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Supervised and Semi-supervised Methods for Abdominal Organ Segmentation: A Review

International Journal of Automation and computing 2021年第6期18卷 887-914页

作者： Isaac Baffour Senkyire zhe Liu School of Computer Science and Communication Engineering Jiangsu UniversityZhenjiang 212013China Computer Science Department Ghana Communication Technology UniversityAccraGhana

Abdominal organ segmentation is the segregation of a single or multiple abdominal organ(s) into semantic image segments of pixels identified with homogeneous features such as color and texture, and intensity. The abdominal organ(s) condition is mostly connected with greater morbidity and mortality. Most patients often have asymptomatic abdominal conditions and symptoms, which are often recognized late;hence the abdomen has been the third most common cause of damage to the human body. That notwithstanding,there may be improved outcomes where the condition of an abdominal organ is detected earlier. Over the years, supervised and semi-supervised machine learning methods have been used to segment abdominal organ(s) in order to detect the organ(s) condition. The supervised methods perform well when the used training data represents the target data, but the methods require large manually annotated data and have adaptation problems. The semi-supervised methods are fast but record poor performance than the supervised if assumptions about the data fail to hold. Current state-of-the-art methods of supervised segmentation are largely based on deep learning techniques due to their good accuracy and success in real world applications. Though it requires a large amount of training data for automatic feature extraction, deep learning can hardly be used. As regards the semi-supervised methods of segmentation, self-training and graph-based techniques have attracted much research attention. Self-training can be used with any classifier but does not have a mechanism to rectify mistakes early. Graph-based techniques thrive on their convexity, scalability, and effectiveness in application but have an out-of-sample problem. In this review paper, a study has been carried out on supervised and semi-supervised methods of performing abdominal organ segmentation. An observation of the current approaches, connection and gaps are identified, and prospective future research opportunities are enu

关键词： Abdominal organ supervised segmentation semi-supervised segmentation evaluation metrics image segmentation machine learning

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A Study of Magnetized White Dwarf+Helium Star Binary Evolution to Type Ia Supernovae

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Research in Astronomy and Astrophysics 2022年第2期22卷 1-15页

作者： zhe Cui Xiang-Dong Li School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityMinistry of EducationNanjing 210023China

The white dwarf(WD)+helium(He)star binary channel plays an important role in the single degenerate scenario for the progenitors of type Ia supernovae(SNe Ia).Previous studies on the WD+main sequence star evolution have shown that the magnetic fields of WDs may significantly influence their accretion and nuclear burning *** this work we focus on the evolution of magnetized WD+He star binaries with detailed stellar evolution and binary population synthesis(BPS)*** the case of magnetized WDs,the magnetic fields may disrupt the inner regions of the accretion disk,funnel the accretion flow onto the polar caps and even confine helium burning within the *** find that,for WDs with sufficiently strong magnetic fields,the parameter space of the potential SN Ia progenitor systems shrinks toward shorter orbital periods and lower donor masses compared with that in the non-magnetized WD *** reason is that the magnetic confinement usually works with relatively high mass transfer rates,which can trigger strong wind mass loss from the WD,thus limiting the He-rich mass accumulation *** surviving companion stars are likely of low-mass at the moment of the SN explosions,which can be regarded as a possible explanation for the non-detection of surviving companions after the SNe or inside the SN ***,the corresponding birthrate of Galactic SNe Ia in our high-magnetic models is estimated to be~(0.08–0.13)×10^(-3)yr^(-1)(~0.17–0.28×10^(-3)yr^(-1)for the non-magnetic models),significantly lower than the observed Galactic SN Ia birthrate.

关键词： stars:evolution (stars:)supernovae:general–(stars:)binaries:general stars:magnetic field (stars:)white dwarfs

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Metal substrates-induced phase transformation of monolayer transition metal dichalcogenides for hydrogen evolution catalysis

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Chinese Physics B 2021年第11期30卷 481-487页

作者： zhe Wang Wenguang Zhu Department of Physics University of Science and Technology of ChinaHefei 230026China International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at the Microscaleand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of Strongly-Coupled Quantum Matter Physics Chinese Academy of SciencesSchool of Physical SciencesUniversity of Science and Technology of ChinaHefei 230026China

Monolayer transition metal dichalcogenides can normally exist in several structural polymorphs with distinct electrical,optical,and catalytic *** control of the relative stability and transformation of different phases in these materials is thus of critical importance for *** density functional theory calculations,we investigate the effects of low-work-function metal substrates including Ti,Zr,and Hf on the structural,electronic,and catalytic properties of monolayer MoS_(2) and WS_(2).The results indicate that such substrates not only convert the energetically stable structure from the 1H phase to the 1T'/1T phase,but also significantly reduce the kinetic barriers of the phase ***,our calculations also indicate that the 1T' phase of MoS_(2) with Zr or Hf substrate is a potential catalyst for the hydrogen evolution reaction.

关键词： transition metal dichalcogenides phase transformation hydrogen evolution reaction density functional theory

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Column adsorption of Cu(Ⅱ) by polymer-supported nano-iron oxides in the presence of sulfate: Experimental and mathematical modeling

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Chinese Journal of Chemical Engineering 2017年第9期25卷 1163-1169页

作者： Hui Qiu Xiaolin Zhang zhe Xu Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET) School of Environmental Science and Engineering Nanjing University of Information Science & Technology State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University

Polymer-supported hydrous iron oxides(HFOs) are promising for heavy metals removal from aqueous *** ubiquitous inorganic ligands, e.g., sulfate, are expected to exert considerable impacts on pollutants removal by these hybrid sorbents. Herein, we obtained a hybrid sorbent HFO-PS by encapsulating nanosized HFO into macroporous polystyrene(PS) resin. Both batch and column sorption experiments of Cu(Ⅱ) by HFO-PS were carried out in the presence of sulfate. Obviously, the presence of sulfate is favorable for Cu(Ⅱ) sorption onto *** performances of column Cu(Ⅱ) removal were fitted and predicted with Adams–Bohart, Clark, Thomas and BDST models. Thomas model is suggested best-fit to predict the breakthrough curves. Besides, a linear correlation is observed between breakthrough time and column length based on BDST model, which might be useful for predicting the breakthrough time for Cu(Ⅱ) removal by HFO-PS.

关键词： Composite Nanotechnology Waste water Hydrous iron oxide Fixed-bed adsorption Thomas model

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Design of multi-band frequency selective surfaces using multi-periodicity combined elements

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Journal of Systems Engineering and Electronics 2009年第4期20卷 675-680页

作者： Lu Mingyun Huang Minjie Wu zhe School of Aeronautic Science and Technology Beihang Univ. Beijing 100191 P. R. China

Traditional multi-band frequency selective surface （FSS） approaches are hard to achieve a perfect resonance response in a wide band due to the limit of the onset grating lobe frequency determined by the array. To solve this problem, an approach of combining elements in different period to build a hybrid array is presented. The results of series of numerical simulation show that multi-periodicity combined element FSS, which are designed using this approach, usually have much weaker grating lobes than the traditional FSS. Furthermore, their frequency response can be well predicted through the properties of their member element FSS. A prediction method for estimating the degree of expected grating lobe energy loss in designing multi-band FSS using this approach is provided.

关键词： frequency selective surface multi-band grating lobe multi-periodicity combined element

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Modified constriction particle swarm optimization algorithm

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Journal of Systems Engineering and Electronics 2015年第5期26卷 1107-1113页

作者： zhe Zhang Limin Jia Yong Qin Traffic and Transportation School Beijing Jiaotong University State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing Research Center of Urban Traffic Information Sensing and Service Technologies Beijing Jiaotong University

To deal with the demerits of constriction particle swarm optimization(CPSO), such as relapsing into local optima, slow convergence velocity, a modified CPSO algorithm is proposed by improving the velocity update formula of CPSO. The random velocity operator from local optima to global optima is added into the velocity update formula of CPSO to accelerate the convergence speed of the particles to the global optima and reduce the likelihood of being trapped into local optima. Finally the convergence of the algorithm is verified by calculation examples.

关键词： particle swarm optimization random speed operator convergence global optima

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Review of characterization and modeling of polymer electrolyte fuel cell catalyst layer： The blessing and curse of ionomer

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Frontiers in Energy 2017年第3期11卷 334-364页

作者： Jun HUANG zhe LI Jianbo ZHANG Department of Automotive Engineering State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China College of Chemistry and Chemical Engineering Central South University Changsha 410083 China Beijing Co-innovation Center for Electric Vehicles Beijing Institute of Technology Beijing 100081 China

Ionomer impregnation represents a milestone in the evolution of polymer electrolyte fuel cell （PEFC） catalyst layers. Ionomer acts as the binder, facilitates proton transport, and thereby drastically improves catalyst utilization and effectiveness. However, advanced morpho- logical and functional characterizations have revealed that up to 60% of Pt nanoparticles can be trapped in the micropores of carbon support particles. Ionomer clusters and oxygen molecules can hardly enter into micropores, leading to low Pt utilization and effectiveness. Moreover, the ionomer thin-films covering Pt nanoparticles can cause significant mass transport loss especially at high current densities. Ionomer-free ultra-thin catalyst layers （UTCLs） emerge as a promising alternative to reduce Pt loading by improving catalyst utilization and effectiveness, while theoretical issues such as the proton conduction mechan- ism remain puzzling and practical issues such as the rather narrow operation window remain unsettled. At present, the development of PEFC catalyst layer has come to a crossroads： staying ionomer-impregnated or going iono- mer-free. It is always beneficial to look back into the past when coming to a crossroads. This paper addresses the characterization and modeling of both the conventional ionomer-impregnated catalyst layer and the emerging ionomer-free UTCLs, featuring advances in characterizing microscale distributions of Pt particles, ionomer, support particles and unraveling their interactions; advances in fundamental understandings of proton conduction and flooding behaviors in ionomer-free UTCLs; advances in modeling of conventional catalyst layers and especially UTCLs; and discussions on high-impact research topics in characterizing and modeling of catalyst layers.

关键词： polymer electrolyte fuel cell ultra-thin cata-lyst layer electrostatic interactions characterization andmodeling structure-property-performance relation watermanagement

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Lessons from the seismic behavior of a steel grid roof structure heavily damaged in Lushan earthquake

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Earthquake Engineering and Engineering Vibration 2019年第1期18卷 95-111页

作者： Li Jichao Qu zhe Wang Tao Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration

The seismic behavior of a school gymnasium, whose steel grid roof was heavily damaged during the Mw6.6 Lushan earthquake in 2013, is simulated through nonlinear dynamic analysis. The simulated damage is compared with field observations to validate the numerical model, based on which a parametric study was performed to provide insight into the failure process and damage patterns of steel grids. The results suggest that the grid damage is strongly related to roofsubstructure interactions. These include not only the substructure's amplification of the vibration, but the uncoordinated displacement of the substructure's columns which support the grid also play an equally important role. In particular, the latter effect may significantly alter the internal force distribution in the steel grid and lead to unexpected buckling of members that are proportioned as tension-only members. While such interactions are generally not accounted for in the design practice for grid structures in China, similar seismic damage may be expected for other existing grid roofs in future earthquakes. As is also demonstrated in this study, seismic isolation of the roof is a promising solution to protect grid roof structures by mitigating the detrimental effects of roof-substructure interactions.

关键词： Lushan earthquake steel space structure roof-substructure interaction nonlinear dynamic analysis seismic isolation vertical ground motion

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Progressive LiDAR Adaptation for Road Detection

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IEEE/CAA Journal of Automatica Sinica 2019年第3期6卷 693-702页

作者： zhe Chen Jing Zhang Dacheng Tao IEEE the UBTECH Sydney Artificial Intelligence Centre and the School of Computer Science Faculty of Engineering and Information Technologies University of Sydney the School of Automation Hangzhou Dianzi University the University of Technology Sydney

Despite rapid developments in visual image-based road detection, robustly identifying road areas in visual images remains challenging due to issues like illumination changes and blurry images. To this end, LiDAR sensor data can be incorporated to improve the visual image-based road detection,because LiDAR data is less susceptible to visual noises. However,the main difficulty in introducing LiDAR information into visual image-based road detection is that LiDAR data and its extracted features do not share the same space with the visual data and visual features. Such gaps in spaces may limit the benefits of LiDAR information for road detection. To overcome this issue, we introduce a novel Progressive LiDAR adaptation-aided road detection(PLARD) approach to adapt LiDAR information into visual image-based road detection and improve detection performance. In PLARD, progressive LiDAR adaptation consists of two subsequent modules: 1) data space adaptation, which transforms the LiDAR data to the visual data space to align with the perspective view by applying altitude difference-based transformation; and 2) feature space adaptation, which adapts LiDAR features to visual features through a cascaded fusion structure. Comprehensive empirical studies on the well-known KITTI road detection benchmark demonstrate that PLARD takes advantage of both the visual and LiDAR information, achieving much more robust road detection even in challenging urban scenes. In particular, PLARD outperforms other state-of-theart road detection models and is currently top of the publicly accessible benchmark leader-board.

关键词： Autonomous driving computer vision deep learning LiDAR processing road detection

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Shifted-Ectropy Based Nonlinear Dynamic Output-Feedback Power-Level Control for Pressurized Water Reactors

Shifted-Ectropy Based Nonlinear Dynamic Output-Feedback Powe...

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第25届中国控制与决策会议

作者： zhe Dong Institute of Nuclear and New Energy Technology Tsinghua University

ISBN: (纸本)9781467355322

Nuclear fission energy is currently the sole energy that can substitute fossil in a centralized way and great amount with commercial availability and economic competitiveness. Power-level control is one of the key techniques which provide safe, stable and efficient operation for nuclear power plants. The physically-based regulation theory is definitely a promising trend of modem control theory, which can provide a control design method that suppresses the unstable part of the system dynamics and remains the stable part. Usually, control laws designed by the physically-based control theory have a simple form and high performance. Stimulated by this, a novel nonlinear dynamic output feedback power-level control law is established in this paper for the pressurized water nuclear reactors （PWRs） based upon its natural dynamic features. This newly-developed controller guarantees not only the globally asymptotic closed-loop stability but also the satisfactory transient performance through properly adjusting the feedback gains. Furthermore, this controller has the L2 disturbance attenuation performance. Numerical simulation results not only verify the correctness of the theoretical results but also illustrate the high control performance.

关键词： Power-level control shifted-ectropy Lyapunov function pressurized water reactor (PWR)

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