Predicting of Power Quality Steady State Index Based on Chaotic Theory Using Least Squares Support Vector Machine

An effective power quality prediction for regional power grid can provide valuable references and contribute to the discovering and solving of power quality problems. So a predicting model for power quality steady state index based on chaotic theory and least squares support vector machine (LSSVM) is proposed in this paper. At first, the phase space reconstruction of original power quality data is performed to form a new data space containing the attractor. The new data space is used as training samples for the LSSVM. Then in order to predict power quality steady state index accurately, the particle swarm algorithm is adopted to optimize parameters of the LSSVM model. According to the simulation results based on power quality data measured in a certain distribution network, the model applies to several indexes with higher forecasting accuracy and strong practicability.

Patient State Index Detects Changes in Cerebral Blood Flow and May Predict New Ischemic Lesions during Carotid Stenting—Case Report

Carotid angioplasty and stenting (CAS) was developed to be a less invasive and complex procedure compared to carotid endarterectomy (CEA). It has emerged as an alternative for patients who are considered to have high surgical risks due to medical comorbidities or anatomical high-risk features [1]. The procedure is usually done under local anesthesia with light sedation, with the subsequent expectation of less neurologic injury, venous thromboembolisms, and myocardial infarctions—all well-known clinical risks of undergoing surgical procedures under general anesthesia. CAS, however, carries some increased risks of arterial dissection, dislocation of atherothrombotic debris and embolization to the brain or eye, late embolization due to thrombus formation on the damaged plaque, and bradycardia and hypotension as a result of carotid sinus stimulation. Electroencephalography can detect cerebral ischemia and hypoxia along with measuring hypnotic effects, but has not been reported to be used during CAS to signal impending neurological deficit and allow for intervention to prevent stroke. We report on the use of patient state index (PSI), an electroencephalographic (EEG) derived variable used by SEDLine monitor (Masimo Inc., San Diego, CA) to monitor changes in cerebral blood flow during carotid angioplasty and stenting in an awake patient under local anesthesia. PSI was developed to measure the level of hypnosis and sedation during anesthesia and in the ICU. The PSI is based on quantitative electroencephalogram features, recorded from anterior and posterior scalp sites, as input to a multivariate algorithm that quantifies the most probable level of anesthesia or sedation. The PSI is reported as a range from 0 to 100, with decreasing values indicating increasing levels of anesthesia or sedation. Adequate depth of anesthesia is reflected by PSI value of 25 - 50, and a fully awake state by a PSI of 100 [2]. Other EEG analysis techniques have been explored to detect changes in cerebral blood flow during carotid surgery [3], such as entropy described by Khan and Ozcan in his recent work entitled Disagreement in Bilateral State Entropy Values in Carotid Artery Disease [4], but there are no previous reports of the use of PSI during procedural sedation in carotid angioplasty and stenting in an awake patient.

Target reliability index for serviceability limit state of single piles

The objective is to develop an approach for the determination of the target reliability index for serviceability limit state(SLS) of single piles. This contributes to conducting the SLS reliability-based design(RBD) of piles. Based on a two-parameter,hyperbolic curve-fitting equation describing the load-settlement relation of piles, the SLS model factor is defined. Then, taking into account the uncertainties of load-settlement model, load and bearing capacity of piles, the formula for computing the SLS reliability index(βsls) is obtained using the mean value first order second moment(MVFOSM) method. Meanwhile, the limit state function for conducting the SLS reliability analysis by the Monte Carlo simulation(MCS) method is established. These two methods are finally applied to determine the SLS target reliability index. Herein, the limiting tolerable settlement(slt) is treated as a random variable. For illustration, four load test databases from South Africa are compiled again to conduct reliability analysis and present the recommended target reliability indices. The results indicate that the MVFOSM method overestimates βsls compared to that computed by the MCS method. Besides, both factor of safety(FS) and slt are key factors influencing βsls, so the combination of FS and βsls is welcome to be used for the SLS reliability analysis of piles when slt is determined. For smaller slt, pile types and soils conditions have significant influence on the SLS target reliability indices; for larger slt, slt is the major factor having influence on the SLS target reliability indices. This proves that slt is the most key parameter for the determination of the SLS target reliability index.

Estimation and Prediction of Bioconcentration Factors of Nonionic Organic Chemicals in Fish by Electrotopological State Indices and Structural Parameter

Based on the characteristics of atom types, Hall＇s electrotopological state indices （En） are calculated for 165 nonionic organic compounds. On the basis of the characteristics of substituent and conjugated matrix, a novel molecular structure parameter （G） is defined and calculated for 165 molecules in this paper. En and G show good structural selectivity for organic molecules. G, a satisfactory relationship between bioconcentration factor （BCF） and En, is expressed as： 1gBCF = -0.283 ＋ 1.246G ＋ 0.079E42 ＋ 0.351E9- 0.063E17 （n＇ = 122, R = 0.967, F = 425.636, s = 0.394）, which could provide estimation and prediction for the lgBCF of nonionic organic chemicals. Furthermore, the model is examined to validate overall robustness with Jackknife tests, and the independent variables in model do not exist cross correlation with VIF. All these regression results show that the new parameter G and electrotopological state index have good rationality and efficiency. It is concluded that the En and G will be used widely in quantitative structure-property/activity relationship （QSPR/QSAR） research.

Under the New Normal a Relevant EmpiricalAnalysis on Real Estate and Stock Market

2008年金融危机后,全球经济基本步入“新常态”.为应对“新常态”,中国政府采取措施,使全国经济呈现新“外貌”.针对新常态背景下房地产和股市状况,以国房景气指数代表中国房地产行业发展情况、上证综合指数收盘价表示股市行情,建立Y A R 模型进行分析.之后引入货币供给量,重新建立模型,经脉冲响应、方差分解分析,得出上证综指、国房景气指数主要受自身行业的影响;货币供给量给房市和股市造成的影响度大于两个市场相互间的影响程度;观察短期内房地产行业、股市两者之间相互的贡献度,房市对股市的贡献度更大.

MODIFIED SCHEME BASED ON SEMI-ANALYTIC APPROACH FOR COMPUTING NON-PROBABILISTIC RELIABILITY INDEX

A new computation scheme proposed to tackle commensurate problems is devel- oped by modifying the semi-analytic approach for minimizing computational complexity. Using the proposed scheme, the limit state equations, usually referred to as the failure surface, are obtained from transformation of an interval variable to a normalized one. In order to minimize the computational cost, two algorithms for optimizing the calculation steps have been proposed. The monotonicity of the objective function can be determined from narrowing the scope of interval variables in normalized infinite space by incorporating the algorithms into the computational scheme. Two examples are used to illustrate the operation and computational efficiency of the approach. The results of these examples show that the proposed algorithms can greatly reduce the computation complexity without sacrificing the computational accuracy. The advantage of the proposed scheme can be even more efficient for analyzing sophistic structures.

Plankton- Based Assessment of the Trophic State of Three Tropical Lakes

In developing countries, lakes being important sources of water supply and fishing are vulnerable to anthropogenic impact, yet knowledge of their trophic state in relation to changes in species composition, and environmental variables, are limited. This study is aimed at assessing the trophic status of lakes by monthly sampling of three lakes located along the floodplain of Cross River, Nigeria between January 2008 and December 2009. Samples were analyzed for water quality parameters, zooplankton and phytoplankton composition and distribution. Results were subjected to community structure analysis using trophic state index, species richness and diversity indexes. Essential primary productivity nutrients, nitrates, sulphates and phosphates were highest in Ejagham Lake, and lowest in Ikot Okpora Lake. Dominant phytoplankton species Oscillatoria lacustria (Cyanophyceae), Cyclotella operculata (Bacilliarophyceae) and zooplankton Keratella tropica, Keratella quadrata, Filinia longiseta, Branchionus anguillaris and Trichocerca pusilla (rotifers) all typical of eutrophic communities were recorded in high densities in Ejagham Lake in both dry and wet seasons while Cladocerans, Bosmina longirostris and Moina micrura and copepods considered indicators of oligotrophy and mesotrophy were recorded in large numbers in Ikot Okpora and Obubra Lakes respectively. Higher values of species richness, Evenness and Shannon-Wiener diversity index for both phytoplankton and zooplankton, were recorded in Ejagham Lake during the dry season than wet. Also values of the Trophic state index were generally highest at the Ejagham Lake in the savanna region of the floodplain and lowest at Ikot Okpora in the forest region of the floodplain. Forest region is therefore a limiting factor in the productivity of lakes in the tropics.

State fragility and the coronavirus disease 2019(COVID-19)pandemic:an ecologic analysis of data from 146 countries

Background:Global spread and impact of the coronavirus disease 2019(COVID-19)pandemic are determined to a large extent,by resistance to the pandemic and public response of all countries in the world;while a country's resistance and response are in turn determined by its political and socio economic conditions.To inform future disease prevention and control,we analyzed global data to exam the relationship between state vulnerabilities and COVID-19 incidences and deaths.Methods:Vulnerability was measured using the Fragile States Index(FSI).FSI is created by the Fund for Peace to assess levels of fragility for individual countries.Total FSI score and scores for 12 specific indicators were used as the predictor variables.Outcome variables were national cumulative COVID-19 cases and deaths up to September 16,2020,derived from the World Health Organization.Cumulative incidence rates were computed using 2019 National population derived from the World Bank,and case fatality rates were computed as the ratio of deaths/COVID-19 cases.Countries with incomplete data were excluded,yielding a final sample of 146 countries.Multivariate regression was used to examine the association between the predictor and the outcome measures.Results:There were dramatic cross-country variations in both FSI and COVID-19 epidemiological measurements.FSI total scores were negatively associated with both COVID-19 cumulative incidence rates(β=-0.0135,P<0.001)and case fatality rates(β=-0.0147,P<0.05).Of the 12 FSI indicators,three negatively associated with COVID-19 incidences were E1(Economic Decline and Poverty),E3(Human Flight and Brain Drain),and S2(Refugees and Internally Displaced Persons);two positively associated were P1(State Legitimacy)and X1(External Intervention).With regard to association with case fatality rates,C1(Security Apparatus)was positive,and P3(Human Rights and Rule of Law)and X1 was negative.Conclusion:With FSI measures by the Fund of Peace,overall,more fragile countries are less likely to be affected by the COVID-19 pandemic,and even if affected,death rates were lower.However,poor in state legitimacy and lack of external intervention are risk for COVID-19 infection and lack of security apparatus is risky for COVID-19 death.Implications of the study findings are discussed and additional studies are needed to examine the mechanisms underpinning these relationships.

Qualitative Analysis of Relationship between Refractive Index and Atomic Parameters of Solid Materials

The refractive index is one of the important parameters describing the optical properties of solid materials. However, it is difficult to obtain a quantitative relation between the refractive index and the structure and composition of materials. A qualitative relation between the refractive index and some atomic parameters of materials was proposed and demonstrated by some oxide optical crystals. A parameter P=r~-/F=r~-/(r~+ΔxD) is defined, in which Δx is the difference of the electronegativities between cations and anions in the materials and r~+ and r~- are the radii of cations and anions respectively. On the other hand, the factor D was introduced to describe the effect of mass difference of the ions. It is demonstrated by both theoretical discussion and experimental data that refractive index is a decreasing function of parameter P. The relation may be useful for the investigation of optical materials.

Excited state refraction of C_(70)/toluene studied by using 4f coherent imaging system with phase object

Dynamic nonlinearities of C70/toluene solution are measured and analysed by an improved picosecond timeresolved pump-probe system based on a nonlinear imaging technique with phase object. The photophysical parameters are determined by the five-level model, which is adopted to interpret the experimental data. The change of refraction index per unit density of the excited state obtained by a numerically simulation is a critical factor to determine the nonlinear behaviour of C70 in picosecond time regime.

基于定位校正指数的嘧啶类含能材料爆轰性能

为研究嘧啶类含能化合物的爆轰性能与其分子结构的构效关系,根据嘧啶类含能化合物分子中原子相互连接的空间特性,提出了一种新的分子结构指数——定位校正指数B;此外还计算了19个含能化合物分子的电拓扑态指数,并优化筛选出其中的E 13作为分子结构描述符,将E 13与定位校正指数B结合,与嘧啶类含能化合物的爆轰性能进行回归分析;将B和E 13这两种结构指数作为BP神经网络的输入变量,神经网络结构采用2-3-1的结构方式,构建了预测嘧啶类含能化合物爆轰性能好的神经网络法模型。结果表明,每个模型的总相关系数均超过0.99,达优级相关,计算得到的氧平衡、爆热、爆速和爆压的预测值与文献值的平均相对误差分别为1.59%、1.05%、0.37%和1.28%;如将指数扩展到与噁三唑稠环类含能材料分子、含氟唑类含能化合物分子的爆轰性能等进行分析预测,同样能得到令人满意的结果。说明嘧啶类含能材料分子的爆轰性能与定位校正指数、电拓扑态指数有良好的非线性关系。

基于BIRCH聚类的航空器自主运行风险状态评价

为解决自主运行模式下航空器风险评价指标缺失和风险状态实时评估困难等问题,提出1种自主运行模式下航空器风险状态评价方法。从航空器冲突、气象规避区侵入、操纵裕度3个方面建立风险状态评价指标体系,运用BIRCH算法建立聚类特征树对多维航空器特征样本进行风险模型训练,引入增量式聚类的概念,更新特征树,实时评估动态目标航空器的风险状态。然后,以广州05扇区为运行场景展开仿真实验。研究结果表明:所提方法准确度达99.5%,平均计算时间约为0.0249 s。研究结果可有效支撑自主运行理念实施,提高风险预警能力,保障航空器自主运行安全。

UAV and Satellite-Based Sensing to Map Ecological States at the Landscape Scale

Mapping ecological states in semi-arid rangelands is crucial for effective land management and conservation efforts because it identifies difference in the ecological conditions across a landscape. This study presents an innovative approach for mapping two ecological states, Large Shrub Grass (LSG) and Large Shrub Eroded (LSE), within the Sandy Loam Upland and Deep (SLUD) ecological sites using a combination of drone and satellite data. The methodology leverages the Largest Patch Index (LPI) as a proxy metric to estimate eroded areas and classify ecological states. The integration of unmanned aerial vehicle (UAV) data with satellite-based remote sensing provides a scalable approach that can benefit various stakeholders involved in rangeland management. The study demonstrates the potential of this methodology by generating spatial layers at the landscape scale to inform on the state of rangeland ecosystems. The workflow showcases the power of remote sensing technology to map ecological states and addresses limitations in spatial coverage by integrating UAV and satellite data. By utilizing the bare ground LPI metric, which indicates the connectedness of bare ground, the methodology enables the classification of ecological states at a regional scale. This cost-effective approach potentially offers a standardized and reproducible method applicable across different sites and regions. The accuracy of the classification process is evaluated by comparing the results to ground-based polygons, dirt roads, and water locations. While the model performs well in identifying eroded areas, misclassifications occur in regions with mixed vegetation cover or low biomass. Future research should focus on incorporating temporal information from historical remote sensing archives to improve understanding of ecological state dynamics. Additionally, validation efforts can be enhanced by incorporating more ground-truth data and testing the methodology in diverse rangeland areas. The workflow serves as a blueprint for scaling up ecological states mapping in similar semi-arid rangelands. Further work should involve refining the approach through additional validation and exploring new remote sensing datasets. The methodology can be replicated in other regions to inform land management decisions, promote sustainable resource use, and advance the field of ecological states mapping.

美国媒体与国家关系研究:索引假设和层叠模式

研究美国媒体与国家政策的学者一般认为在外交事务上白宫在新闻框定中具有决定性影响,而媒体在设置美国政府的政治议程方面起着十分重要的作用,在外交政策方面尤其如此。本文关于“索引假设”和“层叠模式”的介绍和讨论表明,虽然美国主流媒体与政府的关系会随具体事件、时间和形势的不同而处于不断变化中,但在外交事务上它们之间存在一种共生关系,媒体与政府往往保持着高度一致的立场,尤其当涉及到国家利益和核心价值观时更是如此。

经验性膳食炎症指数与老年冠心病患者病情及炎症状态的关系

目的:探讨经验性膳食炎症指数(eDⅡ)与老年冠心病患者病情及炎症状态的关系。方法:选取2021年1月—2023年1月在本院收治的老年冠心病患者45例作为病例组,选取同期30名健康体检者作为对照组。进一步依据Gensini评分评估患者病情,分为轻度组、中度组、重度组。采用酶联免疫吸附法检测IL-6、IL-10、CTP、CatK、MMP-2、MMP-9,采用双抗体夹心酶联免疫吸附试验检测TNF-α,采用免疫散射比浊法检测hs-CRP。比较不同组eDⅡ评分、炎症因子、Gensini评分,相关性分析eDⅡ与病情及炎症状态的关系。结果:病例组eDⅡ、炎症因子均高于对照组(P<0.05);3组eDⅡ、炎症因子、Gensini评分比较差异有统计学意义(P<0.05),重度组最高,中度组次之,轻度组最低;3组斑块稳定性相关指标(CTP、CatK、MMP-2、MMP-9)比较差异有统计学意义(P<0.05),重度组最高,中度组次之,轻度组最低;相关性分析显示,老年冠心病患者eDⅡ与斑块稳定性相关指标、炎症因子均呈正相关(P<0.05)。结论:高eDⅡ值与较高的炎症因子水平和Gensini评分相关,提示了膳食炎症对冠心病的发展和炎症状态的影响,通过调整饮食以降低膳食炎症指数,可能有助于改善老年冠心病患者的病情和炎症状态。

目标导向液体治疗在腹腔镜肝脏手术中的应用效果

目的探讨对腹腔镜肝脏手术患者实施目标导向液体治疗(GDFT)后获得的临床效果。方法选取2020年3月至2023年8月烟台市烟台山医院收治的62例腹腔镜肝脏手术患者作为研究对象,按照随机数字表法分为参照组(31例)与研究组(31例),参照组采用常规方法治疗,研究组采用GDFT治疗。比较两组的简易精神状态检查量表(MMSE)评分、血流动力学指标水平、尿素氮(BUN)水平、乳酸(Lac)水平。结果术前1 d,两组患者MMSE评分比较,差异无统计学意义(P>0.05);术后1、3 d,研究组患者MMSE评分高于参照组,差异有统计学意义(P<0.05)。研究组患者切肝时(T_(2))及手术完毕时(T_(3))心脏指数(CI)高于参照组;T_(2)时中心静脉压(CVP)水平高于参照组,T_(3)时CVP水平低于参照组,差异有统计学意义(P<0.05);入室时(T_(0))、T_(3)时及术后24 h,两组患者BUN水平比较,差异无统计学意义(P>0.05);T_(0)时,两组患者Lac水平比较,差异无统计学意义(P>0.05);T_(3)及术后24 h,研究组患者Lac水平低于参照组,差异有统计学意义(P<0.05)。结论临床对腹腔镜肝脏手术患者合理给予GDFT治疗,对于患者重要脏器血流灌注稳定性以及患者的血流动力学水平维持表现出的作用明显,可以保护患者的脑组织,对于患者的术后认知功能改善有促进作用。

考虑填充墙的RC框架结构性能指标限值确定方法

填充墙钢筋混凝土(RC)框架结构是我国应用最为广泛的结构形式之一,而我国规范中给出的此类结构性能指标限值并未充分考虑填充墙对整体结构破坏状态的影响。遵循我国规范中对结构破坏状态的定义原则,提出基于构件破坏率的填充墙RC框架结构性能指标限值确定方法,为此类结构破坏状态与工程需求参数对应关系的研究提供新的思路。以典型结构为例建立数值分析模型,采用该文方法计算考虑填充墙的RC框架结构性能指标限值,并与不考虑填充墙的“纯框架”限值进行了对比分析。相较于“纯框架指标”,该文指标完好、轻微破坏、中等破坏和严重破坏四个破坏状态的层间位移角上限值均更小,其中,完好状态的上限值为1/832,远小于规范中规定的弹性层间位移角限值1/550,说明判定填充墙RC框架结构的破坏状态时,直接应用规范限值会低估结构的破坏程度。

基于准连续域束缚态的全介质超构表面双参数传感器

本文设计了由不对称半圆柱对阵列组成的全介质超构表面,获得了两个高品质因子的准连续域束缚态模式(quasi-bound states in the continuum,QBIC).通过选择不同形式的对称破缺,在近红外频段均可产生两个稳健的QBIC,并且二者的谐振波长、品质因子、偏振依赖等表现出不同的特性.模拟计算表明,通过测量两个QBIC的谐振波长,能够实现折射率和温度的双参数传感;通过调节不对称参数,利用QBIC的品质因子依赖于不对称参数的二次方反比关系,理论上能够提高品质因子到任意的数值,从而实现传感性能的提升和调节.该超构表面的折射率传感灵敏度、品质因子和优值分别达到194.7 nm/RIU,45829和8197,其温度传感灵敏度达到24 pm/℃.

高强钢筋超高性能混凝土框架结构易损性分析

为了研究高强钢筋超高性能混凝土(ultra-high performance concrete, UHPC)结构的抗震能力,本文选取了8条地震动分别对普通钢筋混凝土框架结构(模型Frame-C)和高强钢筋UHPC框架结构(模型Frame-UHPC)进行了增量动力分析,分别以最大层间位移角和谱加速度为结构需求参数和地震动强度参数,拟合出概率地震需求模型,进而计算出2个模型的地震易损性曲线,得到了结构的风险预测和损伤评估结果。研究结果表明:规范性态点下,相较于模型Frame-C,模型Frame-UHPC达到最大中等破坏或严重破坏状态概率时所对应的地震动强度更大,表明模型Frame-UHPC在强震作用下具有更好的抗震能力;小震作用下,模型Frame-UHPC的易损性指数明显小于模型Frame-C,体现了高强钢筋UHPC结构的高强优势。当使用规范性态点时,2个模型在中震和大震作用下的易损性指数相差较小,模型Frame-UHPC不能充分发挥UHPC和高强钢筋的材料优势。通过对文献中配筋UHPC柱数据整理分析,给出了适用于模型Frame-UHPC的建议性态点。与规范性态点相比,建议性态点下模型Frame-UHPC达到极限状态的概率更低,易损性指数也明显减小,小震和中震所应对的易损性指数分别减小了19.5%和42.3%,模型Frame-UHPC在建议性态点下可以更好地发挥其材料优势。

子流域景观格局对丹江口水库营养状态的影响分析

探究子流域景观格局与水体富营养化空间异质性间的关系对水源地保护具有重要意义。本文通过遥感影像和半解析方法揭示2013-2023年丹江口水库营养状态的时空变化格局,并利用SHAP机器学习解释方法,量化分析土地利用组成和景观格局指数与水体营养状态间的关系。结果表明:①丹江口水库营养状态指数呈现明显的空间异质性,以中营养为主,富营养化区域主要分布在岸线库湾区及支流附近。泄洪期水体营养状态相对优于蓄水期。②子流域的土地利用和景观格局存在明显的空间差异,在汉江上游和库区南部支流地区斑块密度(PD)、景观形状指数(LSI)和香农多样性指数(SHDI)呈低值聚集,而最大斑块指数(LPI)和蔓延度指数(CONTAG)呈现高值聚集。③土地利用组成和景观格局指数在不同时期对富营养化的影响程度不同,景观格局指数在全年、蓄水期和泄洪期的贡献度分别达到49.31%、50.99%和57.41%。其中斑块密度、林地、草地和不透水面在各时期均具有较高的影响贡献度,而蔓延度指数和香农多样性指数在蓄水期和泄洪期分别具有较高的影响。研究显示,保持子流域自然地表优势景观,降低耕地和不透水面的破碎度有助于改善水库富营养问题。