摘要:
A method for defending against MAC table overflow attacks comprises a plurality of operations. An operation is performed for determining whether each one of a plurality of MAC addresses within a MAC table has one-way traffic or two-way traffic corresponding thereto. Thereafter, operations are performed for designating each MAC address having two-way traffic corresponding thereto as a first category of MAC address and for designating each MAC address having one-way traffic corresponding thereto as a second category of MAC address. In response to the number of the MAC addresses designated as the second category of MAC address exceeding a prescribed threshold value, an operation is performed for causing a timeout value of at least a portion of the MAC addresses designated as the second category of MAC address to be less than a timeout value of the MAC addresses designated as the first category of MAC address.
摘要:
A method for achieving converter transformer for suppressing DC bias magnet comprises increasing the seaming width of the transformer core lamination, which comprises in detail calculating the width and the height of each stage of lamination according to the reserved seaming width of the lamination, the sectional area of the core, the space between columns, and the height of the window, shearing the lamination based on the width and the height of the lamination obtained by calculating, overlapping two pieces of laminations into one piece of lamination according to the order of stages, placing them on the core frame alternately by stages, and after overlapping all the laminations, fastening each stage of lamination.
摘要:
Codebook based communication of precoding data between two stations involves determining a ‘best fit’ precoding at a receiving station, on the basis of channel state measurements taken therein. The best fit precoding is compared with pre-agreed entries in a codebook, and an indicator is sent back to the terminal emitting the analysed signal. The determination is separated into two elements, one being sufficient for use with SU-MIMO, and another being provided, with a second codebook indicator, if MU-MIMO is to be employed. This second codebook indicator points to a codebook of eigenvector representations for the multi-user space in which the channel is persisting.
摘要:
Code designs for channel coding with side information (CCSI) based on combined source-channel coding are disclosed. These code designs combine trellis-coded quantization (TCQ) with irregular repeat accumulate (IRA) codes. The EXIT chart technique is used for IRA channel code design (and especially for capacity-approaching IRA channel code design). We emphasize the role of strong source coding and endeavor to achieve as much granular gain as possible by using TCQ. These code designs synergistically combine TCQ with IRA codes. By bringing together TCQ and EXIT chart-based IRA code designs, we are able to approach the theoretical limit of dirty-paper coding.
摘要:
In a wireless communications system, a method of processing data prior to transmission thereof to a plurality of stations. The method includes determining a channel matrix using a plurality of weighted channel responses, each of which is associated with one of the plurality of stations and weighted by a gain factor corresponding to the station, wherein the gain factor is inversely proportional to a noise power of the station. The data is then processed in accordance with a precoding scheme using the determined channel matrix.
摘要:
A process for distributed source coding (DSC) using context is presented. By forming contexts from prior coded bitplanes of both a reference and DSC coded peer, the DSC virtual channel is split into several virtual sub-channels of different characteristics. The selection of the sub-channel becomes side information that is known to the receiver. As a result, the DSC coding bitrate is reduced.
摘要:
A system and method for identifying the number of computer hosts and types of operating systems behind a network address translation is provided. The method includes processing an internet protocol packet associated with the host computer system. The process may involve capturing the internet protocol packet and extracting key fields from the internet protocol packet to produce a fingerprint. The method continues with analyzing the fields in order to determine if a network address translator is connected between the host computer and a public network (e.g. the internet). If there is a network address translator connected, fields may be analyzed in order to determine the number of computers using the network address translator. The fields may also be analyzing in order to determine with a level of probability that the fingerprint identifies the correct operating system running the host computers. Generally, the internet protocol packet that is analyzing will be captured from an aggregation point in the carrier network.
摘要:
A method for defending against MAC table overflow attacks comprises a plurality of operations. An operation is performed for determining whether each one of a plurality of MAC addresses within a MAC table has one-way traffic or two-way traffic corresponding thereto. Thereafter, operations are performed for designating each MAC address having two-way traffic corresponding thereto as a first category of MAC address and for designating each MAC address having one-way traffic corresponding thereto as a second category of MAC address. In response to the number of the MAC addresses designated as the second category of MAC address exceeding a prescribed threshold value, an operation is performed for causing a timeout value of at least a portion of the MAC addresses designated as the second category of MAC address to be less than a timeout value of the MAC addresses designated as the first category of MAC address.
摘要:
NOx and soot emissions from internal combustion engines, and in particular compression ignition (diesel) engines, are reduced by varying fuel injection timing, fuel injection pressure, and injected fuel volume between low and greater engine loads. At low loads, fuel is injected during one or more low-pressure injections occurring at low injection pressures between the start of the intake stroke and approximately 40 degrees before top dead center during the compression stroke. At higher loads, similar injections are used early in each combustion cycle, in addition to later injections which preferably occur between about 90 degrees before top dead center during the compression stroke, and about 90 degrees after top dead center during the expansion stroke (and which most preferably begin at or closely adjacent the end of the compression stroke). These later injections have higher injection pressure, and also lower injected fuel volume, than the earlier injections.