http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Research and Design of Coal PLC Control System in Coal-fired Power Plants
Yuheng Yin,Zhongzhe Yue 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.1
Coal handling system in thermal power plant is the important component of the auxiliary system of power plant, it takes on the power plant's power to produce fuel supply missions with other corresponding mechanical and electrical equipments. During the operation of thermal power plants, the improvement of working efficiency of coal handling system is the key factor to improve the work efficiency of the whole power plant, the whole process of remote monitoring of coal is also put forward higher requirements on the design of automatic control system, so we choose the most widely used PLC control system in coal handling system, it makes the dream a reality.
Selective Demodulation Scheme Based on Log-Likelihood Ratio Threshold
( Yuheng Huang ),( Yan Dong ),( Minho Jo ),( Yingzhuang Liu ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.4
This paper aims at designing a selective demodulation scheme based on Log-likelihood Ratio threshold (SDLT) instead of the conventional adaptive demodulation (ADM) scheme, by using rateless codes. The major difference is that the Log-likelihood ratio (LLR) threshold is identified as a key factor to control the demodulation rate, while the ADM uses decision region set (DRS) to adjust the bit rate. In the 16-QAM SDLT scheme, we deduce the decision regions over an additive white Gaussian channel, corresponding to the variation of LLR threshold and channel states. We also derived the equations to calculate demodulation rate and bit error rate (BER), which could be proven by simulation results. We present an adaptation strategy for SDLT, and compare it with ADM and adaptive modulation (AM). The simulation results show that our scheme not only significantly outperforms the ADM in terms of BER, but also achieves a performance as good as the AM scheme. Moreover, the proposed scheme can support much more rate patterns over a wide range of channel states.
Yuheng Li,최면천,정극민,정재훈,이혁기,김규현,하창식 한국고분자학회 2017 Macromolecular Research Vol.25 No.6
To investigate the effects of holding time after deposition of polyethylenimine (PEI) solution and molecular weight of PEI on the surface morphology of multilayer films prepared by layer-by-layer (LbL) method, polyamic acid (PAA)/PEI/ graphene oxide (GO) films were prepared using different holding times and different molecular weights of PEI. To convert PAA into polyimide (PI), the films were thermally imidized after film deposition. In this process, GO was also converted into partially reduced GO (rGO). The effects of holding time and molecular weight of PEI on the surface morphology and the sheet resistance of PI/PEI/rGO films were investigated. Also, to investigate the effect of rGO on the barrier properties of PI based multilayer films, (PI/PEI/rGO/PEI)6 films were prepared by LbL method. Longer holding time (10 min) and smaller molecular weight (25,000) of PEI lead to relatively flat surfaces, but shorter holding time (5 min) and larger molecular weight (75,000) result in wrinkled and overlapped surfaces. The sheet resistance of PI/ PEI25K/rGO films prepared with holding time 10 and 5 min is 502.1 kΩ/sq and out of range (> 2000 kΩ/sq), respectively. The sheet resistance of PI/PEI75K/rGO films prepared with holding time 10 min is out of range (> 2000 kΩ/sq). Gas transmission rate (GTR) and permeability coefficient of (PI/PEI25K/rGO/PEI25K)6 are lower than those of (PI/PEI75K/rGO/PEI75K)6, respectively.
Study on SOC Estimation of Power Battery Based on Kalman Filter Optimization Algorithm
Yuheng Yin,Weifeng Zhong 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.7
Power battery's remaining capacity is affected by many interior and exterior uncertainties during use. To achieve estimate of current remaining measurable battery power by using battery measurable parameter data, which has always been the core issue of electric vehicle battery management system and the technical difficulties need to be resolved. In this paper, Kalman filtering theory is introduced in estimation algorithm, and then combined with open circuit voltage method and ampere measurement method, the SOC estimation according with the requirements of the electric car is achieved.
Understanding Watching Patterns of Live TV Programs on Mobile Devices: A Content Centric Perspective
( Yuheng Li ),( Qianchuan Zhao ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.9
With the rapid development of smart devices and mobile Internet, the video application plays an increasingly important role on mobile devices. Understanding user behavior patterns is critical for optimized operation of mobile live streaming systems. On the other hand, volume based billing models on cloud services make it easier for video service providers to scale their services as well as to reduce the waste from oversized service capacities. In this paper, the watching behaviors of a commercial mobile live streaming system are studied in a content-centric manner. Our analysis captures the intrinsic correlation existing between popularity and watching intensity of programs due to the synchronized watching behaviors with program schedule. The watching pattern is further used to estimate traffic volume generated by the program, which is useful on data volume capacity reservation and billing strategy selection in cloud services. The traffic range of programs is estimated based on a naive popularity prediction. In cross validation, the traffic ranges of around 94% of programs are successfully estimated. In high popularity programs (>20000 viewers), the overestimated traffic is less than 15% of real happened traffic when using upper bound to estimate program traffic.
Separation of Taxanes from Taxus canadensis Using Dynamic Pressurized Liquid Extraction
Yuheng Wang,Joanne Gamage,Zisheng Zhang 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.4
An extraction technique, dynamic pressurized liquid extraction (DPLE), was proposed to extract the taxanes; including 10-DAB III, Baccatin III, 9-DHB III and paclitaxel, from powdered Taxus canadensis needles. A dual-solvent approach was adopted in which the impurities were firstly removed by extraction with hexane,and the taxanes were subsequently extracted with an appropriate solvent. The performance of chloroform, dichloromethane,and mixtures of methanol/dichloromethane was compared for use as the taxane-extracting solvent, and it was found that solvents containing a higher proportion of methanol had higher extraction capabilities. The effect of temperature on DPLE extraction of the taxanes was also studied, and it was found that higher extraction efficiencies could be realized with increasing temperature up to a threshold of 90℃. Based on a progressive conversion model, a kinetic equation for the extraction process was proposed. This model successfully confirmed that smaller needle powder particle sizes would result in higher extraction rates, which is consistent with the data obtained by experimentation.
Dual-Band Antenna with OAM Mode Radiated by Ground Plane
Li Yuheng,Yang Guang,Li Weiwen,Liu Qing Huo 한국전자파학회 2023 Journal of Electromagnetic Engineering and Science Vol.23 No.3
Antennas that radiate orbital angular momentum (OAM) modes are usually large and have complex structures. In this paper, in combination with characteristic mode analysis, the ground plane is used as the OAM wave radiator. To excite degenerate modes of the ground plane with phase quadrature by using a single-fed structure, two bent metal strips with grounded ends are introduced around the rectangular ground plane, and a corner of one of the bent strips is set as the feeding point. For ground radiators, a first-order OAM mode is generated at the high-frequency end by synthesizing the degenerate modes. In case of the bent side strip, an inverted-F antenna that operates in the low-frequency mode is formed. This compact antenna has dual-band characteristics and facilitates simple feeding, which makes it suitable for mobile terminal applications.
Xueqi Guo,Yuheng Zeng,Zhi Zhang,Yuqing Huang,Mingdun Liao,Qing Yang,Zhixue Wang,Minyong Du,Denggao Guan,Baojie Yan,Jichun Ye 한국물리학회 2019 Current Applied Physics Vol.19 No.7
The junction properties of tunnel silicon oxide (SiOx) passivated contact (TOPCon) with n-type poly-Si on p-type c-Si wafer are characterized using current-voltage (J-V) and capacitance-voltage (C-V) measurements. The dark J-V curves show a standard diode characteristic with a turn-on voltage of ∼0.63 V, indicating a p-n junction is formed. While the C-V curve displays an irregular shape with features of 1) a slow C increase with the decrease of the magnitude of reverse bias voltage, being used to estimate the built-in potential (Vbi), 2) a significant increase at a given positive bias voltage, corresponding to the geometric capacitance crossing the ultrathin SiOx, and 3) a sharp decrease to negative values, resulting from the charge tunneling through the SiOx layer. The C of depleting layer deviates from the normal linear curve in the 1/C2-V plot, which is caused by the diffusion of P dopants from the n-type poly-Si into the p-type c-Si wafer as confirmed by the electrochemical capacitance-voltage measurements. However, the 1/C2+γ-V plots with γ > 0 leads to linear curves with a proper γ and the Vbi can still be estimated. We find that the Vbi is the range of 0.75–0.85 V, increases with the increase of the doping ratio during the poly-Si fabrication process, and correlates with the passivation quality as measured by the reverse saturated current and implied open circuit voltage extracted from transient photoconductivity decay.