Real-time unmanned aerial vehicle flight path prediction using a bi-directional long short-term memory network with error compensation

Chen Sifan,Chen Baihe,Shu Peng,Wang Zhensheng,Chen Chengbin 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.1

In recent years, unmanned aerial vehicle (UAV) autonomous flight technology has been applied in many fields. However, in the process of autonomous operation, the UAV may deviate from the set flight path due to various disturbance factors, which results in mission failure. In order to find the abnormal situation in time and take corresponding measures, it is necessary to monitor the operation state of the UAV. Predicting the UAV flight path is the main monitoring method at present; however, the accuracy and real-time of the existing prediction methods are limited. Therefore, this paper proposes an error compensation Bessel bidirectional long short-term memory real-time path prediction model deployed in ground stations. First, because of inconsistency of the units in all directions of the original positioning information provided by global positioning system, the Bessel geodetic coordinate transformation is introduced to unify the units of three-dimensional coordinate data, so as to improve the prediction accuracy. Second, considering the problems of poor data quality and data missing in the operation process, the least square fitting method is used to supplement and correct the positioning coordinate data to obtain more reliable and accurate path observation values as the model input. Finally, a deep learning path prediction model based on bi-directional long short-term memory (BiLSTM) network is constructed, and the appropriate network parameters are determined with the prediction accuracy and time as evaluation indicators. In order to further improve the prediction accuracy, a compensator based on proportional integral differential error control theory is designed according to the output characteristics of the BiLSTM network, which is used for providing compensation values for the prediction results of the model. The training and testing results using the actual flight data of UAV operation show that, under the experimental environment built, the model proposed in this paper can complete the UAV flight path prediction with root mean square error < 1 meter within 0.1 second, and has better performance and higher prediction accuracy than other neural network models.

Chemoenzymatic Synthesis of Dual-responsive Amphiphilic Block Copolymers and Drug Release Studies

Peng Chen,Ya-Peng Li,Shu-Wei Wang,Xin-Lei Meng,Ming Zhu,Jing-Yuan Wang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

Dual-responsive amphiphilic block copolymers were synthesized by combining enzymatic ring-opening polymerization (eROP) of ε-caprolactone (CL) and ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA). The obtained block copolymers were characterized by gel permeation chromatography (GPC), 1H NMR and FTIR-IR. The critical micelle concentration (CMC) of copolymer was determined by fluorescence spectra, it can be found that with hydrophilic block (PDMAEMA) increasing, CMC value of the polymer sample increased accordingly, and the CMC value was 0.012 mg/mL, 0.025 mg/mL and 0.037 mg/ mL for PCL50-b-PDMAEMA68, PCL50-b-PDMAEMA89, PCL50-b-PDMAEMA112, PCL50-b-PDMAEMA89 was chosen as drug carrier to study in vitro release profile of anti-cancer drug (taxol). The temperature and pH dependence of the values of hydrodynamic diameter (Dh) of micelles, and self-assembly of the resulting block copolymers in water were evaluated by dynamic light scattering (DLS). The result showed that with the temperature increasing and pH decreasing, the Dh decreased. Drug-loaded nanoparticles were fabricated using paclitaxel as model. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) had been explored to study the morphology of the hollow micelles and the nanoparticles, revealing well-dispersed spheres with the average diameters both around 80 nm. In vitro release kinetics of paclitaxel from the nanoparticles was also investigated in different conditions (pH and temperature, etc.), revealing that the drug release was triggered by temperature changes upon the lower critical solution temperature (LCST) at pH 7.4, and at 37 °C by an increase of pH.

Chemoenzymatic Synthesis of Dual-responsive Amphiphilic Block Copolymers and Drug Release Studies

Chen, Peng,Li, Ya-Peng,Wang, Shu-Wei,Meng, Xin-Lei,Zhu, Ming,Wang, Jing-Yuan Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

Dual-responsive amphiphilic block copolymers were synthesized by combining enzymatic ring-opening polymerization (eROP) of ${\varepsilon}$-caprolactone (CL) and ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA). The obtained block copolymers were characterized by gel permeation chromatography (GPC), $^1H$ NMR and FTIR-IR. The critical micelle concentration (CMC) of copolymer was determined by fluorescence spectra, it can be found that with hydrophilic block (PDMAEMA) increasing, CMC value of the polymer sample increased accordingly, and the CMC value was 0.012 mg/mL, 0.025 mg/mL and 0.037 mg/mL for $PCL_{50}$-b-$PDMAEMA_{68}$, $PCL_{50}$-b-$PDMAEMA_{89}$, $PCL_{50}$-b-$PDMAEMA_{112}$, $PCL_{50}$-b-$PDMAEMA_{89}$ was chosen as drug carrier to study in vitro release profile of anti-cancer drug (taxol). The temperature and pH dependence of the values of hydrodynamic diameter (Dh) of micelles, and self-assembly of the resulting block copolymers in water were evaluated by dynamic light scattering (DLS). The result showed that with the temperature increasing and pH decreasing, the Dh decreased. Drug-loaded nanoparticles were fabricated using paclitaxel as model. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) had been explored to study the morphology of the hollow micelles and the nanoparticles, revealing well-dispersed spheres with the average diameters both around 80 nm. In vitro release kinetics of paclitaxel from the nanoparticles was also investigated in different conditions (pH and temperature, etc.), revealing that the drug release was triggered by temperature changes upon the lower critical solution temperature (LCST) at pH 7.4, and at $37^{\circ}C$ by an increase of pH.

A GFP-labeled Human Colon Cancer Metastasis Model Featuring Surgical Orthotopic Implantation

Chen, Hong-Jin,Yang, Bo-Lin,Chen, Yu-Gen,Lin, Qiu,Zhang, Shu-Peng,Gu, Yun-Fei Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.9

Colorectal cancer has become a major disease threatening human health. To establish animal models that exhibit the characteristics of human colorectal cancer will not only help to study the mechanisms underlying the genesis and development effectively, but also provide ideal carriers for the screening of medicines and examining their therapeutic effects. In this study, we established a stable, colon cancer nude mouse model highly expressing green fluorescent protein (GFP) for spontaneous metastasis after surgical orthotopic implantation (SOI). GFP-labeled colon cancer models for metastasis after SOI were successfully established in all of 15 nude mice and there were no surgery-related complications or deaths. In week 3, primary tumors expressing GFP were observed in all model animals under fluoroscopy and two metastatic tumors were monitored by fluorescent imaging at the same time. The tumor volumes progressively increased with time. Seven out of 15 tumor transplanted mice died and the major causes of death were intestinal obstruction and cachexia resulting from malignant tumor growth. Eight model animals survived at the end of the experiment, 6 of which had metastases (6 cases to mesenteric lymph nodes, 4 hepatic, 2 pancreatic and 1 mediastinal lymph node). Our results indicate that our GFP-labeled colon cancer orthotopic transplantation model is useful with a high success rate; the transplanted tumors exhibit similar biological properties to human colorectal cancer, and can be used for real-time, in vivo, non-invasive and dynamic observation and analysis of the growth and metastasis of tumor cells.

The Experience to Implement Palliative Care in Long-term Care Facilities: A Grounded Theory Study of Caregivers

Shu-Wan Chiang,Shu-Chen Wu,Tai-Chu Peng 한국간호과학회 2021 Asian Nursing Research Vol.15 No.1

Purpose: The purpose of this study was to explore the experiences of caregivers in long-term care facilities as they implement palliative care. Although palliative care has been available in Taiwan for more than 30 years, it is often provided in hospitals, few models in the long-term care facilities. Methods: Semi-structured interviews using grounded theory methodology and purposive sampling. Two small long-term care facilities that had performed well in palliative care were selected from eastern Taiwan. A total of 12 caregivers participated in in-depth semi-structured face-to-face interviews. Results: Four major stages in the implementation of palliative care were identified: (1) feeling insecure, (2) clarifying challenges, (3) adapting to and overcoming the challenges, and (4) comprehending the meaning of palliative care. The core category of these caregivers as “the guardians at the end of life” reflects the spirit of palliative care. Conclusion: This study demonstrates that successful palliative care implementation would benefit from three conditions. First, the institution requires a manager who is enthusiastic about nursing care and who sincerely promotes a palliative care model. Second, the institution should own caregivers who possess personality traits reflective of enthusiasm for excellence, unusual ambition, and a true sense of mission. Third, early in the implementation phase of the hospice program, the institution must have the consistent support of a high-quality hospice team.

Predatory efficacy of Orius strigicollis (Hemiptera: Anthocoridae) against Tetranychus urticae (Acarina: Tetranychidae) on strawberry

Shu-Jen Tuan,Yung-Hsiang Lin,Shu-Chen Peng,Wei-Han Lai 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.1

In this study, the predatory efficacy of Orius strigicollis (Poppius), a predacious flower bug, against the twospotted spider mite (TSSM), Tetranychus urticae Koch, on strawberry (Fragaria ananassa) was investigated. Our results showed that release of 2, 4, 6, and 12 neonates of O. strigicollis per strawberry plant could suppress 58.9, 72.6, 88.6, and 92.8% of T. urticae, respectively, at 14 days after treatment. A single release of 12 neonate bugs per plant achieved and maintained, over a period of 3 months, 82% to 98% control of T. urticae population. A biweekly release of 6 neonate bugs per plant; likewise, suppressed ca. 90% of T. urticae population throughout the same period. However, predatory efficacy was reduced by an over-release of predators which may cause cannibalism as well as lower possibility of finding prey. Since the released neonates survived well to adults with offspring that retained their predatory ability, this study has demonstrated that O. strigicollis is a predatorwith good potential for sustainable suppression of T. urticae on strawberry, and one application of O. strigicollis neonates at a predator:prey ratio of 1:200 egg plus motile TSSM or 1:60 motiles per strawberry plant promises a season-long control and substantial management of spider mite infestation.

Key challenges, recent advances and future perspectives of rechargeable lithium-sulfur batteries

Ze-Chen Lv,Peng-Fei Wang,Jian-Cang Wang,Shu-Hui Tian,Ting-Feng Yi 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

Lithium-sulfur (Li-S) battery, which releases energy by coupling high abundant sulfur with lithium metal,is considered as a potential substitute for the current lithium-ion battery. Thanks to the lightweight andmulti-electron reaction of sulfur cathode, the Li-S battery can achieve a high theoretical specific capacityof 1675 mAh g1 and specific energy of 2600 Wh kg1. However, some key scientific issues limit its practicalapplication, such as the ‘‘shuttle effect” of lithium polysulfides, large volume change, poor conductivityof sulfur and its solid-state products, and self-discharge phenomenon. Of these, the ‘‘shuttle effect”is recognized as the most critical challenge affecting on electrochemical performance. Hence, this reviewfirst systematically introduces the development of Li-S batteries and the corresponding ‘‘shuttle effect”. Then, the latest work on anode, cathode, separator and electrolyte are summarized. Finally, some promisingviews on the future research direction of this battery system are put forward.

Preparation and Study on Thermal Conductive Composites of Chlorinated Polyethylene Rubber Reinforced by Boron Nitride Particles

Junjie Shu,Ru Xia,Jiasheng Qian,JIBIN MIAO,LIFEN SU,Ming Cao,Hongyun Lin,Peng Chen,Jinyang Chen 한국고분자학회 2016 Macromolecular Research Vol.24 No.7

The composites of chlorinated polyethylene rubber (CM) filled with boron nitride (BN) were prepared and examined systematically. Scanning electron microscopy (SEM) was used to observe microscopic morphology of composites. Mechanical properties of composites were analyzed by a rubber process analyzer (RPA) and dynamic mechanical thermal analyzer (DMTA). Thermal conductivity as well as thermo stability of composites was improved by adding BN particles into the CM rubber. It was found that BN particles can reinforce the rubber matrix while they also break down the network of polymer chains and ruin the physical properties of the rubber matrix. During the dynamic compressing process, BN particles can transfer heat from the matrix and alleviate the heat build-up phenomenon. The BN/CM composites (volume content CBN=18%) with thermal conductivity 1.179 W/(m·K) and good flexibility (Elongation at break=320%) were prepared, which may be used as thermal interface materials in a dynamic compressing process.

Study on mechanism of macro failure and micro fracture of local nearly horizontal stratum in super-large section and deep buried tunnel

Li, Shu-cai,Wang, Jian-hua,Chen, Wei-zhong,Li, Li-ping,Zhang, Qian-qing,He, Peng Techno-Press 2016 Geomechanics & engineering Vol.11 No.2

The stability of surrounding rock will be poor when the tunnel is excavated through nearly horizontal stratum. In this paper, the instability mechanism of local nearly horizontal stratum in super-large section and deep buried tunnel is revealed by the analysis of the macro failure and micro fracture. A structural model is proposed to explain the mechanics of surrounding rock collapse under the action of stress redistribution and shed light on the macroscopic analytical approach of the stability of surrounding rock. Then, some highly effective formulas applied in the tunnel engineering are developed according to the theory of mixed-mode micro fracture. And well-documented field case is made to demonstrate the effectiveness and accuracy of the proposed analytical methods of mixed-mode fracture. Meanwhile, in order to make the more accurate judgment about yield failure of rock mass, a series of comprehensive failure criteria are formed. In addition, the relationship between the nonlinear failure criterion and $K_I$ and $K_{II}$ of micro fracture is established to make the surrounding rock failure criterion more comprehensive and accurate. Further, the influence of the parameters related to the tension-shear mixed-mode fracture and compression-shear mixed-mode fracture on the propagation of rock crack is analyzed. Results show that ${\sigma}_3$ changes linearly with the change of ${\sigma}_1$. And the change rate is related to ${\beta}$, angle between the cracks and ${\sigma}_1$. The proposed simple analytical approach is economical and efficient, and suitable for the analysis of local nearly horizontal stratum in super-large section and deep buried tunnel.

A False Positive 18F-FDG PET/CT Scan Caused by Breast Silicone Injection

Chao-Jung Chen,Bi-Fang Lee,Wei-Jen Yao,Pei-Shan Wu,Wen-Chung Chen,Shu-Lin Peng,Nan-Tsing Chiu 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.2

We present here the case of a 40-year-old woman with a greater than 10 year prior history of bilateral breast silicone injection and saline bag implantation. Bilateral palpable breast nodules were observed, but the ultrasound scan was suboptimal and the magnetic resonance imaging showed no gadoliniumenhanced tumor. The 18F-FDG PET/CT scan showed a hypermetabolic nodule in the left breast with a 30% increase of 18F-FDG uptake on the delayed imaging, and this mimicked breast cancer. She underwent a left partial mastectomy and the pathology demonstrated a siliconoma.