Segmented Douglas-Peucker Algorithm Based on the Node Importance

( Xiaofei Wang ),( Wei Yang ),( Yan Liu ),( Rui Sun ),( Jun Hu ),( Longcheng Yang ),( Boyang Hou ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.4

Vector data compression algorithm can meet requirements of different levels and scales by reducing the data amount of vector graphics, so as to reduce the transmission, processing time and storage overhead of data. In view of the fact that large threshold leading to comparatively large error in Douglas-Peucker vector data compression algorithm, which has difficulty in maintaining the uncertainty of shape features and threshold selection, a segmented Douglas-Peucker algorithm based on node importance is proposed. Firstly, the algorithm uses the vertical chord ratio as the main feature to detect and extract the critical points with large contribution to the shape of the curve, so as to ensure its basic shape. Then, combined with the radial distance constraint, it selects the maximum point as the critical point, and introduces the threshold related to the scale to merge and adjust the critical points, so as to realize local feature extraction between two critical points to meet the requirements in accuracy. Finally, through a large number of different vector data sets, the improved algorithm is analyzed and evaluated from qualitative and quantitative aspects. Experimental results indicate that the improved vector data compression algorithm is better than Douglas-Peucker algorithm in shape retention, compression error, results simplification and time efficiency.

Latent Classes of Circadian Type and Presenteeism and Work-Related Flow Differences Among Clinical Nurses: A Cross-Sectional Study

Xiaofei Kang,Lijuan Yang,Linjing Xu,Yang Yue,Min Ding 대한신경정신의학회 2022 PSYCHIATRY INVESTIGATION Vol.19 No.4

Objective To classify the characteristics of circadian type among clinical nurses and examine their relationships with presenteeism and work-related flow.Methods Using a cross-sectional design, 568 nurses were recruited through convenience sampling in January 2021 from three hospitals in Shandong Province, China. The data were collected using self-report measures, including the 11-item Circadian Type Inventory, Stanford Presenteeism Scale-6, and Work-Related Flow Inventory. Latent class analysis was performed to identify any clustering of circadian types. One-way analysis was performed to compare the differences between presenteeism and work-related flow in different circadian types.Results Four latent classes were identified, including high response class (14.4%), high flexible class (20.1%), high languid class (51.1%), and low response class (14.4%). Regarding presenteeism, the high languid class had higher scores than others. Regarding work-related flow, the scores of high flexible class were higher than those of high languid class, while the differences in all three dimensions were statistically significant.Conclusion Although the shift work mode is not expected to change, nursing managers could use circadian type as a predictive index to select and employ individuals for shift work to enhance work performance and provide sufficient support to staff who are intolerant to shift work.

Analysis of Factors Influencing the Generation of Unqualified Clinical Samples and Measures to Prevent this Generation

Xiaofei Lai,Ping Yang,Yuhong Zhang,Ju Cao,Liping Zhang 대한진단검사의학회 2012 Annals of Laboratory Medicine Vol.32 No.3

Background: We investigated the influence of pre-analytical factors on the results of clinical tests and thereby analyzed approaches to improve quality management in clinical laboratories. Methods: Unqualified clinical samples were selected from all the samples received at our clinical laboratory. The data were collected for 2009 and 2010, i.e., the years before and after the establishment of the laboratory quality management system. The rate and causes of generation of unqualified samples were analyzed, and measures to improve the laboratory practices were studied and implemented. Results: A total of 1,051 unqualified samples were identified from among the 553,158 samples (the overall incidence rate of unqualified samples was 0.19%). The number of unqualified samples substantially varied according to the nature of the sample, and clinical samples collected for routine blood tests or coagulation tests were the predominant unqualified samples. The main causes of generation of unqualified samples were insufficient sample volumes and improper methods of mixing the samples. The rate of generation of unqualified samples decreased significantly after the implementation of improvement measures (0.26% in 2009 vs. 0.13% in 2010, P<0.001). Conclusions: The number of unqualified samples decreased significantly after the establishment of the laboratory quality management system, which promoted active communication among and training of the clinical staff to reduce the occurrence of pre-analytical errors. Comprehensive control of pre-analytical factors is an important approach in improving the clinical laboratory practices.

Research on Embedded Network Real-Time Video Monitoring System Based on Zynq

Yang Nie,Xiaofei Yin,Yu Hu,Hanbin Xu,Ruofei Yan 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.11

With the improvement of the performance of the embedded processor, the real-time network video monitoring system based on embedded technology becomes a developing direction of the network video with its low price and portability. In this paper, software and hardware co-design method is adopted to design an embedded system. ARM of the Zynq chip is responsible for embedded system structures and high definition video processing, and FPGA is used to design other logic and hardware expansion. Compared with the traditional network video monitoring technology, the embedded network video monitoring technology based on Zynq not only improves the quality of the image, but also has better real-time performance and scalability.

Abnormal Event Detection in Nature Settings

Yang Liu,Yibo Li,Xiaofei Ji 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.4

MiR-218-5p Suppresses the Killing Effect of Natural Killer Cell to Lung Adenocarcinoma by Targeting SHMT1

Quanjun Yang,Jingjing Li,Yili Hu,Xiaofei Tang,Lili Yu,Lihua Dong,Diandian Chen 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.6

Purpose: Lung adenocarcinoma (LA) is one of the major types of lung cancer. MicroRNAs (miRNAs) play an essential role in regulatingresponses of natural killer (NK) cells to cancer malignancy. However, the mechanism of miR-218-5p involved in the killingeffect of NK cells to LA cells remains poorly understood. Materials and Methods: The expression of miR-218-5p was examined by quantitative real-time polymerase chain reaction (qRTPCR). Serine hydroxymethyl transferase 1 (SHMT1) level was detected by qRT-PCR or western blots. Cytokines production ofinterferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) were detected by ELISA. The killing effect of NK cells to LA cells was investigatedusing lactate dehydrogenase cytotoxicity assay kit. The interaction of miR-218-5p and SHMT1 was probed by luciferaseactivity assay. Xenograft model was established to investigate the killing effect of NK cells in vivo. Results: miR-218-5p was enhanced and SHMT1 was inhibited in NK cells of LA patients, whereas stimulation of interleukin-2(IL-2) reversed their abundances. Addition of miR-218-5p reduced IL-2-induced cytokines expression and cytotoxicity in NK-92against LA cells. Moreover, SHMT1 was negatively regulated by miR-218-5p and attenuated miR-218-5p-mediated effect on cytotoxicity,IFN-γ and TNF-α secretion in IL-2-activated NK cells. In addition, miR-218-5p exhaustion inhibited tumor growth bypromoting killing effect of NK cells. Conclusion: miR-218-5p suppresses the killing effect of NK cells to LA cells by targeting SHMT1, providing a potential target forLA treatment by ameliorating NK cells function.

Thermal field of large-diameter concrete filled steel tubular members under solar radiation

Daigeng Yang,Guorong Chen,Xiaofei Ding,Juncai Xu 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.26 No.4

Concrete-filled steel tubular (CFST) members have been widely used in engineering, and their tube diameters have become larger and larger. But there is no research on the thermal field of large-diameter CFST structure. These studies focused on the thermal field of the large-diameter CFST structure under solar radiation. The environmental factors and the actual placement position were considered, and the finite element model (FEM) of the thermal field of CFST members under solar radiation (SR) was established. Then the FEM was verified by practical experiments. The most unfavorable temperature gradient model in the cross-section was proposed. The testing results showed that the temperature field of the large-diameter CFST member section was non-linearly distributed due to the influence of SR. The temperature field results of CFST members with different pipe diameters indicated that the larger the core concrete diameter was, the slower the central temperature changed, and there was a significant temperature difference between the center and the boundary. Based on the numerical model, the most unfavorable temperature gradient model in the section was proposed. The model showed that the temperature difference around the center of the circle is small, and the boundary temperature difference is significant. The maximum temperature difference is 15.22°C, which appeared in the southern boundary area of the specimen. Therefore, it is necessary to consider the influence of SR on the thermal field of the member for large-diameter CFST members in actual engineering, which causes a large temperature gradient in the member.

Displacement aging component-based stability analysis for the concrete dam

Huang, Xiaofei,Zheng, Dongjian,Yang, Meng,Gu, Hao,Su, Huaizhi,Cui, Xinbo,Cao, Wenhan Techno-Press 2018 Geomechanics & engineering Vol.14 No.3

The displacement monitoring data series reconstruction method was developed under equal water level effects based on displacement monitoring data of concrete dams. A dam displacement variation equation was set up under the action of temperature and aging factors by optimized analysis techniques and then the dam displacement hydraulic pressure components can be separated. Through the dynamic adjustment of temperature and aging effect factors, the aging component isolation method of dam displacement was developed. Utilizing the isolated dam displacement aging components, the dam stability model was established. Then, the dam stability criterion was put forward based on convergence and divergence of dam displacement aging components and catastrophe theory. The validity of the proposed method was finally verified combined with the case study.

Highly Reliable Product Code for Error Correction

Bingrui Wang,Xiaofei Yang,Xingzhong Yao,Hongzhi Zhang,Yue Zhang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.8

In storage and communication systems, the product and concatenation codes, which consist of Reed–Solomon (RS) codes and other error-correction codes, can be utilized to effectively correct burst errors by performing erasures-and-errors decoding. However, the RS codes have two drawbacks: 1) the RS decoders may not detect received erroneous codewords, and 2) the RS decoders may generate valid codewords which are not equal to the transmitted codewords. In the implementation of the product and concatenation codes, such decoding drawbacks can cause the RS code to provide incorrect error-detection information or erasure information to other error-correction codes, resulting in unreliable error-correction performance of the systems. In this study, we propose a new product code to overcome these drawbacks by studying the RS product code (RSPC). The new code combines CRC code with RSPC which is called as CRSPC. In addition, the results of experiments show that the new CRSPC can significantly reduce the probabilities of these drawbacks, thereby improving the performance of erasures-and-errors decoding. With minor modifications, the CRSPC algorithm can be applied to Blue-ray disc systems which have powerful recording functions in multimedia.

A new virtual-real gravity compensated inverted pendulum model and ADAMS simulation for biped robot with heterogeneous legs

Hualong Xie,Xiaofei Zhao,Qiancheng Sun,Kun Yang,Fei Li 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

Our research team combined humanoid robots with intelligent lower limb prostheses to study the dynamic characteristics of intelligent lower extremity prostheses for disabled people in the walking process, and proposed a biped robot with heterogeneous legs (BRHL). This paper proposes a new virtual-real inverted pendulum system model to unify the models for both single support phase and double support phase in walking process and builds a special simulation platform which can acquire the real-time center of mass (COM) trajectory. Initially, a gravity-compensated inverted pendulum model was built and improved the stability of gait, a natural ZMP trajectory improved the anthropomorphism of the gait. Furthermore, in double support phase, a virtual inverted pendulum model was established and a virtual-real inverted pendulum model was proposed and used to plan the gait of both single support phase and double support phase in the walking process. Additionally, the joint angles were obtained by inverse kinematics; the stability of the system was analyzed to be feasible and effective by phase trajectories. A special ADAMS simulation platform was built to simulate the walking process and acquire real-time COM trajectory. The feasibility of the gait planning was also verified. Finally, the trajectory of COM was optimized based on the minimum energy criterion according to the geodesic equation.