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A Novel Method to Extract Rocks from Mars Images

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Chinese Journal of Electronics 2015年第3期24卷 455-461页

作者： WANG Shuliang CHEN Yasen YUAN Hanning School of Software Beijing Institute of Technology Tencent Inc. Hi-tech park Nanshan District

Automatically extracting rocks from Martian surface images is valuable for hazard avoidance and rover localization in rover missions. To extract rocks, data field on image is proposed to model the interaction between two pixels of an image under the imagery characteristics of Martian surface. Foreground rocks are firstly grouped into clusters by locating the centers and edges in data field after they are differed from background information via binarizing partition. Then target rocks are discovered for the Rover to keep healthy paths. The experiment shows the data field on image is practical and potential.

关键词： Data fields Mars image Rock extraction

Corrigendum:Hydrogen station technology development review through patent analysis

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Clean Energy 2018年第1期2卷 82-83页

作者： Chengyu Wen Guangli He National Institute of Clean-and-Low-Carbon Energy Future Science Park Changping District Beijing China

This is a correction notice for article zky006(DOI:https://***/10.1093/ce/zky006),published on 10 May *** to an error,the images for figures 1,2,and 3 were swapped *** have now been corrected in the published article.

关键词： DOI correction figures

A Camouflaged Film Imitating the Chameleon Skin with Color-Changing Microfluidic Systems Based on the Color Information Identification of Background

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Journal of Bionic Engineering 2021年第5期18卷 1137-1146页

作者： Huanhuan Li Tianhang Yang Lujia Li Sining Lv Songjing Li Department of Fluid Control and Automation Harbin Institute of TechnologyScience ParkNo.2Yikuang Street Nangang DistrictBox 3040Harbin 150001China

To adapt to a complex and variable environment,self-adaptive camouflage technology is becoming more and more important in all kinds of military applications by overcoming the weakness of the static *** nature,the chameleon can achieve self-adaptive camouflage by changing its skin color in real time with the change of the background *** imitate the chameleon skin,a camouflaged film controlled by a color-changing microfluidic system is proposed in this *** film with microfluidic channels fabricated by soft materials can achieve dynamic cloaking and camouflage by circulating color liquids through channels inside the *** sensing and collecting environmental color change information,the control signal of the microfluidic system can be adjusted in real time to imitate chameleon *** microstructure of the film and the working principle of the microfluidic color-changing system are *** mechanism to generate the control signal by information processing of background colors is illustrated.“Canny”double-threshold edge detection algorithm and color similarity are used to analyze and evaluate the *** tested results show that camouflaged images have a relatively high compatibility with environmental backgrounds and the dynamic cloaking eff ect can be achieved.

关键词： Microfluidic Self-adaptive Camouflage Chameleon Bionic skin

A New Multiple Gateway Transmit Diversity Technique for Future Satellite Networks

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China Communications 2022年第8期19卷 214-233页

作者： Xinhua Li Huibin Wang Wenbo Zhao Qiushi Tian Zehao Xu Bo Yang Space Star Technology Co. LtdZhongguancun Environmental Science and Technology ParkHaidian DistrictBeijing 100095China China Academy of Space Technology Beijing 100094China

The next generation of High Throughput Satellite(HTS)will exploit Q/V band for the feeder link and Ka band for the user *** exploitation of multiple gateways(GWs)is a transmit diversity measure to compensate severe rain attenuation of Q/V band feeder *** paper introduces a new smart gateway diversity combination scheme that combinates N-active(K=2)and N+1 diversity method in detail from the working principle,gateway switching strategy,evaluation of system availability and implementation *** addition,a feeder link outage event prediction algorithm featuring combination scheme is given detailly based on modified time-adaptive linear *** with the existing N+P scheme,the proposed scheme can provide higher system availability and more stable user’s experience under the condition of properly increasing the complexity of payload *** with Nactive scheme that has been reported,it is much easier to implement in engineering and more *** a result,the combination scheme is a realistic solution based on a trade-off between performance improvement and implementation complexity.

关键词： Q/V frequency band smart gateway diversity outage prediction gateway switching

Role of entropy generation minimization in thermal optimization

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Chinese Physics B 2017年第12期26卷 160-166页

作者：程雪涛梁新刚 Key Laboratory for Thermal Science and Power Engineering of Ministry of Education School of Aerospace Tsinghua University Beijing 100084 China The Administrative Committee of the Modern Industrial park New District of Zhengpu Port Maanshan 238261 China

Thermal optimization is very important for improving the performances of thermal systems. In engineering, the entropy generation minimization （EGM） has been widely used to optimize and evaluate the performances of thermal systems. However, the consistency between the EGM and the optimization objective should be specified when the EGM is used. In this paper, we discuss the view angle of irreversibility of entropy generation, and show that entropy generation directly reflects the exergy destruction or the ability loss of doing work. As the design objective in a thermal system is not often consistent with the view angle of irreversibility of entropy generation, the EGM may not lead to the optimal value of the design objective. In heat transfer and heat-work conversion, the inconsistence between the design objectives and the EGM is shown with some examples, and the applicability of the EGM is found to be conditional. The “entropy generation paradox” in heat exchanger analyses is also discussed, and it is shown that there is no direct monotonic relation between the minimum entropy generation rate and the best heat transfer performance of heat exchangers.

关键词： entropy generation thermal analysis heat transfer heat-work conversion

Entransy analyses of the thermodynamic cycle in a turbojet engine

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Science China(Technological Sciences) 2017年第8期60卷 1160-1167页

作者： CHENG XueTao LIANG XinGang Key Laboratory for Thermal Science and Power Engineering of Ministry of Education School of Aerospace Tsinghua University Beijing 100084 China The Administrative Committee of the Modern Industrial park New District of Zhengpu Port Maanshan 238261 China

The analysis and the design of turbojet engines are of great importance to the improvement of the system *** researchers focus on these topics,and many important and interesting results have been *** this paper,the thermodynamic cycle in a turbojet engine is analyzed with the entransy theory and the T-Q *** ideal thermodynamic cycle in which there is no inner irreversibility is analyzed,as well as the influences from some inner irreversible factors,such as the heat transfer process,the change of the component of the working fluid and the viscosity of the working *** the discussed cases,it is shown that larger entransy loss rate always results in larger output power,while smaller entropy generation rate does not *** corresponding T-Q diagrams are also presented,with which the change tendencies of the entransy loss rate and the output power can be shown very *** is shown that the entransy theory is applicable for analyzing the inner irreversible thermodynamic cycles discussed in this *** with the concept of entropy generation,the concept of entransy loss and the corresponding T-Q diagram are more suitable for describing the change of the output power of the analyzed turbojet engine no matter if the inner irreversible factors are considered.

关键词： turbojet engine entransy analyses T-Q diagram inner irreversible cycle

A NOTE ON SINGULAR INTEGRALS WITH DOMINATING MIXED SMOOTHNESS IN TRIEBEL-LIZORKIN SPACES

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Acta Mathematica Scientia 2014年第4期34卷 1331-1344页

作者： Hung Viet LE Faculty of Science and Technology Hoa Sen UniversityQuang Trung Software ParkSection 10Ward Tan Chanh HiepDistrict 12Ho Chi Minh CityViet Nam

Let h, be a measurable function defined on R^＋ ×R^＋. Let Ω ∈ L（log L^＋）^υq （S^n1-1 × S^n2-1）（1≤ υq ≤ 2） be homogeneous of degree zero and satisfy certain cancellation conditions. We show that the singular integral Tf（x1,x2）=p.v.∫∫R^n1＋n2 Ω（y′1,y′2）h（｜y1｜,｜y2｜）/｜y1｜^n1｜y2｜^n2 f（x1-y1,x2-y2）dy1dy2maps from Sp,q^α1,α2F（R^n1×R^n2）boundedly to itself for 1 〈 p, q 〈 ∞, α1, α2 ∈R.

关键词： singular integrals Marcinkiewicz integrals mixed smoothness Triebel-Lizorkin spaces

BDS satellite clock offset prediction based on a semiparametric adjustment model considering model errors

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Satellite Navigation 2020年第1期1卷 113-125页

作者： Xiong Yan Wentao Li Yufeng Yang Xiong Pan School of Information and Engineering China University of GeosciencesNo.388Lu Mill RoadHongshan DistrictWuhanChina Chihiro Location Network Co. Ltd.Bay Valley Science and Technology ParkNo.38Lane 1688Guoquan North RoadYangpu DistrictShanghaiChina

In view of the influence of model errors in conventional BeiDou prediction models for clock offsets,a semiparametric adjustment model for BeiDou Navigation Satellite System(BDS)clock offset prediction that considers model errors is proposed in this ***,the model errors of the conventional BeiDou clock offset prediction model are ***,the relationship among the polynomial model,polynomial model with additional periodic term correction,and its periodic correction terms is explored in ***,considering the model errors,combined with the physical relationship between phase,frequency,frequency drift,and its period in the clock sequence,the conventional clock offset prediction model is *** kernel estimation and comprehensive least squares,the corresponding parameter solutions of the prediction model and the estimation of its model error are derived,and the dynamic error correction of the clock sequence model is ***,the BDS satellite precision clock data provided by the IGS Center of Wuhan University with a sampling interval of 5 min are used to compare the proposed prediction method with commonly used *** results show that the proposed prediction method can better correct the model errors of BDS satellite clock offsets,and it can effectively overcome the inaccuracies of clock offset *** average forecast accuracies of the BeiDou satellites at 6,12,and 24 h are 27.13%,37.71%,and 45.08%higher than those of the conventional BeiDou clock offset forecast models;the average model improvement rates are 16.92%,20.96%,and 28.48%,*** addition,the proposed method enhances the existing BDS satellite prediction method for clock offsets to a certain extent.

关键词： BDS Satellite clock offset Model errors Semiparametric adjustment model Clock offset forecast

Identification of cancer stem cells provides novel tumor models for drug discovery

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Frontiers of Medicine 2012年第2期6卷 112-121页

作者： Douglas D.Fang Danyi Wen Yajun Xu Shanghai ChemPartner Co. Ltd.998 Halei RoadZhangjiang Hi-Tech ParkPudong New DistrictShanghai 201203China

Cancer stem cells(CSCs)have received considerable attention from the research community since they were first reported in human acute myeloid leukemia 15 years *** evidence suggests that CSCs are responsible for tumor initiation and progression,drug resistance,and metastasis in both liquid and solid *** findings lead to the development of novel compounds targeting CSC populations that is becoming increasingly important for eradicating CSCs in heterogeneous tumor masses and to cure the *** 2003,we have participated in CSC studies and encountered crucial early events in the *** article reviews the history of CSC biology,clarifies the term and its definition,and further addresses the issue of how to utilize CSCs in therapeutic target discovery and drug development based on our substantial experience.

关键词： cancer stem cell tumor model drug discovery