Comparison of the local pivotal method and systematic sampling for national forest inventories

Background:The local pivotal method(LPM)utilizing auxiliary data in sample selection has recently been proposed as a sampling method for national forest inventories(NFIs).Its performance compared to simple random sampling(SRS)and LPM with geographical coordinates has produced promising results in simulation studies.In this simulation study we compared all these sampling methods to systematic sampling.The LPM samples were selected solely using the coordinates(LPMxy)or,in addition to that,auxiliary remote sensing-based forest variables(RS variables).We utilized field measurement data(NFI-field)and Multi-Source NFI(MS-NFI)maps as target data,and independent MS-NFI maps as auxiliary data.The designs were compared using relative efficiency(RE);a ratio of mean squared errors of the reference sampling design against the studied design.Applying a method in NFI also requires a proven estimator for the variance.Therefore,three different variance estimators were evaluated against the empirical variance of replications:1)an estimator corresponding to SRS;2)a Grafström-Schelin estimator repurposed for LPM;and 3)a Matérn estimator applied in the Finnish NFI for systematic sampling design.Results:The LPMxy was nearly comparable with the systematic design for the most target variables.The REs of the LPM designs utilizing auxiliary data compared to the systematic design varied between 0.74–1.18,according to the studied target variable.The SRS estimator for variance was expectedly the most biased and conservative estimator.Similarly,the Grafström-Schelin estimator gave overestimates in the case of LPMxy.When the RS variables were utilized as auxiliary data,the Grafström-Schelin estimates tended to underestimate the empirical variance.In systematic sampling the Matérn and Grafström-Schelin estimators performed for practical purposes equally.Conclusions:LPM optimized for a specific variable tended to be more efficient than systematic sampling,but all of the considered LPM designs were less efficient than the systematic sampling design for some target variables.The Grafström-Schelin estimator could be used as such with LPMxy or instead of the Matérn estimator in systematic sampling.Further studies of the variance estimators are needed if other auxiliary variables are to be used in LPM.

Pivotal与VMware推出先进企业云解决方案

4月28日,Pivotal和VMware公司发布了搭载Pivotal Cloud Foundry和VMware Photon Platform的企业云原生堆栈,将Pivotal持续创新的云平台与VMware的云原生基础设施整合在一个解决方案之中,借助内置应用和基础设施管理加速应用开发和部署。两家公司最初在VMworld 2015大会上预演了该联合解决方案。为了更加高效地完成工作,开展创新,各企业都在不断提高灵活性,因此数字化转型已成为其头等大事。

People's Assessor Systems Pivotal to Protection of Human Rights

Back in August 2004, the Standing Committee of the National People＇s Congress, the highest legislature of China, published the Decision on Improving the People＇s Assessor System （hereinafter referred to as the Decision）. Since it became effective on May 1, 2005, the Decision has proved important to ensuring the right of citizens to participate in activities of adjudication in accordance with the law. It has helped expand judicial democracy and safeguard the legitimate rights and interests of the litigant parties.

Fiducial inference in the pivotal family of distributions

In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distributions are pivotal. In a pivotal family of distributions a general method of deriving fiducial distributions of parameters is proposed. In the method a fiducial model plays an important role. A fiducial model is a function of a random variable with a known distribution, called the pivotal random element, when the observation of a statistic is given.The method of this paper includes some other methods of deriving fiducial distributions. Specially the first fiducial distribution given by Fisher can be derived by the method. For the monotone likelihood ratio family of distributions, which is a pivotal family, the fiducial distributions have a frequentist property in the Neyman-Pearson view. Fiducial distributions of regular parametric functions also have the above frequentist property. Some advantages of the fiducial inference are exhibited in four applications of the fiducial distribution. Many examples are given, in which the fiducial distributions cannot be derived by the existing methods.

Pivotal Technology Research of Grid Based on Mobile Agent

Grid Based on Mobile Agent is a new grid scheme.The purpose of the paper is to solve the pivotal technology ofGrid Based on Mobile Agent(GBMA)combined with thought of Virtual Organization(VO).In GBMA,virtual orga-nization is viewed as the basic management unit of the grid,and mobile agent is regarded as an important interactivemeans.Grid architecture,grid resource management and grid task management are the core technology problem of GB-MA.The simulation results showy that Inter-VO pattern has the obvious advantage because it can make full use of resourcesfrom other virtual organizations in GBMA environment.

Pivotal principles for digital earth development in the twenty-first century

Reductionist thinking will no longer suffice to address contemporary,complex challenges that defy sectoral,national,or disciplinary boundaries.Furthermore,lessons learned from the past cannot be confidently used to predict outcomes or guide future actions.The authors propose that the confluence of a number of technology and social disruptors presents a pivotal moment in history to enable real time,accelerated,and integrated action that can adequately support a‘future earth’through transformational solutions.Building on more than a decade of dialogues hosted by the International Society for Digital Earth(ISDE),and evolving a briefing note presented to delegates of Pivotal 2015,the paper presents an emergent context for collectively addressing spatial information,sustainable development,and good governance through three guiding principles for enabling prosperous living in the twenty-first century.These are:(1)open data,(2)real-world context,and(3)informed visualization for decision support.The paper synthesizes an interdisciplinary dialogue to create a credible and positive future vision of collaborative and transparent action for the betterment of humanity and planet.It is intended that these Pivotal Principles can be used as an elegant framework for action toward the Digital Earth vision,across local,regional,and international communities and organizations.

Power Pivot技术在工程建设信息化中的应用

为了工程项目和合同明细的管理,跟踪合同的执行情况,及时分析合同工期和费用的偏差,采用Power Pivot技术应用于工程建设信息化。通过建立数据表、关联关系,运用Power Pivot内置的度量值,分别建立查询相关度量值;最后通过Power Pivot内置的度量值,分别建立统计分析相关度量值。该方法实现了单人工程信息的合同管理,为工程建设信息化提供了可靠的技术支持。

A Pivotal Year for Afghanistan

The Central Asian nation faces a critical transition in 2014 as NATO forces prepare to pull out With the impending large-scale withdrawal of NATO forces led by the United States in 2014,Afghanistan will usher in a vital turning point for its transition.The U.S.-Afghanistan Bilateral Security Agreement,the upcoming Afghan general election as well as the national reconciliation of Afghanistan will have a heavy influence on the country’s

乌克兰危机下俄罗斯加速“转向东方”及其前景

Following the beginning of the Ukraine crisis in 2022,Russia accelerated its so-called pivot to East,using diplomacy,trade,energy,infrastructure logistics,and identity,due to the rapid decoupling from Russia by the United States and the West across all directions.The timing,depth,and significance of this pivot to East are unparalleled,but its implementation continues to face much uncertainty.At present,this turn to East does not entail a permanent turn away from the West on the part of Russia,nor does it mean that Russia will only rely on the East,and still less does it imply any transformation of Russia’s national identity.On the contrary,as a center of sovereignty in the world and with its unique national civilization,Russia will continue to rely more on its own strength and shoulder its unique historical mission in the current period of change in the international order.

Demonstration of Center Pivot Uniformity Evaluation and Retrofit to Improve Water Use Efficiency

Agricultural irrigation is a primary user for freshwater withdrawal. Irrigation plays an important role in crop production, as it provides the benefit of reducing the effects of prolonged dryness and erratic precipitation. Center pivot irrigation system is the most common irrigation system in agriculture. As the center pivot irrigation system ages, the system could develop a leaking joint, clogged sprinklers, and physical damage. This can cause areas of non-uniformity that can lead to under- or over-irrigated in some areas of the land, resulting in excess energy use and cost, wasting resources, and environmental impacts. Thus, it is important to evaluate the performance of a center pivot irrigation system regularly to maximize return on investments and minimize wasting resources. This study focuses on evaluating the impacts and benefits of improved center pivot irrigation distribution uniformity by performing distribution uniformity evaluations pre- and post-retrofit. This study also focused on demonstrating an unmanned aerial vehicle (UAV) to assess the performance of the center pivot irrigation system in two irrigated farmlands. The Coefficient of Uniformity (CU), Distribution Uniformity (DU), and Scheduling Coefficient (SC) were calculated based on the catch can test data. The values were utilized to evaluate water and energy savings from the improved coefficients. The team has found that replacing sprinkler packages increased the CU from 78 to 89 and the DU from 77 to 82, and reduced the SC from 1.3 to 1.2 in Field A. In Field B, replacing sprinkler packages increased the CU from 73 to 91 and the DU from 62 to 84 and reduced the SC from 1.6 to 1.2. The estimated water savings in Field A due to the reduced scheduling coefficient was approximately 151,000 liters/hectare/year, with consideration of the corn and soybean rotation field in Michigan. The estimated water savings in Field B was 608,000 liters/hectare/year. The data from this demonstration study showed the value of distribution uniformity evaluation and retrofit of irrigation systems. This information will encourage farmers and agricultural industries to consider performing more distribution uniformity evaluations, ultimately improving irrigation water use efficiency and supporting sustainable water management in agriculture.

Part-Time Learners’Perceptions of Success During Emergency Remote Teaching and Implications for Future

The Faculty of Lifelong Learning at South East Technological University’s Carlow campus is one of the largest providers of part-time,adult learning in the Irish HE sector.Therefore,the perspectives of our part-time learners offer us valuable insights into adult learner experiences in the Irish HE sector.The outbreak of Covid 19 saw us pivot our provision to an emergency remote teaching(ERT)model in the first wave of the epidemic.The faculty undertook an extensive study of its learners in 2021 to examine the impacts of ERT on learners,and this article takes a qualitative approach to the findings of this study,looking specifically at learners’comments about success,and the barriers to success,which ERT posed.Our study provided an opportunity to learn about our learners’conceptions of student identity,and how they interpret success as part-time learners.

Equilibrium Energy and Entropy of Vortex Filaments in the Context of Tornadogenesis and Tornadic Flows

In this work, we study approximations of supercritical or suction vortices in tornadic flows and their contribution to tornadogenesis and tornado maintenance using self-avoiding walks on a cubic lattice. We extend the previous work on turbulence by A. Chorin and collaborators to approximate the statistical equilibrium quantities of vortex filaments on a cubic lattice when both an energy and a statistical temperature are involved. Our results confirm that supercritical (smooth, “straight”) vortices have the highest average energy and correspond to negative temperatures in this model. The lowest-energy configurations are folded up and “balled up” to a great extent. The results support A. Chorin’s findings that, in the context of supercritical vortices in a tornadic flow, when such high-energy vortices stretch, they need to fold and transfer energy to the surrounding flow, contributing to tornado maintenance or leading to its genesis. The computations are performed using a Markov Chain Monte Carlo approach with a simple sampling algorithm using local transformations that allow the results to be reliable over a wide range of statistical temperatures, unlike the originally used pivot algorithm that only performs well near infinite temperatures. Efficient ways to compute entropy are discussed and show that a system with supercritical vortices will increase entropy by having these vortices fold and transfer their energy to the surrounding flow.

余ribbon Turaev π-代数

讨论了Turaev π-代数余模范畴中的pivotal群交叉结构和ribbon群交叉结构,引入余pivotal Turaev π-代数和余ribbon Turaev π-代数的定义,并分别给出Turaev π-代数伴有余pivotal结构和余ribon结构的充要条件.

冷弯薄壁型钢墙体恢复力模型及房屋地震反应简化分析方法研究

基于10片1∶1冷弯薄壁型钢墙体抗剪滞回性能试验结果,采用SAP2000中多线段塑性Pivot连接单元的滞回规则,进行墙体的恢复力模型及冷弯薄壁型钢房屋的动力非线性简化分析方法研究。研究表明:墙体的骨架曲线可采用退化四线型模型模拟;双柱墙体Pivot模型参数可取α=10、β=0.1,单柱墙体可取α=10、β=0.15;非线性简化分析与试验分析得到的滞回曲线的外包络线基本一致,耗能能力相当,简化方法能较好地模拟墙体的强度、刚度退化和捏缩效应;三层房屋结构简化计算模型的第1、第2阶振型与试验观测一致,频率分别相差11%和2%;模型结构与试验的地震反应分析结果吻合较好,表明简化计算方法可用于冷弯薄壁型钢房屋的弹性和弹塑性地震反应分析。

基于OLAP的玉溪植烟土壤养分含量数据分析

介绍了采用OLAP组件ExpressPivotGrid Suite实现OLAP软件系统的过程,并采用所实现的OLAP软件对5 171个玉溪烟区植烟土壤养分含量数据进行分析。结果显示,玉溪市8县一区的植烟土壤,所有县旱地土壤的pH值均在5～7之间,水田土壤pH值除元江县外均高于旱地土壤pH值;玉溪各县区土壤有机质含量均大于20g/kg,土壤肥力水平属于最适宜烤烟种植的水平。

基于虚拟观测的CORS定位数据处理方法及应用

针对城市连续运行参考系统(CORS)下网络实时动态(RTK)在特殊环境中无法获取固定解的情况,提出了基于虚拟观测数据的后处理解算方法,探讨了基于Trimble Pivot platform软件生成虚拟观测数据和利用TBC软件网求解观测点位置的解算流程和步骤,分析了虚拟观测数据的使用对解算精度的影响.实例分析结果表明,虚拟观测数据各项质量评估指标均与真实观测数据相当,且通过实际工程进行了验证,确定了虚拟观测数据具有一定的可靠性.

面向Web服务组合的pivot事务嵌套模型

Web服务组合中的事务具有执行周期长的特性,一个全局事务会被划分为多个分布的子事务。各个子事务对全局事务而言具有不同的重要程度,关键子事务执行的成功与否,直接影响到全局事务执行的成败。另一方面,对某些出现故障的事务需要进行补偿,而执行过多的补偿事务会带来巨大的补偿开销。针对这些问题,提出了一个基于pivot事务的嵌套事务模型,模型中的事务分为pivot事务和非pivot事务,且含有至少一个pivot事务。同时基于该模型,给出了一个pivot事务优先调度(pivot transaction priority scheduling,PTPS)算法,通过优先执行pivot事务,来减少在pivot事务失败时执行的补偿事务数目,降低补偿开销。

Why Well Spread Probability Samples Are Balanced

When sampling from a finite population there is often auxiliary information available on unit level. Such information can be used to improve the estimation of the target parameter. We show that probability samples that are well spread in the auxiliary space are balanced, or approximately balanced, on the auxiliary variables. A consequence of this balancing effect is that the Horvitz-Thompson estimator will be a very good estimator for any target variable that can be well approximated by a Lipschitz continuous function of the auxiliary variables. Hence we give a theoretical motivation for use of well spread probability samples. Our conclusions imply that well spread samples, combined with the Horvitz- Thompson estimator, is a good strategy in a varsity of situations.

浅谈克拉申的“输入假说”与留学生“使”字兼语句的习得

克拉申的"输入假说"阐述了人们习得语言的过程,是第二语言习得的一个重要理论。"使"字兼语句是留学生在汉语语法学习过程中的重难点。"使"字兼语句是兼语句的一种,但与一般兼语句又有所不同,它是汉语中特殊的动词谓语句中非常重要的一块。本文主要尝试将克拉申的"输入假说"运用到留学生"使"字兼语句的习得过程中,帮助留学生更快更好地理解和掌握"使"字兼语句以及在教学的过程中教师应采取哪些适当的教学方法。

Nonalcoholic steatohepatitis and insulin resistance in children

Various pathological conditions can cause fatty liver in children. Nonalcoholic steatohepatitis(NASH) in children has been known since 1983. However, NASH diagnosed in childhood does not have a favorable outcome.The pathological characteristics of NASH are significantly different between children and adults. Nonalcoholic fatty liver disease(NAFLD)/NASH is accompanied by insulin resistance, which plays a pivotal role in its pathophysiology in both children and adults. In NASH,a "two-hit" model involving triglyceride accumulation(first hit) and liver damage(second hit) has been accepted. Insulin resistance was found to correlate with changes in fat levels; however, it did not correlate with fibrosis or NAFLD activity score in children. Therefore,insulin resistance may be important in the first hit.Because there is obvious familial clustering in NASH,genetic predisposition as well as environmental factors including diet might be the second hit of NAFLD/NASH.