Improved Gauss Pseudospectral Method for UAV Trajectory Planning with Terminal Position Constraints

Qingquan Hu,Ping Liu,Jinfeng Yang 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.5

Trajectory planning is a key technology for unmanned aerial vehicles (UAVs) to achieve complex flightmissions. In this paper, a terminal constraints conversion-based Gauss pseudospectral trajectory planningoptimization method is proposed. Firstly, the UAV trajectory planning mathematical model is established withconsidering the boundary conditions and dynamic constraints of UAV. Then, a terminal constraint handlingstrategy is presented to tackle terminal constraints by introducing new penalty parameters so as to improve theperformance index. Combined with Gauss-Legendre collocation discretization, the improved Gausspseudospectral method is given in detail. Finally, simulation tests are carried out on a four-quadrotor UAVmodel with different terminal constraints to verify the performance of the proposed method. Test studiesindicate that the proposed method performances well in handling complex terminal constraints and theimprovements are efficient to obtain better performance indexes when compared with the traditional Gausspseudospectral method.

Terbium Tetra-Sulfosalicylate Complex as Quantitative Luminescent Sensing of Chromate Ions with High Selectivity and Sensitivity

Wei Yang,Jinfeng Xia,Guohong Zhou,Tianxi Hu,Danwang Ye,Danyu Jiang,Qiang Li 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.5

In this study, a terbium(?) complex, Tb(SSA)4 (SSA?=?sulfosalicylate), was synthesized and employed to detect toxic chromate anion (CrO42?) as a visually identifiable probe. Luminescence investigations confirmed that the Tb complex is an excellent probe with high selectivity, high sensitivity (I0/I100 ?M = 9.5), and a low detection limit (2.8???10?8 M), targeting CrO42? in aqueous solution. The simple fluorescence-based probe can be quickly and easily prepared, and enables the reliable, visual detection of CrO42? ion in daily applications.

Contribution Evaluation from Each Optimization Factor of Cantilevered Harvesters in the Improvement of their Energy Harvesting Performance

Xie Xiangdong,Zhang Jinfeng,Wang Zijing,Hu Xiaobin 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.1

In order to quantitatively evaluate the contribution from each optimization factor of cantilevered harvesters in the improvement of their energy harvesting performance, sets of test specimens are designed and customized. The eff ect of taper ratio, substrate thickness, proof mass, excitation frequency, load resistance and the number of bonded piezoelectric patches on the output electric parameters from the harvesters are tested and evaluated. The experimental results show that the improvements of the output voltage/voltage density, the output power/power density from the harvesters depend on the factors in the contribution turn from big to small as: the increase of the proof mass value, the decrease of the substrate thickness, and the increase of the taper ratio. For a cantilevered harvester ( l 2 = 50.5 mm, b = 15 mm, h 2 = 1 mm, λ = 4/5), its output power and power density can improve 5092.6% by adding a proof mass of 4.31 g. This research obtains some important and instructive conclusions for the practical design of the cantilevered harvester with ideal energy harvesting effi ciency and cost-eff ectiveness.

Cone-beam computed tomographic evaluation of the temporomandibular joint and dental characteristics of patients with Class II subdivision malocclusion and asymmetry

Mingna Huang,Yun Hu,Jinfeng Yu,Jicheng Sun,Ye Ming,Leilei Zheng 대한치과교정학회 2017 대한치과교정학회지 Vol.47 No.5

Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Conebeam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t -tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

Web-Based Collaborative Learning System and Its Key Techniques

Yanhui Xia,Zhengyou Wang,Yi Li,Jinfeng Hu 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.12

On the basis of concept, characteristics and related work of collaborative learning, this paper proposes an intelligent web collaborative learning system prototype based on multi-agent technology. At first, the paper introduces a collaborative learning framework which supporting group learning and illustrates the whole learning process. Secondly, the paper presents some key issues to implementation of the virtual learning environment, such as intelligent grouping, automatic question answering, knowledge management, and opinion mining. Preliminary learning practice shows that it is a practical and efficient way.

The Impacts of Childhood Trauma on Psychosocial Features in a Chinese Sample of Young Adults

Dandan Wang,Shaojia Lu,Weijia Gao,Zhaoguo Wei,Jinfeng Duan,Shaohua Hu,Manli Huang,Yi Xu,Lingjiang Li 대한신경정신의학회 2018 PSYCHIATRY INVESTIGATION Vol.15 No.11

Objective The aims of the present study were to explore the occurrence of childhood trauma and importantly to determine the impacts of childhood trauma on psychosocial features in a Chinese sample of young adults. Methods A survey was carried out in a group of 555 university students by using Childhood Trauma Questionnaire (CTQ), Self-rating Depression Scale (SDS), Self-rating Anxiety Scale (SAS), Dysfunctional Attitudes Questionnaire (DAS), Eysenck Personality Questionnaire (EPQ), and Social Support Rating Scale (SSRS). The moderate-severe cut-off scores for CTQ were used to calculate the prevalence of childhood trauma, and then psychosocial features were compared between individuals with and without childhood trauma. Results A proportion of 18.6% of university students had self-reported childhood trauma exposures. Subjects with childhood trauma reported higher scores of SDS, SAS, DAS, and psychoticism and neuroticism dimensions of EPQ (t=4.311–5.551, p<0.001); while lower scores of SSRS and extraversion dimension of EPQ (t=-4.061– -3.039, p<0.01). Regression analyses further revealed that scores of SAS and DAS were positively (Adjusted B=0.211–0.230, p<0.05), while scores of SSRS were negatively (Adjusted B=-0.273– -0.240, p<0.05) associated with specific CTQ scores. Conclusion Childhood trauma is still a common social and psychological problem. Individuals with childhood trauma show much more depression, anxiety, distorted cognition, personality deficits, and lower levels of social support, which may represent the social and psychological vulnerability for developing psychiatric disorders after childhood trauma experiences.