Abstract: The present application provides a rocket apparatus and a method for changing an electrical environment in a thunderstorm cloud. A corona probe and an atmospheric electric field detector analyzes and obtains, based on spin angular velocity information of a rocket and inclination attitude information of the rocket that are provided by a gravity gyroscope, accurate strength of a three-dimensional electric field and accurate polarity of a charge in the thunderstorm cloud. A charge-neutralizing agent module externally releases a charged agent whose polarity is opposite to the charge in the thunderstorm cloud, to consume the charge in the thunderstorm cloud via neutralization between a heterocharge carried by the charged agent and the charge in the thunderstorm cloud.

Abstract: A method for analyzing signal irregularity of radiation in a lightning leader is provided, which relates to a field of lightning signal processing and includes: S1: acquiring electric field signals; S2: dividing the electric field signals into multiple segments according to time, and calculating an average sample entropy value of each segment of the electric field signals; S3: dividing the multiple segments of electric field signals into three regions according to the time, quantifying irregularity of radiation of the three regions in the leader according to sample entropies and performing classification based on numerical variation characteristics of the irregularity; S4: comparing the classified data with lightning positioning data to form an analysis database; and S5: acquiring real-time electric field signals, calculating average sample entropy values of the electric field signals, and predicting development characteristics of irregular radiation in the lightning leader.

Abstract: The present application discloses a vehicle-mounted heterogeneous network collaborative task unloading method, which comprises the following steps: calculating a communication delay when a vehicle requests a cache from a smart lamp post for a vehicle terminal; taking the maximum communication delay in all the caches as the communication delay between the vehicle and the smart lamp post network, and determining whether the communication delay is less than the time when the vehicle sends a request to a cloud center, if so, unloading a task to the smart lamp post network, otherwise, unloading a task to the cloud center; taking profit of a single smart lamp post itself as an index for the smart lamp post terminal, dividing the smart lamp post network into a plurality of coalitions, taking the profit maximization of the coalition as an optimization objective, optimizing a smart lamp post combination in the coalition.

Abstract: The disclosure relates to a fault-tolerant method and apparatus for a network device system, a computer device, and a storage medium. The method includes: when the link state changes, the source switch acquires and transmits link state change information to the master controller, randomly selects a switch from the first switch unit or the second switch unit, and transmits a copy of the link state change information to the selected switch; such that the master controller forwards the link state change information to the second switch unit, the auxiliary controller receives the copy of the link state change information transmitted by the switch selected by the source switch and transmits it to the second switch unit; after the second switch unit updates the local routing table according to the acquired information, the master controller transmits confirmation information to the source switch.

Abstract: A voltage source converter includes a number of converter modules, one for each of a number of phases, connected in-series between two DC terminals. Each converter module includes an upper director valve in series with a lower director valve, where a junction between the two provides a primary AC terminal, an upper wayshaper section, a common waveshaper block and a lower waveshaper section in parallel with the valves, where the upper and lower waveshaper sections include multilevel cells and the common waveshaper block include at least one common waveshaper connected between the upper and lower waveshaper sections, a first switching element connected between a secondary AC terminal and the upper waveshaper section and a second switching element connected between the secondary AC terminal and the lower waveshaper section.

Abstract: A voltage source converter includes a number of converter modules, one for each of a number of phases, connected in-series between two DC terminals. Each converter module includes an upper director valve in series with a lower director valve, where a junction between the two provides a primary AC terminal, an upper waveshaper section, a common waveshaper block and a lower waveshaper section in parallel with the valves, where the upper and lower waveshaper sections include multilevel cells and the common waveshaper block include at least one common waveshaper connected between the upper and lower waveshaper sections, a first switching element connected between a secondary AC terminal and the upper waveshaper section and a second switching element connected between the secondary AC terminal and the lower waveshaper section.

Abstract: Embodiments are generally based on employing a power transmission line in a HVDC link to provide auxiliary power to one of the ends of the HVDC link for facilitating a black start thereof when the HVDC link is de-energized, i.e. when at least one of the HVDC converter stations is de-energized and there is no transmission of power between inverter and rectifier HVDC converter stations on each side of the HVDC link. A relatively small amount of power can be conveyed towards one of the HVDC converter stations via the power transmission line so as to provide power to any auxiliary system(s) of the converter station, for example prior to a black start of the converter station being carried out.

Abstract: Embodiments are generally based on employing a power transmission line in a HVDC link to provide auxiliary power to one of the ends of the HVDC link for facilitating a black start thereof when the HVDC link is de-energized, i.e. when at least one of the HVDC converter stations is de-energized and there is no transmission of power between inverter and rectifier HVDC converter stations on each side of the HVDC link. A relatively small amount of power can be conveyed towards one of the HVDC converter stations via the power transmission line so as to provide power to any auxiliary system(s) of the converter station, for example prior to a black start of the converter station being carried out.

Abstract: Unique systems, methods, techniques and apparatuses of power transmission systems are disclosed herein. One exemplary embodiment is an AC power transmission system converted for transmission of high voltage direct current (HVDC) power, the converted system comprising an AC cable system, a first converter system, a second converter system, and a control system. The first converter system is structured to receive and convert AC power to DC power and output the DC power. The second power converter system is structured to receive the DC power, convert the DC power to a second AC power, and output the second AC power. The control system is structured to receive power demand information, determine a reduced DC voltage less than a rated HVDC voltage, control the first converter system such that the DC power is controlled to the reduced voltage, and control the second power converter system to operate in an active power control mode.

Abstract: Techniques are disclosed for load balancing in networks such as those networks handling telephony applications. By way of example, such techniques direct requests associated with calls to servers in a system comprised of a network routing calls between a plurality of callers and at least one receiver wherein a load balancer sends requests associated with calls to a plurality of servers as follows. A request associated with a call, a caller, or a receiver is received, depending on the particular load balancing technique. A server is selected to receive the request. A subsequent request is received. A determination is made whether or not the subsequent request is associated with the call, the caller, or the receiver, depending on the particular load balancing technique. The subsequent request is sent to the server based on determining that the subsequent request is associated with the call, the caller, or the receiver, again depending on the particular load balancing technique.

Abstract: Techniques are disclosed for load balancing in networks such as those networks handling telephony applications. By way of example, such techniques direct requests associated with calls to servers in a system comprised of a network routing calls between a plurality of callers and at least one receiver wherein a load balancer sends requests associated with calls to a plurality of servers as follows. A request associated with a call, a caller, or a receiver is received, depending on the particular load balancing technique. A server is selected to receive the request. A subsequent request is received. A determination is made whether or not the subsequent request is associated with the call, the caller, or the receiver, depending on the particular load balancing technique. The subsequent request is sent to the server based on determining that the subsequent request is associated with the call, the caller, or the receiver, again depending on the particular load balancing technique.

Abstract: Techniques are disclosed for load balancing in networks such as those networks handling telephony applications. By way of example, such techniques direct requests associated with calls to servers in a system comprised of a network routing calls between a plurality of callers and at least one receiver wherein a load balancer sends requests associated with calls to a plurality of servers as follows. A request associated with a call, a caller, or a receiver is received, depending on the particular load balancing technique. A server is selected to receive the request. A subsequent request is received. A determination is made whether or not the subsequent request is associated with the call, the caller, or the receiver, depending on the particular load balancing technique. The subsequent request is sent to the server based on determining that the subsequent request is associated with the call, the caller, or the receiver, again depending on the particular load balancing technique.

Abstract: Techniques are disclosed for load balancing in networks such as those networks handling telephony applications. By way of example, a method for directing requests associated with calls to servers in a system comprised of a network routing calls between a plurality of nodes wherein a node participates in a call as a caller or a receiver and wherein a load balancer sends requests associated with calls to a plurality of servers comprises the following steps. A request associated with a node belonging to a group including a plurality of nodes is received. A server is selected to receive the request. A subsequent request is received. A determination is made whether or not the subsequent request is associated with a node belonging to the group. The subsequent request is sent to the server based on determining that the subsequent request is associated with a node belonging to the group.

Abstract: In a computer system comprising a plurality of computing devices wherein the plurality of computing devices processes a plurality of tasks and each task has a task type, a method for determining overheads associated with task types comprises the following steps. Overheads are estimated for a plurality of task types. One of the plurality of computing devices is selected to execute one of the plurality of tasks, wherein the selection comprises estimating load on at least a portion of the plurality of computing devices from tasks assigned to at least a portion of the plurality of computing devices and the estimates of overheads of the plurality of task types. One or more of the estimates of overheads of the plurality of task types are varied.

Abstract: Managing network traffic to improve availability of network services by classifying network traffic flows using flow-level statistical information and machine learning estimation, based on a measurement of at least one of relevance and goodness of network features. Also, determining a network traffic profile representing applications associated with the classified network traffic flows, and managing network traffic using the network traffic profile. The flow-level statistical information includes packet-trace information and is available from at least one of Cisco NetFlow, NetStream or cflowd records. The classification of network flows includes tagging packet-trace flow record data based on defined packet content information. The classifying of network flows can result in the identification of a plurality of clusters based on the measurement of the relevance of the network features.

Abstract: A method and system for distributing requests to multiple back-end servers in client-server environments. A front-end load balancer is used to send requests to multiple back-end servers. In appropriate cases, the load balancer will send requests to the servers based on affinity requirements, while maintaining load balance among servers.

Abstract: In a computer system comprising a plurality of computing devices wherein the plurality of computing devices processes a plurality of tasks and each task has a task type, a method for determining overheads associated with task types comprises the following steps. Overheads are estimated for a plurality of task types. One of the plurality of computing devices is selected to execute one of the plurality of tasks, wherein the selection comprises estimating load on at least a portion of the plurality of computing devices from tasks assigned to at least a portion of the plurality of computing devices and the estimates of overheads of the plurality of task types. One or more of the estimates of overheads of the plurality of task types are varied.

Abstract: A system and method for profiling subnet-level aggregate network data traffic is disclosed. The system allows a user to define a collection of features that combined characterize the subnet-level aggregate traffic behavior. Preferably, the features include daily traffic volume, time-of-day behavior, spatial traffic distribution, traffic balance in flow direction, and traffic distribution in type of application. The system then applies machine learning techniques to classify the subnets into a number of clusters on each of the features, by assigning a membership probability vector to each network thus allowing panoramic traffic profiles to be created for each network on all features combined. These membership probability vectors may optionally be used to detect network anomalies, or to predict future network traffic.

Abstract: Managing network traffic to improve availability of network services by classifying network traffic flows using flow-level statistical information and machine learning estimation, based on a measurement of at least one of relevance and goodness of network features. Also, determining a network traffic profile representing applications associated with the classified network traffic flows, and managing network traffic using the network traffic profile. The flow-level statistical information includes packet-trace information and is available from at least one of Cisco NetFlow, NetStream or cflowd records. The classification of network flows includes tagging packet-trace flow record data based on defined packet content information. The classifying of network flows can result in the identification of a plurality of clusters based on the measurement of the relevance of the network features.

Abstract: Techniques are disclosed for load balancing based on call length in networks such as those networks handling telephony applications. By way of example, one method for directing requests associated with calls to servers in a system comprised of a network routing calls between at least one caller and at least one receiver wherein the network comprises a load balancer sending requests to a plurality of servers comprises the following steps. A first request of a call is received. A server s1 is selected to receive the request based on an estimated duration of the call. Another method for directing requests associated with calls to servers in a system comprised of a network routing calls between at least one caller and at least one receiver wherein the network comprises a load balancer sending requests to a plurality of servers comprises the following steps. Information is maintained regarding load assigned to a plurality of servers. A first request of a call is received.