Applied Mechanics and Materials Vols. 716-717

Abstract: According to the requirements and characteristics of Marine Power Station quasi-synchronizing operation, a new high-precision digital synchronoscope is designed. Proteus and Keil are used as experimental platform. The corresponding software programming and peripheral hardware circuit design are completed. Moreover, the implementation and analysis of the main technical aspects are given. Simulation results show that the new digital synchronoscope fully achieve the functions that display and detection of frequency difference and phase difference between generator voltage and grid voltage. Besides, the operation is reliable, the detection is precise and the cost is low.

Abstract: Research of FBG temperature sensing network base on WDM combined with spatial division multiplexing. Theoretical analysis and numerical simulation proves that the scheme is feasible, and the system has relatively higher measuring accuracy, which realizes the temperature dynamic measurement in large space, forming temperature sensing network.

Abstract: Architecture of adaptive control Bi-OADM is presented. Employing alternate-path switching scheme, the bi-directional traffic can be restored promptly under certain direction fiber failure in passive optical network (PON). The results indicate the adaptive control OADM exhibits a low loss (SMSR=15dB). As all the alternate-path switching is performed at optical switches, the administration and management cost can also be easily optimized.

Abstract: This paper used artificial neural network to forecast the cooling load in the building in 24 hours. The unloading experiment kept the indoor thermal comfort at the ideal range of PMV=0~0.5 and PPD=5~10. Finally, dry bulb temperature, relative humidity, wet-bulb temperature and forecast cooling load were used for modeling by neural network. We can use this model to forecast how much load can be unloaded in summer peak hours accurately. This method controls the demand response for central air conditioning system, not only maintaining comfortable indoor environment, but also attaining the goals for reducing the electric expenses.

Abstract: Scheduling technology plays an important role in avoiding the occurrence of large scope blackout. India "7.30", "7.31" blackout indicates dispatching mechanism is not reasonable. It is more important that it violates scheduling and supervision direction. The network defense mechanism is not perfect. It is lack of dynamic analysis and safety evaluation capacity. Dispatching technology can be a basis for China's high-voltage power grid construction, dispatching management and establishing a perfect accident recovery plan.

Abstract: The existed MCS in ground station is local monitoring and control system , so there must be a man on duty all day long to monitor the whole system . In order to make all the staff of the station get the real time alarm messages of the system , we use a SMS modem and a serial server to realize the SMS alarm system on the basis of existed MCS in the ground station . The program language is Visual C#.Net . Based on the alarm system , the staff not on duty can also get the alarm messages of devices in ground station .

Abstract: The signal coverage technology and the difficulties of TD-LTE coverage in High-speed Train are summarized. The method of the TD-LTE uplink/downlink power budget is mentioned and the path loss and power budget are calculated in ordinary scene and tunnel scene respectively. The results show that in the F working frequency band of the TD-LTE, the maximum path loss of the High-speed Train is allowable to reach 110~130 dB. In the ordinary scene, by using large power station and a high gain antenna, the outdoor coverage radius of TD-LTE is up to 600~1000m. In the tunnel scene, using the leaked cable, the coverage radius of the RRU is up to 500m.

Abstract: The paper takes STM32 microcontroller as the core. The UIP protocol stack is transplanted to STM32 to construct embedded web server and wireless sensor networks is used to construct the internal network of smart home. In combination with GSM communication technology, a smart home control system with the advantages of reliability, simplicity and flexibility is designed. In addition, this article also introduced a low power wireless receiving and transmitting chip CC 1100 in detail, completed software and hardware design of wireless receiving and transmitting module. Aspect of hardware design, completed the peripheral circuit design of CC 1100 and design of interface circuit .Aspect of software design, completed setting of register, communication of SPI with single chip and receiving and transmitting of data, has given the flow chart and the procedure.

Abstract: Wireless signal reflecting, scattering or refracting causes the generation of multipath effects. Multipath causes multiple copies of the same wireless signal, These copies to different path to reach the receiver. The signal generated by a copy of the same produce serious interference. MIMO (Multiple-Input Multiple-Output) technology can make the interference caused by the multipath significantly reduced. In this paper, in the context of indoor and outdoor, through TP-LINK-WR845N (MIMO 2*2, which have 2 launching antennas and 2 receiving antennas) to verify the superior performance of this technology under indoor condition, at the same time we discover that the MIMO technology does not increase the coverage under outdoor condition, because there is only the power gain, no diversity gain.

Abstract: Firstly, this paper introduces the overall framework and design ideas of LTE big data platform. Secondly, it describes the principles of decrypting encrypted data. In view of the distribution characters of keys required by NAS layer decryption, a decryption scheme for analysis and implementation based on the data structure of hash bucket is proposed. Finally, this scheme is validated and analyzed. Aiming to studying decryption scheme of NAS date, applying this scheme to analyze the LTE big data platform and implementing the function of encrypt the NAS PDU in LTE big data platform. The scheme has a good application value in the field of network testing and a great signification to the operation and maintenance of LTE big data platform.