摘要:
A method and system for geocasting data packets in a MANET. The MANET is combined with a long-range network such that a wireless terminal can decide whether to rebroadcast a geocast packet over the MANET, the long-range network, or not at all, depending on the wireless terminal's proximity to the geocast region, the location of the originating wireless terminal, or both. A wireless terminal close to or within the geocast region can rebroadcast on the MANET, whereas a wireless terminal far from the geocast region can rebroadcast on the long-range network.
摘要:
A security gateway provides a secure connection among one or more networks and a protected resource network. One of the local networks may be connected to the remote private network via a VPN IPsec tunnel. The networks may be local networks that share resources without compromising the security of the protected resource network. The local networks may have access to an untrusted network such as the Internet, sharing a single connection through the security gateway. Dynamic source network address translation is used to permit access from the network connected to the protected resource network to other, less trusted networks while concealing the actual IP addresses of hosts within that network.
摘要:
A system for laterally stabilizing a two-wheeled vehicle includes a pair of outrigger struts having respective outrigger wheels on opposite sides of the rear wheel, vertically movable between raised and lowered positions relative to a supporting structure, the struts each being connected by a transverse strut shaft for unison vertical movement and extending forwardly of the strut shaft; an electric motor driven actuator mechanism including a rotatably mounted lead screw shaft that is pivotably mounted relative to the supporting structure, a drive nut threadingly engaging the lead screw shaft that is connected to the strut shaft for driving the wheels between the raised and lowered positions in response to rotation of the lead screw shaft. A controller for electrically powering the motor includes pilot circuit paths of a bidirectional motor bridge circuit, the pilot circuit paths being electrically powered only when motive power of the vehicle is enabled, the actuator mechanism in combination with the motor having sufficient drag and mechanical advantage whereby the outrigger wheels are locked from movement between the raised and lowered positions in the absence of electrical power to the motor. Limit switches are connected for inhibiting corresponding ones of the pilot circuit paths for preventing overtravel of the outrigger wheels.
摘要:
Apparatus for spark perforation of sheet material comprising spaced apart first and second electrodes which define between them a sparking zone through which sheet material to be perforated can be moved in a predetermined direction, and in which the portion of the first electrode which is nearest to the nearest portion of the second electrode is located between an overlap position upstream of the second electrode in the direction of movement of the sheet by a distance of 1 mm and an offset position also equal to 1 mm in the direction of movement of the sheet, and means for guiding the sheet through the sparking zone along a path closer to said second electrode than said first electrode.
摘要:
Security in a geogame is maintained by implementing various security techniques. The various techniques provide specific advantages for different threat modes and attack styles against a geogame implemented via a mobile ad hoc network utilizing a geocast protocol. Jamming is detected by each player device listening for expected retransmissions of its own originated geocasts. If it fails to hear a retransmission, it concludes jamming. Network interdiction is detected by monitoring for received transmissions and/or periodically sending dummy transmissions to support other devices' detections. Location determination attacks are detected by recognizing “impossible” movements. Geogame interruption attacks are detected by detecting unauthorized requests to restart a geogame. Other security measures include utilizing cryptographic keys and/or pass phrases when geocasting. Various penalties within the context of a geogame are levied against a player if a security breach is detected.
摘要:
A first iterative Grover Search process is performed by causing at least one quantum computer to perform a first series of Grover Searches according to a characteristic function for varying numbers of iterations to identify a first search target. The characteristic function is modified according to the identified first search target. A second iterative Grover Search process is performed by causing the at least one quantum computer to perform a second series of Grover Searches according to the modified characteristic function beginning with a number of iterations determined based on a number of iterations required for at least one prior iterative Grover Search process to identify a second search target.
摘要:
A geogame utilizes wireless devices to track the movements of the players. As players move, virtual tails are generated behind each player, and their locations are determined and geocast, via a wireless geographic broadcast protocol, to all players of the geogame. Each player observes all players movements and tail locations on his/her wireless device. Players can draw sketches utilizing their respective virtual tails and/or players can traverse courses which involve various types of terrain. Players can try to avoid virtual obstacles that can be generated within the game. Players can be provided weapons to shoot through boundaries and tails.
摘要:
A method and apparatus for providing service discovery are disclosed. Specifically, each service provider builds or constructs a behavior description or model of its service and, in turn, stores and publishes the behavior description. Each behavior description is implemented in accordance with a set of shared ontology of terms for a particular domain. In turn, a user may generate a query associated with service discovery that will be capable of exploiting the behavior descriptions for a plurality of services.
摘要:
A system and method for circumventing schemes that use duplication detection to detect and block unsolicited e-mail (spam.) An address on a list is assigned to one of m sublists, where m is an integer that is greater than one. A set of m different messages are created. A different message from the set of m different messages is sent to the addresses on each sublist. In this way, spam countermeasures based upon duplicate detection schemes are foiled.
摘要:
A method for enabling different priority messages in a contention-based wireless network where units use a common channel. Relative to high priority messages, if the channel is not busy when a message is ready for transmission, then the message is transmitted immediately. When the channel is busy, the message is not transmitted until the channel becomes available and a selected back-off period (while the channel is available) expires. Back off periods are illustratively randomly selected by the units. Low priority messages are similarly not transmitted when the channel is busy, and additionally are not transmitted for a preselected pre-emption interval when the channel is available to high priority messages but not to low priority messages. Like with high priority messages, low priority messages that not transmitted when ready are held back a back-off period before they are transmitted.