Papers by Keyword: AGC

Abstract: Mangroves have an important role in the carbon storage cycle within coastal ecosystems. Indonesia, home to the largest mangrove forest in the world, has a potential in carbon trading particularly in blue carbon. It is essential to accurately identify the presence of mangrove to realize that potential. Remote Sensing (RS) and Machine Learning (ML) technology can be used to identify the presence of mangroves. In this research, the integration of active, passive sensors, National Digital Elevation Model (DEMNAS) and the used of the Random Forest (RF) algorithm were applied to identify the presence of mangroves. There were 30 independent variables, consisting of 4 independent variables from Sentinel-1A, 25 independent variables from Sentinel-2A and 1 independent variable from DEMNAS. The model was built from 75 sampling plots, 32 cross validation internal plot, and 25 testing plots. The optimal number of trees used for mapping mangrove in Youtefa Bay were 100, 200, and 800 with internal validation model 0.854. The results of this research show that mangrove forest area in Youtefa Bay is 189 ha with total accuracy 91 % and kappa index 0.89. DEMNAS, NDMI and MVI are the best independent variables on identifying mangroves in Youtefa Bay.

Abstract: In hot rolling mills the plastic deformation of the strip is realized at high force and plastic strain speed controlled by electro-hydraulic servo actuators. These hydraulic servo actuators - hydraulic capsules – are capable to adjust the rolling gap at great rolling force dynamically. The dynamic behaviour of the rolling mill’s AGC (automatic gap adjustment) system mainly depends on the correct operation of hydraulic actuators and servo valves. These equipments are great value, planned maintenance is essential for reliable correct operation. The maintenance includes the refurbish of damaged, worn surfaces inside the cylinder and replacement of worn out seals. In the study a laboratory hydraulic positioning system was used to examine the effect of hydraulic actuator internal leakage to dynamic behaviors of the positioning system. Because the laboratory test system is similar to the hydraulic gap adjustment system therefore the laboratory test results can be extended to the rolling mill’s Hydraulic Gap Control system.

Abstract: In this paper, a new design strategy for the hardware implementation of hearing aid algorithms is proposed. Two familiar hearing aid algorithms—Wide Dynamic Range Compression (WDRC) and Automatic Gain Control (AGC)—are implemented in one circuit as an example. By putting the common arithmetic procedures into common module, the operation units can be used repeatedly. In this way, the area and power consumption are visibly reduced.

Abstract: On the basis of a brief introduction of how the automatic gain control (AGC) of the digital reconnaissance receiver works,this article proposed a digital AGC design method based on the digital processor parts, which provide a guarantee for the digital reconnaissance receiver to work in the complex external electromagnetic signal environment. The engineering implementation of AGC is introduced with specific projects. Both simulation and engineering practice verify the feasibility of this program.

Abstract: This paper introduces the current research status of primary frequency regulation and AGC control strategy. Firstly, some important parameters about primary frequency regulation are introduced. Secondly, describes the development on the theory of AGC. Thirdly, the basic concept of CPS and ACE were briefly described, and then the difference between CPS and former A1/A2 standard were compared. Finally, outlook on the coordination between AGC control strategies and primary frequency regulation.

Abstract: The effects of temperature variation on the system performance is discussed in this paper. The temperature characteristic of the natural frequency and quality factor is analyzed theoretically firstly. Then the simulation models of the open-loop drive system, the closed-loop drive system, the closed-loop sense system and the quadrature correction system are constructed to simulate the temperature characteristic of the scale factor and zero bias. The simulation results demonstrate the relative change of the scale factor in the closed-loop drive system, that is 1.35%, almost decreases by 67 times relative to the open-loop drive system and the variation of the zero bias in the closed-loop drive system, that is 0.2789°/s, almost decreases by 364 times relative to the open-loop drive system. At the same time, the relative change of the scale factor in the closed-loop sense system, that is 0.000029%, almost decreases by 46551 times relative to the closed-loop drive system. The variation of the zero bias in the closed-loop sense system, that is 1.2×10^-11°/s, almost decreases by 2.3×10¹⁰ times relative to the closed-loop drive system, which shows the proposed method is feasible and correct.

Abstract: Large delay is the main characteristics of medium-speed pulverizer system which used in subcritical and supercritical unit. By introducing and analyzing the operating principle and working process, considering energy saving and consumption reducing, and combined with the performance requirement of AGC (Automatic Generation control), recommend solutions were put forward. It can effectively solve AGC control problems of load and pressure control accuracy and ensure frequency stability of the grid, provide a reference for similar units.

Abstract: RF front-end is an important part of the communication system. It realizes the functions such as low noise amplifier application, filtering and mixing, completes the conversion between the IF signal and the RF signal, and ensures effective communication system flexibility and versatility. In the paper, according to the superheterodyne structure, a receiver RF front-end has been designed. The total gain of the link circuit is more than 100 dB, with 50 dB AGC range, the center frequency is 750 MHz with 100MHz bandwidth, local oscillator (LO) signal with frequency 935MHz is generated by PLL and the stability is-82dBc/Hz@1KHz.

Abstract: The work mainly by the front level attenuator, the LC tuned amplifier, the push-pull output stage is composed. The first level weakens 40dB fixedly through pi the attenuator realization. Front the double grid field effect manages 3SK223 to make the level to increase the controllable LC tuned amplifier, the LC resonance by double harmonious and the list harmonious cascade way, enhanced the system selectivity. The complete machine gain is bigger than the 80dB, AGC control area to achieve above 60dB.The output stage uses the low pressure high electric current high speed axle to the axle structure integration operational amplifier OPA2354 push-pull transformer coupling output, sharpened the belt load capacity greatly. In order to reduce the amplifier as far as possible the noise and ceases the high frequency auto excitation, this design has adopted the power source filter, the shield, electromagnetic compatibility, the interstate coupling, the impedance matching and so on many kinds of measures. After the test, this plan has completed completely the basic function and the expansion function. Sweeps the frequency source turning on input end after CPLD self-made DDS, May very convenient see the system frequency response on the oscilloscope.

Abstract: The circulating fluidized bed boiler (CFB) power unit with its energy-saving and environmental protection has broad application prospects, but the problem of CFB unit automatic control has not been solved satisfied, so automatic generation control (AGC) can not be stabilized input. Through the improvement of the unit automatic control strategy by the method of intelligent predictive multivariable decoupling control and optimization of parameters, the AGC tests achieved approving results in CFB unit.