JPNIC IDN-TF Status and Implementations

Hongbo Shi 정보통신정책연구원 2000 세미나및공청회 Vol.2000 No.

Re-SSS: Rebalancing Imbalanced Data Using Safe Sample Screening

( Hongbo Shi ),( Xin Chen ),( Min Guo ) 한국정보처리학회 2021 Journal of information processing systems Vol.17 No.1

Different samples can have different effects on learning support vector machine (SVM) classifiers. To rebalance an imbalanced dataset, it is reasonable to reduce non-informative samples and add informative samples for learning classifiers. Safe sample screening can identify a part of non-informative samples and retain informative samples. This study developed a resampling algorithm for Rebalancing imbalanced data using Safe Sample Screening (Re-SSS), which is composed of selecting Informative Samples (Re-SSS-IS) and rebalancing via a Weighted SMOTE (Re-SSS-WSMOTE). The Re-SSS-IS selects informative samples from the majority class, and determines a suitable regularization parameter for SVM, while the Re-SSS-WSMOTE generates informative minority samples. Both Re-SSS-IS and Re-SSS-WSMOTE are based on safe sampling screening. The experimental results show that Re-SSS can effectively improve the classification performance of imbalanced classification problems.

Analysis of MHz 380V-12V DCX with low FoM device

Hongbo Shi,Xinke Wu,Mingchao Xia 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

1MHz isolated high efficiency high power density DC/DC converter is critical for future industrial applications. The GaN devices have a better performance for such high frequency than silicon device of high breakdown voltage due to their much lower parasitic capacitance. The modeling of the primary switches conduction losses is built in this paper. Based on the model the relation between the NFoM (Rdson⋅Cotr) of primary devices and conduction loss is revealed, thus the lower voltage devices with lower FoM is adopted to implemented the experimental verification. Since the equivalent NFoM is independent of the device count of series connection and is decided by single device, an inputseries output-parallel structure prototype with multiple SRC DCX cells is implemented with low voltage MOSFETs. The 380V-12Vprototype achieves a peak efficiency of 98.3% and a power density of 810W/inch3 with multiple 60V MOSFETs.

Design and Development of a Single-photon Laser and Infrared Common Aperture Optical System

Wu Hongbo,Zhang Xin,Tan Shuanglong,Liu Mingxin,Wang Lingjie,Yan Lei,Liu Yang,Shi Guangwei 한국광학회 2022 Current Optics and Photonics Vol.6 No.2

A single-photon laser and mid-wave infrared (MWIR) common aperture optical system was designed and developed to detect and range a long-distance civil aviation aircraft. The secondary mirror of the Ritchey-Chretien (R-C) optical system was chosen as a dichroic lens to realize the design of a common aperture system for the laser and MWIR. Point spread function (PSF) ellipticity was introduced to evaluate the coupling efficiency of the laser receiving system. A small aperture stop and narrow filter were set in the secondary image plane and an afocal light path of the laser system, respectively, and the stray light suppression ability of the small aperture stop was verified by modeling and simulation. With high-precision manufacturing technology by single point diamond turning (SPDT) and a high-efficiency dichroic coating, the laser/MWIR common aperture optical system with a φ300 mm aluminum alloy mirror obtained images of buildings at a distance of 5 km with great quality. A civil aviation aircraft detection experiment was conducted. The results show that the common aperture system could detect and track long-distance civil aviation aircraft effectively, and the coverage was more than 450 km (signal-tonoise ratio = 6.3). It satisfied the application requirements for earlier warning and ranging of long-range targets in the area of aviation, aerospace and ground detection systems.

Distributed Estimation Based on LQG Control over Homogeneous Sensor Networks

Wen Yang,Hongbo Shi 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.6

Motivated by navigation and tracking applications within sensor networks, we consider the distributed estimation problem over wireless sensor network. We propose a consensus based Kalman filtering algorithm based on optimal Linear Quadratic Gaussian control, in which each sensor can observe the dynamical system state, process the information data individually and communicate with each other within a sensing range. We provide a sufficient condition for the convergence of the proposed algorithm, and also give an upper bound for the estimation error covariance. Further, we find an optimal consensus gain for minimizing the network estimation error. Considering the occasional sensor fault and limited sensor energy, we investigate the proposed algorithm using only a subset of sensors to observe the dynamical system. With the assistance of the simulations, we verify the effectiveness of the proposed algorithms and present some interesting examples.

Optimal Harvest-Use-Store Design for Delay-Constrained Energy Harvesting Wireless Communications

Fangchao Yuan,Shi Jin,Kai-Kit Wong,Q. T. Zhang,Hongbo Zhu 한국통신학회 2016 Journal of communications and networks Vol.18 No.6

Recent advances in energy harvesting (EH) technologyhave motivated the adoption of rechargeable mobile devicesfor communications. In this paper, we consider a point-to-point(P2P) wireless communication system in which an EH transmitterwith a non-ideal rechargeable battery is required to send agiven fixed number of bits to the receiver before they expire accordingto a preset delay constraint. Due to the possible energy lossin the storage process, the harvest-use-and-store (HUS) architectureis adopted. We characterize the properties of the optimal solutions,for additive white Gaussian channels (AWGNs) and thenblock-fading channels, that maximize the energy efficiency (i.e.,battery residual) subject to a given rate requirement. Interestingly,it is shown that the optimal solution has a water-filling interpretationwith double thresholds and that both thresholds are monotonic. Based on this, we investigate the optimal double-thresholdbased allocation policy and devise an algorithm to achieve thesolution. Numerical results are provided to validate the theoreticalanalysis and to compare the optimal solutions with existing schemes.

A New Robust Technique for Constructing Intelligent Environment using Video Image

Someya, Naoki,Shi, Hongbo,Hamagami, Tomoki The Korean Institute of Electrical Engineers 2013 The Journal of International Council on Electrical Vol.3 No.2

A new robust technique for constructing intelligent environment with video image for mobile robots is proposed. The state of the art of the technique is an approach using autonomous extraction of feature from video images which captured in daily activities. Intelligent space embedded several sensors for supporting human activities are expected to expand future information infrastructure. However, in terms of practically, the robustness and computational cost are significant issues. In order to extract the feature robustly and to resolve an issue of tradeoff between accuracy and computational cost, support vector machine (SVM) is implemented for the classification and detection. Experiments in real world are conducted to evaluate the algorithm. The results show that the technique enables to detect image tag for constructing intelligent space.

Optimal Harvest-Use-Store Design for Delay-Constrained Energy Harvesting Wireless Communications

Yuan, Fangchao,Jin, Shi,Wong, Kai-Kit,Zhang, Q.T.,Zhu, Hongbo The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.6

Recent advances in energy harvesting (EH) technology have motivated the adoption of rechargeable mobile devices for communications. In this paper, we consider a point-to-point (P2P) wireless communication system in which an EH transmitter with a non-ideal rechargeable battery is required to send a given fixed number of bits to the receiver before they expire according to a preset delay constraint. Due to the possible energy loss in the storage process, the harvest-use-and-store (HUS) architecture is adopted. We characterize the properties of the optimal solutions, for additive white Gaussian channels (AWGNs) and then block-fading channels, that maximize the energy efficiency (i.e., battery residual) subject to a given rate requirement. Interestingly, it is shown that the optimal solution has a water-filling interpretation with double thresholds and that both thresholds are monotonic. Based on this, we investigate the optimal double-threshold based allocation policy and devise an algorithm to achieve the solution. Numerical results are provided to validate the theoretical analysis and to compare the optimal solutions with existing schemes.

Rolling Bearing Incipient Fault Detection via Optimized VMD Using Mode Mutual Information

Shuai Tan,Aimin Wang,Hongbo Shi,Lei Guo 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.4

The complete failure of the rolling bearing is a deterioration process from the incipient weak fault to the severe fault, thus it is important to alarm when the incipient fault appear. This work presents a novel incipient bearing fault diagnosis framework using mode mutual information (MMI) based fitness function, variational mode decomposition (VMD), and cuckoo search (CS) algorithm. MMI based fitness function is proposed in order to obtain the optimal combinations of the VMD parameters. Therefore, the optimal parameters of VMD can be obtained by CS algorithm using proposed fitness function. Afterwards, a vibration signal is decomposed into a set of modes using the optimal VMD, and the kurtosis value of all modes are calculated. The envelop of the mode with maximum kurtosis value between modes and raw signal is computed as the input vector of the stacked denoised autoencoder (SDAE). Comparisons have been conducted via SDAE to evaluate the performance by using EMD and the fixedparameter VMD. The experimental results demonstrate that the proposed method is more effective in extracting the incipient bearing fault characteristics.

Effects of Forage Sources on Rumen Fermentation Characteristics, Performance, and Microbial Protein Synthesis in Midlactation Cows

Xua, Jun,Houa, Yujie,Yang, Hongbo,Shi, Renhuang,Wu, Caixia,Huo, Yongjiu,Zhao, Guoqi Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.5

Eight multiparous Holstein cows ($632{\pm}12$ kg BW; $135{\pm}16$ DIM) were used in a replicated $4{\times}4$ Latin square design to evaluate the effects of forage sources on rumen fermentation characteristics, performance, and microbial protein (MCP) synthesis. The forage portion of the diets contained alfalfa hay (AH), oat hay (OH), Leymus chinensis (LC), or rice straw (RS) as the primary source of fiber. Diets were isonitrogenous and isocaloric, and cows were fed four corn silages based total mixed rations with equivalent nonfiber carbohydrate (NFC) and forage neutral detergent fiber (NDF). Dry matter intake was not affected by the source of dietary forages, ranging from 18.83 to 19.20 kg/d, consequently, milk yield was similar among diets. Because of the numerical differences in milk fat and milk protein concentrations, 4% FCM and ECM yields were unchanged (p>0.05). Mean rumen pH, NH3-N content, and concentrations of volatile fatty acids in the rumen fluid were not affected by the treatments (p>0.05). Dietary treatments did not affect the total tract apparent digestibility of dry matter, organic matter, and crude protein (p>0.05); however, digestibility of NDF and acid detergent fiber in RS diet was higher compared with AH, OH, and LC diets (p<0.05). Total purine derivative excretion was higher in cows fed AH, OH, and LC diets compared with those fed RS diet (p<0.05), consequently, estimated MCP synthesis was 124.35 g/d higher in cows fed AH diet compared with those fed RS diet (p<0.05). The results indicated that cows fed AH, OH, LC, and RS diets with an equivalent forage NDF and NFC have no unfavourable effect on the ruminal fermentation and productive parameters.