持续风补偿下四旋翼无人机滑模轨迹跟踪控制

针对四旋翼无人机(Unmanned aerial vehicle,UAV)在轨迹跟踪过程中存在持续风干扰问题,设计了一种双闭环滑模控制方法。首先,依据四旋翼无人机系统欠驱动特性,将其分为系统位置环和姿态环;其次,基于风扰观测器,采用连续滑模控制算法并设计持续风补偿器,实现无人机位置信息在持续风干扰下的稳定跟踪;再次,采用映射自适应滑模控制算法并同样设计持续风补偿器,实现无人机姿态信息在持续风干扰下的稳定跟踪;最后,与传统比例积分微分(Proportional integral derivative,PID)控制进行仿真对比,验证了该控制方法的有效性和优越性。

加味解痉祛风汤治疗支气管哮喘慢性持续期风哮证临床研究

目的探讨加味解痉祛风汤治疗支气管哮喘慢性持续期风哮证的临床疗效。方法 76例支气管哮喘慢性持续期风哮证患者,随机分为观察组和对照组,各38例。对照组采用沙美特罗替卡松治疗,观察组在对照组基础上联合加味解痉祛风汤治疗,两组患者均治疗1个疗程后,比较两组治疗效果及中医证候积分。结果治疗后,观察组总有效率为97.37%,高于对照组的73.68%,差异有统计学意义(P<0.05)。两组患者治疗后中医证候积分均低于治疗前,且观察组低于对照组,差异有统计学意义(P<0.05)。结论加味解痉祛风汤治疗支气管哮喘慢性持续期风哮证临床疗效佳,患者中医证候积分显著改善,值得临床推广。

春季裸露沙质农田土壤风蚀量动态与变异特征

以春季风蚀活动高发期为特定研究时段 ,采用地面埋设容器的“陷阱诱捕”法 ,对秋收后翻耕的裸露沙质农田春播前的土壤风蚀量动态进行了定位观测 ,同时对影响土壤风蚀的关键因子表土层紧实度和含水量以及风速动态也进行了同步观测。主要研究结果是 :(1)观测期内 ,平均土壤日风蚀量为 2 4 1.2 0 kg/ hm2 ,土壤日有机碳和氮素损失量平均分别为 1.5 2 ,0 .15 kg/ hm2 。 (2 )土壤风蚀过程以细微土粒的跃移和悬移运动为主 ,损失掉的主要是表层土壤中的细砂 (粒径 0 .1～ 0 .0 5 mm)、粉粒 (粒径 0 .0 5～ 0 .0 0 2 mm)和粘粒 (粒径 <0 .0 0 2 mm)等富含营养元素的细微颗粒 ,分别占风蚀沉积物的 4 6 .0 1% ,2 1.0 3%和 2 1.74 %。这表明土壤风蚀导致了农田的粗化。 (3)相关分析表明 ,土壤风蚀量与表土层含水量呈一定的负相关 ;土壤风蚀量与表土层紧实度呈微弱的负相关。然而 ,土壤日风蚀沉积量与日平均风速呈高度正相关 ;同样 ,土壤日风蚀沉积量与日可蚀风持续时数亦呈高度正相关。利用它们之间的回归关系式 ,可以定量地预测。

延庆-张家口地区复杂地形冬季山谷风特征分析

基于2016年12月—2017年2月和2017年12月—2018年2月两年冬季的近地面自动气象站逐时观测数据以及张家口探空数据分析延庆-张家口一带(包括张家口崇礼、赤城、海坨、小五台山区,延怀、怀涿、洋河、蔚县盆地以及北京延庆、昌平、怀柔部分平原地区)复杂地形的风场精细化时、空分布特征,揭示不同复杂地形下局地风场的时、空变化规律,加深对复杂地形动力、热力作用对近地面风场影响的认识,为冬季山区风场预报以及复杂地形数值模式改进提供参考。结果表明:晴朗小风天风持续性作为矢量平均风速和标量平均风速的比值,可以作为研究风场变化规律的重要参数。根据风持续性的日变化特征,可以将研究区域内所有站点分为10种类型,分别代表不同局地地形特征的影响,风持续与风向变化的相关也很强。研究区域主要有3种类型的地形风:斜坡风、峡谷风以及较大尺度的山区平原风。不同地形特征下的风场、风持续性存在明显不同的日变化特征,山风和谷风相互转化的时间也不同,山区最早,盆地次之,平原区最晚;山风时段持续时间较谷风时段长,风速小;晴朗小风天实测风反映了实际风场的特征,而排除环境背景风场,弱化地形动力作用后整个冬季的局地风作为理论山谷风,更能反映热力作用下的山谷风特征。

风电场群出力的汇聚效应分析

分析大规模风电场群的汇聚效应特性,找出其中的规律,可以帮助电网更为合理的接纳风电,提高新能源利用效率。通过实测某省级电网的风电场群运行数据,基于时间序列、频谱分析、概率统计等方法,分析风电场、风电场群的风电功率变化特征,获取风电场群出力的汇聚效应特性。

可持续理念下的健康高层住宅设计

可持续理念下的健康高层住宅,不仅仅是一般意义上的适应性住宅,它除了能满足居民的基本居住功能需求,高度聚集人群,节省用地,达到资源的高效、循环利用外,还应该在人类健康、社会文化和生态环境的可持续方面有所作为,包括居民生理心理的健康,融洽的邻里关系、院落文化的延续,低碳节能的城市生活环境的营造等。

党风廉政建设工作中遇到的问题及应对措施

党的“二十大”报告指出党风廉政建设的重要性及必要性,强调党要管党、从严治党,面对新形势、新任务和新要求,提出了一系列理念、思路、举措,推动党风廉政建设和反腐败斗争不断取得重大成效。本文通过浅析开展党风廉政建设工作中可能遇到的问题,结合医院实际,有针对地制定应对措施,最终达到以高质量纪检监察工作为医院发展提供坚强纪律保障的目的。

风场对明渠输水工程水位的影响及快速预测研究

依据南水北调中线干渠资料,开展了不同风场的影响下闸前水位变化规律的数值模拟研究。采用数值模拟、数学归纳和统计分析方法,提出风速、风持续时间以及风向对水位变幅的影响,并提出风影响下最大水位变幅的快速预测公式。通过实际监测数据验证了公式的可行性。结果表明:风的持续时间对最大水位变幅影响很小;最大水位变幅随风速的增加而增加,随风源距离的增加而减小。风向与水流的夹角β介于0°到360°之间,水位变幅是关于夹角β=180°对称。快速预测公式计算结果与实测结果的误差为3.66%,说明最大水位预测公式对明渠输水工程适用性较强。研究结果可为输水工程日常调度提供参照。

Tourism and Land Transformation:A Case Study of the Li River Basin,Guilin,China

Land-use change is intertwined with tourism because land is used as a resource for human activities.Land-use change also provides an opportunity to evaluate the status of the ecoenvironment.Understanding the relationship between tourism and land use change would help to predict the effect of tourism on land use and encourage sustainable tourism development.Using the Li River Basin as a case study,a hybrid approach using multilevel modeling and logistic regressions was employed to analyze the distribution of land-usechange between 1989 and 2010 to examine potential driving factors.Results reveal that rapid tourism development and construction expansion expose this area to risk of deforestation and forest degradation.Construction increased by 141% between 1989 and 2000 and by 195% between 2000 and 2010.The primary driving force for construction expansion shifted from population growth between 1989 and 2000 to investment growth after 2000.New construction primarily occurred on crop and woodlands areas,with shares of 81.25% and 6.38%,respectively,between 1989 and 2000,and with shares of 57.79% and 15.29%,respectively,between 2000 and 2010.Moreover,these drastic increases in construction also led to frequent transitions between croplands,woodlands,and grasslands.Traits including distances to urban areas and roads and scenic locations exerted significant effects on land-use change.Woodland regrowth in the areas thatsurround scenic locations consisted of fluctuating woodlands,whereas stable woodland regrowth was often absent in these areas.Likewise,permanent woodland clearing tended to be closed to near scenic locations.That is,construction at scenic locations negatively affected forest conservation in the Li River Basin.

Decadal Variations of Extreme Tropical Cyclones Influencing China during 1949-2009

Decadal variations of extreme tropical cyclones （TCs） influencing China were. investigated based on the tracks, landfall information, precipitation and wind data during 1949-2009. The extreme landfall date events are less in the 1970s and 2000s. The number of extreme events of maximum wind speed and minimum pressure near TC＇s center reached the highest in the 2000s. The extreme rain duration events had the highest frequence in the 1970s, and the extreme strong wind duration events had the maximum frequence in the 1980s. The number of stations whereat the extreme maximum daily precipitation or process precipitation is observed, is the largest in the 1960s, and the number of stations whereat daily maximum wind speed events axe observed, is the largest in the 1980s.

Revisiting Asymmetry for the Decaying Phases of El Ni?o and La Ni?a

This study investigated the relationship be- tween the asymmetry in the duration of El Nifio and La Nina and the length of their decaying phases. The results suggested that the duration asymmetry comes from the long decaying ENSO cases rather than the short decaying ones. The evolutions of short decaying El Nino and La Nina are approximately a mirror image with a rapid decline in the following summer for the warm and cold events. However, a robust asymmetry was found in long decaying cases, with a prolonged and re-intensified La Nina in the following winter. The asymmetry for long decaying cases starts from the westward extension of the zonal wind anomalies in a mature winter, and is further contributed to by the air-sea interaction over the tropical Pacific in the following seasons.

Predictors of long-term outcome in patients with biopsy proven inflammatory cardiomyopathy

Background The objective of this study was to identify prognostic indicators in patients with inflammatory cardiomyopathy （iCM） on endomyocardial biopsy （EMB）. Methods and results Between 2007 and 2011 all consecutive patients with diagnosed with iCM at EMB were retrospectively analyzed. The combined primary endpoint （EP） （1E°P） was cardiac death, aborted sudden cardiac death/appropriate implantable cardioverter defibrillator （ICD） shock, progressive heart failure requiring left venWicular assist device （LVAD） implantation and heart transplantation. 503 patients （mean age 58 ° 12 years, 73% male） were available for analysis. Genomes of cardiotrophic viruses were detected in 396 patients （79%） and immuno-histochemical signs of inflammation were present in 223 individuals （44%）. After 3.6 ° 2.4 years of follow-up, cardiac mortality was 3.0% （n = 14） and a total of 8.6% （n = 40） reached the primary endpoint. Independent predictors for the 1 °EP were： age 〉 50 years, presence and duration （〈 28 days） of symptomatic heart failure. A risk stratification approach based on the results of the multivariate analysis demonstrated that absence of signs and/or symptoms of congestive heart failure in younger （〈 50 years） patients with longer （〉 28 days） duration of disease appear to have an excellent prognosis with 100% survival and no events during follow-up The presence of all above mentioned independent risk factors results in an 1°EP occurrence of 35.9%. Conclusions Symptoms of heart fail- ure, short duration of disease, and older age are indicators of poor outcome in patients with iCM.

The Pay-as-You-Go System of Pension Insurance

The most recent trends in population dynamics have provoked a rigorous debate whether the private or the public pension insurance system should be predominant. The pay-as-you-go system is dominated by the state that guarantees its stability. Private pension insurance provides personal retirement accounts and proper ownership of the accumulated funds, but its sustainability during prolonged market crises and inadequate risk sharing are often questioned. In order to address this issue, this paper makes both an assessment and analysis of the arguments put forward in favor of the preservation of the pay-as-you-go system and a comparison of this system with some of the main characteristics of the private accounts system. This is the basis for seeking the objectively defined role of the pay-as-you-go system in the conditions of the market economy. A couple of conclusions that have been formulated might be of interest for the future improvement of the organization and management of pension insurance.

NUMERICAL STUDY OF THE EFFECTS OF PERSISTENT WARMER SEA SURFACE TEMPERATURE IN TROPICAL INDIAN OCEAN ON ATMOSPHERIC CIRCULATION IN THE EARLY SUMMER IN EAST ASIA IN 1991

By employing the CCM1(R15L12)long-range spectral model, study is undertaken of the effects of sea surface temperature anomaly(SSTA) for tropical Indian ocean on circulation transformation in the early summer in East Asia in 1991. The results indicate that warmer SSTA contributes to the increasing of the temperature over the Plateau in early summer, resulting in the intensification of tropical easterly jet on 100 hPa and northward shift of Northern Hemisphere subtropical westerly jet in May. It is obviously favorable for the subtropical high enhancement over western Pacific Ocean in May and subtropical westerly jet maintaining at 35～40 °N in June, making the Mei-Yu come earlier and stay over the Changjiang basin in 1991. Furthermore, warmer SSTA is also advantageous to averaged temperature rise in East Asia land region and Nanhai monsoon development. These roles are helpful in accelerating the seasonal transition for East Asia in early summer.

Study on City Environment,Safety and Health from the Viewpoint of Ecological Risks

Urban ecological risk analysis is a relatively new study field.Rapid industrial modernization and urbanization have significantly improved the living standards of the city.However,as environmental,safety and health issues are causing widespread concern,these problems have potential serious threat on ecosystems and human health.So how to solve many problems arising from city has become a key to sustainable development of human civilization.The present article analyzed the major problems that the city confronts and pointed out the main measures from the aspects of urban environment,safety and health.

The Information Risk in the Latest Crisis： A Driver or a Driven Factor for Global Financial Markets Equilibrium？

The latest financial crisis has been impressive for strength, impact, duration, and reduced efficacy of the economic and financial policies adopted by the authorities. We use an original information risk model to contribute to the analysis of the crisis and to suggest some approaches for a possible early diagnosis. Using data referred to the three main financial markets and comparing the latest crisis with the previous one and with long-term quantitative evidence, we find out that the 2007-2009 crisis was very different in the information risk quality. That gap affected the market risk aversion and its equilibrium, reducing the efficacy of the authorities＇ intervention tools mainly based on payoff risk control and efficient market restoration. Since information risk is an endogenous element of the market dynamics that can be independent form contingent levels of market efficiency. Drivers of information risk in the European Markets differed strongly from the US and Japanese ones; that is why some global decisions had low impact while opportunities of local intervention were missed.

Celebration’s Urban Environment, Sustainable by the Joy of Living

Besides arguments like fighting against dispersed urbanization, improving economies of infrastructure and preserving natural resources, another measure to sustainability is the delight of people in staying together with others sharing a well-designed urban landscape. Analyzing the Celebration’s urban setting is highlighted how some design firms are turning to reclaim the types of urbanism and traditional American architecture, representing the wish for reinforcing the daily vicinity relationships. As a matter of sustainability, it mentioned aspects of vehicular accessibility and the population density which is higher in Celebration than that in other suburban towns in USA. Attention is given both to the management of natural landscape and the role of the entrepreneur to construct a town in a so fragile soil. The relationship between community and sustainability is highlighted, leading to the idea of building spaces to become places, capable to convey the feeling of joy of living.

A fast method to evaluate water eutrophication

Water eutrophication has become a worldwide environmental problem in recent years.Once a water body is eutrophicated,it will lose its primary functions and subsequently influence sustainable development of society and economy.Therefore,analysis of eutrophication becomes one of the most essential issues at present.With the ability to deal with vague and uncertain information,and express knowledge in a rule form,the rough set theory(RST) has been widely applied in diverse domains.The advantage of RST is that it can compress the rule and remove needless features by reduction inference rule.By this way,the rule gets effectively simplified and inference efficiency gets improved.However,if data amount is relatively big,it could be a process with large calculated amount to search rules by looking up tables.Petri nets(PNs) possesses so powerful parallel reasoning ability that inference result could be obtained rapidly merely by simple matrix manipulation with no need for searching rules by looking up tables.In this work,an integrated RPN model combining RST with PN was used to analyze relations between degrees of water eutrophication level and influence factors in the Pengxi River of Three Gorges Reservoir.It was shown that the RPN model could analyze water eutrophicaion accurately and quickly,and yield decision rules for the decision-makers at water purification plants of the water quality and assist them in making more cost-effective decisions.

Investigation of China＇s Village Banks＇ Sustainable Development

In order to address the plight of rural financing, the 2007 China Banking Regulatory Commission, China＇s State Council started rural banks in provinces, towns and villages. There are so many problems faced by rural banks. The most pressing issue is the sustainability of targeting deviate due to restraints, shortage of funds, and loan risks. In order to effectively address these issues, this paper presents some solutions

Neural Networks for Condition Monitoring of Wind Turbines Gearbox

Wind energy is considered a hope in future as a clean and sustainable energy, as can be seen by the growing number of wind farms installed all over the world. With the huge proliferation of wind farms, as an alternative to the traditional fossil power generation, the economic issues dictate the necessity of monitoring systems to optimize the availability and profits. The relatively high cost of operation and maintenance associated to wind power is a major issue. Wind turbines are most of the time located in remote areas or offshore and these factors increase the referred operation and maintenance costs. Good maintenance strategies are needed to increase the health management of wind turbines. The objective of this paper is to show the application of neural networks to analyze all the wind turbine information to identify possible future failures, based on previous information of the turbine.