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Multi-Matching Nested Languages

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Chinese Journal of Electronics 2022年第1期31卷 137-145页

作者： liu Jin DUAN Zhenhua tian Cong ICTT and ISN Laboratory Xidian University

The data with both a linear ordering and a hierarchically nested one-to-one matching of items is ubiquitous, including parenthesis matching languages and hypertext markup language/extensive markup language(HTML/XML) documents. There exist some real-world problems which are beyond one-to-one matching. They have a multi-matching structure including one-to-n or nto-one matching relation. Multiple threads can simultaneously read the same file, one block of memory can be referenced by multiple pointers in programs. We propose a new model of multi-matching nested relations consisting of a sequence of linearly ordered call, return and internal positions and augmented with one-to-one, one-to-n or nto-one matching nested edges from calls to returns. Via linear encoding by introducing tagged letters, multimatching nested words are obtained over a tagged alphabet. We put forward multi-matching nested traceable automata and the accepted languages are called multimatching nested languages. Multi-matching nested grammars are presented which have the same expressive power as the proposed automata. An application is displayed to illustrate how the automata work.

关键词： multimatching nested traceable automata hypermedia markup languages multimatching nested relations multimatching nested languages multimatching structure computational complexity multimatching nested words grammars linear ordering parenthesis matching languages multiple pointers matching nested edges internal positions accepted languages multiple threads multimatching nested grammars XML matching relation via linear encoding

A model for converting thermal analysis to volume fraction of high carbon bearing steels during low-temperature tempering

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Journal of Materials Science & Technology 2023年第5期136卷 212-222页

作者： Qinglong liu Junyu tian Wenting Wei The State Key Laboratory of Refractories and Metallurgy The Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of EducationWuhan University of Science and TechnologyWuhan 430081China School of Automotive Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key Laboratory of Advanced Technology for Automotive Components(Wuhan University of Technology) Wuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan 430070China

Quantitative prediction of phase content is of great importance to control and optimize the heat treat-ment process of *** this work,a model for predicting the phase content of tempered high carbon steels was proposed by taking a martensitic 100Cr6 bearing steel as a model *** microstructural transformations during tempering were studied using thermal analysis,transmission electron microscopy(TEM),and X-ray diffraction(XRD).Kinetics analysis of thermal evolution by employing the isoconver-sional method,and assisted by TEM and XRD characterization,were performed to quantitatively estimate the volume fractions of different phases after tempering.A series of isothermal tempering experiments were designed to verify the *** predicted results were in good agreement with the experimental results of XRD and electrolytic extraction measurements.

关键词： Bearing steel Martensite tempering Retained austenite Thermal analysis Kinetics

Energy and carbon performance of urban buildings using metamodeling variable importance techniques

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Building Simulation 2021年第3期14卷 535-547页

作者： Yunliang liu Wei tian Xiang Zhou School of Mechanical Engineering Tongji UniversityShanghai 200092China tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry&Food Machinery and Equipment College of Mechanical EngineeringTianjin University of Science and TechnologyTianjin 300222China tianjin International Joint Research and Development Center of Low-Carbon Green Process Equipment Tianjin 300222China

Global urbanization causes more environmental stresses in cities and energy efficiency is one of major concerns for urban *** variable importance techniques have been widely used in building energy analysis to determine key factors influencing building energy *** of these applications,however,use only one type of variable importance ***,this paper proposes a procedure of conducting two types of variable importance analysis(predictive and variance-based)to determine robust and effective energy saving measures in urban *** two variable importance methods belong to metamodeling techniques,which can significantly reduce computational cost of building energy simulation models for urban *** predictive importance analysis is based on the prediction errors of metamodels to obtain importance rankings of inputs,while the variance-based variable importance can explore non-linear effects and interactions among input variables based on variance *** campus buildings are used to demonstrate the application of the method proposed to explore characteristic of heating energy,cooling energy,electricity,and carbon emissions of *** results indicate that the combination of two types of metamodeling variable importance analysis can provide fast and robust analysis to improve energy efficiency of urban *** carbon emissions can be reduced approximately 30%after using a few of effective energy efficiency measures and more aggressive measures can lead to the 60%of reduction of carbon ***,this research demonstrates the application of parallel computing to expedite building energy analysis in urban environment since more multi-core computers become increasingly available.

关键词： urban buildings variable importance metamodeling energy performance carbon emissions

Theoretical Study on Mechanism of Reaction of OH with HO2NO2

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Chinese Journal of Chemical Physics 2008年第1期21卷 32-38页

作者： Yan tian tian-jing He Li He Fan-chen liu Dong-ming Chen Department of Chemical Physics University of Science and Technology of China Hefei 230026 China Department of Electronic Science and Technology University of Science and Technology of ChinaHefei 230025 China School of Science Anhui Agricultural University Hefei 230036 China

The reaction of HO2NO2 （peroxynitric acid, PNA） with OH was studied by the hybrid density functional B3LYP and CBS-QB3 methods. Based on the calculated potential energy surface, five reaction channels, H20＋NO2＋O2, HOOH＋NO3, NO2＋HO3H, HO2＋HONO2 and HO2＋HOONO, were examined in detail. The major reaction channel is PNA＋OH→M1→TS1→H2O＋NO2＋O2. Taking a pre-equilibrium approximation and using the CBS-QB3 energies, the theoretical rate constant of this channel was calculated as 1.13×10-12 cm^3/（molecule s） at 300 K, in agreement with the experimental result. Comparison between reactions of HOONO2＋OH and HONO2＋OH was carried out. For HOR＋OH reactions, the total rate constants increase from R=NO2 to R=ONO2, which is consistent with experimental measurements.

关键词： Reaction Peroxynitric acid ab initio calculation Rate constant

Continuous-Time Mean-Variance Portfolio Selection Under Non-Markovian Regime-Switching Model with Random Horizon

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Journal of Systems Science & Complexity 2023年第2期36卷 457-479页

作者： CHEN tian liu Ruyi WU Zhen Zhongtai Securities Institute for Financial Studies Shandong UniversityJinan 250100China School of Mathematics and Statistics University of SydneyNSW 2006Australia School of Mathematics Shandong UniversityJinan 250100China

This paper considers a continuous-time mean-variance portfolio selection with regime-switching and random *** previous works,the dynamic of assets are described by non-Markovian regime-switching models in the sense that all the market parameters are predictable with respect to the filtration generated jointly by Markov chain and Brownian *** Markov chain is assumed to be independent of Brownian motion,thus the market is *** authors formulate this problem as a constrained stochastic linear-quadratic optimal control *** authors derive closed-form expressions for both the optimal portfolios and the efficient *** the results are different from those in the problem with fixed time horizon.

关键词： Backward stochastic differential equation mean-variance portfolio selection random time horizon stochastic LQ control

Inverse design of mission success space for combat aircraft contribution evaluation

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Chinese Journal of Aeronautics 2020年第8期33卷 2189-2203页

作者： Yuan GAO Hu liu Yongliang tian School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

This paper presents a novel design method of the Mission Success Space(MSS) for the evaluation on aircraft contribution effectiveness. MSS concept was proposed for giving success criterion of a mission and judging the success by conventional mission effectiveness with regards to the aircraft capabilities. This space is created by the Mission Success Function(MSF) and the original Effectiveness Index Space(EIS) where empirical equations are usually assumed to be MSFs. Based on this MSS concept, this paper firstly defines the MSS-based evaluation, then further summarizes the evaluation process of the Contribution to System-of-Systems(CSS). More importantly, based on the thought of Inverse Design(ID), a new design method of MSF is presented comprehensively analyzing aircraft's CSS in a combat mission without using any empirical MSF. The definition of MSS based ID is given and the design procedure is sequentially introduced. Two different confrontation cases are depicted with many details as the simulation validation: Air-to-ground and Penetration. There are two design variables considered for designing MSS in the latter case while only one for the former. However, in both cases, the best design is given by evaluating the Gaussian fitting performance of CSS.

关键词： Contribution effectiveness Effectiveness evaluation Gaussian fitting Inverse design Military missions Modelling and simulation Success rate System of systems

From one linear genome to a graph-based pan-genome: a new era for genomics

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Science China(Life Sciences) 2020年第12期63卷 1938-1941页

作者： Yucheng liu Zhixi tian State Key Laboratory of Plant Cell and Chromosome Engineering Center for Genome EditingInstitute of Genetics and Developmental BiologyInnovation Academy for Seed DesignChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

The seeds for genomics were sown with the development of DNA sequencing(Sanger et al., 1977), cultivated with each advance in molecular biology, and have since grown into one of the most important aspects of the life sciences. With the sequencing of the first draft human genome(Venter et al.,2001), the era of post-genomics began. Once one genome has been sequenced, it can be used as the reference for a certain species, and sequences from individuals can be mapped onto it to compare genetic variations among different lines.

关键词： Sanger genome genomics

Convergent selection of a gene in cereals leads to grain yield upgradation

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Science China(Life Sciences) 2022年第7期65卷 1479-1480页

作者： Yucheng liu Zhixi tian State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Crop domestication has been a fundamental step for human and social ***,our ancestors collected plants from the natural environment,which could be used for food and then continually planted and selected to satisfy human needs using artificial *** wild plants that are put into the selection pool come from different species,genera,and families and have dramatic phenotypic differences.

关键词： development planted grain

Development of a compact DOI-TOF detector module for high-performance PET systems

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Nuclear Science and Techniques 2017年第4期28卷 1-7页

作者： Qing-Yang Wei tian-Peng Xu tian-tian Dai Shi Wang Ya-Qiang liu Yu Gu tian-Yu Ma School of Automatic and Electrical Engineering University of Science and Technology Beijing Beijing 100083 China Department of Engineering Physics Tsinghua UniversityBeijing 100084 China Key Laboratory of Particle and Radiation Imaging (Tsinghua University) Ministry of Education Beijing 100084 China Department of Radiation Oncology China-Japan Friendship Hospital Beijing 100029 China

To increase spatial resolution and signal-to-noise ratio in PET imaging,we present in this paper the design and performance evaluation of a PET detector module combining both depth-of-interaction(DOI) and time-offlight(TOF) *** detector module consists of a staggered dual-layer LYSO block with2 mm × 2 mm × 7 mm ***-compatible SiPM sensors(MicroFJ-30035-TSV,SensL) are assembled into an 8× 8 *** signals from both fast and slow outputs are read out by a 128-channel ASIC *** test its performance,a flood histogram is acquired with a ^(22)Na point source on top of the detector,and the energy resolution and the coincidence resolving time(CRT) value for each individual crystal are *** flood histogram shows excellent crystal separation in both *** average energy resolution at 511 keV is 14.0 and 12.7%at the bottom and top layers,*** average CRT of a single crystal is 635 and 565 ps at the bottom and top layers,*** conclusion,the compact DOI-TOF PET detector module is of excellent crystal identification capability,good energy resolution and reasonable time resolution and has promising application prospective in clinical TOF PET,PET/MRI,and brain PET systems.

关键词： Positron emission tomography SiPM Depth of interaction (DOI) Time-of-flight (TOF)