Three-dimensional trajectory tracking for underactuated AUVs with bio-inspired velocity regulation

Jiajia Zhou,Dingqi Ye,Junpeng Zhao,Dongxu He 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.3

This paper attempts to address the motion parameter skip problem associated with three-dimensional trajectory tracking of an underactuated Autonomous Underwater Vehicle (AUV) using backstepping-based control, due to the unsmoothness of tracking trajectory. Through kinematics concepts, a three-dimensional dynamic velocity regulation controller is derived. This controller makes use of the surge and angular velocity errors with bio-inspired models and backstepping techniques. It overcomes the frequently occurring problem of parameter skip at inflection point existing in backstepping tracking control method and increases system robustness. Moreover, the proposed method can effectively avoid the singularity problem in backstepping control of virtual velocity error. The control system is proved to be uniformly ultimately bounded using Lyapunov stability theory. Simulation results illustrate the effectiveness and efficiency of the developed controller, which can realize accurate three-dimensional trajectory tracking for an underactuated AUV with constant external disturbances.

Identification of novel Est-ssr markers by transcriptome sequencing in ridgetail white prawn Exopalaemon carinicauda

Jiajia Wang,Qianqian Ge,Jitao Li,Haiyu Gao,Jian Li,Fazhen Zhao 한국유전학회 2018 Genes & Genomics Vol.40 No.2

The ridgetail white prawn Exopalaemon carinicauda is one of the major commercial mariculture species in eastern China. However, only limited molecular markers are currently available due to the lack of genome information, which hinders its genetic and breeding studies. In this study, we identified new simple sequence repeats from transcriptome sequences by Illumina Hiseq 2500 platform. A total of 14273 SSR loci were identified from 130,082 assembled transcripts, with 6590 pairs of PCR primers designed. A total of 12,155 sequences containing SSR were predicted; and 2764 (22.74%) transcripts had significant matches to the NCBI non redundant protein (Nr) database. 11,563 transcripts were assigned into gene ontology (GO) categories. A set of 200 primers selected randomly were synthesized, of which 152 (76.0%) were successfully amplified. Further test with 60 pairs of polymorphic SSR primers to evaluate the genetic diversity of 30 wild populations and 43 loci were polymorphic, which had a polymorphic information content between 0.204 and 0.911. The results enriched genomic resources of E. carinicauda and provided powerful information for future conservation and breeding researches.

Durable Moisture-wicking and Fast-dry Polyester Fabric Prepared by UV-induced Click Reaction

Jiajia Liu,Wei Wang,Dan Yu,Kai Zhao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.1

Polyester (PET) fabric is an important fabric to make sportswear due to its good mechanical strength, wearresistance and low cost, but poor hygroscopicity will accumulate moisture and excessive heat of human body which therebycausing thermo-physiological dicomfort. To obtain satisfying moisture-wicking, hydroscopic and fast-dry properties, facileand efficient single-sided click chemistry was used to substitute traditional methods. Firstly, PET fabric was alkali treated andmodified with 3-mercaptopropyltrimethoxysilane to obtain thiol groups. Then it was gradiently grafted with potassium 3-sulfopropyl acrylate by thiol-ene click chemistry under single-sided ultraviolet (UV) irradiation to enlarge effects. Thereaction was proved by FTIR and Ellman method, the surface morphology was observed by SEM, and the mass loss atdifferent temperatures in thermalgravimetry (TG) test illustrated the quantity change of grafting. The results demonstratedthat the resultant fabric has good performance of moisture absorbing and sweat releasing, fast drying as well as outstandingantistatic and soil release properties.

Three-dimensional trajectory tracking for underactuated AUVs with bio-inspired velocity regulation

Zhou, Jiajia,Ye, Dingqi,Zhao, Junpeng,He, Dongxu The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.3

This paper attempts to address the motion parameter skip problem associated with three-dimensional trajectory tracking of an underactuated Autonomous Underwater Vehicle (AUV) using backstepping-based control, due to the unsmoothness of tracking trajectory. Through kinematics concepts, a three-dimensional dynamic velocity regulation controller is derived. This controller makes use of the surge and angular velocity errors with bio-inspired models and backstepping techniques. It overcomes the frequently occurring problem of parameter skip at inflection point existing in backstepping tracking control method and increases system robustness. Moreover, the proposed method can effectively avoid the singularity problem in backstepping control of virtual velocity error. The control system is proved to be uniformly ultimately bounded using Lyapunov stability theory. Simulation results illustrate the effectiveness and efficiency of the developed controller, which can realize accurate three-dimensional trajectory tracking for an underactuated AUV with constant external disturbances.

On the plane geometry design method of the loop-free hyperbolic single-layer cable structures

Renjie Liu,Jiajia Cao,Hang Zhao,Su-Duo Xue,Guangyong Wang,Jin Liang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

The plane geometry design of the cable-net structure is the basis for the form-finding and structural design. The loop-free single-layer cable-net structure is a new cable-net scheme, but due to its special and complex shape, it is difficult to determine its plane geometry according to architectural requirements. In this paper, the moving support node method is proposed, which can quickly get the plane geometry of a loop-free single-layer cable-net structure. The form-finding is proceeded based on the existing small elastic modulus method. There are two constraints when using the moving support node method. One is that the projection of all cables is straight line, and the other is that the distance between the two cables of each support node and the inner boundary of the target is equal. The aim is to minimize the sum of the distances from all cables to the inner boundary of the target. Using the plane geometry control parameters and the plane coordinates of the support nodes as decision variables, the plane geometry closest to the target inner and outer boundaries is get through optimization analysis. According to the derivation of the formula, the plane projection shape of a loop-free single-layer cable-net structure is mainly related to three parameters, including the number of supports, the difference between the node numbers of the supports at both ends of each cable, and the target curve equations of the inner and outer boundaries. Finally, taking the roof structure of Linyi Olympic Stadium as an instance, the feasibility of the plane geometry design method of the loop-free single-layer cable-net structures based on the moving support node method is verified.

Map Scale Effects on Soil Phosphorus Storage Estimation in the Uplands of Eastern China

Liming Zhang,Jiajia Li,Dongsheng Yu,Xuezheng Shi,Shihe Xing,Shengxiang Xu,Yongcun Zhao,Fengyun Zhang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Energy Efficiency of Distributed Massive MIMO Systems

Chunlong He,Jiajia Yin,Yejun He,Min Huang,Bo Zhao 한국통신학회 2016 Journal of communications and networks Vol.18 No.4

In this paper, we investigate energy efficiency (EE) of thetraditional co-located and the distributed massive multiple-inputmultiple-output (MIMO) systems. First, we derive an approximateEE expression for both the idealistic and the realistic power consumptionmodels. Then an optimal energy-efficient remote accessunit (RAU) selection algorithm based on the distance between themobile stations (MSs) and the RAUs are developed to maximizethe EE for the downlink distributedmassive MIMO systems underthe realistic power consumption model. Numerical results showthat the EE of the distributedmassiveMIMOsystems is larger thanthe co-locatedmassiveMIMOsystems under both the idealistic andrealistic power consumptionmodels, and the optimal EE can be obtainedby the developed energy-efficient RAU selection algorithm.

Degradation behavior of deep UV-LEDs studied by electro-optical methods and transmission electron microscopy

Huixin Xiu,Yang Zhang,Jiajia Fu,Zhanhong Ma,Lixia Zhao,Jijun Feng 한국물리학회 2019 Current Applied Physics Vol.19 No.1

Degradation mechanism of 265-nm deep ultraviolet light emitting diodes (UV-LEDs) has been investigated by means of electroluminescence, current-voltage measurement, capacitance-voltage measurement, and transmission electron microscopy (TEM) equipped with energy dispersive X-ray spectrometer (EDAX). It is revealed that a major degradation mode of UV-LEDs may be the leakage current induced optical degradation. The current pathway is demonstrated by TEM with EDAX, indicating that the contact metals can partially interact with ptype materials, which accelerate the degradation of LEDs. The presented results can help to understand the degradation mechanisms and improve the reliability of deep UV-LEDs.

Biotechnological Advances and Trends in Engineering Trichoderma reesei towards Cellulase Hyperproducer

Hao Fang,Chaofeng Li,Jiajia Zhao,Chen Zhao 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.4

Cellulase has the biggest contribution to the high production costs of lignocellulose bioconversion and the substantial decrease of its production cost is the key to the commercialization of lignocellulosic biorefineries. Trichoderma reesei has the most robust cellulase among the candidates, which therefore is widely used for cellulase production in industry. This is not because of the size of its cellulase gene pool but its prodigious cargo of cellulase productivity. Still, T. reesei cellulase falls far short of perfection in real-world applications, especially for the composition. This review summarized the biotechnological advances in engineering T. reesei for enhanced cellulase production. Meanwhile, we proposed innovative ideas of systematically optimizing cellulase composition at the transcriptional level and improving cellulase production at the regulation level. Efficient genome editing is essential to achieving that target. Thus, the developments of the tools of multiple gene manipulations were discussed in detail here. This review provides ideas and/or inspirations to the future researches on T. reesei cellulase.

Energy Efficiency of Distributed Massive MIMO Systems

He, Chunlong,Yin, Jiajia,He, Yejun,Huang, Min,Zhao, Bo The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.4

In this paper, we investigate energy efficiency (EE) of the traditional co-located and the distributed massive multiple-input multiple-output (MIMO) systems. First, we derive an approximate EE expression for both the idealistic and the realistic power consumption models. Then an optimal energy-efficient remote access unit (RAU) selection algorithm based on the distance between the mobile stations (MSs) and the RAUs are developed to maximize the EE for the downlink distributed massive MIMO systems under the realistic power consumption model. Numerical results show that the EE of the distributed massive MIMO systems is larger than the co-located massive MIMO systems under both the idealistic and realistic power consumption models, and the optimal EE can be obtained by the developed energy-efficient RAU selection algorithm.