Improvement of OPW-TR Algorithm for Compressing GPS Trajectory Data

( Qingbin Meng ),( Xiaoqiang Yu ),( Chunlong Yao ),( Xu Li ),( Peng Li ),( Xin Zhao ) 한국정보처리학회 2017 Journal of information processing systems Vol.13 No.3

Massive volumes of GPS trajectory data bring challenges to storage and processing. These issues can be addressed by compression algorithm which can reduce the size of the trajectory data. A key requirement for GPS trajectory compression algorithm is to reduce the size of the trajectory data while minimizing the loss of information. Synchronized Euclidean distance (SED) as an important error measure is adopted by most of the existing algorithms. In order to further reduce the SED error, an improved algorithm for open window time ratio (OPW-TR) called local optimum open window time ratio (LO-OPW-TR) is proposed. In order to make SED error smaller, the anchor points are selected by calculating point`s accumulated synchronized Euclidean distance (ASED). A variety of error metrics are used for the algorithm evaluation. The experimental results show that the errors of our algorithm are smaller than the existing algorithms in terms of SED and speed errors under the same compression ratio.

Improvement of OPW-TR Algorithm for Compressing GPS Trajectory Data

Meng, Qingbin,Yu, Xiaoqiang,Yao, Chunlong,Li, Xu,Li, Peng,Zhao, Xin Korea Information Processing Society 2017 Journal of information processing systems Vol.13 No.3

Massive volumes of GPS trajectory data bring challenges to storage and processing. These issues can be addressed by compression algorithm which can reduce the size of the trajectory data. A key requirement for GPS trajectory compression algorithm is to reduce the size of the trajectory data while minimizing the loss of information. Synchronized Euclidean distance (SED) as an important error measure is adopted by most of the existing algorithms. In order to further reduce the SED error, an improved algorithm for open window time ratio (OPW-TR) called local optimum open window time ratio (LO-OPW-TR) is proposed. In order to make SED error smaller, the anchor points are selected by calculating point's accumulated synchronized Euclidean distance (ASED). A variety of error metrics are used for the algorithm evaluation. The experimental results show that the errors of our algorithm are smaller than the existing algorithms in terms of SED and speed errors under the same compression ratio.

A WIND TUNNEL EXPERIMENTAL STUDY OF ICING ON WIND TURBINE BLADE AIRFOIL

Yan LI,Kotaro TAGAWA,Fang FENG,Qingbin HE,Qiang LI 한국신재생에너지학회 2012 AFORE Vol.2012 No.-

Digital finance, absorptive capacity and enterprise dual innovation: an empirical analysis on mediation and threshold effects

Li Yongkui,Liu Xiaokang,Zhao Qingbin 기술경영경제학회 2023 ASIAN JOURNAL OF TECHNOLOGY INNOVATION Vol.31 No.2

Based on the data of listed companies in Chinese A stock marketbetween 2011 and 2020, This paper discusses the empiricalanalysis of digitalfinance on enterprise dual innovation byadopting the mediating effect model and threshold regressionmodel, and estimates the mediation and threshold effects ofabsorptive capacity among them. Our studyfind that thedevelopment of digitalfinance exerts a significant positive effecton enterprise dual innovation. Compared with exploitativeinnovation, digitalfinance exhibits a greater promoting effect onexploratory innovation. Absorptive capacity displays a greatermediating effect between digitalfinance and exploratoryinnovation, and exploitative innovation reveals a significantpositive effect on exploratory innovation. There is non-linearrelationship between digitalfinance and corporate dualinnovation, and the promotion effect shows a leaping growthpattern and significant threshold effect. The heterogeneityanalysis from the perspective of property rights and enterprisesize shows that the incentive effect of digitalfinancedevelopment on enterprises dual innovation is mainly reflected innon-state-owned enterprises and small and medium-sizedenterprises. This research expands the relevant theories ofcorporate innovation and digitalfinance, to provides empiricalevidence for corporate decision-making.

Optimization of ultrasound-assisted magnetic retrieval-linked ionic liquid dispersive liquid–liquid microextraction for the determination of cadmium and lead in water samples by graphite furnace atomic absorption spectrometry

Li Yao,Xie Wang,Haitao Liu,Chaowen Lin,Liangyu Pang,Junwei Yang,Qingbin Zeng 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-

A simple and efficient method for the determination of Cd and Pb in water samples was developed byultrasound-assisted magnetic retrieval-linked ionic liquid dispersive liquid–liquid microextraction (UA-MR-IL-DLLME) preconcentration and graphite furnace atomic absorption spectrometry (GFAAS)detection. Ionic liquid (IL) [Hmim] [PF6] was used as the extractant, ammonium pyrrolidinedithiocarbamate (APDC) as the complexing agent and Fe3O4 nanoparticles as the sorbent, whileultrasound was applied to assist the dispersion of the extractant and accelerate the mass transfer process. The effect of different factors on the extraction efficiency including pH, IL volume, APDC amount,ultrasound extraction time, ultrasound desorption time and Fe3O4 amount was studied by a fractionalfactorial design to screen for the most important factors. Then a central composite design was used tooptimize the significant factors. Under the optimal conditions, the method has linear calibration curvesover the range of 0.3–20 ng/mL for Cd and 0.5–40 ng/mL for Pb, with correlation coefficients (R) of0.9990 and 0.9986 for Cd and Pb, respectively. The limits of detection were 0.1 ng/mL and 0.15 ng/mL withrelative standard deviations of 3.4% and 2.8% for Cd and Pb, respectively. Finally, the method wassuccessfully applied for the determination of Cd and Pb in the real water samples and satisfactoryrecoveries were achieved.

Cooperative Task Scheduling and Planning Considering Resource Conflicts and Precedence Constraints

Donghui Li,Hu Su,Xinyi Xu,Qingbin Wang,Jie Qin,Wei Zou 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.9

The robot-task-sequencing planning problem is investigated in this paper, where multi-robot tasks with resource conflicts and precedence constraints are involved making the problem challenging and complex. An effective approach is proposed to minimize the production cycle time while handling the high complexity effectively. The approach decouples the entire problem into simpler ones and then solves them separately to obtain the final solution. Firstly, given the multi-robot tasks, how to coordinate the operation of each single robot is determined. This is achieved by searching the shortest path in the graph where the tasks are organized in the optimal order without the consideration of resource constraints. Then, the resource allocation is modeled as a constrained assignment problem with the objective of minimal cycle time, which is solved with graph optimization. Consequently, the best-fit robot configurations for task execution are selected according to a heuristic optimality metric, based on which the task execution sequence obtained in previous steps is re-optimized. Finally, the robots involved in the task are regarded as a whole to deduce feasible trajectories. Experimental results demonstrate that the proposed approach can generate solutions where the robot can complete the given tasks effectively with feasible scheduling. Moreover, the proposed approach is successfully implemented in a pragmatic system which tests signals at both ends of components in a circuit board.

Analysis of Cable under Dynamic Contact and Large Deformation

Bingjian Wang,Qingbin Li,Tianyun Liu,Weibing Peng 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.4

For simulating contact interactions and high displacement gradients between the cable and the saddle at the middle tower of tripletower suspension bridges, a cable element is developed by combining the absolute nodal coordinate formulation and the quasiconforming technique. New curvature strains are developed and elastic forces are explicitly formulated for the cable elements. Thereafter, it is compared to the original one to verify its locking remedies. The numerical solutions using the element are compared to analytical results and solutions by the original element. Compared to the original, the proposed element suppresses the highfrequency disturbances in the velocity and acceleration curves. Using the element, the contact and sliding behavior between the cable and the saddle is analyzed by employing parameters obtained experimentally. The saddle’s mechanical and frictional performance subjected to different friction coefficients and unbalanced cable forces is investigated. The proposed model exhibits excellent accuracy in the prediction of the sliding force and the contact status between the cable and the saddle.

Molecular engineering of indoline based organic sensitizers for highly efficient dye-sensitized solar cells

Liu, Bo,Liu, Qingbin,You, Dan,Li, Xiaoyan,Naruta, Yoshinori,Zhu, Weihong The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.26

<P>The increasing electron-donating ability of the donor part is focused to further optimize the light-harvesting capability. Our strategy is to introduce an additional donor group into the indoline unit in the donor part to form a donor–donor structure (D–D moiety). Three different units (carbazole, fluorene and 4-methylphenyl groups) with different degrees of electron-donating capability are incorporated, thus constructing the specific donor–donor–π–acceptor (D–D–π–A) system (C-CA, F-CA and I-3) and giving a systematic view of the absorption evolution. Through molecular engineering, their light-harvesting capabilities, energy levels and photovoltaic performances were studied. As expected, utilizing strong electron-donating carbazole unit as additional donor, the IPCE spectrum of DSSC based on C-CA is successfully broadened to NIR region on the premise of suitable LUMO level, with an extraordinarily high plateau in visible region till around 700 nm. In the system of C-CA and F-CA, the introduction of <I>n</I>-pentyl group in donor part of carbazole and fluorene unit has little effect on preventing the molecular π-aggregation due to the good co-planarity of π-linker (vinyl thiophene), suggesting that the most effective way to prevent π-aggregation is still the incorporation of long alkyl groups into planar π-linker segment. However, the introducing long alkyl group can effectively prevent the electron recombination between electrons in conduction band (CB) of TiO<SUB>2</SUB> and I<SUB>3</SUB><SUP>−</SUP> ions. Along with the preferable light-harvesting capability, C-CA presents excellent IPCE performance with a short-circuit photocurrent (<I>J</I><SUB>sc</SUB>) of 18.53 mA cm<SUP>−2</SUP>, an open-circuit photovoltage (<I>V</I><SUB>oc</SUB>) of 649 mV, a fill factor of 0.71, corresponding to a power conversion efficiency (<I>η</I>) of 8.49%. The internal relations between chemical structure and conversion efficiency provide a strategy for developing highly efficient organic sensitizers working in whole visible region with high photovoltaic performance.</P> <P>Graphic Abstract</P><P>Utilizing a carbazole unit as additional donor, the photoresponse of C-CA is broadened to the NIR region with a <I>η</I> of 8.49%. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm31704d'> </P>

EXPLICIT FORMULAS FOR THE BERGMAN KERNEL ON CERTAIN FORELLI-RUDIN CONSTRUCTION

Zhang, Liyou,Wang, An,Li, Qingbin Korean Mathematical Society 2012 대한수학회지 Vol.49 No.1

In this note, we present certain circular domain, named Forelli-Rudin construction or Hua construction, which is built on Cartan domains. We compute the explicit Bergman kernel for it and get the corresponding weighted Bergman kernel on its base.

Explicit formulas for the Bergman kernel on certain Forelli-Rudin construction

Liyou Zhang,An Wang,Qingbin Li 대한수학회 2012 대한수학회지 Vol.49 No.1

In this note, we present certain circular domain, named Fore\-lli-Rudin construction or Hua construction, which is built on Cartan domains. We compute the explicit Bergman kernel for it and get the corresponding weighted Bergman kernel on its base.