Abstract: The litter bin comprises a chest fixed to the ground and presents a side wall and a top that is pierced by a plurality of openings for receiving waste. The chest contains a plurality of upwardly open inserts each having an inside volume lying in the range 30 liters to 100 liters and each being disposed beneath a respective one of the various waste-receiving openings. The litter bin enables all of the inserts to be removed manually by a single operator, for the purpose of emptying the inserts.

Abstract: The installation is designed to inform users of a bus network about waiting times for buses at stops in the network. An installation comprises a central station suitable for transmitting radio signals about the real instantaneous positions of the buses, and portable receiver appliances (1) suitable for displaying bus waiting times on screens (4). Each appliance can also serve as a ticket for travel purposes, being provided, for this purpose, with means (10) containing "validity" data (e.g. corresponding to a sum of money or to an expiry date) that can be checked remotely by "ticket-stamper" means (9) and that is also remotely "renewable" from the central station.

Abstract: A system for displaying waiting times for buses (2) approaching various stops (1) of a network. The system comprises means for generating electromagnetic signals (8) whose addresses are based on the buses, fixed receivers (9) of said signals for display purposes at the stops themselves, and preferably also portable appliances (10) also capable of receiving said signals and suitable for displaying the waiting times for buses at any stop of the network in response to interrogation by users bearing said appliances.

Abstract: A portable appliance (1) is provided for informing the users of a bus network about waiting times for buses at various stops of the network. Simple depressions of keys (3, 4, 5) cause appropriate displays to appear on a screen (2) of the appliance, enable a plurality of bus driving distances approaching respective predetermined stops of the network to be stored, and simply pressing on a button (6 or 7) makes it possible to cause any stored driving distance to be selectively displayed on said screen, together with visible information concerning the waiting times for buses at the stop approached by the final driving distance.

Abstract: The installation is intended to inform users of a bus network about waiting times for buses at stops in the network, the installation including a central station suitable for transmitting radio signals relating to the real instantaneous positions of the buses and portable receiver appliances (1) suitable for displaying waiting times on their own screens (3). Each appliance has an appliance identification symbol recorded therein and also (at 11) an expiry date, and it is possible to obtain the desired displays on the screen only if said appliance is used earlier than said date. Provision is made for renewing the appliance remotely for new subscription periods at the end of each subscription.

Abstract: A system for informing users of a bus network about waiting times for buses at stops of the network comprises means (3-6) for generating and transmitting electrical signals representative of the distance (d) between each bus (1) and the "next" stop (2), and means (7) associated with each stop and organized to receive said signals, to select therefrom those signals that concern said stop, and to display at said stop data relating to the waiting times for the "approaching" buses. The system also includes means for generating electrical signals representative of two past real average bus speeds relating to two different periods immediately before the instant at which the signals are generated, and means for using the average speeds in order to determine the waiting times to be displayed.

Abstract: To protect a volume (2) arranged inside a room (3) in regard to outside noises E, use is made of an array of acoustic sensors (11.sub.j) receiving the noise E and arranged a distance A from the volume and of an array of acoustic sources (15.sub.k) arranged a distance B less than A from the volume and signals S are applied to these sources, these signals being summations of the double convolution products of the function E.sub.j (t) with two functions f.sub.ij (t) and g.sub.ik (-t) which are directly deducible from the impulse responses gathered, on the one hand, at the sensors (11.sub.j) from pulses emitted by the sources (10.sub.i) carried by a fictitious barrier (6) delimiting the volume and, on the other hand, at sensors (12.sub.i) stationed at the same places as these latter sources (10.sub.i), from pulses emitted by the above sources (15.sub.k).

Abstract: The device is adaptable for any panel of non-opaque material, whether it concerns advertisement, information panel, signboards, signposts or signalling posts or the like. The panel 1 is associated with at least one source of lighting 3 which faces one of the edges 2 of the panel. The panel carries an engraving 7 having a surface which reflects light and divides the incident beam into a series of pencils of light associated with various elements of the engraving.