Radionuclide identification method for NaI low-count gamma-ray spectra using artificial neural network

Sheng Qi,Shanqiang Wang,Ye Chen,Kun Zhang,Xianyun Ai,Jinglun Li,Haijun Fan,Hui Zhao 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

An artificial neural network (ANN) that identifies radionuclides from low-count gamma spectra of a NaIscintillator is proposed. The ANN was trained and tested using simulated spectra. 14 target nuclides wereconsidered corresponding to the requisite radionuclide library of a radionuclide identification devicementioned in IEC 62327-2017. The network shows an average identification accuracy of 98.63% on thevalidation dataset, with the gross counts in each spectrum Nc ¼ 100~10000 and the signal to noise ratioSNR ¼ 0.05e1. Most of the false predictions come from nuclides with low branching ratio and/or similardecay energies. If the Nc>1000 and SNR>0.3, which is defined as the minimum identifiable condition, theaveraged identification accuracy is 99.87%. Even when the source and the detector are covered with leadbricks and the response function of the detector thus varies, the ANN which was trained using nonshieldingspectra still shows high accuracy as long as the minimum identifiable condition is satisfied. Among all the considered nuclides, only the identification accuracy of 235U is seriously affected by theshielding. Identification of other nuclides shows high accuracy even the shielding condition is changed,which indicates that the ANN has good generalization performance.

Proportionally fair load balancing with statistical quality of service provisioning for aerial base stations

Shengqi Jiang,Ying Loong Lee,Mau Luen Tham,Donghong Qin,Yoong Choon Chang,Allyson Gek Hong Sim 한국전자통신연구원 2023 ETRI Journal Vol.45 No.5

Aerial base stations (ABSs) seem promising to enhance the coverage and capacity of fifth-generation and upcoming networks. With the flexible mobility of ABSs, they can be positioned in air to maximize the number of users served with a guaranteed quality of service (QoS). However, ABSs may be overloaded or underutilized given inefficient placement, and user association has not been well addressed. Hence, we propose a three-dimensional ABS placement scheme with a delay-QoS-driven user association to balance loading among ABSs. First, a load balancing utility function is designed based on proportional fairness. Then, an optimization problem for joint ABS placement and user association is formulated to maximize the utility function subject to statistical delay QoS requirements and ABS collision avoidance constraints. To solve this problem, we introduce an efficient modified gray wolf optimizer for ABS placement with a greedy user association strategy. Simulation results demonstrate that the proposed scheme outperforms baselines in terms of load balancing and delay QoS provisioning.

中國企業對外直接投資實證研究

周升起(Zhou Shengqi) 전남대학교 글로벌디아스포라연구소 2008 전남대학교 세계한상문화연구단 국제학술회의 Vol.2008 No.5

SsPsaH, a H subunit of the photosystem I reaction center of Suaeda salsa, confers the capacity of osmotic adjustment in tobacco

Xiaoyan Hao,Jianping Li,Shengqi Gao,Zumuremu Tuerxun,Xiaochun Chang,Wenran Hu,Guo Chen,Quansheng Huang 한국유전학회 2020 Genes & Genomics Vol.42 No.12

Background: Abiotic stress effects agricultural production, so research on improving stress tolerance of crop is important. Suaeda salsa is a halophyte with high salt and drought tolerance and ability to desalinate saline soil and improve soil quality. Objective: To discover and utilize of salt and drought tolerance-related genes, we further investigated the mechanisms of salt and drought tolerance. Methods: Through screening a salt treated Suaeda salsa cDNA library and further cloning a H subunit of the photosystem I reaction center SsPsaH cDNA, and then the protein domain and phylogenetic analyses of PSI genes was conducted with the NCBI Blast, DNAMAN, and MotifScan programs. The S. salsa seedlings were subjected to various stress treatments and analyze expression of SsPsaH under these treatments by real-time RT-PCR. SsPsaH expression construct was introduced into S. pombe cells by electroporation and transformed into N. tabacum plants by the leaf disc transformation method. Results: A member of the H subunit of the Photosystem I reaction center (defined as SsPsaH) was obtained. The expression of SsPsaH was up-regulated by abscisic acid (ABA), salt, and drought stress treatments. Over-expressing SsPsaH in recombinant yeasts enhanced high salinity tolerance and increased tolerance to sorbitol during seed germination and seedling root development in tobacco, respectively. Some stress-related mark genes such as a LEA family gene of NtLEA, a binding protein of a drought response element of NtDREB, the ascorbate peroxidase gene (NtAPX) were also up-regulated in SsPsaH overexpressing transgenic tobacco lines. Conclusions: These results show that SsPsaH may contribute to the salt and osmotic stress response of plants.

Experimental Study on Shear Behavior of Bolted Cement Mortar Blocks under Constant Normal Stiffness

Bo Meng,Hongwen Jing,Shengqi Yang,Tao Cui,Biao Li 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.8

In this paper, the influence of bolting on shear mechanical behavior of cement mortar specimens were studied. First, a shear test apparatus which could provide CNS (constant normal stiffness) condition was designed. Then, more than 140 bolted and non-bolted cement mortar blocks (100 × 100 × 100 mm) were prepared. The strengthening effect of bolts with diameters of 0 − 10 mm on cement mortar specimens was studied under different initial normal loads ranging from 20 kN to 60 kN and constant normal stiffness of 420 kN/mm. Two simplified models of shear behavior of reinforced cement mortar blocks were proposed. The most important influence of bolt on the cement mortar blocks was to strengthen the post-peak shear strength rather than the peak shear strength, and the strengthening effect was reduced under high initial normal force. The cohesion of cement mortar blocks was reduced while internal friction angle was increased in residual sliding stage by bolts. The dilation of reinforced cement mortar specimens in postpeak shear stage was significantly reduced due to bolting, and the larger the bolt diameter, the greater the reduction in the block dilation.

Seismic analysis of bridges based on stress-dependent damping

Li Su,Yuanfeng Wang,Pengfei Li,Shengqi Mei,Kun Guo 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.3

Damping value has considerable influence on the dynamic and seismic behaviors of bridges. However, currently the constant damping ratios that are prescribed by most bridge seismic design codes can’t truly represent the complicated damping character of actual structures. In this paper, a cyclic loading experiment was conducted to study the effect of stress amplitude on material damping of concrete to present an analyzing model of the material damping of concrete. Furthermore, based on the fundamental damping of structure measured under ambient vibration, combined with the presented stress-dependent material damping concrete, the seismic response of a bridge pier was calculated. Comparison between the calculated and experiment results verified the validity of the presented damping model. Finally, a modified design and analysis method for bridge was proposed based on stress-dependent damping theory, and a continuous rigid frame bridge was selected as the example to calculate the actual damping values and the dynamic response of the bridge under different earthquake intensities. The calculation results indicated that using the constant damping given by the Chinese seismic design code of bridges would overestimate the energy dissipation capacity of the bridge.

Influence of some key factors on material damping of steel beams

Wang, Yuanfeng,Pan, Yuhua,Wen, Jie,Su, Li,Mei, Shengqi Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.3

Material damping affects the dynamic behaviors of engineering structures considerably, but up to till now little research is maintained on influence factors of material damping. Based on the damping-stress function of steel, the material damping of steel beams is obtained by calculating the stress distribution of the beams with an analytical method. Some key influence factors of the material damping, such as boundary condition, amplitude and frequency of excitation, load position as well as the cross-sectional dimension of a steel beam are analyzed respectively. The calculated results show that even in elastic scope, material damping does not remain constant but varies with these influence factors. Although boundary condition affects material damping to some extent, such influence can be neglected when the maximum stress amplitude of the beam is less than the fatigue limit of steel. Exciting frequency, load position and cross-section dimension have great effects on the material damping of the beam which maintain the similar changing trend under different boundary conditions respectively.

Composite passivity-based control of DC/DC boost converters with constant power loads in DC Microgrids

Liu, Weipeng,Cui, Xiaofeng,Zhou, Jiyao,Zhang, Zehua,Hou, Mingxuan,Shan, Shengqi,Wu, Shang The Korean Institute of Power Electronics 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.11

In this paper, a composite passivity-based control method based on a finite-time disturbance observer (FTDO) and a passivity-based control (PBC) is proposed to improve the stability of the Boost converters with constant power loads in DC Microgrids. The FTDO improves the robustness and rapidity of the system by accurately estimating system disturbances. The PBC ensures the stability of the system via its transient energy dissipation. The FTDO operates parallel to the PBC, and compensates the observed value to the PBC through a feedforward channel. When compared with other controls, the proposed composite passivity-based control has the advantages of a fast dynamic response and accurate tracking of system disturbances in a wide working range. Finally, the control method proposed in this paper is verified by MATLAB/Simulink simulations and hardware in the hard-ware-in-loop experiments.

Influence of creep on dynamic behavior of concrete filled steel tube arch bridges

Yuan-Feng Wang,Yi-Shuo Ma,Li Su,Shengqi Mei 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.1

Concrete creep, while significantly changing the static behaviors of concrete filled steel tube (CFST) structures, do alter the structures' dynamic behaviors as well, which is studied quite limitedly. The attempt to investigate the influence of concrete creep on the dynamic property and response of CFST arch bridges was made in this paper. The mechanism through which creep exerts its influence was analyzed first; then a predicative formula was proposed for the concrete elastic modulus after creep based on available test data; finally a numerical analysis for the effect of creep on the dynamic behaviors of a long-span half-through CFST arch bridge was conducted. It is demonstrated that the presence of concrete creep increases the elastic modulus of concrete, and further magnifies the seismic responses of the displacement and internal force in some sections of the bridge. This influence is related closely to the excitation and the structure, and should be analyzed case-by-case.

Amentoflavone protects the hematopoietic system of mice against γ‑irradiation

Xin-yan Qu,Qingjun Li,Xiao-juan Zhang,Zhaofen Wang,Shengqi Wang,Zhe Zhou 대한약학회 2019 Archives of Pharmacal Research Vol.42 No.11

Some flavonoids have been shown to exhibitgood antioxidant activity and protect mice from damageinduced by radiation. Amentoflavone (AMF), a biflavonoidderived from the traditional herb-Selaginella tamariscina,has been reported to have antioxidant properties. The protectiveeffects and mechanism of action of AMF against radiationinjury remain unknown. In this study, male C57BL/6mice were subjected to total-body 60Co γ-irradiation at 7.5or 3.0 Gy. The survival rate and mean survival time wereevaluated to determine the radioprotective effect of AMF. Number of peripheral blood cells, frequency of colony formingunit-granulocytes, monocytes and micronuclei weremeasured to assess the protective effects of AMF on thehematopoietic system. Levels of superoxide dismutase andglutathione, and pathological changes in the bone marrowwere determined. Additionally, next-generation sequencingtechnology was used to explore potential targets of AMF. Weobserved that AMF markedly extends average survival time,reduces injury to the hematopoietic system and promotes itsrecovery. Furthermore, treatment with AMF significantlyattenuated radiation-induced oxidative stress. In addition,AMF had a significant effect on gene tumor necrosis factor alpha-induced protein 2. Together, the results of this studysuggest that AMF is a potential protective agent againstradiation injury.