A Non-uniform Correction Algorithm Based on Scene Nonlinear Filtering Residual Estimation

Hongfei Song,Kehang Zhang,Wen Tan,Fei Guo,Xinren Zhang,Wenxiao Cao 한국광학회 2023 Current Optics and Photonics Vol.7 No.4

Due to the technological limitations of infrared thermography, infrared focal plane array (IFPA) imaging exhibits stripe non-uniformity, which is typically fixed pattern noise that changes over time and temperature on top of existing non-uniformities. This paper proposes a stripe non-uniformity correction algorithm based on scene-adaptive nonlinear filtering. The algorithm first uses a nonlinear filter to remove single-column non-uniformities and calculates the actual residual with respect to the original image. Then, the current residual is obtained by using the predicted residual from the previous frame and the actual residual. Finally, we adaptively calculate the gain and bias coefficients according to global motion parameters to reduce artifacts. Experimental results show that the proposed algorithm protects image edges to a certain extent, converges fast, has high quality, and effectively removes column stripes and non-uniform random noise compared to other adaptive correction algorithms.

HDWM-based Consensus Control for Multi-agent Systems Under Communication Delays and DoS Attacks

Hongfei Zhu,Jinhai Liu,Shuo Zhang,Zhigang Zhang,Fuming Qu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

This paper develops a novel framework with hybrid-driven waiting mechanism (HDWM) of consensus control for multi-agent systems (MASs) in the presence of communication delays and denial-of-service (DoS) attacks. Different from the existing waiting mechanism, the proposed HDWM not only involves the event-driven mechanism, but also involves the time-driven mechanism. If DoS attacks causes partial information to be lost, the information in the buffer can still be transmitted to the controller to update the states of agent via the time-driven mechanism. Meanwhile, the communication delays and DoS attacks are considered in the proposed sampled-databased resilient controller. Under the proposed HDWM and resilient controller, the MASs can achieve consensus. Finally, the simulation example is conducted to verify the effectiveness of the proposed method.

Comparison of Corticosteroids by 3 Approaches to the Treatment of Chronic Rhinosinusitis With Nasal Polyps

Yunyun Zhang,Hongfei Lou,Yang Wang,Ying Li,Luo Zhang,Chengshuo Wang 대한천식알레르기학회 2019 Allergy, Asthma & Immunology Research Vol.11 No.4

Purpose: Corticosteroids are regarded as the mainstay of medical treatment of eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP). To date, a head-to-head comparison of the efficacy and safety of glucocorticoid preparations administered via different routes for the treatment of chronic rhinosinusitis with nasal polyps has not been reported. To compare the efficacy and safety of steroids administered via the oral, intranasal spray and transnasal nebulization routes in the management of ECRSwNP over a short course. Methods: Overall, 91 patients with ECRSwNP were recruited prospectively and randomized to receive either oral methylprednisolone, budesonide inhalation suspension (BIS) via transnasal nebulization, or budesonide nasal spray (BNS) for 2 weeks. Nasal symptoms and polyp sizes were assessed before and after the treatment. Similarly, nasal polyp samples were evaluated for immunological and tissue remodeling markers. Serum cortisol levels were assessed as a safety outcome. Results: Oral methylprednisolone and BIS decreased symptoms and polyp sizes to a significantly greater extent from baseline (P < 0.05) than BNS. Similarly, BIS and oral methylprednisolone significantly reduced eosinophils, T helper 2 cells, eosinophil cationic protein, interleukin (IL)-5, and expression of matrix metalloproteinases 2 and 9, and significantly increased type 1 regulatory T cells, IL-10, transforming growth factor-β, and tissue inhibitor of metalloproteinases 1 and 2 in nasal polyps to a greater extent than BNS. Post-treatment serum cortisol levels were significantly decreased by oral methylprednisolone compared to BIS or BNS, which did not significantly alter the cortisol levels. Conclusions: A short course of BIS transnasal nebulization is more efficacious compared to BNS in the management of ECRSwNP and is safer than oral methylprednisolone with respect to hypothalamic-pituitary-adrenal axis function.

Study for Improvement of Laser Induced Damage of 1064 nm AR Coatings in Nanosecond Pulse

Hongfei Jiao,Xinbing Cheng,Jiangtao Lu,Ganghua Bao,Jinlong Zhang,Bin Ma,Huasong Liu,Zhanshan Wang 한국광학회 2013 Current Optics and Photonics Vol.17 No.1

For the conventionally polished fused silica substrate, an around 100 nm depth redeposition polishing layer was formed on the top of surface. Polishing compounds, densely embedded in the redeposition polishing layer were the dominant factor that limited the laser induced damage threshold (LIDT) of transmission elements in nanosecond laser systems. Chemical etching, super-precise polishing and ion beam etching were employed in different ways to eliminate these absorbers from the substrate. After that,Antireflection (AR) coatings were deposited on these substrates in the same batch and then tested by 1064nm nano-pulse laser. It was found that among these techniques only the ion beam etching method, which can effectively remove the polishing compound and did not induce extra absorbers during the disposal process, can successfully improve the LIDT of AR coatings.

A New Method to Measure the Conversion of Radiation Polymerization of Electrolyte Monomer Diallyldimethylammonium Chloride in Dilute Aqueous Solution

Zhang, Yalong,Yi, Min,Ren, Jing,Zhai, Maolin,Ha, Hongfei The Polymer Society of Korea 2003 Macromolecular Research Vol.11 No.3

The dependence of electrical conductivity on concentrations of diallyldimethylammonium chloride (DADMAC) monomer, linear poly(DADMAC) and their mixture monomer/poly(DADMAC) in dilute aqueous solution exhibits a linear relationship. It was possible to calculate conversion of DADMAC polymerization by measuring its electric conductivity. Although the electrical conductivity of the poly(DADMAC) solution decreased with increasing its molecular weight, in the process of UV or ionizing radiation polymerization the molecular weight of the polymers could be kept constant in the case of fixed temperature, UV-luminous intensity or dose rate. Based on the method mentioned above, the kinetics of UV induced polymerization of DADMAC in aqueous solution was studied; the overall activation energy of polymerization of DADMAC in the water phase was calculated to be 18.8 kJ mol$^{-1}$ . ${\gamma}$-Radiation-induced polymerization of DADMAC in aqueous solution as a function of absorbed dose was studied as well. The conversion of DADMAC increased quickly with dose before 30 kGy and then increased slowly. The experimental data of both UV- and ${\gamma}$-induced polymerization were verified to be reliable by inverted ultracentrifugation method.

A Novel Dual-Input Boost-Buck Converter with Coupled Inductors for Distributed Thermoelectric Generation Systems

Zhang, Junjun,Wu, Hongfei,Sun, Kai,Xing, Yan,Cao, Feng The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

Cloning, Expression, and Characterization of a Cold-Active and Organic Solvent-Tolerant Lipase from Aeromicrobium sp. SCSIO 25071

( Hongfei Su ),( Zhimao Mai ),( Jian Yang ),( Yunzhu Xiao ),( Xinpeng Tian ),( Si Zhang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30°C and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0°C and good stability at temperatures below 35°C. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30°C. Its activity was slightly affected by some metal ions such as K(+), Ca(2+), and Na(+). The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.

A New Method to Measure the Conversion of Radiation Polymerization of Electrolyte Monomer Diallyldimethylammonium Chloride in Dilute Aqueous Solution

Yalong Zhang,Min Yi,Jing Ren,Maolin Zhai,Hongfei Ha 한국고분자학회 2003 Macromolecular Research Vol.11 No.3

A Novel Dual-Input Boost-Buck Converter with Coupled Inductors for Distributed Thermoelectric Generation Systems

Junjun Zhang,Hongfei Wu,Kai Sun,Yan Xing,Feng Cao 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

A high sensitivity strategy of nitrite detection based on CoFe@NC nanocubes modified glassy carbon electrode

Yanjiao Zou,Hongfei Gu,Jingjing Yang,Ting Zeng,Juan Yang,Yuanyuan Zhang 한국탄소학회 2023 Carbon Letters Vol.33 No.7

In the present study, an innovative electrochemical sensing platform was established for sensitive detection of NO2 —. This sensor was developed using CoFe alloy encapsulated in nitrogen-doped carbon nanocubes (named as CoFe@NC-NCS), synthesized through the calcination of polydopamine-coated CoFe Prussian-blue analogues (CoFe-PBA@PDA). The morphological and electrochemical characterization reveals that the CoFe@NC-NCS possesses high electrocatalytic activity for electrochemical quantitation of NO2 —, ascribed to the huge surface area and plentiful active positions, benefiting from the porous, hollow, and core–shell structure of CoFe@NC-NCS. Under the optimal conditions, CoFe@NC-NCS/GCE possessed remarkable sensing performance for NO2 — with wide liner ranges and a detection limit of 0.015 μM. NO2 — recovery experiments in real samples exhibited recoveries in the range of 98.8–103.5%. Hence, the CoFe@NC-NCS shows great promise for the construction of electrochemical sensor with more potential application.