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Two-stage Stochastic Programming for Coordinated Operation of Distributed Energy Resources in Unbalanced Active Distribution Networks with Diverse Correlated Uncertainties

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Journal of Modern Power Systems and Clean Energy 2023年第1期11卷 120-131页

作者： Ruoxuan Leng Zhengmao Li Yan Xu school of electrical and electronic engineering Nanyang Technological UniversitySingapore

This paper proposes a stochastic programming(SP)method for coordinated operation of distributed energy resources(DERs)in the unbalanced active distribution network(ADN)with diverse correlated ***,the threephase branch flow is modeled to characterize the unbalanced nature of the ADN,schedule DER for three phases,and derive a realistic DER ***,both active and reactive power resources are co-optimized for voltage regulation and power loss ***,the battery degradation is considered to model the aging cost for each charging or discharging event,leading to a more realistic cost ***,copulabased uncertainty modeling is applied to capture the correlations between renewable generation and power loads,and the twostage SP method is then used to get final ***,numerical case studies are conducted on an IEEE 34-bus three-phase ADN,verifying that the proposed method can effectively reduce the system cost and co-optimize the active and reactive power.

关键词： Active distribution network(ADN) two-stage stochastic programming(SP) uncertainties voltage/var control(VVC) battery degradation

Frequency-selective microwave polarization rotator using substrate-integrated waveguide cavities

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Chinese Physics B 2014年第3期23卷 232-237页

作者：左钰沈忠祥冯一军 school of electronic Science and engineering Nanjing University school of electrical and electronic engineering Nanyang Technological University

A frequency selective polarization rotator that can rotate the polarization angle of an incident electromagnetic wave at the microwave frequency by 45 is presented. The polarization rotator is based on a two-dimensional periodic array of substrate integrated waveguide cavities, realizing the polarization rotation by coupling the input signal to the output wave through three metallic slots. Two layers of frequency selective surfaces are cascaded by substrate and form the polarization rotator. A vertical slot on the top layer is used to select the horizontal polarization from the incident wave, the vertical and the horizontal slots on the bottom layer are, respectively, used to obtain horizontally and vertically polarized outgoing waves. The two orthogonal outgoing waves are combined to result in the 45~ polarized wave. Both full wave simulation and experimental measurement are carried out, together validating the proposed method.

关键词： polarization rotator substrate integrated waveguide (SIW) frequency selective surface (FSS)

Multi-objective differential evolution with diversity enhancement

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Journal of Zhejiang university-Science C(Computers and electronics) 2010年第7期11卷 538-543页

作者： Ponnuthurai-Nagaratnam SUGANTHAN school of electrical and electronic engineering Nanyang Technological University

Multi-objective differential evolution (MODE) is a powerful and efficient population-based stochastic search technique for solving multi-objective optimization problems in many scientific and engineering fields. However, premature convergence is the major drawback of MODE, especially when there are numerous local Pareto optimal solutions. To overcome this problem, we propose a MODE with a diversity enhancement (MODE-DE) mechanism to prevent the algorithm becoming trapped in a locally optimal Pareto front. The proposed algorithm combines the current population with a number of randomly generated parameter vectors to increase the diversity of the differential vectors and thereby the diversity of the newly generated offspring. The performance of the MODE-DE algorithm was evaluated on a set of 19 benchmark problem codes available from http://***/home/epnsugan/. With the proposed method, the performances were either better than or equal to those of the MODE without the diversity enhancement.

关键词： Multi-objective evolutionary algorithm (MOEA) Multi-objective differential evolution (MODE) Diversity enhancement

Biogreen Synthesis of Carbon Dots for Biotechnology and Nanomedicine Applications

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Nano-Micro Letters 2018年第4期10卷 268-313页

作者： Kok Ken Chan Stephanie Hui Kit Yap Ken-Tye Yong school of electrical and electronic engineering Nanyang Technological University

Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties,as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with ***, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers,nitroaromatic explosives, pollutants, vitamins, and ***, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.

关键词： Carbon dots Heavy metal sensing Photoluminescence mechanism Sensing mechanism Sensor design

A multipurpose audio watermarking algorithm with synchronization and encryption

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Journal of Zhejiang university-Science C(Computers and electronics) 2012年第1期13卷 11-19页

作者： Baiying LEI Ing Yann SOON school of electrical and electronic engineering Nanyang Technological University

We propose a new multipurpose audio watermarking scheme in which two complementary watermarks are used. For audio copyright protection, the watermark data with copyright information or signature are first encrypted by Arnold transforma- tion. Then the watermark data are inserted in the low frequency largest significant discrete cosine transform （DCT） coefficients to obtain robustness performance. For audio authentication, a chaotic signal is inserted in the high frequency insignificant DCT coefficients to detect tampered regions. Furthermore, the synchronization code is embedded in the audio statistical characteristics to resist desynchronization attacks. Experimental results show that our proposed method can not only obtain satisfactory detection and tampered location, but also achieve imperceptibility and robustness to common signal processing attacks, such as cropping, shifting, and time scale modification （TSM）. Comparison results show that our method outperforms some existing methods.

关键词： Audio watermarking Copyright protection Content authentication Compound encryption Synchronization

Adaptive failure compensation for uncertain systems with multiple inputs

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Journal of Systems engineering and electronics 2011年第1期22卷 70-76页

作者： Wei Wang Changyun Wen school of electrical and electronic engineering Nanyang Technological University Nanyang Avenue 639798 Singapore

The aim of this paper is to develop controllers for uncertain systems in the presence of stuck type actuator failures.A new scheme is proposed to design output feedback controllers for a class of uncertain systems having redundant control inputs,with which the relative degrees of transfer functions are *** deal with these inputs using backstepping technique,a pre-filter is introduced before each actuator such that its output is the input to the *** orders of the pre-filters are chosen properly to ensure all their inputs can be designed at the same step in the systematic *** compensate for the effects of possible failed actuators,more uncertain parameters than system parameters are required to be *** the proposed scheme,the global boundedness of the closed-loop system can still be ensured and the system output can be regulated to a specific value when some of the actuators＇ outputs are stuck at unknown fixed values.

关键词： adaptive control actuator failure failure compensation pre-filter backstepping.

On Feasible Region of Droop-based Fast Frequency Response Controller Parameters of Wind Turbines

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Journal of Modern Power Systems and Clean Energy 2024年第5期12卷 1690-1695页

作者： Junkai Huang Yan Xu school of electrical and electronic engineering Nanyang Technological University50 Nanyang AvenueSingapore

Droop-based fast frequency response(FFR)control of wind turbines can improve the frequency performance of power systems with high penetration of wind *** formulating the feasible region of the droop-based FFR controller parameters can allow system operators to conveniently assess the feasibility of FFR controller parameter settings to comply with system frequency security,and efficiently tune and optimize FFR controller parameters to meet frequency security ***,the feasible region of FFR controller parameters is inherently nonlinear and implicit because the power point tracking controllers of wind turbine would counteract the effect of FFR *** address this issue,this letter proposes a linear feasible region formulation method,where frequency regulation characteristics of wind turbines,the dead band,and reserve limits of generators are all *** effectiveness of the proposed method and its application is demonstrated on a 10-machine power system.

关键词： Wind turbine fast frequency response feasible region frequency security

Understanding Discrepancy of Power System Dynamic Security Assessment with Unknown Faults: A Reliable Transfer Learning-based Method

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 427-431页

作者： Chao Ren Han Yu Yan Xu Zhao Yang Dong school of Computer Science and engineering Nanyang Technological UniversitySingapore school of electrical and electronic engineering Nanyang Technological UniversitySingapore

This letter proposes a reliable transfer learning(RTL)method for pre-fault dynamic security assessment(DSA)in power systems to improve DSA performance in the presence of potentially related unknown *** takes individual discrepancies into consideration and can handle unknown faults with incomplete *** experiment results demonstrate high DSA accuracy and computational efficiency of the proposed RTL *** analysis shows RTL can guarantee system performance.

关键词： Adversarial training dynamic security assessment maximum classifier discrepancy missing data transfer learning

Characteristics of In_(0.52)Al_(0.48)As Grown on InP(100) Substrates by Molecular Beam Epitaxy: Growth Optimisation and Effects of Si Doping

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Journal of Materials Science & Technology 1997年第2期13卷 91-98页

作者： S.F.Yoon(school of electrical and electronic engineering, nanyang technological university, Nanyng Avenue,Singapore 639798, Rep. of Singapore) school of electrical and electronic engineering Nanyang Technological University Singapore 639798 Nanyang Avenue Singapore

Growth of In0.52Al0.48As epilayers on InP (100) substrates by molecular beam epitaxy at a wide range of substrate tempreatures (470~550℃) and at different Si doping levels has been carried out. Low temperature photoluminescence (PL) and double-axis X-ray diffraction (XRD) analyses shaw a strong dependence of the PL and XRD linewidths, XRD intensity ratio (Lepi/Isub), and lattice-mismatch on the substrate temperature. The X-ray diffraction peaks of samples grown at law temperatures show a composition of smaller peaks, indicating the presence of disorder due to alloy clustering. Raman scattering measurements of the same samples show an additional higher energy mode at 273 cm-1 in addition to the InAs-like and AlAs-like longitudinal-optic (LO) phonon modes. Samples doped with Si show an inverted S-shaped dependence of the PL peak energy variation with the temperature which weakens at high doping levels due to a possible reduction in the donor binding energy. Supported be observations of a reduction in both the AlAs-like and InAs-like LO phonon frequencies and a broadening of the LO phonon line shape as the doping level is increased, the PL intensity also shows in increasing degrees at higher doping levels, a temperature dependence which is characteristic of disordered and amorphous materials.

关键词： As Grown on InP Characteristics of In Growth Optimisation and Effects of Si Doping Substrates by Molecular Beam Epitaxy InP Al Si