Hybrid Model for Renewable Energy and Load Forecasting Based on Data Mining and EWT

Zhang Jinjin,Zhang Qian,Li Guoli,Wu Junjie,Wang Can,Li Zhi 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

Accurate renewable resource (RES) and load prediction play key roles in the power grid planning schemes, eff ective dispatch, and stable operation of power systems. The proportions of wind and solar energy continue to increase, leading to wind and light abandonment. Thus, the absorption of wind and photovoltaic power is particularly important. On the basis of accurately predicting load, wind power and photovoltaic output, the accommodation capacity of wind and photovoltaic power is analyzed. The work contains fi ve parts, as follows: (1) empirical wavelet transform (EWT) is used to decompose wind power and load. At the same time, isolated forest (iForest) and fuzzy C-means clustering (FCM) are used to process photovoltaic data. (2) Low frequency and intermediate frequency components of load are predicted by improved random forest (IRF). High frequency component of load is clustered by improved density-based spatial clustering of applications with noise (IDBSCAN). The processing model is selected on the basis of the characteristics of each class sample. Each component of wind power are predicted by IRF. (3) Photovoltaic power of each category is predicted by IRF. (4) Diff erent components of load and wind power data are added. The photovoltaic power forecast data are synthesized according to the time point. (5) The forecast value of load, wind power, and photovoltaic output of a city are comprehensively evaluated by the summarized prediction level indicators. Three accommodation indicators are used for analyzing the accommodation capacity of wind power and photovoltaic. Results show that the forecasting methods of load, wind power, and photovoltaic power can generate better forecasting results than conventional methods. The analysis results of supplementary prediction level and accommodation indices provide reference for eff ective grid dispatching, sustainable, and healthy energy development.

Vacuum infiltration transformation of non-heading Chinese cabbage (Brassica rapa L. ssp. chinensis) with the pinII gene and bioassay for diamondback moth resistance

Zhang, Junjie,Liu, Fan,Yao, Lei,Luo, Chen,Zhao, Qing,Huang, Yubi The Korean Society of Plant Biotechnology 2011 Plant biotechnology reports Vol.5 No.3

Non-heading Chinese cabbage (Brassica rapa L. ssp. chinensis) is a popular vegetable in Asian countries. The diamondback moth (DBM), Plutella xylostella (L.), an insect with worldwide distribution, is a main pest of Brassicaceae crops and causes enormous crop losses. Transfer of the anti-insect gene into the plant genome by transgenic technology and subsequent breeding of insect-resistant varieties will be an effective approach to reducing the damage caused by this pest. We have produced transgenic non-heading Chinese cabbage plants expressing the potato proteinase inhibitor II gene (pinII) and tested the pest resistance of these transgenic plants. Non-heading Chinese cabbages grown for 45 days on which buds had formed were used as experimental materials for Agrobacterium-mediated vacuum infiltration transformation. Forty-one resistant plants were selected from 1166 g of seed harvested from the infiltrated plants based on the resistance of the young seedlings to the herbicide Basta. The transgenic traits were further confirmed by the Chlorophenol red test, PCR, and genomic Southern blotting. The results showed that the bar and pinII genes were co-integrated into the resistant plant genome. A bioassay of insect resistance in the second generation of individual lines of the transgenic plants showed that DBM larvae fed on transgenic leaves were severely stunted and had a higher mortality than those fed on the wild-type leaves.

Modified Wettability of Micro-structured Steel Surfaces Fabricated by Elliptical Vibration Diamond Cutting

Jianguo Zhang,Andreas Rosenkranz,Junjie Zhang,Jiang Guo,Xiaoqing Li,Xiao Chen,Junfeng Xiao,Jianfeng Xu 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.5

Hardened steel is an important material related to the development of modern industry branches. In order to satisfy the adhesion strength as well as the corrosion and wear resistance under extreme conditions, the modification of the wettability of hardened steel has become an important scientific topic. As micro/nano-structured surfaces play an essential role to induce advanced functional surfaces with wettability control, this contribution aims at presenting the feasibility of micro/nano sculpturing of hardened steels by elliptical vibration diamond cutting. The influence of the fabricated micro/nano structures on the resulting wettability is discussed and related to the contact line density as well as asperity heights. In this regard, it has been verified that a pitch value of 12 μm and structural height of 500 nm are the preferred structural parameters to increase the hydrophobicity of the textured steel specimens.

Insights Into the BR2/PGP1-mediated Patterns for Shoot and Root Growth in Maize Early Seedling Development by Comparative Transcriptome Sequencing

Xiangge Zhang,Lanjie Zheng,Haojun Zhang,Xinrong Huang,Yinghong Liu,Junjie Zhang,Yu-Feng Hu,Hanmei Liu,Guowu Yu,Yangping Li,Yubi Huang 한국식물학회 2019 Journal of Plant Biology Vol.62 No.3

Plant shoot and root growth is regulated by multiplefactors, including the hormone auxin. A maize brachytic2(br2) mutant displays a shortened shoot and root with highauxin concentration in their apexes, where BR2 encodes anauxin transporter P-glycoprotein1 (PGP1). We employedcomparative transcriptome sequencing to explore the BR2/PGP1-mediated patterns for shoot and root growth amongbr2, wild type (WT), and hybrid F1 (br2 × WT). The resultsshow 352 genes in the br2 shoot and 234 genes in the br2root are differentially expressed compared to WT and F1. Zm00001d045203 and Zm00001d031562 were identified astwo auxin-responsive genes in both the shoot and root. TheZm00001d045203 gene is down-regulated in br2 and encodesan Aux/IAA inhibitor involved in the SCFTIR1/AFB-mediatedauxin signaling pathway. The up-regulated Zm00001d031562gene encodes a small GTPase belonging to the Rab/Yptfamily, which takes part in auxin-mediated responses inArabidopsis. Cytology analysis reveals that reduced cellelongation affects the shoot and root growth of br2. TheZm00001d043477 gene is down-regulated and encodes amember of the cellulose synthase protein family, possiblyreducing cell elongation in the br2 shoot and root. Theseresults reveal the specific regulation of auxin actions and cellresponses by BR2/PGP1.

Utilization of electron beam to modulate electron injection over Schottky barrier

Qi Zhang,Junjie Qi,Yunhua Huang,Huifeng Li,Xin Li,Ruoshui Wang,Yue Zhang 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Modulation of electron injection over Schottky barrier was realized by employing electron beam irradiation on the metal/ZnO-nanowire contact. The structure revealed a good response to the illumination at a scanning frequency of 0.1 Hz, which can be enhanced by increasing bias and decreased with the increase of electron beam energy. These phenomena can be attributed to the Schottky barrier formed at the metal/ZnO-nanowire interface which limits the electron transport across the contact. The electron beam irradiation gives rise to high efficiency of electron injection over the barrier, while the interplay between charge discreteness, coherent scattering, and Coulomb interaction may reduce the conductivity.

Night Time Front Vehicle Detection by Using Vehicle Taillight and Lane Information

장준걸(Junjie Zhang),김정하(Jung-Ha Kim) 한국자동차공학회 2015 한국자동차공학회 학술대회 및 전시회 Vol.2015 No.11

In this paper presents an algorithm, aims at practical applications, for the high speed processing and performance enhancement of vehicle detection base on NI machine vision. Detecting the vanishing point and only use extracted low part of the vanishing line. Divides the image into 20 pixels and use the HT(Hough Transform) get the lane candidate point. Fitting the candidate point by RANSAC fitting because it’s robust to outlier. At last use the lane coordinate extraction of ROI. Legally vehicle tail light must be red color, so we use the red plane image with simultaneous processing of noise reduction and edge enhancement using the morphology function. And then give Dilation and Erosion eliminating the noise through the process of Morphology. Finally, using the Projection-Histogram information get the center of mass by restricting threshold detects a vehicle in the ROI. The experimental results were verified in logging video.

Diffusion-controlled adsorption kinetics of aqueous submicellar and micellar solution at air/solution interface in the limit of short time

Junji Liu,Ying Zhang 한국화학공학회 2006 Korean Journal of Chemical Engineering Vol.23 No.5

γeq of aqueous Pentaethylenglycol-monodecylether (C12E5) solutionsat temperature 25oC were measured by means of Wilhelmy plate method and the determined critical micelle concen-tration (cmc) is 6.8×102 mol·m3. To study adsorption kinetics of aqueous submicellar and micellar solutions, the dy-namic surface tensions γ(t) were measured by means of maximal buble pressure method. Using the derived equa-sorption kinetics was studied. For micellar solution (c0>cmc) of C12E5, the demicellization constant was calculated.

Simplified model prediction current control strategy for permanent magnet synchronous motor

Zhang, Housheng,Zhu, Shengjie,Jiang, Junjie,Wang, Qingzhuang,Wang, Ao,Jin, Duo The Korean Institute of Power Electronics 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.11

A simplified model predictive current control strategy based on mathematical auxiliary line method is proposed to increase the permanent magnet synchronous motor (PMSM) predictive current control system's steady-state performance while reducing the system's computational complexity. The mathematical models of current prediction, first-order compensation, and cost function are presented by analyzing the prediction current control strategy of the conventional models. Within a control cycle, the simplified model predictive current control algorithm applies two voltage vectors and omits the error calculation of cost function. The anticipated voltage of transformer obtained from the beat-free current control standard is considered the reference voltage, and the judgment of the area, where the reference voltage vector is found and the strategy for double voltage vector is selected, is put forward. The optimal voltage vector can be directly output without the error calculation of the cost function in the method, thereby effectively reducing the computation load and complexity of the system and improving the steady-state performance. Experimental results verify the validity and accuracy of the proposed simplified model of predictive current control strategy for PMSM control.

High Resolution ISAR Imaging Based on Improved Smoothed L0 Norm Recovery Algorithm

( Junjie Feng ),( Gong Zhang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

In radar imaging, a target is usually consisted of a few strong scatterers which are sparsely distributed. In this paper, an improved sparse signal recovery algorithm based on smoothed l₀ (SL0) norm method is proposed to achieve high resolution ISAR imaging with limited pulse numbers. Firstly, one new smoothed function is proposed to approximate the l₀ norm to measure the sparsity. Then a single loop step is used instead of two loop layers in SL0 method which increases the searching density of variable parameter to ensure the recovery accuracy without increasing computation amount, the cost function is undated in every loop for the next loop until the termination is satisfied. Finally, the new set of solution is projected into the feasible set. Simulation results show that the proposed algorithm is superior to the several popular methods both in terms of the reconstruction performance and computation time. Real data ISAR imaging obtained by the proposed algorithm is competitive to several other methods.

Novel Dead-time Segmented Compensation Strategy for a Wide Impedance Angle Range in a Three-phase Inverter with a Resistance-Inductance Load

Zhang Siyan,Wang Xudong,Ma Junjie,Duan Ruizhen,Zhou Kai 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

The dead-time setting in space vector pulse width modulation (SVPWM) causes inverter output waveform distortion and performance degradation. This paper proposes a novel dead-time segmented compensation strategy for a wide impedance angle range in a three-phase inverter with a resistance-inductance load. Since the load impedance angle ( φ ) of the threephase inverter produces diff erent dead-time eff ects, in this paper, it is divided into two intervals of [0 30°] and [30° 90°] and a corresponding dead-time segmented compensation strategy is proposed, which solves the limitation of the traditional time compensation scheme that analyzes only the resistive load. In addition, this paper uses the conversion relationship between the power factor ( λ ) and φ to determine the current polarity of each sector in the vector space, which avoids the detection error of the current zero-crossing point in the traditional compensation scheme. The simulation and experimental results demonstrate that this method eff ectively reduces the total harmonic distortion (THD) of the inverter output current signal by approximately 30% and is easy to program, which improves the inverter output performance.