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A KNN-based two-step fuzzy clustering weighted algorithm for WLAN indoor positioning

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High Technology Letters 2011年第3期17卷 223-229页

作者： Xu Yubin Sun yongliang ma Lin Communication Research Center Harbin Institute of Technology Harbin 150080 P. R. China

Although k-nearest neighbors （KNN） is a popular fingerprint match algorithm for its simplicity and accuracy, because it is sensitive to the circumstances, a fuzzy c-means （FCM） clustering algorithm is applied to improve it. Thus, a KNN-based two-step FCM weighted （KTFW） algorithm for indoor positioning in wireless local area networks （WLAN） is presented in this paper. In KTFW algorithm, k reference points （RPs） chosen by KNN are clustered through FCM based on received signal strength （RSS） and location coordinates. The right clusters are chosen according to rules, so three sets of RPs are formed including the set of k RPs chosen by KNN and are given different weights. RPs supposed to have better contribution to positioning accuracy are given larger weights to improve the positioning accuracy. Simulation results indicate that KTFW generally outperforms KNN and its complexity is greatly reduced through providing initial clustering centers for FCM.

关键词： wireless local area networks (WLAN) indoor positioning k-nearest neighbors (KNN) fuzzy c-means (FCM) clustering center

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基于联盟链的区块链短信平台研究

邮电设计技术 2024年第6期 78-83页

作者：王九九马永亮沈超中国联合网络通信集团有限公司北京100033 联通在线信息科技有限公司北京100032

为保障用户安宁权,解决现有的垃圾短信溯源效果不佳,用户被大量垃圾信息骚扰的难题,通过对区块链技术在行业短信领域的研究,基于区块链技术公开透明、不可篡改、可追溯的特性,探索用于行业短信应用场景的区块链短信技术。同时,研发了一... 详细信息

为保障用户安宁权,解决现有的垃圾短信溯源效果不佳,用户被大量垃圾信息骚扰的难题,通过对区块链技术在行业短信领域的研究,基于区块链技术公开透明、不可篡改、可追溯的特性,探索用于行业短信应用场景的区块链短信技术。同时,研发了一套基于联盟链技术的区块链短信平台,实现了行业短信全流程上链以及行业短信全程可溯源。通过测试,平台的性能和扩展性能够满足某运营商全行业短信业务需求,取得了较好的效果。

关键词：区块链短信联盟链超级账本

Investigation on sampling artifacts of particle associated PAHs using ozone denuder systems

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Frontiers of Environmental Science & Engineering 2014年第2期8卷 284-292页

作者： Kai LIU Fengkui DUAN Kebin HE yongliang ma Yuan CHENG State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China

Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases, especially ozone, nitrogen oxides （NOx）, hydroxyl radical （OH）, and could be degraded on filters during sampling process, leading to an underestimation of ambient PAH concentrations. The goal of this work was to investigate particle associated PAHs sampling artifacts caused by ozone in summer of Beijing. Comparative sampling systems were operated simultaneously during the whole campaign, one with activated carbon ozone denuder, the other being set as conventional sampling system. Activated carbon denuder was testified to be highly efficient to eliminate ozone from air stream. In general, nine particle-bound PAHs observed from conventional sampler were all lower than those from ozone denuder system. The total PAHs （particle phase） concentration was averagely underestimated by 35.9% in conventional sampling procedure. Benzo[a]pyrene （BaP） had the highest percentage of mass loss. founded to have influences Ambient temperature was on PAHs sampling artifacts. High temperature can increase loss of particle associated PAHs during sampling.

关键词： particle associated polycyclic aromatic hydro- carbons (PAHs) ozone denuder sampling artifacts

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基于流式计算的垃圾短信治理关键技术研究

邮电设计技术 2024年第5期 56-61页

作者：王九九狄秋燕马永亮中国联合网络通信集团有限公司北京100033

某运营商在现网垃圾短信治理中,常采用关键字+规则的方法,难以在拦截成功率和误拦正常短信之间找到平衡。基于文本语义分析识别垃圾短信,则需要解决大数据挖掘算法、海量数据处理、响应时效等问题,因此在大业务量的集约化平台上应用并... 详细信息

某运营商在现网垃圾短信治理中,常采用关键字+规则的方法,难以在拦截成功率和误拦正常短信之间找到平衡。基于文本语义分析识别垃圾短信,则需要解决大数据挖掘算法、海量数据处理、响应时效等问题,因此在大业务量的集约化平台上应用并不广泛。通过算法研究、开发原型系统等工作,探索基于流式计算的垃圾短信治理技术方案,研发了一套基于Storm+mahout架构的垃圾短信识别原型系统,完成了性能和准确率测试,取得了较好的效果。

关键词：垃圾短信治理自然语言处理大数据流式计算

Characteristics and mixing state of S-rich particles in haze episodes in Beijing

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Frontiers of Environmental Science & Engineering 2016年第5期10卷 59-68页

作者： Jun Hu Fengkui Duan Kebin He yongliang ma Shuping Dong Xiande Liu State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Tsinghua University Be(jing 100084 China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control (Tsinghua University) Beijing 100084 China Sino-Japan Friendship Environmental Protection Center Beijing 100029 China Chinese Research Academy of Environmental Sciences Beijing 100029 China

Direct individual analysis using Scanning Electron Microscopy combined with online obscrv ation was conducted to examine the S-rich particles in PM2.5 of two typical polluted haze cpisodes in summer and winter from 2014 to 2015 in Beijing. Four major types of S-rich particles, including sccondary CaSO4 particles （mainly observed in summer）, S-rich mineral particles （SRM）, S-rich water droplets （SRW） and （C, O, S）-rich particles （COS） were identified. We lbund the differcnt typical morphologies and element distributions of S-rich particles and considered that （C, O, S）-rich parliclcs had two major mixing states in different seasons. On the basis of the S-rich particles＂ relative abundances. S concentrations and their relationships with PM2.5 as well as the seasonal comparison, wc revealed that the S-participated formation degrees of SRM and SRW would enhance with increasing PM2.5 concentration. Moreover, C-rich matter and sulfate had seasonally differcnt but significant impacts on the formation of COS.

关键词： S-rich particles Morphology Element distribution Mixing state

Chemical characteristics of PM_(2.5) during a typical haze episode in Guangzhou

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Journal of Environmental Sciences 2009年第6期21卷 774-781页

作者： TAN Jihua DUAN Jingchun HE Kebin ma yongliang DUAN Fengkui CHEN Yuan FU Jiamo Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China Chinese Research Academy of Environmental Sciences Beijing 100012 China State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

The chemical characteristics（water-soluble ions and carbonaceous species） of PM2.5 in Guangzhou were measured during a typical haze *** of the chemical species in PM2.5 showed significant difference between normal and haze *** highest contributors to PM2.5 were organic carbon（OC）,nitrate,and sulfate in haze days and were OC,sulfate,and elemental carbon（EC） in normal *** concentrations of secondary species such as,NO3^-,SO4^2-,and NH4^＋ in haze days were 6.5,3.9,and 5.3 times higher than those in normal days,respectively,while primary species（EC,Ca^2＋,K^＋） show similar increase from normal to haze days by a factor about ***/EC ratio ranged from 2.8 to 6.2 with an average of 4.7 and the estimation on a minimum OC/EC ratio showed that SOC（secondary organic carbon） accounted more than 36.6% for the total organic carbon in haze *** significantly increase in the secondary species（SOC,NO3^-,SO4^2-,and NH4^＋）,especially in NO3^-,caused the worst air quality in this ***,the result illustrated that the serious air pollution in haze episodes was strongly correlated with the meteorological *** the sampling periods,air pollution and visibility had a good relationship with the air mass transport distance;the shorter air masses transport distance,the worse air quality and visibility in Guangzhou,indicating the strong domination of local sources contributing to haze *** concentration of the secondary aerosol in haze episodes was likely due to the higher oxidation rates of sulfur and nitrogen species.

关键词： PM2.5 haze episode water-soluble inorganic ions organic carbon elemental carbon Guangzhou

A comparative study of particle size distribution from two oxygenated fuels and diesel fuel

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Frontiers of Environmental Science & Engineering 2010年第1期4卷 30-34页

作者： Xiaoyan SHI Kebin HE Jie ZHANG yongliang ma Yunshan GE Jianwei TAN Department of Environmental Science and Engineering Tsinghua UniversityBeijing 100084China National Laboratory of Auto Performance and Emission Test Beijing Institute of TechnologyBeijing 100081China

Oxygenated fuels are known to reduce particulate matter(PM)emissions from diesel *** this study,100%soy methyl ester(SME)biodiesel fuel(B100)and a blend of 10%acetal denoted by A-diesel with diesel fuel were tested as oxygenated *** size and number distributions from a diesel engine fueled with oxygenated fuels and base diesel fuel were measured using an Electrical Low Pressure Impactor(ELPI).Measurements were made at ten steady-state operational modes of various loads at two engine *** was found that the geometric mean diameters of particles from SME and Adiesel were lower than that from base diesel *** to diesel fuel,SME emitted more ultra-fine particles at rated speed while emitting less ultra-fine particles at maximum ***-fine particle number concentrations of A-diesel were much higher than those of base diesel fuel at most test modes.

关键词： oxygenated fuel diesel particulate matter particle size distribution biofuel

Organic nitrogen in PM2.5 in Beijing

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Frontiers of Environmental Science & Engineering 2015年第6期9卷 1004-1014页

作者： Qian ZHANG Fengkui DUAN Kebin HE yongliang ma Haiyan LI Takashi KIMOTO Aihua ZHENG State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Tsinghua University Beijing 100084 China Kimoto Electric Co. Ltd. Funahashi-Cho Tennouji-Ku Osaka 543-0024 Japan Analysis and Testing Center of Beijing Normal University Beijing 100875 China

Nitrogenous species, as important chemical components in PM2.5, include organic nitrogen （ON） and inorganic nitrogen （IN）, both of which have potential effects on human health, climate change and visibility degradation. In this study, we analyzed total nitrogen （TN） by CHN Elemental analyzer and inorganic nitrogen by ion chromatography （IC） respectively to obtain ON by calculating the difference between TN and IN. The results show that the mean ON concentrations in winter and summer are both 2.86 μg. m-a, ten times higher than other places reported on average. ON contributes about 20%- 30% to TN on average in both seasons, presenting higher contribution in summer. N：C ratios are much higher in summer than winter. ON sources or formation were strengthened by heavy PM2.5 pollution loads, especially sensitive to sulfate. ON concentrations are higher at night in the both seasons, however with distinguished day and night difference patterns influenced by relative humidity （RH） conditions. In winter, ON concentrations increase with RH on average through low RH values to high RH values. The variations are far larger than the ones caused by day and night difference. However in summer, day and night difference dominates the variations of ON concen- trations at low RH values, and RH conditions promote ON concentrations increase significantly only at high RH values. Dust related source and anthropogenic emission related secondary source are identified as important sources for ON. At heavy pollution loads, ON sources are more of secondary formation, possibly strengthened by combination influence of RH and acidity increase.

关键词： organic nitrogen N:C ratio secondary dayand night variation relative humidity (RH) acidity

Intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid under different water quality and light conditions

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Science China Chemistry 2009年第1期52卷 109-116页

作者： WANG LiDong ZHAO Yi LI QiangWei CHEN ZhouYan LIU SongTao ma yongliang HAO JiMing School of Environmental Science and Engineering North China Electric Power UniversityBaoding 071003China Department of Environmental Science and Engineering Tsinghua UniversityBeijing 100054China

Oxidation of sulfite is an important process in wet flue gas *** highly purified water or distilled water as a reaction medium and a transparent or an opaque intermittent reaction apparatus,the intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid was investigated under four dif-ferent *** reaction order of the reagents and the activation energy were *** re-sults indicate that water quality and light have no obvious effects on the reaction order and activation energy,but have an influence on the reaction rate *** mechanism of the intrinsic reaction is *** results derived with this mechanism are in good agreement with the experimental re-sults.

关键词： light water character peracetic acid catalyzed oxidation sulfite kinetics