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Source Camera Identification with Imbalanced Training Dataset
Yonggang Huang,Jun Zhang,Xinkai Lan 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.2
In this paper, we address the problem of unbalanced training dataset for source camera identification, namely, there are fewer training examples for some camera models compared to other camera models. A new source camera identification approach is proposed to alleviate the influence of imbalanced training dataset. In the proposed approach, firstly, we treat source camera identification as a multi-class classification problem, and decompose it into binary classification problems. After decomposing, the problem of imbalanced training dataset for multiclass classification is transformed to the problem of imbalanced training dataset for binary classification. Then, we incorporate SMOTE and AdaBoost algorithms to construct SVM ensemble to address the issue of imbalanced training dataset for binary classification. A number of experiments show the proposed approach can deal with the imbalanced training dataset effectively.
Dirac semimetal-enabled multi-bit coding metasurface for dynamic manipulation of terahertz beams
Zhang Yonggang,Yin Kehao,Liang Lanju,Yao Haiyun,Yan Xin,Hu Xiaofei,Huang Chengcheng,Qiu Fu,Zhang Rui,Li Yuanping,Wang Yaru,Li Zhenhua,Wang Ziqun 한국물리학회 2024 Current Applied Physics Vol.58 No.-
In this study, a switchable multi-bit coding metasurface that is applied under a terahertz (THz) frequency by adjusting the Fermi level (EF) of Dirac semimetals (DSMs) is proposed. At a EF of 0.2 eV, a 1-bit coding metasurface can be applied in the 2.58–2.62 THz. At 0.3 eV, a 3-bit coding metasurface is realized at 1.88 THz, and at 0.05 eV, the phase of the coding units coincides in the 1.5–3 THz. So, different functions of the metasurface can be realized. The proposed coding metasurfaces has promising applications in terahertz communication.
Guodong Zhao,Yonggang Liu,Kening Zhai,Fengyang Jiang,Qi Huang,Zheng Chen 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7
Vehicle launching has an important influence on driving performance of the vehicle. For vehicles with dual clutch transmissions (DCT), the clutch torque control is the key to the launching control. Therefore, a data-driven control method for DCT launching process based on adaptive neural fuzzy inference system (ANFIS) is proposed. Firstly, the vehicle test data during launching process is collected and the optimal clutch torque is obtained based on multi-objective particle swarm optimization (MOPSO). Afterward, to learn the launching control rules from optimization results, the combination of neural network and fuzzy logic algorithm, referred to as an ANFIS, is established. The dataset of the optimized launching clutch torque is utilized to train the ANFIS controller. Finally, the simulation and test results show that the datadriven control can accurately learn the launching control rules from the optimality, thereby achieving the optimal control for different launching intentions.
Zhihang Chen,Yonggang Liu,Jingchen Zhang,Qi Huang,Zheng Chen 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.4
To overcome the difficulty of real-time optimization during shifting process for dual clutch transmission, a clutch optimal torque prediction method based on Support Vector Regression is proposed. Firstly, a shifting dynamic model of dual clutch transmission system is established. Afterwards, the maximum jerk, friction work and shifting time are weighted and summed as an objective function for the optimization problem, weighting factors of which are determined by driving intention. Meanwhile, the clutch torque is formulated by a Fourier series, coefficients of which during shifting process are optimized by Genetic Algorithm. Subsequently, the data-driven controller is trained by Support Vector Regression to predict the optimal clutch torque in real time during shifting process. Finally, the prediction accuracy of the Support Vector Regression method is verified by simulation and experiment. The results show that the Support Vector Regression algorithm has high accuracy in predicting the optimal clutch torque during shifting process. Consequently, the online optimal control can be realized with the assistance of the optimal torque prediction.
CONTINUUM MODELING OF INTERFACES IN POLYMER MATRIX COMPOSITES REINFORCED BY CARBON NANOTUBES
HONGLAI TAN,LIYING JIANG,JIAN WU,YONGGANG HUANG,KEH-CHIH HWANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2007 NANO Vol.2 No.3
The interface behavior may significantly influence the mechanical properties of carbon nanotube (CNT)-reinforced composites due to the large interface area per unit volume at the composite. The modeling of CNT/polymer interfaces has been a challenge in the continuum modeling of CNT-reinforced composites. This paper presents a review of recent progress to model the CNT/matrix interfaces via a cohesive law established from the van der Waals force. A simple, analytical cohesive law is obtained from the inter-atomic potential, and is used to study the effect of CNT/matrix interfaces on the macroscopic properties of CNT-reinforced composites.
Materials for stretchable electronics in bioinspired and biointegrated devices
Kim, Dae-Hyeong,Lu, Nanshu,Huang, Yonggang,Rogers, John A. Cambridge University Press (Materials Research Soc 2012 MRS bulletin Vol.37 No.3
<▼1><B>Abstract</B><P/></▼1><▼2><P>Inorganic semiconductors such as silicon, gallium arsenide, and gallium nitride provide, by far, the most well-established routes to high performance electronics/optoelectronics. Although these materials are intrinsically rigid and brittle, when exploited in strategic geometrical designs guided by mechanics modeling, they can be combined with elastomeric supports to yield integrated devices that offer linear elastic responses to large strain (∼100%) deformations. The result is an electronics/optoelectronics technology that offers the performance of conventional wafer-based systems, but with the mechanics of a rubberband. This article summarizes the key enabling concepts in materials, mechanics, and assembly and illustrates them through representative applications, ranging from electronic “eyeball” cameras to advanced surgical devices and “epidermal” electronic monitoring systems.</P></▼2>
Xia, Fan,Kim, Seong Been,Cheng, Huanyu,Lee, Jung Min,Song, Taeseup,Huang, Yonggang,Rogers, John A.,Paik, Ungyu,Park, Won Il American Chemical Society 2013 NANO LETTERS Vol.13 No.7
<P>We propose a facile method for synthesizing a novel Si membrane structure with good mechanical strength and three-dimensional (3D) configuration that is capable of accommodating the large volume changes associated with lithiation in lithium ion battery applications. The membrane electrodes demonstrated a reversible charge capacity as high as 2414 mAh/g after 100 cycles at current density of 0.1 C, maintaining 82.3% of the initial charge capacity. Moreover, the membrane electrodes showed superiority in function at high current density, indicating a charge capacity >1220 mAh/g even at 8 C. The high performance of the Si membrane anode is assigned to their characteristic 3D features, which is further supported by mechanical simulation that revealed the evolution of strain distribution in the membrane during lithiation reaction. This study could provide a model system for rational and precise design of the structure and dimensions of Si membrane structures for use in high-performance lithium ion batteries.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2013/nalefd.2013.13.issue-7/nl401629q/production/images/medium/nl-2013-01629q_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl401629q'>ACS Electronic Supporting Info</A></P>
Song, Enming,Li, Rui,Jin, Xin,Du, Haina,Huang, Yuming,Zhang, Jize,Xia, Yu,Fang, Hui,Lee, Yoon Kyeung,Yu, Ki Jun,Chang, Jan-Kai,Mei, Yongfeng,Alam, Muhammad A.,Huang, Yonggang,Rogers, John A. American Chemical Society 2018 ACS NANO Vol.12 No.10
<P>Biomedical implants that incorporate active electronics and offer the ability to operate in a safe, stable fashion for long periods of time must incorporate defect-free layers as barriers to biofluid penetration. This paper reports an engineered material approach to this challenge that combines ultrathin, physically transferred films of silicon dioxide (t-SiO<SUB>2</SUB>) thermally grown on silicon wafers, with layers of hafnium oxide (HfO<SUB>2</SUB>) formed by atomic layer deposition and coatings of parylene (Parylene C) created by chemical vapor deposition, as a dual-sided encapsulation structure for flexible bioelectronic systems. Accelerated aging tests on passive/active components in platforms that incorporate active, silicon-based transistors suggest that this trilayer construct can serve as a robust, long-lived, defect-free barrier to phosphate-buffered saline (PBS) solution at a physiological pH of 7.4. Reactive diffusion modeling and systematic immersion experiments highlight fundamental aspects of water diffusion and hydrolysis behaviors, with results that suggest lifetimes of many decades at physiological conditions. A combination of ion-diffusion tests under continuous electrical bias, measurements of elemental concentration profiles, and temperature-dependent simulations reveals that this encapsulation strategy can also block transport of ions that would otherwise degrade the performance of the underlying electronics. These findings suggest broad utility of this trilayer assembly as a reliable encapsulation strategy for the most demanding applications in chronic biomedical implants and high-performance flexible bioelectronic systems.</P> [FIG OMISSION]</BR>