Hand-eye Calibration of Dual Mechanical Arms of Explosive Ordnance Disposal Robot

Jianfeng Jiang,Xiao Luo,Qingsheng Luo,Lijun Qiao,Yuhan Chen 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.7

The explosive ordnance disposal (EOD) robot works in a special environment, which requires dual robotic arms to work together for removing the bomb. Therefore, the coordinate calibration accuracy is the prerequisite for realizing the coordinated movement and visual positioning of the dual robotic arms. A basic problem encountered in the collaborative work of the dual robotic arms system is to determine the homogeneous transformation matrix of the frame, including: hand-eye, base-base, and gripper-camera. We formulate the hand-eye calibration problem of the dual robotic arm as the matrix equation AXB = YCZD. 1) An improved closed solution for singlerobotic arm hand-eye calibration is proposed. This closed solution of the single-robotic arm is used to quickly obtain the initial estimate of the iterative method to improve the efficiency and accuracy of the iteration. 2) The iterative solution of dual robotic arms hand-eye calibration based on the rotation vector is proposed. 3) In addition, a motion trajectory plan of the mechanical gripper is proposed to guide the operator to select the appropriate robot posture during the calibration process. In order to show the feasibility and superiority of the proposed method, a real EOD robot experiment is carried out. The comparison results from experiments show that the proposed simultaneous calibration method has higher accuracy and efficiency.

Energy-Efficient Power Control for Underlaying D2D Communication with Channel Uncertainty: User-Centric Versus Network-Centric

Jianfeng Ding,Lingge Jiang,Chen He 한국통신학회 2016 Journal of communications and networks Vol.18 No.4

Most existing resource management problem modelsarise from the original desire of allocating resources in either auser-centric or network-centric manner. The difference betweentheir objectives is obvious: user-centric methods attempt to optimizethe utility of individual users, whereas network-centric modelsintend to optimize the collective utilities of the entire network. In this paper, from the above two aspects, we analyze the robustpower control problem in device-to-device (D2D) communicationunderlaying cellular networks, where two types of channel uncertaintyset (e.g., ellipsoidal and column-wise) are considered. In theuser-centric method, we formulate the problem into the form of aStackelberg game, where the energy efficiency (EE) of each useris the ingredient of utility function. In order to protect the cellularuser equipment’s (CUE) uplink transmission, we introduce aprice based cost function into the objectives of D2D user equipment(DUE). The existence and uniqueness of the game with theinfluence of channel uncertainty and price are discussed. In thenetwork-centric method, we aim to maximize the collective EE ofCUEs and DUEs. We show that by the appropriate mathematicaltransformation, the network-centric D2D power control problemhas the identical local solution to that of a special case of the usercentricproblem, where price plays a key role. Numerical resultsshow the performance of the robust power control algorithms inthe user-centric and network-centric models.

Pd nanoparticles immobilized on TiO2 nanotubes-functionalized ceramic membranes for flow-through catalysis

Jianfeng Miao,Xiaoyue Liu,Hong Jiang,Yefei Liu,Rizhi Chen 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.3

A high performance catalytic membrane was fabricated with Pd nanoparticles supported by TiO2 nanotubes, where the TiO2 nanotubes were synthesized on the ceramic membrane via a simple hydrothermal etching. A flow-through catalytic membrane reactor was developed for testing the catalytic properties in the p-nitrophenol reduction. The effect of etching time was investigated in detail and an optimal etching time was determined to be 16 h. The characterization results highlighted that the as-prepared bouquet-like TiO2 nanotubes could significantly improve the loading amount and dispersity of Pd nanoparticles. The fabricated catalytic membrane exhibited considerably improved catalytic activity and stability, with a 100% conversion of p-nitrophenol and no loss in catalytic activity during five reaction cycles. The obtained activation energy was much lower than the values in literatures, implying that the p-nitrophenol reduction could take place more easily on our catalytic membranes compared to other catalysts.

Molecular and Cellular Microbiology / Biomedical Sciences : Isorhamnetin Attenuates Staphylococcus aureus-Induced Lung Cell Injury by Inhibiting Alpha-Hemolysin Expression

( Lanxiang Jiang ),( Hongen Li ),( Laiying Wang ),( Zexin Song ),( Lei Shi ),( Wenhua Li ),( Xuming Deng ),( Jianfeng Wang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.3

Staphylococcus aureus, like other gram-positive pathogens, has evolved a large repertoire of virulence factors as a powerful weapon to subvert the host immune system, among which alpha-hemolysin (Hla), a secreted pore-forming cytotoxin, plays a preeminent role. We observed a concentration-dependent reduction in Hla production by S. aureus in the presence of sub-inhibitory concentrations of isorhamnetin, a flavonoid from the fruits of Hippophae rhamnoides L., which has little antibacterial activity. We further evaluate the effect of isorhamnetin on the transcription of the Hla-encoding gene hla and RNAIII, an effector molecule in the agr system. Isorhamnetin significantly down-regulated RNAIII expression and subsequently inhibited hla transcription. In a co-culture of S. aureus and lung cells, topical isorhamnetin treatment protected against S. aureus-induced cell injury. Isorhamnetin may represent a leading compound for the development of anti-virulence drugs against S. aureus infections.

An investigation of the mechanical property and thermal shock behavior of machinable B₄C/BN ceramic composites

Tao Jiang,Haiyun Jin,Zhihao Jin,Jianfeng Yang,Guanjun Qiao 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.1

Machinable B₄C/BN ceramic composites were fabricated by a hot-pressing process at 1,850 ℃ for 1 h under a pressure of 30MPa. In this article, the mechanical property, thermal shock behavior and machinability of the B₄C/BN ceramic composites were investigated. The fracture strength and fracture toughness of B₄C/BN nanocomposites were significantly improved in comparison with B₄C/BN microcomposites. The Vickers hardness of B₄C/BN nanocomposites and B₄C/BN microcomposites decreased gradually with an increase in the content of h-BN, while the machinability of B₄C/BN nanocomposites and B₄C/BN microcomposites were significantly improved. The B₄C/BN ceramic composites with an h-BN content of more than 20 wt% exhibited excellent machinability. The thermal shock resistance of the B₄C/BN ceramic composites was much better than that of the B₄C monolith, and the thermal shock resistance of B₄C/BN nanocomposites was much better than that of B₄C/BN microcomposites. The thermal shock temperature difference (ΔTc) of the B₄C monolith was about 300℃, while the ΔTc of B₄C/BN microcomposites was about 500℃ and the ΔTc of B₄C/BN nanocomposites was about 600℃. Machinable B₄C/BN ceramic composites were fabricated by a hot-pressing process at 1,850 ℃ for 1 h under a pressure of 30MPa. In this article, the mechanical property, thermal shock behavior and machinability of the B₄C/BN ceramic composites were investigated. The fracture strength and fracture toughness of B₄C/BN nanocomposites were significantly improved in comparison with B₄C/BN microcomposites. The Vickers hardness of B₄C/BN nanocomposites and B₄C/BN microcomposites decreased gradually with an increase in the content of h-BN, while the machinability of B₄C/BN nanocomposites and B₄C/BN microcomposites were significantly improved. The B₄C/BN ceramic composites with an h-BN content of more than 20 wt% exhibited excellent machinability. The thermal shock resistance of the B₄C/BN ceramic composites was much better than that of the B₄C monolith, and the thermal shock resistance of B₄C/BN nanocomposites was much better than that of B₄C/BN microcomposites. The thermal shock temperature difference (ΔTc) of the B₄C monolith was about 300℃, while the ΔTc of B₄C/BN microcomposites was about 500℃ and the ΔTc of B₄C/BN nanocomposites was about 600℃.

Energy-Efficient Power Control for Underlaying D2D Communication with Channel Uncertainty: User-Centric Versus Network-Centric

Ding, Jianfeng,Jiang, Lingge,He, Chen The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.4

Most existing resource management problem models arise from the original desire of allocating resources in either a user-centric or network-centric manner. The difference between their objectives is obvious: user-centric methods attempt to optimize the utility of individual users, whereas network-centric models intend to optimize the collective utilities of the entire network. In this paper, from the above two aspects, we analyze the robust power control problem in device-to-device (D2D) communication underlaying cellular networks, where two types of channel uncertainty set (e.g., ellipsoidal and column-wise) are considered. In the user-centric method, we formulate the problem into the form of a Stackelberg game, where the energy efficiency (EE) of each user is the ingredient of utility function. In order to protect the cellular user equipment's (CUE) uplink transmission, we introduce a price based cost function into the objectives of D2D user equipment (DUE). The existence and uniqueness of the game with the influence of channel uncertainty and price are discussed. In the network-centric method, we aim to maximize the collective EE of CUEs and DUEs. We show that by the appropriate mathematical transformation, the network-centric D2D power control problem has the identical local solution to that of a special case of the user-centric problem, where price plays a key role. Numerical results show the performance of the robust power control algorithms in the user-centric and network-centric models.

Experimental research on preparation and machining performance of porous electrode in electrical discharge machining

Yi Jiang,Linglei Kong,Jianfeng Yu,Chunjian Hua,Wansheng Zhao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.12

The present describes a porous electrode for electrical discharge machining (EDM) that can decrease the concentration of corrosion products in the discharge gap. The electrode is prepared by high-temperature sintering of copper particles. A large number of red copper particles become connected together through sintering necks to form a structure with a large number of pores that act as flushing channels. By exploring the preparation method, material, sintering temperature, and holding time, a porous electrode is prepared such that copper particles do not fall off during the discharge process. The flow of the flushing medium is simulated in the porous electrode, and the action of the flushing flow field in the discharge gap on erosion products is identified. In agreement with the simulation results, experimental results for the EDM of the titanium alloy Ti6Al4V show that the material removal rate with a porous electrode is 3 times higher than that for traditional EDM with a solid electrode. Moreover, the electrode wear is lower due to the effective discharge of the corrosion products by the flushing liquid. Experimental results when rough machining a complex semi-closed cavity show that the porous electrode can greatly shorten the machining time by 47 %, which demonstrates that a porous electrode improves the machining of a complex cavity in a titanium alloy.

A Molybdenum Disulfide Additive for the Simple and Sensitive Electrochemical Detection of DNA

Yiran Li,Jianfeng Li,Huaide Jiang,이은철 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.10

A simple but sensitive system for the detection of DNA using molybdenum disulfide (MoS2) as an additive to the DNA solution is reported. According to the described method, the target DNA can be identified by differential pulse voltammetry (DPV) because single- and double-stranded DNA molecules have different affinities to both the electrochemical indicator used (methylene blue) and MoS2. The MoS2 additive does not require any functionalization to achieve adequate sinking speed, contrary to graphene- and carbon nanotube-based additives. The easy fabrication of the sensitive DNA sensor developed in this study is achieved by simply adding the MoS2 additive into the DNA sample solutions, and does not require any sophisticated processes, such as probe immobilization and chemical modification. The results described in this study pave the way for utilizing semiconducting or insulating two-dimensional materials as additives for simple electrochemical DNA sensors with a great potential for commercial mass production.

LCT: A Lightweight Cross-domain Trust Model for the Mobile Distributed Environment

( Zhiquan Liu ),( Jianfeng Ma ),( Zhongyuan Jiang ),( Yinbin Miao ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.2

In the mobile distributed environment, an entity may move across domains with great frequency. How to utilize the trust information in the previous domains and quickly establish trust relationships with others in the current domain remains a challenging issue. The classic trust models do not support cross-domain and the existing cross-domain trust models are not in a fully distributed way. This paper improves the outstanding Certified Reputation (CR) model and proposes a Lightweight Cross-domain Trust (LCT) model for the mobile distributed environment in a fully distributed way. The trust certifications, in which the trust ratings contain various trust aspects with different interest preference weights, are collected and provided by the trustees. Furthermore, three factors are comprehensively considered to ease the issue of collusion attacks and make the trust certifications more accurate. Finally, a cross-domain scenario is deployed and implemented, and the comprehensive experiments and analysis are conducted. The results demonstrate that our LCT model obviously outperforms the Bayesian Network (BN) model and the CR model in our cross-domain scenario, and significantly improves the successful interaction rates of the honest entities without increasing the risks of interacting with the malicious entities.

Cryptanalysis of a Biometric-based Multi-Server Authentication Scheme

Tao Wan,Nan Jiang,Jianfeng Ma,Lin Yang 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.2

Authentication and key agreement protocol becomes an important security issue for multi-server architecture. Combining biometrics with password enhances the level of security. Recently, Baruah et al. analyzed that Mishra et al.’s protocol has several drawbacks and proposed an improved biometric based multi-server authentication scheme. They claimed that their scheme satisfies all the required security attributes for a secure authentication. In this paper, we indicate that their scheme is not secure against key reveal attack, replay attack, and smart card forgery attack. Any registered user can retrieve the session key or launch the replay attack by eavesdropping on the communication channel. In addition, registered user can forge smart card when colluding with registered server.