Importance Analysis of a Multi-state System Based on Direct Partial Logic Derivatives and Multi-valued Decision Diagrams

Importance analysis quantifies the critical degree of individual component. Compared with the traditional binary state system,importance analysis of the multi-state system is more aligned with the practice. Because the multi-valued decision diagram( MDD) can reflect the relationship between the components and the system state bilaterally, it was introduced into the reliability calculation of the multi-state system( MSS). The building method,simplified criteria,and path search and probability algorithm of MSS structure function MDD were given,and the reliability of the system was calculated. The computing methods of importance based on MDD and direct partial logic derivatives( DPLD) were presented. The diesel engine fuel supply system was taken as an example to illustrate the proposed method. The results show that not only the probability of the system in each state can be easily obtained,but also the influence degree of each component and its state on the system reliability can be obtained,which is conducive to the condition monitoring and structure optimization of the system.

Value Analysis among the Parties on Imported Product in Indonesia Using Process Activity Mapping： Freight Forwarder, Distributor, and Retailer

National logistics system in Indonesia can be categorized as inefficient logistics system due to current number of non-value added （NVA） activities. The unreliable National logistics system and the complexity of distribution system are the big obstacles. This study aims to analyze the value and to propose recommendation for further improvement of National distribution system for imported product. This study employed convenience sampling through in-depth interview to analyze the activity in freight forwarder （FF）, distributor and retailer. To demonstrate and analyze the activity process in each party, Process Activity Mapping （PAM） was used as a tool. The study results showed that the delivery speed in Jakarta （8.4 min/km） is slower than that of Surabaya （6.6 min/km）. The government support through creating adequate infrastructure, good bureaucracy system and good collaboration directly affects the activities of FF, distributor and retailer. Improving FF performance in a timely and reliable manner is required to reduce errors that may occur. Moreover, encouraging the practice of cold chain management is also necessary in distributing the product throughout Indonesia. The pull strategy can be chosen by retailer to eliminate storage activity. Meanwhile, the use of information technology （IT） system is essential to encourage better inventory management, database management and sharing information in distributor and retailer stage.

Variations of population structure and important value of the main edificators along the elevation gradient on the northern slope of Changbai Mountain

From 700 m to 1900 m on the northern slope of Changbai Mountain, 13 plots with an interval of 100 m in elevation were investigated to study the variations of population structure and important value of the main edificators along the elevation gradient. In their core distribution areas, most of the edificators had healthy population structure and could regenerate smoothly except Larix olgensis, but important value of Larix olgensis had no obvious variations with elevation changes, which showed that Larix olgensis had its own particularity and strong adaptability. At high elevation above 1800 m, Betula ermanii was the only species that could form a mono-dominant community. Important values of Pinus koraiensis and Acer mono had similar changing trends, and they had the similar ecological adaptabilities.

Predictive value of alarm symptoms in Rome IV irritable bowel syndrome:A multicenter cross-sectional study

BACKGROUND Irritable bowel syndrome(IBS)is a common functional bowel disease that shares features with many organic diseases and cannot be accurately diagnosed by symptom-based criteria.Alarm symptoms have long been applied in the clinical diagnosis of IBS.However,no study has explored the predictive value of alarm symptoms in suspected IBS patients based on the latest Rome IV criteria.AIM To investigate the predictive value of alarm symptoms in suspected IBS patients based on the Rome IV criteria.METHODS In this multicenter cross-sectional study,we collected data from 730 suspected IBS patients evaluated at 3 tertiary care centers from August 2018 to August 2019.Patients with IBS-like symptoms who completed colonoscopy during the study period were initially identified by investigators through medical records.Eligible patients completed questionnaires,underwent laboratory tests,and were assigned to the IBS or organic disease group according to colonoscopy findings and pathology results(if a biopsy was taken).Independent risk factors for organic disease were explored by logistic regression analysis,and the positive predictive value(PPV)and missed diagnosis rate were calculated.RESULTS The incidence of alarm symptoms in suspected IBS patients was 75.34%.Anemia[odds ratio(OR)=2.825,95%confidence interval(CI):1.273-6.267,P=0.011],fecal occult blood[OR=1.940(95%CI:1.041-3.613),P=0.037],unintended weight loss(P=0.009),female sex[OR=0.560(95%CI:0.330-0.949),P=0.031]and marital status(P=0.030)were independently correlated with organic disease.The prevalence of organic disease was 10.41%in suspected IBS patients.The PPV of alarm symptoms for organic disease was highest for anemia(22.92%),fecal occult blood(19.35%)and unintended weight loss(16.48%),and it was 100%when these three factors were combined.The PPV and missed diagnosis rate for diagnosing IBS were 91.67%and 74.77%when all alarm symptoms were combined with Rome IV and 92.09%and 34.10%when only fecal occult blood,unintended weight loss and anemia were combined with Rome IV,respectively.CONCLUSION Anemia,fecal occult blood and unintended weight loss have high predictive value for organic disease in suspected IBS patients and can help identify patients requiring further examination but are not recommended as exclusion criteria for IBS.

Jiangsu's Top Enterprises with Import and Export Value of More Than US$ 200 Million in 1995

Name of the Enterprise1. Jiangsu Overseas Enterprises (Group) Co. Ltd2. Yizheng Chemical Fibers Co. Ltd3. Jiangsu Silk Products Imp. & Exp. (Group) Co. Ltd4. Jiangsu Garments Imp. & Exp. (Group) Co. Ltd5. Zhangjiagang Foreign Trading Company6. Jiangsu Textiles Imp. & Exp. (Group) Co.

Concepts of keystone species and species importance in ecology

This paper discussed the keystone species concept and introduced the typical characteristics of keystone species and their identification in communities or ecosystems. Based on the research of the keystone species, the concept of species importance (SI) was first advanced in this paper. The species importance can be simply understood as the important value of species in the ecosystem, which consists of three indexes: species structural important value (SIV), functional important value (FIV) and dynamical important value (DIV). With the indexes, the evaluation was also made on species importance of arbor trees in the Three-Hardwood forests (Fraxinus mandshurica, Juglans mandshurica, and Phellodendron amurense) ecosystem.

Evaluation of water resources conserved by forests in the Hani rice terraces system of Honghe County,Yunnan,China：an application of the fuzzy comprehensive evaluation model

The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in the sustainable development of this system. The value of water conserved by the forest is influenced by natural, economic and social factors. In this paper, the water quality, per capita water resources, per capita GDP and population density are chosen as indices to construct an index system for a comprehensive evaluation of water resources value. The weights of these indices are 0.443, 0.31, 0.141 and 0.106 respectively, which are determined by the analytic hierarchy process(AHP) method. The water resources value has been assessed by the fuzzy comprehensive evaluation model. The results show that the water resources value in the Hani Rice Terraces System is 4.25 RMB/m^3. Evaluating the value of water resources in the Hani Rice Terraces System can provide a reference for ecological compensation, for raising public awareness of the importance of protecting the system, and ultimately achieving its sustainable development.

不同龄级瑞香狼毒影响微尺度高寒草甸群落结构

通过样圆法群落调查探究不同龄级狼毒对微尺度草地群落结构和土壤化学计量特征的影响,结果表明:(1)狼毒能显著降低微尺度草地的群落盖度、群落加权平均高度、植物密度和地上生物量等指标,且影响程度随着狼毒龄级的增加而增大。(2)狼毒显著改变了草地的群落结构,降低了禾本科和莎草科植物的优势度,增加了杂草植物的优势度,随着狼毒龄级的增加,杂草的优势度逐渐增加。(3)狼毒的生长增加了退化草地物种多样性,但当狼毒龄级达到Ⅴ龄时,草地物种多样性逐渐降低。(4)随着狼毒龄级的增加,土壤全碳含量、全氮含量和全磷含量整体呈显著下降趋势,而碳磷比和氮磷比呈显著上升趋势。总之,狼毒对微尺度高寒草甸植物群落结构和土壤化学计量特征有显著影响,且与龄级有关,建议在修复狼毒型退化草地时,应及时进行人工干预,尤其在狼毒龄级达到Ⅴ龄之前,采取围栏封育、施氮肥和补播豆科优良牧草等措施,加强退化草地的生态修复。

新时代良好家风建设的重要价值、主要内容与实践路径

家风是一个家族代代相传沿袭下来的体现家族成员精神风貌、道德品质、审美格调和整体气质的家族文化风格。新时代良好家风建设是传承中华优秀传统文化的重要载体,是涵育时代新人的核心内容,是构建和谐社会的坚实基础,是中华民族伟大复兴的重要支撑,包含着厚植家国一体的崇高情怀、发扬孝长慈幼的道德风尚、继承耕读传家的精神品质、秉持俭以养德的立身之本等主要内容。新时代良好家风建设需要探寻新的路径,用正确的价值观引领家风建设,用日常生活涵育优良家风,用家长言传身教传承良好家风,用家校社协同建设良好家风,成就“积善之家”,创造和谐家园,为孩子的健康成长打造良好的“生态圈”。

基于三重混合采样和集成学习的潜在高价值旅客发现

考虑潜在高价值旅客特有的数据高度不平衡、旅客特征和价值类别弱相关等问题,提出一种基于三重混合采样和集成学习的潜在高价值旅客发现模型。采用RFM(Recency Frequency Monetary)方法标注旅客类别;使用三重混合采样对不平衡旅客数据集进行重采样;使用融合特征选择算法遴选旅客特征;使用梯度提升决策树作为分类器,构建旅客价值预测模型,识别潜在高价值旅客。在PNR数据集上的实验结果表明,与基准算法相比,该模型能取得更好的AUC值和F1值,可以较好地识别潜在高价值旅客。

基于重要值排序和自适应阈值的Douglas-Peucker算法

矢量数据压缩长久以来一直是地理信息系统(GIS)领域的关注焦点,旨在缩减数据规模以满足应用性能方面的需求,同时减少数据传输、系统处理时长以及储存成本,从而提高系统性能和运行开销。虽然在该问题上已取得了一些研究成果,但由于技术进步和新需求的涌现,对矢量数据压缩的压缩率和精度都提出了更高的要求,同时如何确定最优的阈值也成为了一个亟待解决的问题。因此,本文从矢量数据中不同节点对整个矢量图形产生变化的重要性以及如何确定最佳阈值出发,设计了结合重要值排序和自适应阈值的Douglas-Peucker算法。通过对上海市民政部门内部矢量数据集的实验表明,改进算法在压缩率相同情况下,数据压缩效果整体优于Douglas-Peucker算法及其改进算法。

奥运奖牌可以被预测吗?——基于可解释机器学习视角

基于1992-2021年夏季奥运会的分项目成绩大数据,使用随机森林模型评估不同项目金牌和奖牌的可预测性,发现各项目存在较大的差异:对奖牌而言,可预测性最强的是乒乓球、羽毛球和游泳,而最弱的是水球、现代五项和排球。基于可解释机器学习方法挖掘社会经济因素对奥运奖牌的影响发现:(1)对同一个项目而言,女子项目的可预测准确性普遍高于男子项目;(2)代表队所在地区的人口规模、人均GDP、是否为主办国等因素对奖牌总数具有一定影响;(3)在特定项目上,代表队的传统优势(如中国的乒乓球、美国的田径等)对奖牌预测具有较大影响。

论郧阳“伍子胥堰”的历史逻辑与世界灌溉工程遗产价值

“伍子胥堰”是春秋时期以伍子胥为代表的伍氏先贤接续创建的杰出农耕文明成果,是兼具科学性与价值性、民族性与世界性、历史性与现实性、物质遗产与精神遗产特质的灌溉工程杰作,具有极其重要的实用价值和人文价值。探讨其形成的历史逻辑,发掘其丰富内涵,阐释其审美内蕴,有利于彰显其世界灌溉工程遗产的价值意蕴。

甘肃马先蒿入侵对巴音布鲁克草原植物群落特征的影响

入侵性物种常通过竞争排斥群落中其他物种,改变入侵地群落的物种组成和结构,破坏生态系统的稳定性。甘肃马先蒿(Pedicularis kansuensis)在巴音布鲁克草原快速蔓延,对当地生态系统造成威胁,是典型的入侵性植物。本研究以入侵性植物甘肃马先蒿群落为研究对象,调查4个入侵程度(未入侵、低度入侵、中度入侵、高度入侵)的甘肃马先蒿群落物种组成和群落特征,分析不同入侵程度下群落的物种多样性差异。结果表明:1)甘肃马先蒿3种入侵群落中均记录了30种维管植物,未入侵群落共记录27种维管植物,3种入侵群落与未入侵群落相比均多3种植物,但多的3种植物在入侵群落中并不相同。2)甘肃马先蒿入侵降低了群落中二裂委陵菜(Potentilla bifurca)、拉普兰棘豆(Oxytropis lapponica)、紫花针茅(Stipa purpurea)、洽草(Koeleria litvinowii)、火绒草(Leontopodium leontopodioides)的重要值;禾本科的密度在群落中的比例随入侵程度的增加呈先上升后下降趋势,豆科与禾本科密度和盖度在中度和高度入侵群落中的比例显著降低(P<0.05)。3)随入侵程度增加,物种丰富度和Margalef丰富度指数呈先上升后下降趋势,Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数均呈下降-上升-下降趋势。本研究可为巴音布鲁克草原生物多样性的保护提供科学依据。

黄土高原南部麻栎不同群落类型乔木种群结构及演替模拟

由于对黄土高原南部麻栎天然次生林的群落稳定机制缺乏了解,以不同群落类型麻栎天然次生林为研究对象,通过样地监测及时间序列模型预测的方法,重点研究了不同群落类型中重要乔木的种群结构动态,并根据不同群落类型重要乔木种群的年龄结构数据,用时间序列模型预测未来20、30、40和50年的种群发展趋势。结果表明:(1)不同群落类型中各重要乔木种群生存能力均较好,但松栎混交林中的槲栎种群及麻栎纯林中的茶条槭种群生存能力欠佳;(2)除麻栎纯林中杜梨种群及栎阔混交林中槲栎种群,其余乔木种群的存活曲线皆呈Deevey-Ⅲ型;(3)不同麻栎群落类型中各个重要值较高的乔木种群幼龄级个体数量相对丰富,时间序列分析表明,在未来20、30、40和50年中,不同群落类型中各重要乔木种群均可持续发育,并未出现衰退迹象。同时麻栎纯林具有向混交林演替的趋势,说明未来对不同类型麻栎林经营均应以顺应自然演替规律的近自然经营方式为主。研究结果可为促进次生林持续经营及恢复提供理论依据。

进口竞争、创新与企业出口价值攀升

在中国主动扩大进口的政策背景下,本文从理论和实证两方面考察了关税削减引致的进口竞争对中国制造业企业出口价值攀升的影响及内在机制。研究发现,进口竞争通过提高企业创新产出水平、推动创新成果转化从而促进了出口价值的攀升。异质性分析表明,进口竞争显著促进了非国有企业、中、东部地区企业的出口价值攀升,但对国有企业产生了显著的抑制效应。此外,对于本就生存于激烈的市场竞争环境中的企业,其对进口竞争冲击的应对能力更强。鉴于此,本文从政府和企业两个角度提出了如何在进口竞争中推动企业出口价值攀升的政策建议。

基于IVFS的IV—模糊度与IV—贴近度及积分表示

在区间值模糊集空间上,给出描述IV—模糊度与IV—贴近度的公理化定义,借助于Lebesgue积分构造一种具体的IV—模糊度和IV—贴近度,从而获得由IV—贴近度刻划IV—模糊度的两种方法。

面向类集成测试序列确定的强化学习方法

面向类集成测试序列的强化学习方法能够自适应地根据系统集成状态调整集成测试策略,是测试优化的关键技术之一,但现有方法普遍存在计算成本高且不适用于大规模软件系统、忽略测试风险的滞后性问题,大幅降低了适用性和可靠性。针对上述问题,提出一种具有重要值加权奖励的基于测试顺序的强化学习方法。优化强化学习建模,忽略节点在测试序列上的具体位置,减弱状态之间的相关性,提升模型可用性。结合深度强化学习模型,端到端地更新集成测试策略,减少值函数的误差。在奖励函数的设计上,引入修正的节点重要值,实现降低整体测试桩复杂度且提升关键类优先级的多目标优化求解。在SIR开源系统上的实验结果表明:优化的强化学习建模方式能够有效降低整体测试桩复杂度,并适用于大规模软件系统;融入修正节点重要值的奖励函数能够有效提升软件系统中关键类的优先级,平均提升幅度为55.38%。

东北中东部山区天然次生林乔木物种组成和群落结构特征

【目的】研究东北中东部地区天然次生林林分内物种组成和群落结构特征,旨在为东北中东部地区天然次生林物种研究与经营提供科学的理论和数据支持。【方法】按照地理网络布点在长白山、张广才岭和老爷岭地区设置样地进行群落调查,共调查0.1 hm^(2)(半径为17.85 m的样圆)样地183块,并对调查样地内物种组成、区系特征、重要值、径级结构和多样性等进行研究。【结果】调查区内胸径(DBH)≥5 cm乔木数量共15 601株,隶属于15科31属60种,主要以蔷薇科和槭树科物种种类最多,以壳斗科和槭树科物种数量最多,以蒙古栎、紫椴、色木槭、春榆和桦树为主要构成树种,该地区物种组成丰富,物种科分属6个区系,以北温带与南温带间断分布为主;物种属共包含9个区系,以北温带分布为主;重要值排名前3的树种,除长白山地区蒙古栎和紫椴的径级结构呈现正态分布、树种个体集中在8~18 cm径级外,长白山地区春榆,张广才岭地区蒙古栎、色木槭和春榆以及老爷岭地区蒙古栎、黑桦和紫椴的径级结构均呈倒“J”形分布,树种个体主要集中在18cm径级以下,整体林分更新良好。3个地区物种丰富度相似,除Shannon-Wiener多样性指数(H’)外,老爷岭地区物种与长白山和张广才岭地区存在显著性差异(P≤0.05),其他多样性指标在各地区之间无显著性差异,且3个地区物种相似性均属于中等相似。【结论】我国东北中东部山区森林乔木种类较为丰富,林分中小、中径级林木居多,更新状况良好,未来该区域森林仍能较为稳定发展。该研究成果可为我国东北中东部地区天然次生林的研究和经营提供科学的理论和数据支持。

河南黄河中游、下游湿地优势草本植物生态位与种间联结性研究

本研究以河南黄河中游及下游湿地为研究区,对区内19种优势草本植物的生态位与种间联结性进行分析,以期对黄河中游、下游湿地的生态恢复和科学治理提供依据。结果显示,研究区共调查到116种草本植物,其中19种优势草本植物种间生态位差异较大。黄河中游、下游湿地总体联结性呈显著正联结;黄河中游和下游AC值≥0.4的均为2对,优势种种间联结性较弱,物种独立性较强。研究结果表明,黄河湿地植物群落总体呈现正向演替,但这种演替不稳定,还处于初级阶段。在生态修复过程中可以优先考虑具有较高生态位宽度且适应性强的植物,如芦苇(Phragmites australis(Cav.)Trin.ex Steud.)、香附子(Cyperus rotundus L.)作为先锋植物以加快演替进程。