In this letter, a distributed TDMA-based data gathering scheme for wireless sensor networks, called DTDGS, is proposed in order to avoid transmission collisions, achieve high levels of power conservation and improve network lifetime. Our study is based on corona-based network division and a distributed TDMA-based scheduling mechanism. Different from a centralized algorithm, DTDGS does not need a centralized gateway to assign the transmission time slots and compute the route for each node. In DTDGS, each node selects its transmission slots and next-hop forwarding node according to the information gathered from neighbor nodes. It aims at avoiding transmission collisions and balancing energy consumption among nodes in the same corona. Compared with previous data gathering schemes, DTDGS is highly scalable and energy efficient. Simulation results show high the energy efficiency of DTDGS.
The present invention relates to a rotary seal chuck of an optical fiber preform rod deposition lathe, comprising a fixed socket sleeve and a rotary shaft. The fixed socket sleeve is provided with a central hole base. The central hole base bears the rotary shaft through a bearing. An end of the central hole base is connected to an air hose. The rotary shaft is a hollow rotary shaft provided with a through hole. One end of the through hole communicates with the air hose, and the other end of the through hole is provided with a liner tube connecting sealing hole base. A magnetic fluid seal ring is disposed at a joint between an inner side of the rotary shaft and the central hole base of the fixed socket sleeve, to form a rotary dynamic seal. An outer side of the rotary shaft is connected to a rotary driving disk. In the present invention, the rotational torque is small, the use performance is stable, the service life is long, and the device manufacturing and maintenance costs are low; when the magnetic fluid rotary seal device is used, the degree of cleanliness is high and no abrasion-incurred dust is generated, thereby ensuring the purity of input chemical gas during deposition, improving the quality of chemical vapor deposition of a glass liner tube, and improving the manufacturing precision and quality of an optical fiber preform rod.
Disclosed is a data centre system, including a plurality of first load balancing devices for receiving a first class network request sent by a client through a core network device and translating the source address and the destination address; a plurality of second load balancing devices for receiving the first class network request and converting same to a second network class request and translating the source address and destination address of the second class network request; and a plurality of servers for receiving the second class network request from the second load balancing device, generating a second class network response and returning same to the second load balancing device. The present invention can simply and transparently provide service among different class networks under the premise of not changing the existing IDC network structure, large-scale system and application upgrade. Also disclosed are a method for a data centre to provide service, an evolved deployment method based on the above data centre system, a layer 4 load balancing device and a layer 7 load balancing device.
The present invention provides a low-frequency mutation enrichment sequencing method for free target DNA in plasma, comprising plasma DNA extraction and library construction, general library TT COLD PCR amplification enrichment, probe enrichment capture, PCR and computer sequencing of captured products, and positive and negative double-strand error-correction low-frequency information analysis.
The present disclosure relates to VoWLAN call handover solutions. In particularly, the present disclosure provides a method used in a User Equipment (UE) for facilitating voice call handover, the method comprising: making (S2120) a voice call through a Wireless Local Area Network (WLAN) under whose coverage the UE is located, with a Packet Date Network (PDN) address obtained from a PDN to which the WLAN is connected; determining (S2130) that a signal quality of the WLAN is not suitable for the voice call any more; and sending (S2160) the PDN address to a base station of a mobile communication network covering the UE, for facilitating a core network node of the mobile communication network to perform voice call handover from WLAN to the mobile communication network. The present disclosure also provides a UE and a core network node for implementing the same. With the proposed VoWLAN call handover method and UE, the successful rate for VoWLAN call handover either to a mobile communication network or to another WLAN can be increased.
Provided are a method for controlling an enhanced dedicated physical control channel (E-DPCCH) overhead and a base station. The method comprises: a base station monitoring first designated information, and notifying a terminal to enter a mode for reducing the E-DPCCH overhead through a downlink high speed shared control channel command if the first designated information satisfies a first predetermined condition; and after entering the mode for reducing the E-DPCCH overhead, the base station monitoring second designated information, and notifying the terminal to quit the mode for reducing the E-DPCCH overhead through a downlink high speed shared control channel command if the second designated information satisfies a second predetermined condition. The embodiments of the present invention can reduce the transmission power of a UE, thereby reducing the interference between UEs, improving the system capacity, and alleviating the uplink pressure.
The present invention provides a power control method, system, device and computer storage medium. The method comprises: when it is determined that preset entry conditions are met, a base station notifies a UE to close dedicated physical control channel (DPCCH) transmission during hybrid automatic repeat request (HARQ) process deactivation (101); when it is determined that preset exit conditions are met, a base station notifies a UE to open DPCCH transmission during HARQ process deactivation (102).
The present invention relates to a channel switching method for a playing device and the playing device. The method comprises: separately setting favorite channels corresponding to multiple first preset time periods; acquiring the current time; and when the current time is within a first preset time period of the multiple first preset time periods, or the interval between the current time and the start time of a first preset time period of the multiple first preset time periods is smaller than or equal to a preset switching period, and when a favorite channel corresponding to the first preset time period is set, switching the playing device to the favorite channel corresponding to the first preset time period, or prompting to switch to the favorite channel corresponding to the first preset time period.
A method, apparatus and system for improving system accuracy of an XY motion platform. The method comprises: taking a pre-set calibration board as a reference, when a controlled device on the XY motion platform moves, synchronously shooting an image of the calibration board, and analysing the image to obtain a pixel coordinate of a calibration point in the image (S101); reading an actual coordinate of the calibration point in the calibration board, and calculating an actual position coordinate of the controlled device according to the actual coordinate and the pixel coordinate (S102); and adjusting a motion control system of the XY motion platform according to the actual position coordinate, and controlling the XY motion platform to perform a corresponding motion so as to perform motion compensation on the controlled device (S103). The method can improve system accuracy, and reduce the requirements for assembly and element selection.
Step and relay feedback tests have been widely used for model identification in the process industry. The corresponding identification methods developed in the past three decades are surveyed in this paper. Firstly, the process models with time delay mainly adopted for identification in the literature are presented with a classification on different response types. By categorizing the major technical routes developed in the existing references for parameter estimation relating to different applications, the identification methods are subsequently clustered into groups for overview, along with two specific categories for robust identification against load disturbance and the identification of multivariable or nonlinear processes. The rationales of each category are briefly explained, while a typical or state-of-the-art identification algorithm of each category is elucidated along with application to benchmark examples from the literature to illustrate the achievable accuracy and robustness, for the purpose of facilitating the readers to have a general knowledge of the research development. Finally, an outlook on the open issues regarding step or relay identification is provided to call attention to future exploration.