Extraction of visual texture features of seabed sediments using an SVDD approach

Li, Yan,Liu, Shijie,Zhu, Puqiang,Yu, Jiancheng,Li, Shuo Pergamon Press 2017 Ocean engineering Vol.142 No.-

<P><B>Abstract</B></P> <P>Perception of the seabed environment is an important capability of autonomous underwater vehicles. This paper focuses on defining and extracting robust texture features from visual images that lead to useful and practical automated identification of the types of seabed sediments. The visual texture features are described by using a gray-level co-occurrence matrix (GLCM) and fractal dimension, after which an unsupervised learning method, self-organizing map (SOM), is adopted to evaluate the validity of features descriptors on three types of seabed sediments. Subsequently, a kernel-based approach that exhibits robustness versus low numbers of high-dimensional samples, named support vector domain description (SVDD), is applied to classify the types of seabed sediments. In comparison with state-of-the-art classifiers, the experimental results demonstrated the effectiveness of the SVDD on the classification of seabed sediments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The visual images of seabed sediments are characterized by the texture features which are extracted based on the GLCM and fractal theory. </LI> <LI> A multi-class classification strategy for seabed sediments is proposed by adding a distance measure after SVDD implementation. </LI> <LI> The experimental results demonstrate that the proposed classification strategy is feasible in recognizing the type of seabed sediments. </LI> </UL> </P>

Firm size affecting efficiency of production and commercialization of knowledge: embedded in cluster development

Li Yawen,Zhong Zhou,Guan Jiancheng,Zhou Jinyi,Li Jizhen 기술경영경제학회 2020 ASIAN JOURNAL OF TECHNOLOGY INNOVATION Vol.28 No.1

This study examines the impact of platform innovation on the efficiency of firms located in different clusters. The sample contains data for 1,257 firms from 2005 to 2015 in Beijing’s Zhongguancun Science Park, which is known as China’s ‘Silicon Valley’. Using the DEA model to gauge the efficiency of each firm over time, we found that firm size has a significantly negative correlation with knowledge production efficiency, a significantly positive correlation with its knowledge commercialisation efficiency, and an inverted-U shaped relationship with overall efficiency. We then explored the mediating effect of firm size on the relationship between the characteristics of clusters and firm efficiency, before concluding with both managerial and academic implications.

Discrete-time Linear Descriptor System Unknown Input Observer Design: an Auxiliary Output-based Approach

Jiancheng Zhang,Jun Li,Fanglai Zhu,Xiaohang Li 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.6

This paper develops a new unknown input observer (UIO) design method for a class of discrete-timelinear descriptor systems when the observer matching condition is not satisfied. By equivalent transformations, thestate and unknown input observations of the descriptor system are changed to the UIO design problem for a generallinear dynamic system firstly. Then based on some further discussion on the concept of the system left invertibility,a new auxiliary output vector is constructed which allows us to remove the unknown inputs from the dynamicequation, and thereby a Luenberger-type observer can be constructed. One of the advantages of the present methodis that it can work only under the single strongly detectable condition. Finally, a simulation example is given toverify the effectiveness and show the superiorities of our methods.

Partition-based 3 + 2-axis tool path generation for freeform surface machining using a non-spherical tool

Hao Jiancheng,Li Zhaoyu,Li Xiangyu,Xie Fubao,He Dong,Tang Kai 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.5

When machining a complex freeform part, using a non-spherical tool could significantly improve the machining efficiency, as one can adaptively adjust the tool posture to maximize its contact area with the part surface. However, since adjusting the tool posture requires changing the tool orientation, a five-axis machine tool is needed, which is extremely expensive as compared to a conventional three-axis machine tool. Moreover, for a complex freeform surface with high curvature variation, to match its curvature change, the tool axis has to drastically change accordingly, thus inducing high velocity and acceleration on the machine tool’s rotary axes. To address these issues, in this paper we propose a partition-based 3 + 2-axis strategy for machining a general complex freeform surface with a non-spherical tool. As only a finite small number of distinct tool orientations are needed for 3 + 2-axis machining, an indexed three-axis machine tool suffices, thus relieving the need of an expensive five-axis machine tool. In addition, the much-increased rigidity of the three linear axes of the machine tool will greatly improve the kinematics and dynamics of the machine tool and thus enhance the machining accuracy. Experiments in both computer simulation and physical machining are carried out, whose results confirm that, when compared to using a conventional spherical cutter, by using a non-spherical cutter and adaptively adjusting the contacting tool posture and the feed direction, significant improvement in machining efficiency could be achieved, e.g., more than 50% achieved in our experiments.

Long non-coding RNA NEAT1 decreases the chemosensitivity of gastric cancer cells via regulating P-glycoprotein expression

Jian Wang,Qiong Niu,Ning Shi,Chengxia Liu,Haifeng Lian,Jiancheng Li,Kun Li,K. Li 대한독성 유전단백체 학회 2017 Molecular & cellular toxicology Vol.13 No.3

Drug resistance remains to be one of the major challenges in clinical treatment of gastric cancer (GC). Accumulating evidences have highlighted the involvement of long non-coding RNA (lncRNA) in carcinogenesis, chemoresistance, and metastasis. NEAT1, a recently identified lncRNA, was identified as an oncogene to regulate carcinogenesis. This present study aimed to investigate the role of NEAT1 in the drug resistance in GC. Our study found that NEAT1 expression was significantly upregulated in relapsed GC patients and cisplatin (CDDP)-resistant cell lines compared with primary GC patients and parental GC cell lines. NEAT1 upregulation was largely companied with the induction of P-gp. Overexpression of NEAT1 significantly increased the expression of several drug-resistance proteins, thereby compromising the sensitivity of GC cells to CDDP. In contrast, NEAT1 knockdown by RNAi did the opposite. Therefore, lncRNA NEAT1 is an important modulator for drug resistance of GC via promoting the expression of P-gp and other associated proteins.

A Novel Passivity-Based Resonant Instability Suppression Method for Grid-Connected VSC

Jiancheng Zhao,Kai Li,Xiaodong Wang,Chuan Xie,Hongbing Xu 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

The interaction between the three-phase voltage source converters (VSCs) and the power grid may cause high-frequency resonant instable problems. Studies have indicated that the non-passivity of VSCs is the main reason that leads to the resonances. The above-mentioned passive means that the equivalent output admittance of the VSC has a positive real part. In this paper, a novel damped Smith predictor is proposed to suppress the resonant instability problem that caused by time delay. The research proved that the proposed Smith predictor can signifi cantly improve the passivity of the VSC by reducing the width of the negative real part at the high-frequencies. Simulation and experimental results demonstrate that the proposed Smith predictor can distinctly improve the robustness of the VSC.

The triply periodic minimal surface-based 3D printed engineering scaffold for meniscus function reconstruction

Lan Li,Peng Wang,Jing Jin,Chunmei Xie,Bin Xue,Jiancheng Lai,Liya Zhu,Qing Jiang 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: The meniscus injury is a common disease in the area of sports medicine. The main treatment for this disease is the pain relief, rather than the meniscal function recovery. It may lead to a poor prognosis and accelerate the progression of osteoarthritis. In this study, we designed a meniscal scaffold to achieve the purposes of meniscal function recovery and cartilage protection. Methods: The meniscal scaffold was designed using the triply periodic minimal surface (TPMS) method. The scaffold was simulated as a three-dimensional (3D) intact knee model using a finite element analysis software to obtain the results of different mechanical tests. The mechanical properties were gained through the universal machine. Finally, an in vivo model was established to evaluate the effects of the TPMS-based meniscal scaffold on the cartilage protection. The radiography and histological examinations were performed to assess the cartilage and bony structures. Different regions of the regenerated meniscus were tested using the universal machine to assess the biomechanical functions. Results: The TPMS-based meniscal scaffold with a larger volume fraction and a longer functional periodicity demonstrated a better mechanical performance, and the load transmission and stress distribution were closer to the native biomechanical environment. The radiographic images and histological results of the TPMS group exhibited a better performance in terms of cartilage protection than the grid group. The regenerated meniscus in the TPMS group also had similar mechanical properties to the native meniscus. Conclusion: The TPMS method can affect the mechanical properties by adjusting the volume fraction and functional periodicity. The TPMS-based meniscal scaffold showed appropriate features for meniscal regeneration and cartilage protection.

The effect of Lfcin-B on non-small cell lung cancer H460 cells is mediated by inhibiting VEGF expression and inducing apoptosis

Shusheng Wang,Jiancheng Tu,Cuijie Zhou,Jianwei Li,Long Huang,Lei Tao,Lei Zhao 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.2

Lfcin-B, an antimicrobial peptide found invarious exocrine secretions of mammals, showed antitumoreffects. However, the effect and relative mechanism ofLfcin-B on non-small cell lung cancer is unclear. In thisstudy, assay of cell viability, quantitative real-time PCR,Western blot, annexin V/propidium iodide assay, flowcytometry and tumor-xenograft model were applied toelucidate the mechanism of Lfcin-B on non-small cell lungcancer NCI-H460 (H460) cells. Lfcin-B significantly suppressedthe proliferation of H460 cells in vitro. Additionally,the transcription and translation of the VEGF gene inH460 cells were restrained after exposure to Lfcin-B. Moreover, the apoptosis of H460 cells was induced byLfcin-B through stimulating caspase-3, caspase-9 andpreventing survivin expression on both the transcriptionand translation level. Meanwhile, Lfcin-B increased theproduction of reactive oxygen species and suppressed theRNA of antioxidant enzymes (GPX1, GPX2, SOD3 andcatalase) in H460 cells. Finally, Lfcin-B significantly preventedthe tumor growth in the H460-bearing mice model. These results indicated that Lfcin-B could be a potentialcandidate for the treatment of lung cancer.

Stress and fatigue analysis of engine pistons using thermo-mechanical model

Zhenlei Chen,Jiancheng Li,Junxiong Liao,Fan Shi 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

This paper presents a thermo-mechanical finite element analysis model for the stress and fatigue analyses of engine pistons. The model consists of the piston, piston pin, piston ring, bushing, cylinder liner and connecting rod. The oil film and contact pressure are considered in the contact surfaces between the piston and piston pin, the piston pin and bush, and the piston skirt and cylinder liner. A self-compiled code, which considers the factors of the piston skirt profile and ellipticity, is applied to calculate the initial clearance at the oil film surfaces between the piston and piston pin, the piston pin and bush, and the piston skirt and cylinder liner. The dynamic loads of the piston and connecting rod under the peak torque and peak power cases are calculated using powertrain commercial software, which are then used to carry out the stress and fatigue analyses. Compared with those published in literature, the present model is able to simulate the actual working conditions of the piston more accurately. The model can be used to evaluate and assess the piston skirt pressure, the stress and fatigue life of the concerned areas of the piston.

A Slot Allocated Blocking Anti-Collision Algorithm for RFID Tag Identification

( Yang Qing ),( Li Jiancheng ),( Wang Hongyi ),( Zeng Xianghua ),( Zheng Liming ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.6

In many Radio Frequency Identification (RFID) applications, the reader recognizes the tags within its scope repeatedly. For these applications, some algorithms such as the adaptive query splitting algorithm (AQS) and the novel semi-blocking AQS (SBA) were proposed. In these algorithms, a staying tag retransmits its ID to the reader to be identified, even though the ID of the tag is stored in the reader`s memory. When the length of tag ID is long, the reader consumes a long time to identify the staying tags. To overcome this deficiency, we propose a slot allocated blocking anti-collision algorithm (SABA). In SABA, the reader assigns a unique slot to each tag in its range by using a slot allocation mechanism. Based on the allocated slot, each staying tag only replies a short data to the reader in the identification process. As a result, the amount of data transmitted by the staying tags is reduced greatly and the identification rate of the reader is improved effectively. The identification rate and the data amount transmitted by tags of SABA are analyzed theoretically and verified by various simulations. The simulation and analysis results show that the performance of SABA is superior to the existing algorithms significantly.