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UAV-assisted data collection for wireless sensor networks with dynamic working modes

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Digital Communications and Networks 2024年第3期10卷 805-812页

作者： jie chen Jianhua Tang Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou511442China

Wireless Sensor Network(WSN)is a cornerstone of Internet of Things(IoT)and has rich application *** this work,we consider a heterogeneous WSN whose sensor nodes have a diversity in their Residual Energy(RE).In this work,to protect the sensor nodes with low RE,we investigate dynamic working modes for sensor nodes which are determined by their RE and an introduced energy ***,we employ an Unmanned Aerial Vehicle(UAV)to collect the stored data from the heterogeneous *** aim to jointly optimize the cluster head selection,energy threshold and sensor nodes’working mode to minimize the weighted sum of energy con-sumption from the WSN and UAV,subject to the data collection rate *** this end,we propose an efficient search method to search for an optimal energy threshold,and develop a penalty-based successive convex approximation algorithm to select the cluster *** we present a low-complexity iterative approach to solve the joint optimization problem and discuss the implementation *** results justify that our proposed approach is able to reduce the energy consumption of the sensor nodes with low RE significantly and also saves energy for the whole WSN.

关键词： Unmanned aerial vehicle Wireless sensor networks Cluster heads Dynamic working modes

Adsorption of lead on multi-walled carbon nanotubes with different outer diameters and oxygen contents: Kinetics, isotherms and thermodynamics

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Journal of Environmental Sciences 2013年第1期25卷 195-203页

作者： fei Yu Yanqing Wu jie Ma Chi Zhang School of Environmental Science and Engineering Shanghai Jiao Tong University State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and EngineeringTongji University

The effects of different outer diameters and surface oxygen contents on the adsorption of heavy metals onto six types of multi-walled carbon nanotubes （MWCNTs） were investigated in an aqueous solution and lead was chosen as a model metal ion. The results indicated that the percentage removal and adsorption capacity of lead remarkably increased with decreasing outer diameter due to larger specific surface area （SSA）. The SSA-normalized maximum adsorption capacity （qJSSA） and SSA-normalized adsorption coefficient （KdSSA） were strongly positively correlated with surface oxygen content, implying that lead adsorption onto MWCNTs significantly increases with the rise of oxygen content and decreases with decreasing SSA. The calculated thermodynamic parameters indicated that adsorption of lead on MWCNTs was endothermic and spontaneous. When the oxygen content of MWCNTs increased from 2.0% to 5.9%, the standard free energy （AGt） became more negative, which implied that the oxygenated functional groups increased the adsorption affinity of MWCNTs for lead. Through calculation of enthalpy （△H0）, AGO and free energy of adsorption （Ea）, lead adsorption onto MWCNTs was recognized as a chemisorption process. The chemical interaction between lead and the phenolic groups of MWCNTs could be one of the main adsorption mechanisms due to highly positive correlations between the phenolic groups and Kd/SSA or qm/SSA.

关键词： adsorption lead multi-walled carbon nanotube diameter surface oxygen content

Diagnosis of pancreatic cancer by cytology and telomerase activity in exfoliated cells obtained by pancreatic duct brushing during endoscopy

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Hepatobiliary & Pancreatic Diseases International 2007年第3期6卷 308-311页

作者： Zhou, Guo-Xiong Huang, jie-fei Zhang, Hong chen, Jian-Ping Nantong Univ Affiliated Hosp Dept Gastroenterol Nantong 226001 Peoples R China

BACKGROUND: Telomerase activity is reported to be specific and frequent in human pancreatic cancer. We conducted this study to assess the usefulness of monitoring telomerase activity in exfoliated cells obtained by pancreatic duct brushing during endoscopic retrograde cholangiopancreatography (ERCP) for the diagnosis of pancreatic cancer. METHODS: Exfoliated cells obtained by pancreatic duct brushing during ERCP from 21 patients (18 with pancreatic cancer, 3 with chronic pancreatitis) were examined. Telomerase activity was detected by polymerase chain reaction and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA). RESULTS: D450 values of telomerase activity were 0.446 +/- 0.2700 in pancreatic cancer and 0.041 +/- 0.0111 in chronic pancreatitis. 77.8% (14/18) of patients with pancreatic cancer had cells with telomerase activity. None of the samples from patients with chronic pancreatitis showed telomerase activity, when the cutoff value of telomerase activity was set at 2.0. Cytological examination showed cancer cells in 66.7% (12/18) of the patients. CONCLUSIONS: Telomerase activity may be an early malignant event in pancreatic cancer development. Cytology and telomerase activity in cells obtained by pancreatic duct brushing may complement each other for the diagnosis of pancreatic cancer.

关键词： pancreatic carcinoma cytology telomerase

An improved quaternion Gauss–Newton algorithm for attitude determination using magnetometer and accelerometer

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Chinese Journal of Aeronautics 2014年第4期27卷 986-993页

作者： Liu fei Li jie Wang Haifu Liu Chang School of Mechatronical Engineering Beijing Institute of Technology

For the vector attitude determination, the traditional optimal algorithms which are based on quaternion estimator（QUEST） measurement noise model are complicated for just two observations. In our application, the magnetometer and accelerometer are not two comparable kinds of sensors and both are not small field-of-view sensors as well. So in this paper a new unit measurement model is derived. According to the Wahba problem, the optimal weights for each measurement are obtained by the error variance researches. Then an improved quaternion Gauss–Newton method is presented and adopted to acquire attitude. Eventually, simulation results and experimental validation employed to test the proposed method demonstrate the usefulness of the improved algorithm.

关键词： Accelerometer Attitude determination Gauss-Newton algorithm Magnetometer Measurements

Adaptive unscented Kalman filter for parameter and state estimation of nonlinear high-speed objects

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Journal of Systems Engineering and Electronics 2013年第4期24卷 655-665页

作者： Fang Deng jie chen chen chen School of Automation Beijing Institute of Technology Key Laboratory of Intelligent Control and Decision of Complex Systems

An adaptive unscented Kalman filter （AUKF） and an augmented state method are employed to estimate the timevarying parameters and states of a kind of nonlinear high-speed objects. A strong tracking filter is employed to improve the tracking ability and robustness of unscented Kalman filter （UKF） when the process noise is inaccuracy, and wavelet transform is used to improve the estimate accuracy by the variance of measurement noise. An augmented square-root framework is utilized to improve the numerical stability and accuracy of UKF. Monte Carlo simulations and applications in the rapid trajectory estimation of hypersonic artillery shells confirm the effectiveness of the proposed method.

关键词： parameter estimation state estimation unscented Kalman filter (UKF) strong tracking filter wavelet transform.

Hybrid optimization of dynamic deployment for networked fire control system

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Journal of Systems Engineering and Electronics 2013年第6期24卷 954-961页

作者： chen chen jie chen Bin Xin School of Automation Beijing Institute of Technology Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education

With applying the information technology to the military field, the advantages and importance of the networked combat are more and more obvious. In order to make full use of limited battlefield resources and maximally destroy enemy targets from arbitrary angle in a limited time, the research on firepower nodes dynamic deployment becomes a key problem of command and control. Considering a variety of tactical indexes and actual constraints in air defense, a mathematical model is formulated to minimize the enemy target penetration probability. Based on characteristics of the mathematical model and demands of the deployment problems, an assistance-based algorithm is put forward which combines the artificial potential field （APF） method with a memetic algorithm. The APF method is employed to solve the constraint handling problem and generate feasible solutions. The constrained optimization problem transforms into an optimization problem of APF parameters adjustment, and the dimension of the problem is reduced greatly. The dynamic deployment is accomplished by generation and refinement of feasible solutions. The simulation results show that the proposed algorithm is effective and feasible in dynamic situation.

关键词： deployment optimization artificial potential field (APF) constraint handling generation of feasible solutions memetic algorithm

振动疗法联合悬吊训练前交叉韧带重建后患者运动及膝关节功能的变化

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中国组织工程研究 2025年第11期29卷 2225-2230页

作者：陈文汉门杰杨伟赵小宇山西医科大学汾阳学院山西省吕梁市032200

背景:物理疗法对前交叉韧带重建术后恢复至关重要。近年来,许多医师都在优化前交叉韧带重建术后的物理康复方案,但仍然缺乏高效的前交叉韧带重建术后康复训练疗法。目的:探讨振动疗法联合悬吊训练对前交叉韧带重建患者术后运动及膝关节... 详细信息

背景:物理疗法对前交叉韧带重建术后恢复至关重要。近年来,许多医师都在优化前交叉韧带重建术后的物理康复方案,但仍然缺乏高效的前交叉韧带重建术后康复训练疗法。目的:探讨振动疗法联合悬吊训练对前交叉韧带重建患者术后运动及膝关节功能的影响。方法:纳入在上海体育大学附属体育医院就诊的80例首次行单侧前交叉韧带重建患者,按照随机数字表法将患者随机分为振动疗法组和振动疗法+悬吊训练组,每组40例。振动疗法组患者在前交叉韧带重建术后第13周开始进行振动疗法训练(每次10 min,1次/d,每周6次),振动疗法+悬吊训练组患者在前交叉韧带重建术后第13周开始进行振动疗法(每次10 min,1次/d,每周6次)联合悬吊训练(每周2次),共训练8周。训练前及训练8后,采用膝关节Lysholm评分评价膝关节功能,采用等速肌力评估训练系统评估屈膝对称性指数,采用平衡测试系统评估双侧多轴平均轨迹误差差值。结果与结论:(1)与训练前比较,两组患者训练8周后的膝关节Lysholm评分、屈膝与伸膝对称性指数均升高(P<0.05),双侧多轴平均轨迹误差差值降低(P<0.05);与振动疗法组比较,振动疗法+悬吊训练组患者膝关节Lysholm评分、屈膝与伸膝对称性指数均升高(P<0.05),双侧多轴平均轨迹误差差值降低(P<0.05);(2)结果表明,与单独进行振动疗法相比,振动疗法联合悬吊训练可显著改善前交叉韧带重建患者的膝关节功能,增加肌肉力量和对称性,提高平衡稳定性。

关键词：前交叉韧带重建振动疗法悬吊训练膝关节功能肌肉力量对称性平衡稳定性

热塑性纤维素与PVA混溶性的分子动力学模拟

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原子与分子物理学报 2025年第3期42卷 149-158页

作者：冯彦洪陈帅杰孙航华南理工大学机械与汽车工程学院聚合物新型成型装备国家工程研究中心聚合物成型加工工程教育部重点实验室广东省高分子先进制造技术及装备重点实验室广州510000

首次提出了将氧化还原改性纤维素(Oxidation-reduction modified cellulose,ORC)与聚乙烯醇(Poly(vinyl alcohol),PVA)共混进行制备复合材料,并采用分子动力学模拟研究了ORC与PVA的混溶性.对分子链间相互作用能和氢键数量分析发现,随着... 详细信息

首次提出了将氧化还原改性纤维素(Oxidation-reduction modified cellulose,ORC)与聚乙烯醇(Poly(vinyl alcohol),PVA)共混进行制备复合材料,并采用分子动力学模拟研究了ORC与PVA的混溶性.对分子链间相互作用能和氢键数量分析发现,随着改性程度增加,ORC与PVA会产生更强烈的相互作用,这促进了组分间的混溶.当ORC的改性程度达到40%后,ORC与PVA的溶解度参数差值为2.02(J/cm^(3))^(1/2),达到混溶条件.根据Flory-Huggins理论确定了醇解度为88%和99%的PVA与ORC的混溶性,结果表明PVA(88%)与ORC的混溶性更好.对共混体系中形成氢键原子的径向分布函数分析发现,醋酸乙烯酯重复单元上的羰基更倾向与ORC形成分子链间氢键,而乙烯醇重复单元上的羟基更倾向形成分子链内氢键,这促使PVA(88%)/ORC共混体系中形成更多的分子链间氢键,从而混溶性更好.研究结果可为ORC/PVA复合材料的制备提供理论指导.

关键词：混溶性氧化还原改性纤维素分子动力学聚乙烯醇

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Interactive multiobjective evolutionary algorithm based on decomposition and compression

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Science China(Information Sciences) 2021年第10期64卷 166-181页

作者： Lu chen Bin XIN jie chen School of Automation Beijing Institute of Technology State Key Laboratory of Intelligent Control and Decision of Complex Systems

Many real-world optimization problems involve multiple conflicting objectives. Such problems are called multiobjective optimization problems(MOPs). Typically, MOPs have a set of so-called Pareto optimal solutions rather than one unique optimal solution. To assist the decision maker(DM) in finding his/her most preferred solution, we propose an interactive multiobjective evolutionary algorithm(MOEA)called iDMOEA-εC, which utilizes the DM’s preferences to compress the objective space directly and progressively for identifying the DM’s preferred region. The proposed algorithm employs a state-of-the-art decomposition-based MOEA called DMOEA-εC as the search engine to search for solutions. DMOEA-εC decomposes an MOP into a series of scalar constrained subproblems using a set of evenly distributed upper bound vectors to approximate the entire Pareto front. To guide the population toward only the DM’s preferred part on the Pareto front, an adaptive adjustment mechanism of the upper bound vectors and two-level feasibility rules are proposed and integrated into DMOEA-εC to control the spread of the population. To ease the DM’s burden, only a small set of representative solutions is presented in each interaction to the DM,who is expected to specify a preferred one from the set. Furthermore, the proposed algorithm includes a two-stage selection procedure, allowing to elicit the DM’s preferences as accurately as possible. To evaluate the performance of the proposed algorithm, it was compared with other interactive MOEAs in a series of experiments. The experimental results demonstrated the superiority of iDMOEA-εC over its competitors.

关键词： multiobjective optimization interactive decision making preference incorporation decomposition compression