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| 1 | 基于LDA话题演化研究方法综述显示文摘现实生活中不断有新话题的产生和旧话题的衰减,同时话题的内容也会随着时间发生变化。自动探测话题随时间的演化越来越受到人们的关注。Latent Dirichlet Allocation模型是近年提出的概率话题模型,已经在话题演化领域得到较为广泛的应用。该文提出了话题演化的两个方面:内容演化和强度演化,总结了基于LDA话题模型的话题演化方法,根据引入时间的不同方式将目前的研究方法分为三类:将时间信息结合到LDA模型、对文本集合后离散和先离散方法。在详细叙述这三种方法的基础上,针对时间粒度、是否在线等多个特征进行了对比,并且简要描述了目前广泛应用的话题演化评测方法。文章最后分析了目前存在的挑战,并且对该研究方向进行了展望。 | 单斌 李芳 | 2010 | 中文信息学报2010，24，6： | 81 |
| 2 | Carbon density and distribution of six Chinese temperate forests显示文摘Quantifying forest carbon(C) storage and distribution is important for forest C cycling studies and terrestrial ecosystem modeling.Forest inventory and allometric approaches were used to measure C density and allocation in six representative temperate forests of similar stand age(42-59 years old) and growing under the same climate in northeastern China.The forests were an aspen-birch forest,a hardwood forest,a Korean pine plantation,a Dahurian larch plantation,a mixed deciduous forest,and a Mongolian oak forest.There were no significant differences in the C densities of ecosystem components(except for detritus) although the six forests had varying vegetation compositions and site conditions.However,the differences were significant when the C pools were normalized against stand basal area.The total ecosystem C density varied from 186.9 tC hm-2 to 349.2 tC hm-2 across the forests.The C densities of vegetation,detritus,and soil ranged from 86.3-122.7 tC hm-2,6.5-10.5 tC hm-2,and 93.7-220.1 tC hm-2,respectively,which accounted for 39.7% ± 7.1%(mean ± SD),3.3% ± 1.1%,and 57.0% ± 7.9% of the total C densities,respectively.The overstory C pool accounted for > 99% of the total vegetation C pool.The foliage biomass,small root(diameter < 5mm) biomass,root-shoot ratio,and small root to foliage biomass ratio varied from 2.08-4.72 tC hm-2,0.95-3.24 tC hm-2,22.0%-28.3%,and 34.5%-122.2%,respectively.The Korean pine plantation had the lowest foliage production efficiency(total biomass/foliage biomass:22.6 g g-1) among the six forests,while the Dahurian larch plantation had the highest small root production efficiency(total biomass/small root biomass:124.7 g g-1).The small root C density decreased with soil depth for all forests except for the Mongolian oak forest,in which the small roots tended to be vertically distributed downwards.The C density of coarse woody debris was significantly less in the two plantations than in the four naturally regenerated forests.The variability of C allocation patterns in a specific forest is jointly influenced by vegetation type,management history,and local water and nutrient availability.The study provides important data for developing and validating C cycling models for temperate forests. | ZHANG QuanZhi & WANG ChuanKuan* College of Forestry,Northeast Forestry University,Harbin 150040,China | 2010 | Science China(Life Sciences)2010，53，7： | 36 |
| 3 | Deep reinforcement learning-based joint task offloading and bandwidth allocation for multi-user mobile edge computing显示文摘The rapid growth of mobile internet services has yielded a variety of computation-intensive applications such as virtual/augmented reality. Mobile Edge Computing (MEC), which enables mobile terminals to offload computation tasks to servers located at the edge of the cellular networks, has been considered as an efficient approach to relieve the heavy computational burdens and realize an efficient computation offloading. Driven by the consequent requirement for proper resource allocations for computation offloading via MEC, in this paper, we propose a Deep-Q Network (DQN) based task offloading and resource allocation algorithm for the MEC. Specifically, we consider a MEC system in which every mobile terminal has multiple tasks offloaded to the edge server and design a joint task offloading decision and bandwidth allocation optimization to minimize the overall offloading cost in terms of energy cost, computation cost, and delay cost. Although the proposed optimization problem is a mixed integer nonlinear programming in nature, we exploit an emerging DQN technique to solve it. Extensive numerical results show that our proposed DQN-based approach can achieve the near-optimal performance。 | Liang Huang Xu Feng Cheng Zhang Liping Qian Yuan Wu | 2019 | Digital Communications and Networks2019，5，1： | 25 |
| 4 | Unmanned aerial systems coordinate target allocation based on wolf behaviors显示文摘Unmanned aerial systems (UASs), especially the cluster of UAS, are highly focused and widely used in various domains. The application of small and inexpensive UAS with a large-scale group to perform complex tasks has become a mainstream trend. Thus, collaborative task assignment of UAS has become a problem that must be solved. | Haibin DUAN Qing YANG Yimin DENG Pei LI Huaxin QIU Tianjie ZHANG Daifeng ZHANG Mengzhen HUO Yankai SHEN | 2019 | Science China(Information Sciences)2019，62，1： | 22 |
| 5 | 基于LDA主题特征的微博转发预测显示文摘微博转发是微博传播的重要途径,也是研究微博信息传播、舆情监控的最关键问题之一。研究用户转发行为对信息传播分析、舆情监控和热点提取有很大帮助。然而,当前对微博转发行为的研究大多是在宏观层面,为了解决微观层面预测用户转发行为问题,在分析影响用户转发的各类因素基础上,首先构建了微博特征和用户特征,然后通过将LDA抽取的微博隐含主题特征,与微博特征和用户特征相结合建立起基于主题特征的微博预测模型。实验结果验证了该模型在微博转发行为预测的有效性。 | 李志清 | 2015 | 情报杂志2015，34，9： | 20 |
| 6 | Changes in individual plant traits and biomass allocation in alpine meadow with elevation variation on the Qinghai-Tibetan Plateau显示文摘Plant traits and individual plant biomass allocation of 57 perennial herbaceous species,belonging to three common functional groups (forbs,grasses and sedges) at subalpine (3700 m ASL),alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes,plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts,especially storage organs,as altitude increases,so as to geminate and resist environmental stress.However,results indicate that some divergence in biomass allocation exists among organs.With increasing altitude,the mean fractions of total biomass allocated to aboveground parts decreased.The mean fractions of total biomass allocation to storage organs at the subalpine site (7%±2% S.E.) were distinct from those at the alpine (23%±6%) and subnival (21%±6%) sites,while the proportions of green leaves at all altitudes remained almost constant.At 4300 m and 5000 m,the mean fractions of flower stems decreased by 45% and 41%,respectively,while fine roots increased by 86% and 102%,respectively.Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation,while sedges showed opposite trends.For all three functional groups,leaf area ratio and leaf area root mass ratio decreased,while fine root biomass increased at higher altitudes.Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots,while the proportion of leaves remained stable.It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots.In contrast to forbs and grasses that had high mycorrhizal infection,sedges had higher single leaf area and more root fraction,especially fine roots. | MA WeiLing1,2,SHI PeiLi1*,LI WenHua1,HE YongTao1,ZHANG XianZhou1,SHEN ZhenXi1 & CHAI SiYue1,2 1Lhasa National Ecological Research Station,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China 2Graduate University of Chinese Academy of Sciences,Beijing 100049,China | 2010 | Science China(Life Sciences)2010，53，9： | 19 |
| 7 | 科学家合作网络中的社区发现显示文摘从科学家合作网络中发现隐含的研究社区对于理解科研人员的合作和交流模式,挖掘科研人员的研究兴趣具有十分重要的意义。本文在Latent Dirichlet Allocation模型的基础上,提出了一个社区一作者一主题模型,该模型能够根据科研人员之间的合著关系和论文的内容来发现隐性的子社区,并提取出每个子社区中的研究主题以及每个子社区中有代表性的科研人员。本文还给出了基于Gibbs抽样的社区一作者一主题模型的推断算法。在NIPS数据集上的实验表明,本文提出的社区发现算法所发现的研究社区和研究主题都是有效的。 | 苗蕊 刘鲁 | 2011 | 情报学报2011，30，12： | 19 |
| 8 | Energy-Efficient Computation Offloading and Resource Allocation in Fog Computing for Internet of Everything显示文摘With the dawning of the Internet of Everything(IoE) era, more and more novel applications are being deployed. However, resource constrained devices cannot fulfill the resource-requirements of these applications. This paper investigates the computation offloading problem of the coexistence and synergy between fog computing and cloud computing in IoE by jointly optimizing the offloading decisions, the allocation of computation resource and transmit power. Specifically, we propose an energy-efficient computation offloading and resource allocation(ECORA) scheme to minimize the system cost. The simulation results verify the proposed scheme can effectively decrease the system cost by up to 50% compared with the existing schemes, especially for the scenario that the computation resource of fog computing is relatively small or the number of devices increases. | Qiuping Li Junhui Zhao Yi Gong Qingmiao Zhang | 2019 | China Communications2019，16，3： | 19 |
| 9 | Cross-Layer Adaptive Resource Allocation Algorithm with Diverse QoS Requirements for Single-Cell OFDMA Systems显示文摘The orthogonal frequency division multiple access( OFDMA) based communication system has been considered as the main trend of next-Generation communication system. But the existing resource allocation algorithm designed for such system is always with high complexity thus hard to be realized. To solve such problem with the constraints of spectrum efficiency and buffer state,a novel cross-layer resource allocation algorithm( RAA) is proposed in this paper. The goal of our RAA is to maximize the system throughput while satisfying several practical constraints,such as fairness among services,head of line( Ho L) delay and diverse quality of service( Qo S) requirements. Due to these constraints,finding the optimal solution becomes a NPhard problem. Therefore in this paper a novel method to solve such problem with acceptable complexity is proposed within following steps: firstly,based on the link state we formulate the ideal subchannel allocation strategy as a convex optimization problem,which can be efficiently solved by our proposed lagrange multiplier technique subchannel allocation( LMTSA) algorithm; secondly,according to the obtained channel allocation matrix,a power allocation algorithm based on the water-filling power allocation( WPA) idea is deployed to get the optimal power allocation matrix combining with adaptive modulation and coding( AMC); finally,through a greedy algorithm,the ultimate subchannel and power allocation matrix can be obtained based on iterative method. The simulation results illustrate that we can achieve the higher throughput and better Qo S performance than the widely-used maximum throughput( MT) algorithm and round robin( RR) algorithm. | Li Zeng Xi Li Hong Ji Ke Wang | 2015 | Journal of Harbin Institute of Technology(New Series)2015，22，1： | 14 |
| 10 | Non-Orthogonal Multiple Access(NOMA) for Future Downlink Radio Access of 5G显示文摘Multiple access(MA) technology is of most importance for 5G. Non-orthogonal multiple access(NOMA) utilizing power domain and advanced receiver has been considered as a promising candidate MA technology recently. In this paper, the NOMA concept is presented toward future enhancements of spectrum efficiency in lower frequency bands for downlink of 5G system. Key component technologies of NOMA are presented and discussed including multiuser transmission power allocation, scheduling algorithm, receiver design and combination of NOMA with multi-antenna technology. The performance gains of NOMA are evaluated by system-level simulations with very practical assumptions. Under multiple configurations and setups, the achievable system-level gains of NOMA are shown promising even when practical considerations were taken into account. | LI Anxin LAN Yang CHEN Xiaohang JIANG Huiling | 2015 | China Communications2015，12，S1： | 12 |
| 11 | Recent development of a refined multiple air pollutant emission inventory of vehicles in the Central Plains of China显示文摘Central Plains region of China,represented by Henan Province,is facing serious air pollution problems.Vehicular exhaust emissions had adverse impacts on the atmospheric environment.The first comprehensive and novel vehicle emission inventory for Henan Province using vehicle kilometers traveled,localized emission factors,and activity data at city-level was developed.Furthermore,3 km×3 km gridded emission and temporal variations were determined by using localized information.Results show that the total emissions of sulfur dioxide(SO2),nitrogen oxides(NOx),carbon monoxide(CO),particular matter with aerodynamic diameter<10μm(PM10),aerodynamic diameter<2.5μm(PM2.5),volatile organic compounds(VOCs),VOCs-evaporation and ammonia in 2015 were 9.1,533.4,1190.7,23.7,21.6,150.8,31.5 and 10.4 Gg,respectively,and the emission intensities of the above pollutants were 0.05,2.7,6.0,0.1,0.1,0.8,0.2 and 0.05 g/km,respectively.Vehicles meeting the Primary China 1,China 3 and China 4 contributed 89.1%,82.7%,75.3%,75.5%,75.5%,68.2%,68.4%and 82.3%for SO2,NOx,CO,PM10,PM2.5,VOCs,VOCs-evaporation and ammonia emissions,respectively.Zhengzhou,Zhoukou,Nanyang,Luoyang,Shangqiu and Xinyang showed relatively higher emissions and contributed more than 50%of each pollutant.The spatial distribution indicated obvious characteristics of the road network,and high-level emission was concentrated in the downtown areas.Additionally,the ozone formation potential(OFP)based on the estimated speciated VOC emissions was 569.6 Gg in Henan Province.Aliphatic and aromatic hydrocarbons were the main species of VOCs,whereas olefins contributed the largest proportion of OFP,with 42.2%. | Xingke Gu Shasha Yin Xuan Lu Huan Zhang Lingling Wang Ling Bai Chen Wang Ruiqin Zhang Minghao Yuan | 2019 | Journal of Environmental Sciences2019，31，10： | 11 |
| 12 | AI for 5G: research directions and paradigms显示文摘Wireless communication technologies such as fifth generation mobile networks(5 G) will not only provide an increase of 1000 times in Internet traffic in the next decade but will also offer the underlying technologies to entire industries to support Internet of things(IOT) technologies. Compared to existing mobile communication techniques, 5 G has more varied applications and its corresponding system design is more complicated. The resurgence of artificial intelligence(AI) techniques offers an alternative option that is possibly superior to traditional ideas and performance. Typical and potential research directions related to the promising contributions that can be achieved through AI must be identified, evaluated, and investigated.To this end, this study provides an overview that first combs through several promising research directions in AI for 5 G technologies based on an understanding of the key technologies in 5 G. In addition, the study focuses on providing design paradigms including 5 G network optimization, optimal resource allocation, 5 G physical layer unified acceleration, end-to-end physical layer joint optimization, and so on. | Xiaohu YOU Chuan ZHANG Xiaosi TAN Shi JIN Hequan WU | 2019 | Science China(Information Sciences)2019，62，2： | 10 |
| 13 | Antenna Selection and Power Allocation Design for 5G Massive MIMO Uplink Networks显示文摘Massive MIMO is one of the key technologies in future 5G communications which can satisfy the requirement of high speed and large capacity. This paper considers antenna selection and power allocation design to promote energy conservation then provide good quality of service(QoS) for the whole massive MIMO uplink network. Unlike previous related works, hardware impairment, transmission efficiency, and energy consumption at the circuit and antennas are involved in massive MIMO networks. In order to ensure the QoS, we consider the minimum rate constraint for each user and the system, which increases the complexity of power allocation problem for maximizing energy and spectral efficiency in massive MIMO system. To this end, a quantum-inspired social emotional optimization(QSEO) algorithm is proposed to obtain the optimal power control strategy in massive MIMO uplink networks. Simulation results assess the great advantages of QSEO which previous strategies do not have. | Hongyuan Gao Yumeng Su Shibo Zhang Ming Diao | 2019 | China Communications2019，16，4： | 10 |
| 14 | 基于LDA主题的改进TFIDF 95598工单智能分类研究显示文摘为了提高95595工单智能分类的准确率,提出了基于LDA(Latent Dirichlet Allocation)的改进TFIDF算法。先对文本提取特征词,然后采用K-means算法进行聚类处理。构建LDA模型,获得概率分布函数θ和φ,求取语义影响力SI(semantic influence,SI)作为特征词的权重,该改进算法记作SI-TFIDF(semantic influence-term frequency inverse document frequency,SI-TFIDF)。将SI-TFIDF算法与传统的TFIDF算法在sougou的数据库进行特征词提取,并采用K-means算进行聚类,对比结果显示,采用SI-TFIDF算法提取的特征词聚类效果优于TFIDF,验证了所提出方法的可靠性。在95598投诉工单上进行仿真实验,SI-TFIDF算法的投诉工单聚类准确率高于传统的TFIDF算法,验证了SI-TFIDF更适用于处理工单投诉的分类研究。 | 武光华 李洪宇 刘二刚 柳长发 李倩 | 2020 | 微型电脑应用2020，36，3： | 9 |
| 15 | 基于地表水和地下水联合调控的水资源配置模型研究显示文摘基于水库与地下水联合运用的耦合模拟模型,建立了基于河道内与河道外生态环境需水及下游灌溉用水需求双重作用的水资源优化调控模型,研制和开发了集数据库、模型库和人机交互界面等于一体的水资源优化调控模型计算软件,并以沈阳市沈北地区为例进行了实证研究。通过对石佛寺供水系统不同组合方案长系列逐月调算和对比分析,提出了推荐的石佛寺供水系统地表水与地下水联合优化调控模式和设计供水规模。研究结果为沈阳市的协调发展尤其是沈北地区未来的跨越式发展提供了安全的供水保障,且可推动我国地表水与地下水联合优化调控理论研究和应用,为其他地区和流域开展类似工作提供参考。 | 杨丽丽 王云霞 谢新民 叶勇 丁飞 | 2010 | 水电能源科学2010，28，7： | 9 |
| 16 | Game theory approach to optimal capital cost allocation in pollution control显示文摘GametheoryapproachtooptimalcapitalcostalocationinpolutioncontrolChenWenyingInstituteofNuclearEnergyTechnology,TsinghuaUniver... | Chen Wen ying Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084,China Hou Dun Urban Water Resources Center, Ministry of Construction, Beijing 100007,China | 1998 | Journal of Environmental Sciences1998，10，2： | 8 |
| 17 | MAV/UAV task coalition phased-formation method显示文摘The formation of the manned aerial vehicle/unmanned aerial vehicle(MAV/UAV) task coalition is considered. To reduce the scale of the problem, the formation progress is divided into three phases. For the task clustering phase, the geographical position of tasks is taken into consideration and a cluster method is proposed. For the UAV allocation phase, the UAV requirement for both constrained and unconstrained resources is introduced, and a multi-objective optimal algorithm is proposed to solve the allocation problem. For the MAV allocation phase, the optimal model is firstly constructed and it is decomposed according to the ideal of greed to reduce the time complexity of the algorithm. Based on the above phases, the MAV/UAV task coalition formation method is proposed and the effectiveness and practicability are demonstrated by simulation examples. | JIAO Zhiqiang YAO Peiyang ZHANG Jieyong ZHONG Yun WANG Xun | 2019 | Journal of Systems Engineering and Electronics2019，30，2： | 8 |
| 18 | 面向自主意识的标签个性化推荐方法研究显示文摘在标签系统中,用户使用资源以及标签的习惯受到自身自主意识的影响.当前的标签个性化推荐方法缺乏对此类自主意识信息的描述,限制了个性化推荐的效果.通过采用类似LDA的概率模型,建模了用户的资源使用以及标签使用两方面的自主意识信息,实现了面向用户自主意识的标签推荐.模型的参数使用基于吉布斯抽样的方法进行估计,为快速高效计算模型参数提供了可能.实验结果显示该方法可以提供更高质量的标签个性化推荐结果. | 张引 张斌 高克宁 郭朋伟 孙达明 | 2012 | 电子学报2012，40，12： | 8 |
| 19 | 结合LDA和谱聚类的多文档摘要显示文摘自动文摘技术的目标是致力于将冗长的文档内容压缩成较为简短的几段话,将信息全面、简洁地呈现给用户,提高用户获取信息的效率和准确率。所提出的方法在LDA(Latent Dirichlet Allocation)的基础上,使用Gibbs抽样估计主题在单词上的概率分布和句子在主题上的概率分布,结合LDA参数和谱聚类算法提取多文档摘要。该方法使用线性公式来整合句子权重,提取出字数为400字的多文档摘要。使用ROUGE自动摘要评测工具包对DUC2002数据集评测摘要质量,结果表明,该方法能有效地提高摘要的质量。 | 付玲 张晖 | 2013 | 计算机工程与应用2013，49，16： | 8 |
| 20 | China’s WUB Community vs. America’s TOD Community显示文摘1. Critiques and reflections on WUB CommunityThe working unit system and the WUB Community, i.e., working-unit-based community, are two completely | YU Wenbo,Postdoctoral,Department of Architecture,Zhejiang University Associate Professor,Department of Architecture and Planning,Zhejiang University of Technology,Hangzhou,P. R. China. WANG Zhu,Professor,Chair of Department of Architecture,Zhejiang University,Hangzhou,P. R. China. MENG Haining,Associate Professor,Chair of Department of Architecture,Zhejiang University,Hangzhou,P. R. China. Editorial Department | 2007 | China City Planning Review2007，16，4： | 7 |
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