A New Kmeans Clustering Algorithm for Point Cloud

Kun Zhang,Weihong Bi,Xiaoming Zhang,Xinghu Fu,Li Zhu,Kunpeng Zhou 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.9

With development of 3D scanner, it becomes more convenient to access point data. However, for processing the large-scale point cloud, it raised a new challenge for computer graphics. This paper places an emphasis on the point data own characteristics, and then the point data have been divided into certain point sets by clustering algorithm, that is will be divided into different clusters. In order to suit for the point data organization or space division, the clustering algorithm would be improved. This paper provided a new Kmeans algorithm with density constraints. Before processing the point cloud by Kmeans algorithm with density constraints, the density of the point cloud have been defined in this paper, the density of the point cloud can be used for quantification of the convergence. Finally, the Kmeans algorithm with density constraints is verified by the experiment results. Our experiment showed that the improved Kmeans can reduce the processing time, especially, As the increase of the value of K, that is number of cluster, the calculating time of the clustering algorithm can be decreased greatly. In addition, with the increases of the the scale of data size, the stability of the improved Kmeans algorithm has been verified.

Expression of Serum PTTG1 in Laryngeal Carcinoma and Its Correlation to Prognosis

Kunpeng Ma,Xiuxia Sun,Limin Ma,Shenglin Zhang 대한이비인후과학회 2020 Clinical and Experimental Otorhinolaryngology Vol.13 No.1

Objectives. The purpose of this study was to investigate serum pituitary tumor transforming gene (PTTG1) expression in laryngeal carcinoma and its relationship with the clinical pathological characteristics and prognosis. Methods. Expression of serum PTTG1 was measured by enzyme-linked immunosorbent assay in 110 patients with laryngeal carcinoma and 60 patients with vocal cord polyps. Expression of the serum PTTG1 levels relationship with the clinicopathological characteristics and prognosis were analyzed. Results. In laryngeal carcinoma patients’ serum, the PTTG1 median concentration was 141.43 pg/mL (interquartile range [IQR], 111.387 to 160.837 pg/mL), significantly higher than that of the vocal cord polyp group of 94.01 pg/mL (IQR, 81.26 to 108.59 pg/mL), and the difference was statistically significant (z=–6.715, P<0.001). PTTG1 expression with lymph node metastasis, clinical stage, and patients with laryngeal carcinoma was significantly correlated with the tumor differentiation degree (P<0.05). The total survival rate of the PTTG1 high expression group was significantly lower than the low expression group, and the difference of total survival time of the two groups was statistically significant (P<0.001). Conclusion. The PTTG1 expression level can be used as an index for evaluating prognosis of laryngeal cancer. High PTTG1 expression is one of the factors of poor prognosis of laryngeal carcinoma patients.

Phtotoelectrochemical water oxidation to H2O2 based on N-TiO2 derived from NH2-MIL-125 and in-situ application on degradation dye

Kunpeng Liu,Nan Wang,Jianhua Li,Fanglin Du,Baorong Hou,Ruiyong Zhang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Electrochemical two-electron water oxidation reaction (2e WOR) to produce H2O2 has been widely concerned. However, four-electron competition reaction causes the large overpotential and low productionrates of 2e WOR, which restrict its’ development and application. Herein, we prepared N-TiO2 derivedfrom NH2-MIL-125 by the hydrothermal combined with calcination method. We found that N-TiO2 asphotoanode exhibited the well properties of photoelectrocatalysis water oxidation, which gave an overpotentialof 630 mV at 1 mA cm2. The overpotentials of N-TiO2 was approximately 130 mV (at1 mA cm2) lower than NH2-MIL-125, and even lower than the previous reported TiO2, which may attributeto the increased oxygen vacancy with the calcination process and N doping. In addition, we investigatedthe degradation performance of the prepared catalysts to degrade methylene blue byphotoelctrocatalysis on-site the preparation of H2O2. It was shown that N-TiO2 performed high degradationefficiency (91%) and excellent stability. The possible mechanism was speculated due to theincreased oxygen vacancy and N doping. This work provides a new idea for photoelectrocatalysis wateroxidation materials and points out a new way for on-site H2O2 production for direct use

Topology and start-up strategy for DC-DC transformers based on voltage balancing unit

Zhang, Jialin,Zha, Kunpeng,Tang, Xiaojun,Yang, Yuefeng,Yan, Hui,Wen, Fuyue,Shi, Mingming The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.7

As a core piece of equipment in DC distribution networks, DC solid-state transformers (DCSSTs) are attracting more and more attention in academia and industry. Due to the limitations in terms of the electrical stress of the switches, the input series output parallel (ISOP) structure is adopted in DCSSTs. This paper proposed an improved DCSST topology based on a voltage balancing unit (VBU). This topology has the advantages of higher power density, reduced weight, and cascaded number without compromising efficiency, cost, or reliability. The working modes, mathematical models, and control strategy are analyzed. In addition, a start-up strategy and a parameter design method are proposed in this paper. Simulation and experimental results verify the correctness and effectiveness of the proposed solution. The proposed DCSST is a practical scheme for the application of DC distribution networks.

Effect of naphthalene quinoline and H2S on DBT hydrodesulfurization over unsupported NiMoW catalyst

Changlong Yin,Haonan Zhang,Tongtong Wu,Zhuyan Wu,Kunpeng Li,Yan Kong,Chengwu Dong,Chenguang Liu 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.12

Unsupported catalysts have attracted much attention for high activity in comparison with the traditional supported catalyst. Meanwhile, the clear structure of unsupported catalysts is helpful for the recognition of active phase for conducting the industry production. The NiMoW unsupported catalyst was prepared by hydrothermal synthesis and characterized by BET, XRD and HRTEM. The effects of naphthalene, quinoline and H2S on the hydrodesulfurization reactivity of dibenzothiophene (DBT) were investigated in both a batch autoclave and a continuous 10 ml fixed bed micro-reactor over NiMoW and supported catalyst for comparison. The results showed that the hydrogenation reaction and the hydrogenolysis reaction occurred on different active sites. For supported catalyst, the inhibition was relatively weaker, and the inhibition of the hydrodesulfurization pathway was much higher than the direct desulfurization pathway. Although unsupported catalyst was very sensitive to quinoline and H2S in this experiment, the HDS ratio on the unsupported catalyst was maintained at a high level above 99.7%, which is attributed to the very high active site density of unsupported catalysts.

Bioinformatic and integrated analysis identifies an lncRNA–miRNA–mRNA interaction mechanism in gastric adenocarcinoma

Yong Liao,Wen Cao,Kunpeng Zhang,Yang Zhou,Xin Xu,Xiaoling Zhao,Xu Yang,Jitao Wang,Shouwen Zhao,Shiyu Zhang,Longfei Yang,Dengxiang Liu,Yanpeng Tian,Weizhong Wu 한국유전학회 2021 Genes & Genomics Vol.43 No.6

Background lncRNAs–miRNAs–mRNAs networks play an important role in Gastric adenocarcinoma (GA). Identifcation of these networks provide new insight into the role of these RNAs in gastric cancer. Objectives Biological information databases were screened to characterize and examine the regulatory networks and to further investigate the potential prognostic relationship this regulation has in GA. Methods By mining The Cancer Genome Atlas (TCGA) database, we gathered information on GA-related lncRNAs, miRNAs, and mRNAs. We identifed diferentially expressed (DE) lncRNAs, miRNAs, and mRNAs using R software. The lncRNA–miRNA–mRNA interaction network was constructed and subsequent survival examination was performed. Representative genes were selected out using The Biological Networks Gene Ontology plug-in tool on Cytoscape. Additional analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms were used to screen representative genes for functional enrichment. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) were used to identify the expression of fve candidate diferential expressed RNAs. Results Information of samples from 375 cases of gastric cancer and 32 healthy cases (normal tissues) were downloaded from the TCGA database. A total of 1632 DE-mRNAs, 1008 DE-lncRNAs and 104 DE-miRNAs were identifed and screened. Among them, 65 DE-lncRNAs, 10 DE-miRNAs, and 10 DE-mRNAs form lncRNAs–miRNAs–mRNAs regulatory network. Additionally, 10 lncRNAs and 2 mRNAs were associated with the prognosis of GA. Multivariable COX analysis revealed that AC018781.1 and VCAN-AS1 were independent risk factors for GA. GO functional enrichment analysis found DE-mRNA was signifcantly enriched TERM (P<0.05). The KEGG signal regulatory network analysis found 11 signifcantly enrichment networks, the most prevailing was for the AGE-RAGE signaling pathway associated with Diabetic complications. Results of RT-qPCR was consistent with the in silico results. Conclusions The results of the present study represent a view of GA from a analysis of lncRNA, miRNA and mRNA. The network of lncRNA–miRNA–mRNA interactions revealed here may potentially further experimental studies and may help biomarker development for GA.

Theoretical and numerical investigation on impact noise radiated by collision of two cylinders

Yinggang Li,Tianning Chen,Xiaopeng Wang,Kunpeng Yu,Chao Zhang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.6

Impact noise characterized by high peak value and short duration is very common source of noise in the industries and in many casescan be summed up in the noise radiated by collision of two cylinders. In order to precisely predict the impact noise radiated by collisionof two cylinders, a modified theoretical prediction model was established based on the Palmgren’s cylinder contact empirical model andacoustics theory. Then a numerical simulation method combining the finite element method (FEM) and the transient boundary elementmethod (TBEM) had been presented to verify the modified theoretical model and further discuss the mechanism of impact noise. Boththe contact force and impact noise of collision cylinders by the modified theoretical model were compared with the numerical results aswell as the prediction results by the original theoretical model. It indicated that the results by modified theoretical prediction model are ingood agreement with the numerical results, indicating better prediction superior to the original model. The impact noise radiated by collisioncylinders is attributed to the rigid body acceleration. Furthermore, the experimental validations were conducted to verify the modifiedtheoretical prediction model and numerical simulation results.

Transcriptome profiling analysis reveals the role of Elongases in development and reproduction of Tribolium castaneum

Xue Shuang,Gao Shanshan,Cao Yizhuo,Gao Tian,Yin Se,Zhang Yong-lei,Lu Ruixue,Zhang Kunpeng 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.2

Elongases (ELO) is a large class of enzymes involved in the development and reproduction of insects. Although some ELOs have been isolated and characterized in a small number of insects, little is known about the specific function of ELOs in insects, especially in the regulatory mechanism of ELOs. In this study, the function and regulation of TcELO were investigated in Tribolium castaneum. Spatiotemporal expression profiling indicated that TcELO expressed in all development stages, and high expressed in the head, epidermis, and ovary of T. castaneum. By comparing the transcriptome profiles of RNAi-treated larvae (dsTcELO) and control larvae of T. canstaneum using RNA sequencing, 320 differentially expressed genes (DEGs) were identified from the ds-ELO-treated group. Compared with the control group, five genes including cytc2, sfxn3 and H2A.V were significantly up-regulated in the dsTcELO group, suggesting that TcELO may be involved in the apoptosis of insect biological cells to control the growth and development system of insects. However, NAT was significantly down-regulated, indicating that it cooperates with TcELO to control the reproductive process of insects. Knockdown of TcELO also significantly up-regulated related genes in environmental adaptation pathways, such as COXIV, COXc6, and ATPs, which suggested that these genes may regulate TcELO to involve in epidermal function of insects and thier adaptability to the environment. These results provide new insights into the regulatory mechanism of TcELO involved in insect physiology, and can provide theoretical support for the control of agricultural pests.