Methods, systems and computer program products for communication auditory alert to aircraft

Systems, methods, and computer-program products for communicating auditory alerts about runway hazards to aircraft. A conflict on at least one arrival runway is identified using information received from an existing conflict detection system. An auditory alert associated with the conflict is generated and then modulated onto a carrier frequency. The carrier frequency may be a 75 MHz marker beacon carrier frequency, and further, the carrier frequency may be slightly offset from the 75 MHz marker beacon carrier frequency. The modulated alert is transmitted to an aircraft approaching the arrival runway through a directional antenna, which receives the transmitted auditory alert through a marker beacon receiver without requiring additional flight deck equipment. The transmitted alert does not interfere with transmissions from both an outer marker beacon associated with the arrival runway and marker beacons associated with adjacent runways due to transmitted power levels and antenna directivity. Also, with the transmitted carrier frequency shifted slightly from the marker beacon carrier frequency, the transmitted alert would not interfere with the inner or outer marker on the arrival runway.

Semantic system for integrating software components

A system and method for integrating databases and/or web services into a searchable ontological structure. The structure allows for free-form searching of the combined system and for the discovery of an execution path through the ontology. The discovered execution path (or paths) provides for the generation of code that integrate databases and services for the purpose of fusing information from disparate databases and Web services.

Rate adjustable differential phase shift key (DPSK) modulation

In a fixed delay optical communication system, rate adjustable differential phase shift key (DPSK) techniques eliminate the need for multiple comparing modules, each corresponding to a different data rate. Setting alternative data rates at integer multiples of the fundamental data rate of the optical communication system allows the system to process the respective integer number of symbols per period of the system, wherein the period of the system is the inverse of the fundamental data rate. Pulse carving techniques may be used to set the duty cycle of clock levels associated with a clock signal. The clock levels may be combined with respective symbols to provide optical symbols having a duty cycle less than 100%.

System and method to emulate mobile logic in a communication system

A system includes hosts that may be infected with mobile logic. One type of mobile logic is a worm, which can be a process that is capable of causing a (possibly evolved) copy of itself to execute on one or more hosts of the system. An infected host of the system can infect other hosts based on criteria, such as targeting, visibility, vulnerability, or infectability of the other hosts. A worm can be represented as a Turing Machine whose state can be determined using computational methods. A worm can be emulated in the system to determine worm detection capabilities of the system. Emulating the worm can allow the system to be tested with less negative impact than using the actual worm.

Efficient construction of quantum computational clusters using Hadamard rotations

A method of creating two-dimensional quantum computational cluster states is demonstrated that is considerably more efficient than previously proposed approaches. The method uses local unitaries and type-I fusion operations. The increased efficiency of the method compared to previously proposed constructions is obtained by identifying and exploiting local equivalence properties inherent in cluster states.

Echo MIMO: a method for optimal multiple input multiple output channel estimation and matched cooperative beamforming

A method for estimating a communication channel comprising one or more sub-channels between at least a first transceiver and at least a second transceiver is provided. The method comprises transmitting a first set of training data from the first transceiver to the second transceiver, receiving observed signals at the second transceiver, re-transmitting said observed signal back to the first transceiver, and calculating a roundtrip channel estimate at the first transceiver. The method further comprises transmitting a second set of training data from the second transceiver to the first transceiver, receiving observed signals at the first transceiver, and calculating a reverse link channel estimate. From the roundtrip channel estimate and the reverse link channel estimate, a forward link channel estimate is computed at the first transceiver.

Spectrum shaping using code-hopping CDMA

A method for spectrally shaping a communication signal is provided. The method comprises generating a plurality of spreading codes, assigning a probability to each of the plurality of spreading codes, and modulating the communication signal by hopping between the plurality of spreading codes such that a time-average proportion of time spent using any one of the plurality of spreading codes is equal to the probability assigned to that spreading code.

Reliable neighbor node discovery

Methods and systems for reliable neighbor discovery in wireless ad hoc networks are provided herein. In one aspect, embodiments of the present invention provide methods and systems for analyzing the quality of a communication link. In embodiments, several factors affecting link quality may be incorporated in the analysis, and basic and/or complex statistical and/or probabilistic analysis may be used. In another aspect, embodiments of the present invention provide methods and systems for neighbor node discovery that adapt to network and/or node operating conditions and that dynamically maintain a neighbor node set at a given node according to these conditions. In a further aspect, embodiments of the present invention extend the utility of neighbor node discovery beyond the customary role of data routing support into the problem of deploying an ad hoc network by providing a display module for displaying node connectivity information.

System and method for using performance enhancing proxies with IP-layer encryptors

A mechanism to allow hosts on the plaintext side of IP-layer encryptors to utilize Performance Enhancing Proxies (PEPs) on the ciphertext side of IP-layer encryptors is provided. Two processes are utilized for each IP-layer encryptor to extend a higher-level protocol (as represented, for example, by OSI layers 4-7) from the plaintext or red-side of the IP-layer encryptor to the ciphertext or black-side of the IP-layer encryptor. These two processes are known as the red-side Performance Enhancing Proxy Enabler (PEPE) and the black-side PEPE. The red-side and black-side PEPEs of a local IP-layer encryptor work together with red-side and black-side PEPEs of a remote IP-layer encryptor to transmit packets between the IP-layer encryptors using a higher-level protocol. Hence, PEPEs allow packets exchanged by red-side hosts separated by IP-layer encryptors to be transmitted on the black-side using a higher-level protocol. Therefore, PEPEs allow hosts on the red-side to take advantage of PEPs on the black-side.

Method for representing security features of a distributed system

A method for representing security features of a distributed system is presented. The method includes creating abstractions to describe security mechanisms of a system, and creating a specification using the abstractions. The specification models components of the security mechanisms, features of an environment in which the system operates, and supporting security features. The method may further include linking the specification to graphical representations, and using the specification to construct an instance diagram that graphically depicts the security features of the system and its operational environment. The specification or the instance diagram may be used to construct an instance model, which may be a textual rendering, that models the security features of the system and its operational environment. Where the specification is used to construct the instance model, the method may further include using the instance model to construct the instance diagram.