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Circulant Double Coverings of a Circulant Graph of Valency Five

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Acta Mathematica Sinica,English Series 2007年第1期23卷 23-28页

作者： rong quan feng Jin Ho KWAK LMAM School of Mathematical Sciences Peking University Beijing 100871 P. R. China Mathematics Pohang University of Science and Technology Pohang 790-784 Korea

Enumerating the isomorphism classes of several types of graph covering projections is one of the central research topics in enumerative topological graph theory. A covering of G is called circulant if its covering graph is circulant. Recently, the authors [Discrete Math., 277, 73-85 （2004）1 enumerated the isomorphism classes of circulant double coverings of a certain type, called a typical covering, and showed that no double covering of a circulant graph of valency three is circulant. Also, in [Graphs and Combinatorics, 21,386 400 （2005）], the isomorphism classes of circulant double coverings of a circulant graph of valency four are enumerated. In this paper, the isomorphism classes of circulant double coverings of a circulant graph of valency five are enumerated.

关键词： graph covering voltage assignment Cayley circulant graph

Typical Frobenius Coverings

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Acta Mathematica Sinica,English Series 2010年第11期26卷 2209-2214页

作者： Yan WANG rong quan feng Jaeun LEE Department of Mathematics Yah Tai University Yah Tai 264005 P. R. China LMAM School of Mathematical Sciences Peking University Beijing 100871 P. R. China Department of Mathematics Yeungnam University Kyongsan 712-749 Korea

A covering p from a Cayley graph Cay（G, X） onto another Cay（H, Y） is called typical Frobenius if G is a Frobenius group with H as a Frobenius complement and the map p ： G →H is a group epimorphism. In this paper, we emphasize on the typical Frobenius coverings of Cay（H, Y）. We show that any typical Frobenius covering Cay（G, X） of Cay（H, Y） can be derived from an epimorphism /from G to H which is determined by an automorphism f of H. If Cay（G, X1） and Cay（G, X2） are two isomorphic typical Frobenius coverings under a graph isomorphism Ф, some properties satisfied by Фare given.

关键词： Frobenius group typical Frobenius covering isomorphic

Constructions of 11/2-designs from Symplectic Geometry over Finite Fields

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Acta Mathematica Sinica,English Series 2015年第9期31卷 1367-1378页

作者： Zhao CHAI rong quan feng Li Wei ZENG LMAM School of Mathematical Sciences Peking University

In this paper, we construct some 1 1/2-designs, which are also known as partial geometric designs, using totally isotropic subspaces of the symplectic space and generalized symplectic graphs. Furthermore, these 1^-des... 详细信息

关键词： 1 1/2-design totally isotropic subspace generalized symplectic graph directed strongly reg-ular graph

Classification of Regular Planar Graphs with Diameter Two

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Acta Mathematica Sinica,English Series 2007年第3期23卷 411-416页

作者： Moo Young SOHN Sang Bum KIM Young Soo KWON rong quan feng Mathematics Changwon National University Changwon 641-773 Korea Mathematics Pohang University of Science and Technology Pohang 790-784 Korea LMAM School of Mathematical Sc-iencesPeking University Beijing 100871 P. R. China

In the present paper, the regular planar graphs with diameter two are classified.

关键词： graph regular diameter planar outer planar

Coupled conditional nonlinear optimal perturbations and their application to ENSO ensemble forecasts

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Science China Earth Sciences 2024年第3期67卷 826-842页

作者： Wansuo DUAN Lei HU rong feng LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Limitations are existed in current ensemble forecasting initial perturbation methods for describing the interactions among various spheres of the Earth system. In this study, a new method is proposed, namely, the coupled conditional nonlinear optimal perturbation(C-CNOP) method, which incorporates multisphere interactions much appropriately. The El Nino-Southern Oscillation(ENSO) is a typical ocean-atmosphere “coupling”(or “interaction”) phenomenon. The C-CNOP method is applied to ensemble forecasting of ENSO. It is demonstrated that the C-CNOP method can generate coupled initial perturbations(CPs) that appropriately consider initial ocean-atmosphere coupling uncertainty for ENSO ensemble forecasts. Results reveal that the CPs effectively improve the ability of ENSO ensemble-mean forecasts in both temporal variability of Nio3.4 sea surface temperature anomalies(SSTAs) and spatial variability of ENSO mature-phase SSTAs. Notably, despite the weakest ocean-atmosphere coupling strength in the tropical Pacific occurring during the boreal spring and summer, CPs still capture the uncertainties of this weak coupling when ENSO predictions are initialized at these seasons. This performance of CPs significantly suppresses the rapid increase of ENSO prediction errors due to the high ocean-atmosphere coupling instability during these seasons, and thus effectively extends the lead time of skillful ENSO forecasting. Hence, the C-CNOP method is a suitable initial perturbation approach for ENSO ensemble forecast that can describe initial ocean-atmosphere coupling uncertainty. It is expected that the CCNOP method plays a significant role in predictions of other high-impact climate phenomena, and even future Earth system predictions.

关键词： Ensemble forecast Multisphere interaction Initial perturbations ENSO

Self-Triggered Set Stabilization of Boolean Control Networks and Its Applications

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1631-1642页

作者： rong Zhao Jun-e feng Dawei Zhang the School of Mathematics Shandong UniversityShandong UniversityJinan 250100China

Set stabilization is one of the essential problems in engineering systems, and self-triggered control(STC) can save the storage space for interactive information, and can be successfully applied in networked control systems with limited communication resources. In this study, the set stabilization problem and STC design of Boolean control networks are investigated via the semi-tensor product technique. On the one hand, the largest control invariant subset is calculated in terms of the strongly connected components of the state transition graph, by which a graph-theoretical condition for set stabilization is derived. On the other hand, a characteristic function is exploited to determine the triggering mechanism and feasible controls. Based on this, the minimum-time and minimum-triggering open-loop, state-feedback and output-feedback STCs for set stabilization are designed,respectively. As classic applications of self-triggered set stabilization, self-triggered synchronization, self-triggered output tracking and self-triggered output regulation are discussed as well. Additionally, several practical examples are given to illustrate the effectiveness of theoretical results.

关键词： Boolean control networks(BCNs) output regulation self-triggered control semi-tensor product of matrices set stabilization synchronization

Investigating Sulfur Chemistry in the HD163296 Disk

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Research in Astronomy and Astrophysics 2024年第7期24卷 215-225页

作者： rong Ma Donghui quan Yan Zhou Jarken Esimbek Dalei Li Xiaohu Li Xia Zhang Juan Tuo Yanan feng Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China BinZhou University Binzhou 256600China Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China

Sulfur chemistry in the formation process of low-mass stars and planets remains poorly *** protoplanetary disks are the birthplace of planets and its distinctive environment provides an intriguing platform for investigating models of sulfur *** analyzed the Atacama Large Millimeter/submillimeter Array observations of CS 7-6 transitions in the HD 163296 disk and performed astrochemical modeling to explore its sulfur *** simulated the distribution of sulfur-containing molecules and compared it with observationally deduced fractional column *** have found that the simulated column density of CS is consistent with the observationally deduced fractional column densities,while the simulated column density of C_(2)S is lower than the observationally deduced upper limits on column *** results indicate that we have a good understanding of the chemical properties of CS and C_(2)S in the *** also investigated the influence of the C/O ratio on sulfur-containing molecules and found that the column densities of SO,SO_(2),and H_2S near the centra star are dependent on the C/O ***,we found that the N[CS]/N[SO]ratio can serve as a promising indicator of the disk’s C/O ratio in HD ***,the disk of HD 163296 provides a favorable environmen for the detection of sulfur-containing molecules.

关键词： Protoplanetary Disks-Astrochemistry-Molecular Processes

Thermal-force control ability under variation of electromagnetic stick structure parameters in RPECT

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Journal of Iron and Steel Research International 2024年第1期31卷 224-236页

作者： Ting-song Yang Wen-quan Sun feng-shan Du An-rui He quan Yang National Engineering Research Center of Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing100083China Institute of Engineering and Technology University of Science and Technology BeijingBeijing100083China College of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina

Thermal-force driving of roll profile electromagnetic control technology(RPECT),which can be used to adjust the roll profile,can be affected by the sequential temperature rise between the electromagnetic stick(ES)and electromagnetic control *** to the limited space of ES and induction coil,the cross-sectional area of induction coil can be inevitably affected by changing the size of the ES induction zone,which can further change the energy input under the same electromagnetic parameters,the temperature rising effect and the bulging *** investigate this phenomenon,the effects of the radius of the induction zone on the thermal-force contribution ratio,the heating ability of ES and the temperature distribution were analyzed through an electromagnetic-thermal-structural finite element *** ensure that the results are applicable to RPECT,the thermal energy conversion ability and thermal-force roll crown control ability under different lengths of the induction zone were *** was found that whether the current density regulation mode or the current frequency regulation mode is adopted,the cases with 20 or 25 mm radius of the induction zone have the great thermal energy conversion ability and the good thermal-force roll crown control *** reasonable adjustment of the length of the induction zone can reduce the radius required for the maximum energy efficiency *** with the results of the simulation analysis,the optimization of ES based on the control ability maximization requirement is achieved,which provides the base for the design and configuration of ES in RPECT.

关键词： Roll profile electromagnetic control technology Electromagnetic stick Electromagnetic control roll Induction area Thermal-force driving

Hydrodynamic Performance of An Integrated System of Breakwater and A Multi-Chamber OWC Wave Energy Converter

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China Ocean Engineering 2024年第4期38卷 543-556页

作者： NING De-zhi ZHANG Xiang-yu WANG rong-quan ZHAO Ming State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Dalian Key Laboratory of Offshore Renewable Energy Dalian University of TechnologyDalian 116024China School of Computing Engineering and MathematicsUniversity of Western SydneyPenrith NSW 2751Australia

A multi-chamber oscillating water column wave energy converter(OWC-WEC)integrated to a breakwater is *** hydrodynamic characteristics of the device are analyzed using an analytical model based on the linear potential flow theory.A pneumatic model is employed to investigate the relationship between the air mass flux in the chamber and the turbine *** effects of chamber width,wall draft and wall thickness on the hydrodynamic performance of a dual-chamber OWC-WEC are *** results demonstrate that the device,with a smaller front wall draft and a wider rear chamber exhibits a broader effective frequency *** device with a chamber-width-ratio of 1:3 performs better in terms of power ***,results from the analysis of a triplechamber OWC-WEC demonstrate that reducing the front chamber width and increasing the rearward chamber width can improve the total performance of the *** the number of chambers from 1 to 2 or 3 can widen the effective frequency bandwidth.

关键词： oscillating water column power extraction efficiency potential flow theory wave energy converter multi-chamber