Papers by Keyword: Timing

Abstract: In order to solve the issues of time synchronization that occurs in simultaneous measurement in power system, designing a GPS clock synchronization method based on time different compensation which can guarantee high-precision whether the GPS satellites are locked or not. The paper provides the basic idea describe and the overall hardware and software design. Simulation results show that the scheme provides second pulse with error in 0.8μs when GPS is locked and provides second pulse with error in 7μs when GPS is unlocked for 12 hours. The accuracy is better than the existing references.

Abstract: Based on modified natural gas direct injection engine, we studied the impacts of ignition timing and jet timing on natural gas engine start process in this paper. The results shows that: when the first jet ignition occurs in the first compression stroke, the engine reaches idle speed 400rpm fastest; as the jet timing is delayed, emissions during engine start is gradually reduced, but when the jet late, HC surge occurs, the emissions deteriorates; with the ignition advance angle increasing, the engine speed growth accelerates, the peak moves forward; with the ignition advance angle increasing, HC emissions peak increases, the peak moves forward.

Abstract: In the practical application of developmental internet, often synchronizing Oracle database tables, the establishment of a reliable remote database synchronization scheme is necessary. The paper uses the EXP/IMP logical backup tool of oracle, tuning of EXP/IMP, and combined with shell command, to implement a remote database synchronization scheme. In addition, this program implements the timing of the Oracle database synchronization.

Abstract: The linear array CCD spectral acquisition system for a Photoelectric Direct Reading Spectrometer is presented. The spectral acquisition circuit, data processing and shortage circuit are designed. Taking microcontroller MSP430 as a control chip, Using PWM signals generated by MSP430 timer, the correct timing of CCD clock pulse, ADC clock and FIFO write enable signal was established. The experiment shows that the synchronization of spectral acquisition, data conversion and shortage was achieved, and the spectral acquisition system is feasible and reliability.

Abstract: For the permanent magnet synchronous motor used in electric vehicle wheel, in order to obtain high torque at low speed, a lot of pole pairs are designed in the structure. So the electrical angle will rotate too fast, and the commutation delay will appear apparently at high speed. The commutation process of permanent magnet synchronous motor is analyzed and the timing control according to rotate speed is deduced. A motor simulation model is built to verify the control strategy. The result shows that the strategy can effectively improve high speed performance of motor.

Abstract: To solve the hiding problem of hardware Trojan in chip, we first analyzed the self-protection technology of malicious software, and then proposed a trigger mechanism that base on timing finite state machine (TFSM), energy flow, and distributed Trojan design method. As for the trigger mechanism that based on TFSM, one must enter the right pattern on the correct time to activate the Trojan. The mechanism based on energy flow can make the hardware Trojan keep hiding in the RTL code logical analysis. The distributed hardware Trojan design is to divide a complete Trojan into several components, and the Trojan will keep silent if all the components are not in order. The design methods of hardware Trojan have been verified in our self-made hardware threat simulate platform, it can reduce the rate of been detected out, and the possibility of been triggered out by random operations.

Abstract: According to the theoretical analysis of Zadoff-Chu sequence and theoretical derivation.A kind of low complexity implementation method of algorithm in cell search in TD-LTE system is proposed in this paper. Both the theory analysis and simulation results show that the algorithm proposed can reduce computational complexity and this algorithm is feasible and efficient, which gains good performance of cell search in TD-LTE system.

Abstract: For an established control system, scan cycle time of the PLC is almost constant during steady operation. Scan cycle time of PLC can be act as a timing unit and realize the function of timer by appropriate programming. The timing method based on PLC scan cycle time is practiced in judgment of start success of generator set and grasping of ACB (air circuit breaker of generator) closing opportunity in automatic synchronization control and achieved the desired results. Application of this timing method reduced the hardware of the control system, improved the reliability and economical efficiency. Several years of operation in training lab proved that this control method is reliable and steady.

Abstract: In this paper, we proposed a joint timing and fractionally-spaced blind equalization algorithm. It adopts Gardner algorithm instead of simple down-sampling in conventional fractionally-spaced equalization in order to overcome the problem of that the filter can’t compensate timing error. The simulations show that the performance of the proposed fractionally-spaced equalization algorithm is better than CMA in different SNR and in different number of channel taps.

Abstract: Time is the core of GPS satellite navigation system, and time service is one of the basic functions of the GPS system. The application of GPS technology in time service is more and more extensive, basing on its high accuracy, real-time, good continuity, low cost, etc.. In this paper, firstly, the building and maintaining of GPS time system is summarized, then GPS time service technology and GPS time transfer technology and their practical application in society is illustrated furtherly, secondly the prospects of GPS in time service technology and time transfer technology are discussed. With the development of GPS system performance and data processing technology, its application in time-frequency domain will widen continuously, which has important society significance for country's economic construction, national security and scientific research, etc.