Diversity and Distribution of Host Animal Species of Hantavirus and Risk to Human Health in Jiuhua Mountain Area,China

Objective To investigate the diversity and the distribution of host animal species of hantavirus and the effect on human health in Jiuhua Mountain area,China.Methods The host animal species of hantavirus was surveyed by using the trap method and the species diversity was evaluated by using the Simpson,Shannon-Weaner,and Pielou indices.Hantavirus antigens or antibodies in lung and blood samples of all the captured host animals were detected by direct or indirect immunofluorescence.Results Nine animal species of hantavirus were distributed in the forest ecosystem of Jiuhua Mountain.Of these,Niviventer confucianus and Apodemus agrarius were predominant,and N.confucianus,Rattus norvegicus,and Mus musculus had relatively large niche breadth index values.The host animals in the eastern and western mountain regions shared similar biodiversity index characteristics,predominant species,and species structures.Hantavirus was detected in 5 host animal species in Jiuhua Mountain area,the carriage rate of hantavirus was 6.03%.The average density of host animals in forest areas of the mountainous area was only 2.20%,and the virus infection rate in the healthy population was 2.33%.Conclusion The circulation of hantavirus was low in the forest areas of Jiuhua Mountain and did not pose a threat to human health.

Randomized Constraint Limit Linear Programming in Risk Management

Traditional linear program (LP) models are deterministic. The way that constraint limit uncertainty is handled is to compute the range of feasibility. After the optimal solution is obtained, typically by the simplex method, one considers the effect of varying each constraint limit, one at a time. This yields the range of feasibility within which the solution remains feasible. This sensitivity analysis is useful for helping the analyst get a feel for the problem. However, it is unrealistic because some constraint limits can vary randomly. These are typically constraint limits based on expected inventory. Inventory may fall short if there are overdue deliveries, unplanned machine failure, spoilage, etc. A realistic LP is created for simultaneously randomizing the constraint limits from any probability distribution. The corresponding distribution of objective function values is created. This distribution is examined directly for central tendencies, spread, skewness and extreme values for the purpose of risk analysis. The spreadsheet design presented is ideal for teaching Monte Carlo simulation and risk analysis to graduate students in business analytics with no specialized programming language requirement.

考虑风险和碳交易机制的微电网分布鲁棒优化调度

提高微电网风电的消纳能力是实现双碳目标的重要手段。该文构建了一种考虑极限场景和净负荷条件风险价值的微电网低碳分布鲁棒优化模型。首先,针对源-荷不确定性构造基于Wasserstein距离的概率分布模糊集,并考虑极限场景修正该模糊集,以提高模糊集的鲁棒性,减少场景数目,提高求解效率。其次,以包括供能成本、阶梯式碳交易成本和风险成本的微电网日运行成本最小为优化目标,建立分布鲁棒优化调度模型,并利用分段线性近似法和对偶理论将模型转换为线性规划问题求解。最后,通过算例仿真进行验证,结果表明,考虑极限场景的分布鲁棒优化方法具有较强的鲁棒性;引入阶梯式碳交易成本可以有效减少微电网的碳排放量,并提高风电的消纳能力;净负荷条件风险价值可以有效平衡微电网运行的经济性与风险性。

考虑条件风险价值的交直流系统两阶段分布鲁棒低碳经济优化调度

考虑到海上风电出力的随机性以及日益突出的生态环境问题,以含柔性直流输电技术(voltagesource converter high voltage direct current,VSC-HVDC)的交直流系统为研究对象,提出了考虑条件风险价值(conditional valueatrisk,CVaR)的两阶段分布鲁棒低碳经济优化模型,构建了基于Kullback-Leibler(KL)散度的概率分布模糊集,同时利用条件风险价值量化了极端场景下的尾部风险,使得模型能够同时考虑概率分布不确定性以及处于最坏概率分布中极端场景下的尾部损失;此外,将阶梯型碳交易机制并入所提分布鲁棒模型中,通过合理利用柔性资源和储能装置,增强系统运行的灵活性,在兼顾运行风险的前提下,降低碳排放量的目标。再者,为了提高计算效率,在列和约束生成算法(column-and-constraint generation method,C&CG)和Multi-cut Benders分解算法的基础上提出了双循环分解算法。最后,在基于改进的IEEE RTS 79测试系统中验证了所提模型及算法的有效性。

基于分布鲁棒机会约束的高韧性配电网多类型储能配置

针对当前多类型储能系统(ESS)配置尚未充分计及正常工况与极端灾害等多元场景下源、网、荷多重不确定性复杂耦合影响的问题,提出了一种兼顾配电网韧性和经济性的多类型ESS配置方法。提出了面向多元场景差异化需求的多类型ESS优化配置框架,建立了以配电网韧性和经济性最优为目标的配置模型。考虑元件故障、源荷出力等多重不确定性,将原模型构建为两阶段分布鲁棒机会约束模型。提出了基于Big-M和条件风险价值理论的系统化线性方法,基于列和约束生成算法对线性化模型求解。在改进的IEEE 33节点配电网与43节点交通网算例上验证,结果表明,所提方法可显著降低负荷损失及投资,提升配电网韧性和经济性。

基于矩不确定模糊集的分布鲁棒风险-回报优化模型研究

本文研究随机变量分布不确定下的风险-回报优化模型。针对传统的风险-回报三类典型问题和分布不确定性背景,提出了更一般性条件下的分布鲁棒风险-回报优化新模型;基于矩不确定集合和优化对偶理论,化简复杂的新优化模型为常规结构的非线性优化问题。理论上证明了分布鲁棒风险-回报三类优化模型效率前沿的等价性。数值实验验证了理论分析的有效性。

考虑配电网灵活性不足风险的分布鲁棒低碳优化调度

双碳目标下高占比可再生能源接入配电网,其不确定性导致配电网灵活性需求剧增。为提高配电网灵活运行能力,减少碳排放,提出考虑配电网灵活性不足风险的分布鲁棒低碳优化调度方法。首先,考虑智能储能软开关作为网络灵活性资源,以减少线路阻塞并提高节点灵活性资源网络互济水平。引入功率传输分布因子表征灵活性供需在线路上的传输情况,提出资源灵活性裕度指标和线路容量裕度指标,评估配电网灵活性。其次,基于条件风险价值理论,推导出当资源-线路裕度不足时给配电网造成的灵活性不足风险。然后,考虑风光出力的不确定性与相关性,运用Frank-Copula函数生成风光出力场景,采用改进的KL散度构造概率分布模糊集。以综合运行成本最低为目标,建立分布鲁棒优化调度模型,采用列与约束生成算法求解。最后,通过算例验证表明,智能储能软开关的加入减少了线路阻塞的情况,所提方法能够减少配电网碳排放和灵活性不足风险。

计及多重不确定性的规模化电动汽车接入配电网调度方法

规模日益增长的电动汽车和可再生能源带来的不确定性给配电网的安全运营带来了严峻挑战。为综合考虑多重不确定性、平衡运营成本与系统可靠性,首先,提出一种基于分布鲁棒联合机会约束的电动汽车-配电网充放电调度模型。该模型将节点电压、支路功率、备用需求等通过联合机会约束建模,可以直观地管理系统整体的可靠性。然后,为求解该模型,基于最优Bonferroni近似方法将联合机会约束问题转化为混合整数二次规划模型,其中,风险等级也被视为决策变量。随后,在不同电力系统上验证了所提模型的有效性和可扩展性。结果表明,所提模型克服了经典的随机优化和鲁棒优化存在的问题,能够有效平衡成本和可靠性,计算效率高、可扩展性好,较Bonferroni近似方法降低约6.5%的成本。

Public-private partnership project success circumstances

The public-private partnership has been in use in the world for over 40 years, and has been growing at a varying rate and with mixed success in different countries. Based on the experience gained in selected countries, this article shows key success factors of the public-private partnership.

综合多阶段安全校正与风险管控的储能分布鲁棒优化配置

为了提高系统在不确定运行环境下应对故障的调控能力,以含柔性直流输电技术(voltage source converter high voltage direct current,VSC-HVDC)的交直流系统为研究对象,提出一种综合风险管控与多阶段校正控制的储能分布鲁棒优化配置方法。通过在考虑最恶劣概率分布的情况下进行储能的配置决策,改善传统鲁棒规划方法过于保守的问题,提高潜在尾部风险度量结果的鲁棒性;同时,将日内校正控制划分成无故障、故障短期与长期3个校正阶段,并通过最大化所配置储能、柔性负荷以及VSC的快速校正能力,弥补常规调控装置难以快速响应指令的缺陷。针对所提配置模型,在列和约束生成算法(column and constraint generation,C&CG)和Multi-cut Benders分解算法的基础上,提出一种双循环分解快速求解算法,通过返回多割约束的方式,降低模型规模、提高求解效率。最终,在改进的IEEE RTS 79测试系统中验证所提模型与方法的有效性。

Distribution of chlorpyrifos in rice paddy environment and its potential dietary risk

Chlorpyrifos is one of the most extensively used insecticides in China. The distribution and residues of chlorpyrifos in a paddy environment were characterized under field and laboratory conditions. The half-lives of chlorpyrifos in the two conditions were 0.9–3.8 days（field） and 2.8–10.3 days（laboratory）, respectively. The initial distribution of chlorpyrifos followed the increasing order of water 〈 straw 〈 soil, and soil was characterized as the major absorber. The ultimate residues in rice grain were below the maximum residue limit（MRL） with a harvest interval of 14 days. The chronic exposure for chlorpyrifos was rather low compared to the acceptable daily intake（ADI = 0.01 mg/kg bw） due to rice consumption. The chronic exposure risk from chlorpyrifos in rice grain was 5.90% and 1.30% ADI from field and laboratory results respectively. Concerning the acute dietary exposure,intake estimated for the highest chlorpyrifos level did not exceed the acute reference dose（ARf D = 0.1 mg/kg bw）. The estimated short-term intakes（ESTIs） were 0.78% and 0.25% of the ARf D for chlorpyrifos. The results showed that the use of chlorpyrifos in rice paddies was fairly safe for consumption of rice grain by consumers.

考虑单峰分布的电热综合能源系统风险调度

不确定可再生能源并入电热综合能源系统后将引发系统运行风险,而通过合理量化风险,实现风险可控性和调度经济性平衡是电热综合能源系统风险调度的关键。依据随机风电功率的单峰分布特性构建矩模糊集并以此刻画风电功率的不确定性,同时采用分布鲁棒机会约束方法来刻画系统的运行风险,进而建立了电热综合能源系统的分布鲁棒风险调度模型。在此基础上,从风险发生概率和经济成本的角度,提出了评估不确定风电功率引发运行风险的量化指标:均值风险概率和风险调度成本。最后,以改进的巴厘岛电热综合能源系统为例进行算例分析,验证了所提模型及其风险评估指标的可行性和有效性,并给出了电热综合能源系统的最优调度决策。

考虑风电出力不确定的分布鲁棒经济调度

随着大规模可再生能源参与到电力系统运行中,其波动性和间歇性增加了电力系统经济调度的困难和挑战。考虑可再生能源出力不确定,以发电成本、可再生能源削减成本和旋转备用成本最小为目标,提出了一种两阶段分布鲁棒经济调度模型。假设风电发电的波动性服从未知概率分布,利用可获取的风电出力历史数据矩信息,建立分布鲁棒模糊集以刻画风电出力特性。采用条件风险价值理论对分布鲁棒模型进行转换,进而得到具有数学可解性的优化模型。基于随机对偶动态规划方法,提出一种改进的迭代算法求解模型,该算法通过反复进行向前和向后迭代,能够快速收敛到模型最优解。最后,以IEEE 6节点系统和IEEE 118节点系统作为仿真系统,通过分析文中所提算法收敛度、置信度和样本量3个评价指标与总成本关系,验证提出的模型和方法的有效性。

带有CVaR罚的分布鲁棒指数跟踪模型:易求解的转化

提出了一种带有条件在险价值(CVaR)惩罚的分布鲁棒指数跟踪模型,该模型将分布鲁棒优化的思想与CVaR惩罚相结合。模型中概率的不确定性通过随机向量的一阶和二阶矩的置信区域来描述。将该模型由一个“min-max-min”形式的优化问题,等价转化为一个非光滑最小化问题。同时提供了一个近似求解带有连续型随机向量的非光滑极小化问题的离散化方案,通过该方案离散化之后的目标函数包含众多但有限个的非光滑函数的最大化。在较弱的条件下证明了离散化之后的模型收敛到原问题等价转化后的非光滑连续分布模型。采用了光滑投影梯度(Smoothing Projected Gradient,SPG)方法求解离散化后的模型,并证明了由SPG方法产生的迭代点序列的任何聚点都是离散化之后模型的全局最小值点。在2008年1月至2023年7月的纳斯达克日度指数数据集上与先进模型进行比较,数值结果验证了所提模型以及SPG方法的有效性。

Climate change and Aedes albopictus risks in China:current impact and future projection

Background Future distribution of dengue risk is usually predicted based on predicted climate changes using general circulation models(GCMs).However,it is difficult to validate the GCM results and assess the uncertainty of the predictions.The observed changes in climate may be very different from the GCM results.We aim to utilize trends in observed climate dynamics to predict future risks of Aedes albopictus in China.Methods We collected Ae.albopictus surveillance data and observed climate records from 80 meteorological stations from 1970 to 2021.We analyzed the trends in climate change in China and made predictions on future climate for the years 2050 and 2080 based on trend analyses.We analyzed the relationship between climatic variables and the prevalence of Ae.albopictus in different months/seasons.We built a classification tree model(based on the average of 999 runs of classification and regression tree analyses)to predict the monthly/seasonal Ae.albopictus distribution based on the average climate from 1970 to 2000 and assessed the contributions of different climatic variables to the Ae.albopictus distribution.Using these models,we projected the future distributions of Ae.albopictus for 2050 and 2080.Results The study included Ae.albopictus surveillance from 259 sites in China found that winter to early spring(November–February)temperatures were strongly correlated with Ae.albopictus prevalence(prediction accuracy ranges 93.0–98.8%)—the higher the temperature the higher the prevalence,while precipitation in summer(June–September)was important predictor for Ae.albopictus prevalence.The machine learning tree models predicted the current prevalence of Ae.albopictus with high levels of agreement(accuracy>90%and Kappa agreement>80%for all 12 months).Overall,winter temperature contributed the most to Ae.albopictus distribution,followed by summer precipitation.An increase in temperature was observed from 1970 to 2021 in most places in China,and annual change rates varied substantially from-0.22℃/year to 0.58℃/year among sites,with the largest increase in temperature occurring from February to April(an annual increase of 1.4–4.7℃ in monthly mean,0.6–4.0℃ in monthly minimum,and 1.3–4.3℃ in monthly maximum temperature)and the smallest in November and December.Temperature increases were lower in the tropics/subtropics(1.5–2.3℃ from February–April)compared to the high-latitude areas(2.6–4.6℃ from February–April).The projected temperatures in 2050 and 2080 by this study were approximately 1–1.5℃ higher than those projected by GCMs.The estimated current Ae.albopictus risk distribution had a northern boundary of north-central China and the southern edge of northeastern China,with a risk period of June–September.The projected future Ae.albopictus risks in 2050 and 2080 cover nearly all of China,with an expanded risk period of April–October.The current at-risk population was estimated to be 960 million and the future at-risk population was projected to be 1.2 billion.Conclusions The magnitude of climate change in China is likely to surpass GCM predictions.Future dengue risks will expand to cover nearly all of China if current climate trends continue.

Do China's Outward Direct Investors Prefer Countries with High Political Risk? An International and Empirical Comparison

This paper focuses on a conventional debate regarding whether Chinese outward direct investors tend to invest in countries with high political risk. Using 2003 -2011 data from the World Bank, the Heritage Foundation and the KOF Swiss Economic Institute, we investigate China ＇s political risk distribution and political risk index （PRI）. Our results indicate that China ＂s political risk index was ranked 48th among 153 economies in 2011, in the lower risk level of the PRI spectrum. In an international comparison of political risk distribution, the proportion of Chinese outward direct investment （ODI） among countries with high political risk is less than the world average. The Chinese ODI political risk index has significantly improved and remains lower than the world average. To improve Chinese ODI PRI, the Chinese Government should continue to implement differentiation strategies and to offer official development assistance to improve the investment environment in developing countries and reduce political risk.

Basin flood control system risk evaluation based on variable sets

Flood control system risk evaluation is an effective measure for flood risk management and decisions.In order to make better flood risk decisions and thereby improve social and economic benefits,the flood control risk evaluation index system should be built to quantify and normalize flood risk effectively and efficiently.Because the current evaluation index has the binary miscibility characteristic of fuzziness and clarity,this paper establishes a new flood control system risk evaluation method based on the theory of variable sets(VS).Through a comparison of flood control risk evaluation with variable fuzzy sets(VFS) in the same basin flood control system risk evaluation,it is revealed that the new method,i.e.,flood control risk evaluation with variable fuzzy/clear mixture sets(variable sets),will be reasonable in all cases.Finally,in one case study,i.e.,the flood control system risk evaluation of Fengman Reservoir Basin,which is located in the southeast central of Jilin Province in China,the risk evaluation levels for each county in the basin as well as the whole flood risk distribution map of the basin could be provided with the new method.This provides useful information for basin flood control planning and design.

Recent advances in pharmaceuticals and personal care products in the surface water and sediments in China

Pharmaceuticals and personal care products （PPCPs） have been regarded as an emerging problem in the surface water environment in the past few decades. In China, although related studies were initiated several years ago, an increasing number of studies on this topic have been conducted in recent years. These studies have expanded knowledge of their occurrence, behavior and associated risk in the surface water environment in China. This review compiles the most recent literature related to the studies of PPCPs in the surface water environment in China. It includes PPCP occurrence in surface water and sediments, their geographical distribution, and outcomes of the associated risk assessment. It shows that antibiotics have received much more attention in both surface water and sediments than other PPCPs. Compared to other countries; most antibiotics in the collected sediments in China showed higher contamination levels. Many more study areas have been covered in recent years; however, attention has been given to only specific areas. Environmental risk assessment based on risk quotients indicated that sulfamethoxazole presents the most significant environmental risk to relevant aquatic organisms; followed by ofloxacin, ciprofloxacin, enrofloxacin, 17α-ethynylestradiol, ibuprofen and diclofenac. Despite limited research on the environmental risk assessment of PPCPs in sediments, higher risks posed by PPCPs in the sediments rather than surfhce water were identified highlighting the need for further risk assessment of PPCPs in sediment samples.

考虑动态功率调节裕度的高比例风电系统水-火-荷分布鲁棒优化调度

具有随机性、波动性的风电大规模接入给电网安全调度带来严峻挑战.针对风电反调峰性和不确定性,本文提出考虑动态功率调节裕度的水-火-荷分布鲁棒优化调度方法.首先,针对风电和负荷双重不确定的概率分布难以准确估计的特点,提出净负荷(风电与负荷功率之差)波动速率矩不确定集合刻画系统功率变化的随机性,并结合水、火、荷的功率调节特性,建立系统动态功率调节裕度模型.其次,借助分布鲁棒条件风险价值具有描述尾部概率的良好特性,刻画恶劣风况下系统由于功率调节裕度不足所造成的弃风风险.以系统运行成本和弃风风险成本最小、系统总动态功率调节裕度最大为目标,提出高比例风电消纳的分布鲁棒优化调度模型.通过对偶优化理论将模型转化为易求解的半定规划问题进行计算.所提出的模型可有效提高风电消纳量,保证经济运行的同时,提高了应对净负荷不确定波动的能力.