a nozzle and means for positioning the nozzle. The nozzle is configured to dispense a concrete mix. The means for positioning the nozzle may include cable and control systems. The cable system includes positioning cables that are connected to the nozzle. The control system includes control modules each connected to a different corresponding one of the positioning cables. Each of the control modules controls a distance that the corresponding positioning cable positions the nozzle from the control module. Alternatively, the means for positioning the nozzle may include first and second flying drones.

Abstract: Methods of classifying files performed by a computing system. The methods include uploading a file from a client computing device, receiving a category identification, and associating a root node of a category tree with the file. The root node is a previous node and associated with the category identification. A number of sub-category identifications are received from the client computing device. The number was previously unknown by the computing system. For each sub-category identification, the computing system may determine whether the sub-category identification is a synonym of an existing sub-category identification associated with a child node of the previous node. When the sub-category identification is not a synonym, a linked node associated with the file and sub-category identification is created in the category tree, the linked node is associated with the previous node as a new child node, and the new child node becomes the previous node after this association.

Abstract: A solar energy collection system that can be retrofitted into pavement covered lots, such as macadam covered parking lots has a pump and heat exchanger, and a conduit buried below the pavement surface that contains a heat transfer fluid such as water. The conduit has a hollow unitary, one piece casing with an oval cross section and an internal divider that divides the interior of said casing into two passageways having substantially the same cross sectional area. Heat conducting fins preferably made of copper are mounted on the casing and extend coaxially outwardly in opposite directions therefrom along the major oval axis.

Abstract: A device for exercising the lower back and upper leg region of a user which includes a foot mount for attachment of a user's foot and a planar, flexible fin affixed to the foot mount and extending perpendicular to a user's foot when attached thereto. Front and rear edges of the fin are substantially parallel to each other and form an acute angle with the plane of the sole.