HMM and HSS Based Social Behavior of Intelligent Vehicles for Freeway Entrance Ramp

Guangming Xiong,Yong Li,Shiyuan Wang,Xiaoyun Li,Peng Liu 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10

In this paper, a novel approach of intelligent vehicle to interact and cooperate with other human driving vehicles is proposed at the freeway entrance ramp scenario. The system consists of a Safety Alert Module and Vehicle Control Module. The Safety Alert System module includes intention estimation and conflict judgment. A two dimension Hidden Markov Model (2DHMM) is used to estimate social vehicle’s driving intention in the intention estimation module. Then the conflict judgment module predicts the potential conflicts between the intelligent vehicle and social vehicle. Moreover, the hybrid state system (HSS) is introduced to control the intelligent vehicle while considering its decision making, states and dynamics. Co-simulation using PreScan and Simulink is conducted. The experiment results show that the intelligent vehicle performs well with a commendable social behavior in the freeway entrance ramp.

Individualized Functional Decompression Options for Adult Chiari Malformation With Syringomyelia and A Novel Scale for Syringomyelia Resolution: A SingleCenter Experience

Shiyuan Han,Bo Hou,Zhimin Li,Feng Feng,Yongning Li,Jun Gao 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

Objective: To compare outcomes of posterior fossa bony decompression alone (PFD) versus PFD with duraplasty (PFDD) versus PFDD with additional obex exploration (PFDDO) in patients with Chiari malformation type I (CMI) combining syringomyelia. Methods: Clinical records of adult patients who underwent decompressions from 2014 to 2022 were retrospectively analyzed. The decompression procedure was individualized based on the cerebrospinal fluid pulse in the surgical field. The Chicago Chiari Outcome Scale (CCOS) was used to assess the prognosis of the patients and a novel syringomyelia resolution scale, based on 3-dimensional volume, was introduced. The percentage change in the cervical syrinx volume was classified as follows by resolution: ≥ 70%, 30%–70%, and < 30%. Results: Seventy-eight individuals were enrolled, of which 22, 20, and 36 underwent PFD, PFDD, and PFDDO, respectively. The three decompression groups had no significant difference in the preoperative characteristics and postoperative prognosis. Multivariate analyses revealed that better CCOS was significantly correlated with younger age at surgery (p = 0.018), syrinx originated from lower cervical levels (p = 0.037), narrower preoperative cerebral aqueduct (p = 0.005), and better syrinx volume resolution (p = 0.004). Additionally, a better cervical syrinx volume resolution was significantly correlated with higher CCOS (p = 0.017), narrower cerebral aqueduct (p = 0.035), and better tonsillar descent resolution (p = 0.007). Conclusion: Individualized functional decompression induced an equal effect on CCOS and syrinx volume resolution for all CMI patients with syringomyelia. Our syringomyelia resolution scale facilitates communication and prediction of CMI prognosis.

Study on Cooperative Air-to-Ground Surveillance Planning and Controlling for Unmanned Aerial Vehicles

Shiyuan Chai,Zhen Yang,Jichuan Huang,Xiaoyang Li,Yiyang Zhao,Deyun Zhou 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

The use of unmanned aerial vehicles (UAVs) for air-to-ground mission in complex environments has increased considerably in recent years. The numerous studies on UAVs cooperative air-to-ground mission controlling have been reported, but few have considered the impact of the communication instability due to electromagnetic interference (EMI) which is common in many air-to-ground applications. Under the influence of EMI, the air-to-ground mission stages are represented as a dynamic combination of several communication-available and communication-unavailable stages. Traditional cooperative surveillance algorithms cannot handle such situations well. In this study, we presented a method which based on Voronoi diagrams to solve the impact of communication outages, and an attention mechanism ant-colony optimization (AACO) algorithm was proposed for UAV path-planning control in air-to-ground surveillance missions. The controlling strategy is adaptively updated by introducing an attention mechanism for regular instruction information, a priori information, and emergent information of the mission to satisfy the mission target. Simulation results show that the proposed algorithm achieves better search performance than traditional algorithms in scenarios which include communication-available and communication-unavailable situations.

Modelling and Prediction of Stress Relaxation for Thermal Bonded Nonwoven Geotextiles

Shiyuan Sun,Xiaoping Gao,Chunhong Fu,Yudong Zhou,Xiaoying Wei,Jiaxin Li,Yiping Qiu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.7

Stress relaxation experiments were performed on three types of thermal bonded nonwoven geotextiles in this studyto model and predict their stress relaxation behaviors. Four mechanical models, including the standard linear solid mechanicsmodel, Eyring’s model, the modified two-Maxwell-unit model and the modified three-Maxwell-unit model were used topredict stress values for 600 h based on 3 and 90 h experimental relaxation data. Results indicated that Eyring’s model and themodified three-Maxwell-unit model fitted the experimental results better than the other two. Estimation using modified three-Maxwell-unit model seemed to construct an upper bound while that using Eyring’s model form a lower bound for thecorresponding experimental data. In addition, predicted curves were much closer to the experimental curve when equationsof the two models were built with the 90 h experimental data than those data of 3 h. Thus, the prediction capability of the twomodels can be substantially improved by employing the data with longer time. In summary, the combination of the modifiedthree-Maxwell-unit model and Eyring’s model can well forcast the range of actual stress during stress relaxation experimentswith the longer term experimental data.

Epidemiologic characteristics and a prognostic nomogram for patients with vulvar cancer: results from the Surveillance, Epidemiology, and End Results (SEER) program in the United States, 1975 to 2016

Shiyuan Wei,Lu Li,Tingting Yi,Licong Su,Qi Gao,Liangzhi Wu,Zhenbo OuYang 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.6

Objective: To elucidate clinical characteristics and build a prognostic nomogram for patients with vulvar cancer. Methods: The study population was drawn from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were randomly assigned to training and validation sets. Cox proportional hazards model and competing risk model were used to identify the prognostic parameters of overall survival (OS) and cancer-specific survival (CSS) to construct a nomogram. The nomogram was assessed by concordance index (C-index), area under the curve (AUC), calibration plot, and decision curve analysis (DCA). Results: A total of 20,716 patients were included in epidemiological analysis, of whom 7,025 patients were selected in survival analysis, including 4,215 and 2,810 in training and validation sets, respectively. The multivariate Cox model showed that the predictors for OS were age, marital status, histopathology, differentiation and tumor node metastasis (TNM) stages, whether to undergo surgery and chemotherapy. However, the predictors for CSS were age, race, differentiation and TNM stages, whether to undergo surgery and radiation. The C-index for OS and CSS in the training set were 0.76 and 0.80. The AUC in the training set for 1-, 3- and 5-year OS and CSS were 0.84, 0.81, 0.80 and 0.88, 0.85, 0.83, respectively, which was similar in the validation set. The calibration curves showed good agreement between prediction and actual observations. DCA revealed that the nomogram had a better discrimination than TNM stages. Conclusions: The nomogram showed accurate prognostic prediction in OS and CSS for vulvar cancer, which could provide guidance to clinical practice.

Extractive bioconversion of xylan for production of xylobiose and xylotriose using a PEG6000/sodium citrate aqueous two-phase system

Xin Li,Zhina Lian,Bo Dong,Yong Xu,Qiang Yong,Shiyuan Yu 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.9

Aqueous two-phase system (ATPS) was applied for extraction bioconversion of xylan by xylanase from Trichoderma viride. Phase diagrams for poly (ethylene glycol) (PEG) and sodium citrate were determined at room temperature. The ATPS composed of 12.99% (w/w) PEG6000 and 12.09% (w/w) sodium citrate was favorable for partition of xylanase and used for extraction bioconversion of xylan. Batch hydrolysis demonstrated that higher concentrations of xylobiose and xylotriose were obtained in the PEG6000/sodium citrate ATPS compared to those in the aqueous system. These results present the potential feasibility of production of xylo-oligosaccharides by extraction bioconversion in ATPS.

Effect of Ultrasonic Power on the Microstructure and Properties of 304 Stainless Steel Welded Joints Through Cold Metal Transfer Welding Assisted with Ultrasonication

Fei Li,Furong Chen,Peihu Gao,Wei Wang,Chenlong Yang,Shiyuan Liu 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.10

With the development of welding technology, low heat input and high efficiency cold metal transfer welding have become the main methods of thin plate welding. However, low heat input easily forms columnar crystals, which will endanger the mechanical properties of joints. Therefore, ultrasonication treatment was applied to the cold metal transfer welding of 304 stainless steel to conduct cold metal transfer welding assisted with ultrasonication in this paper. The comparison between cold metal transfer welding assisted with ultrasonication and cold metal transfer showed that the weld grain diameter obtained by cold metal transfer welding assisted with ultrasonication was finer. In the welded joint, the maximum grain size diameter of the weld seam in cold metal transfer welding assisted with ultrasonication decreased to 375 μm, and the maximum tensile strength of cold metal transfer welding assisted with ultrasonication increased to 734 MPa. The texture intensity of the weld seam in cold metal transfer was significantly greater than that of the weld seam in cold metal transfer welding assisted with ultrasonication, which was ascribed to the improvement of the microstructure of the weld seam in cold metal transfer welding assisted with ultrasonication. In cold metal transfer welding assisted with ultrasonication, the flow performance of the welding pool increased, and the ultrasonic cavitation degree was intensified. This resulted in the significant refinement of the weld grain, the reduction of texture intensity, and an increase in the tensile strength.

Detection and quantification of phenol in liquid and gas phases using a clay/dye composite

Guocheng Lv,Shiyuan Liu,Meng Liu,Libing Liao,Limei Wu,Lefu Mei,Zhaohui Li,Caofeng Pan 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.62 No.-

In this study, an organic dye lucigenin (BNMA) was successfully intercalated into the interlayer of montmorillonite (MMT) to prevent fluorescence quenching. With its enhanced fluorescent property, the composite was fabricated into solid strips for it fast and sensitive phenol detection in both liquid and gas phases. Under proper optimizations it is anticipated that the composite would show great potential for phenol determination in real world environment such as wastewater treatment industry.

Vertical dielectric screening of few-layer van der Waals semiconductors

Koo, Jahyun,Gao, Shiyuan,Lee, Hoonkyung,Yang, Li The Royal Society of Chemistry 2017 Nanoscale Vol.9 No.38

<P>Vertical dielectric screening is a fundamental parameter of few-layer van der Waals two-dimensional (2D) semiconductors. However, unlike the widely-accepted wisdom claiming that the vertical dielectric screening is sensitive to the thickness, our first-principles calculation based on the linear response theory (within the weak field limit) reveals that this screening is independent of the thickness and, in fact, it is the same as the corresponding bulk value. This conclusion is verified in a wide range of 2D paraelectric semiconductors, covering narrow-gap ones and wide-gap ones with different crystal symmetries, providing an efficient and reliable way to calculate and predict static dielectric screening of reduced-dimensional materials. Employing this conclusion, we satisfactorily explain the tunable band gap in gated 2D semiconductors. We further propose to engineer the vertical dielectric screening by changing the interlayer distance<I>via</I>vertical pressure or hybrid structures. Our predicted vertical dielectric screening can substantially simplify the understanding of a wide range of measurements and it is crucial for designing 2D functional devices.</P>

Demand‐based charging strategy for wireless rechargeable sensor networks

Ying Dong,Yuhou Wang,Shiyuan Li,Mengyao Cui,Hao Wu 한국전자통신연구원 2019 ETRI Journal Vol.41 No.3

A wireless power transfer technique can solve the power capacity problem in wireless rechargeable sensor networks (WRSNs). The charging strategy is a widespread research problem. In this paper, we propose a demand‐based charging strategy (DBCS) for WRSNs. We improved the charging programming in four ways: clustering method, selecting to‐be‐charged nodes, charging path, and charging schedule. First, we proposed a multipoint improved K‐means (MIKmeans) clustering algorithm to balance the energy consumption, which can group nodes based on location, residual energy, and historical contribution. Second, the dynamic selection algorithm for charging nodes (DSACN) was proposed to select on‐demand charging nodes. Third, we designed simulated annealing based on performance and efficiency (SABPE) to optimize the charging path for a mobile charging vehicle (MCV) and reduce the charging time. Last, we proposed the DBCS to enhance the efficiency of the MCV. Simulations reveal that the strategy can achieve better performance in terms of reducing the charging path, thus increasing communication effectiveness and residual energy utility.