GIS-based Analysis for Hotspot Identification of Tradeoff Between Ecosystem Services： A Case Study in Yanhe Basin, China

Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots, Based on previous studies of ecosys- tem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further ana- lyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production （NPP） and water yield （WY） in 2000 and 2008 were estimated by using biophysical models, Secondly, correla- tion analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index （TINpp/wy） was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINpp/wy is 24.4 g/（mm·m2） for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the mid- dle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek poten- tial influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential irtfluencing factor for formulatiort of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem.

Multi-factor analysis of initial poor graft function after orthotopic liver transplantation

BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P < 0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors.

A Hybrid Neural Network Model for Marine Dissolved Oxygen Concentrations Time-Series Forecasting Based on Multi-Factor Analysis and a Multi-Model Ensemble

Dissolved oxygen(DO)is an important indicator of aquaculture,and its accurate forecasting can effectively improve the quality of aquatic products.In this paper,a new DO hybrid forecasting model is proposed that includes three stages:multi-factor analysis,adaptive decomposition,and an optimizationbased ensemble.First,considering the complex factors affecting DO,the grey relational(GR)degree method is used to screen out the environmental factors most closely related to DO.The consideration of multiple factors makes model fusion more effective.Second,the series of DO,water temperature,salinity,and oxygen saturation are decomposed adaptively into sub-series by means of the empirical wavelet transform(EWT)method.Then,five benchmark models are utilized to forecast the sub-series of EWT decomposition.The ensemble weights of these five sub-forecasting models are calculated by particle swarm optimization and gravitational search algorithm(PSOGSA).Finally,a multi-factor ensemble model for DO is obtained by weighted allocation.The performance of the proposed model is verified by timeseries data collected by the pacific islands ocean observing system(PacIOOS)from the WQB04 station at Hilo.The evaluation indicators involved in the experiment include the Nash–Sutcliffe efficiency(NSE),Kling–Gupta efficiency(KGE),mean absolute percent error(MAPE),standard deviation of error(SDE),and coefficient of determination(R^(2)).Example analysis demonstrates that:①The proposed model can obtain excellent DO forecasting results;②the proposed model is superior to other comparison models;and③the forecasting model can be used to analyze the trend of DO and enable managers to make better management decisions.

Multi-factor sensitivity analysis of shallow unsaturated clay slope stability

An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.

Logistic Regression Analysis of Influencing Factors on Serum ALT and HCV RNA Changes in Patients with Chronic Hepatitis C

Objective This study was undertaken to investigate the influencing factors on serum ALT level and hepatitis C virus(HCV)RNA titer in chronic hepatitis C(CHC)patients.Methods All patients enrolled into this study were anti-HCV positive.Retrospective tracing method was applied to detect serum ALT level and HCV RNA titer and to collect general information of the patients such as genders,age groups,interferon medication history,infection pathways,height and weight.Then the multi-factor analysis was adopted with the application of binominal logistic regression mode.Results The abnormal rate of ALT level was positively correlated to HCV RNA and gender while negatively correlated to interferon medication history and age group,with Wald value of the 4 factors as 39.604,11.823,18.991 and 7.389,respectively.The positive rate of HCV RNA was negatively correlated to interferon medication history and gender while positively correlated to ALT level,with corresponding Wald value of the 3 factors as81.394,7.618 and 27.562,respectively.Conclusions The normal ALT level in HCV infected patients was associated with viral load,age,gender and interferon medication history,while the normal rate of HCV RNA titer was closely associated with gender,interferon medication history and ALT level.

基于InVEST模型的渭河流域生境质量评估

基于生态系统服务评估与权衡模型和ArcGIS软件探索2000-2020年渭河流域生境质量的时空变化,利用地形分布指数分析生境质量的地形梯度效应.结果表明, 20 a间,研究区土地利用变化主要包括耕地向建设用地和草地的转移,以及草地向耕地和林地的转移,不同类型之间的转移是影响局部生境质量变化的主要因素;生境质量的空间分布以中等生境为主,占比约57%,主要分布在关中城市群外围和西北部.低等生境占比约5%,但面积增长最快,增幅达到105.80%,原因是关中城市群的大面积扩张;研究区生境质量空间分布存在一定的正相关性,且聚集程度增加1.15%,局部自相关类型以高-高和低-低集聚为主,高-高集聚分布在研究区东北部黄土高原和南部秦岭北坡,低-低集聚分布在关中城市群;2020年生境质量具有显著的地形梯度效应,表现在生境质量等级随着地形梯度级别的增加而增加.

德清县生态系统服务价值时空分析

生态系统服务价值评估作为合理配置土地资源、保护生态环境、助力碳交易、制定生态补偿标准的重要前提,是当今学术界的热点研究课题之一,而基于栅格的县域生态系统服务价值测算与分析,则对推动县域的高质量发展具有十分重要的意义。为此,本文以浙江省湖州市德清县作为研究对象,基于2010年、2015年、2020年德清县的国土数据和社会经济发展数据,运用物质量评价法及其协同与权衡分析,从测算德清县的生态系统服务价值入手,不但研究了该县生态系统服务价值的空间分布,以及各乡镇生态系统服务价值的时间序列变化情况,而且还对德清县及其德清县各个乡镇的不同生态系统服务价值之间的相关性进行了深入探索。研究结果表明:1)2010年、2015年、2020年德清县的生态系统服务价值分别为30.337亿元、35.906亿元、38.806亿元,呈现出了递增的发展趋势,而德清县生态系统服务价值的空间分布特征则是西部地区的生态系统服务价值高于中部和东部地区的生态系统服务价值。2)由2010年、2015年、2020年德清县各乡镇生态系统服务价值的时间序列变化情况可以看出,3年间德清县各乡镇的生态系统服务价值均呈现出了上升趋势。3)在德清县各生态系统服务价值之间的相关性方面,供给价值与固碳价值、释氧价值、水源涵养价值、土壤保持价值、生产有机质价值之间均表现为权衡关系;固碳价值、释氧价值、水源涵养价值、土壤保持价值、生产有机质价值之间则表现为协同关系。4)德清县大部分乡镇生态系统服务的固碳价值、释氧价值、水源涵养价值、土壤保持价值、生产有机质价值之间均表现为了协同关系。

软件定义网络中的流量工程与安全性研究

为保证网络安全,提升网络性能,文中研究了软件定义网络(SDN)业务工程与安全性的关系。在此基础上,从网络性能与安全两个方面对网络性能进行了平衡分析,从而实现对网络性能的优化,防止恶意行为与攻击。研究结果表明,结合业务工程与安全性,可最大程度地改善网络性能,同时防止网络受到攻击,对软件定义网络的应用与发展具有一定的指导意义,有利于促进相关领域的研究与探索。

Grain production space reconstruction and land system function tradeoffs in China

Grain production space reconstruction referred to the changes in the quantity,quality and pattern of grain produc-tion space caused by functional tradeoffs and conflicts between grain production space,urban-rural development space,and ecological service space.Exploring tradeoffs between land system functions caused by grain produc-tion space reconstruction was particularly important for ensuring food security,promoting the construction of ecological civilization,and achieving sustainable development.Therefore,this study identified four relationships of land system functions during the process of grain production space reconstruction(1980-2018)in China by using Set Pair Analysis.Research results showed that the reconstruction of grain production space was achieved mainly through three pathways:Grain for Green,deforestation and reclamation,and urban expansion.Generally,ecological service had spatial negative correlation with grain production,economic development and population carrying capacity(P<0.01),but grain production,economic development and population carrying capacity were positively correlated with each other(P<0.01).In the process of grain production space reconstruction,eco-logical services and economic development,ecological services and population carrying capacity had all shown inverse synergies;there was a tradeoffbetween grain production and ecological services,a codirectional tradeoffbetween grain production and economic development,but a strong synergy between economic development and population carrying capacity.However,the functions of land systems only appeared as synergies or tradeoffs,and there were no inverse synergies and codirectional tradeoffs in the separate processes of Grain for Green,deforestation and reclamation,and urban expansion.It can be concluded that the relationships between land system functions were relatively simple in a single process,but it became complex and diverse when multiple processes were integrated for system analysis.

基于多要素权衡分析的航天产品质量综合评价框架

探讨了以系统工程方法为指导,从全过程(系统工程过程V模型)、多视角(正向质量绩效和逆向风险评价)、全层次(产品分解结构)、多维度(多维要素量化与综合)提炼航天产品质量评价要素、评价方法和评价流程,构建基于多要素权衡分析的航天产品质量综合评价框架(基本模型),为航天产品质量管理方法创新、质量保证能力提升提供参考。

面向横向比较的可持续发展综合评估方法改进

2030年可持续发展议程以“不让任何人掉队”的发展理念,提出了17个可持续发展目标(SDGs)和169个指标,几乎涵盖了人类发展的方方面面。围绕SDGs的评估工作是一项世界性难题,既有理论上的不足使得定性目标难以全部有效转为定量指标,也有方法学上的缺陷导致多指标合成存在困难,不能进行有效和客观的横向比较。该研究主要围绕SDGs综合评估方法优化开展讨论。研究认为,由于SDGs的经济、社会、环境三个维度指标存在着一定的相关性,传统算术平均赋值权重的方法学可能引起历时性和共时性问题,从而拉大可持续发展目标完成情况评估结果的区域差距。该研究提出了指标权重客观赋值的方法学,采用多因子分析方法对指标的两两关系进行拟合,同时结合层次分析法构建SDGs的判断矩阵,实现指标权重的客观量化和赋值。以此为基础,开展中国31个省份在落实2030年可持续发展议程方面的进展评估,结果显示:各省份SDGs的评估得分总体上呈现出从东部逐渐向中西部递减的趋势,其中浙、沪、京等排名领先;通过将新方法的结果与传统的算术平均评估方法进行对比,发现新方法显著降低了经济发达地区和落后地区在落实SDGs方面的得分差异。这种情况也反映,在可持续发展框架下,不应该过于夸大经济增长的作用,应该追求经济、社会和环境三个支柱的均衡发展,实现生活质量和幸福指数的提升。

权衡城市扩张、耕地保护与生态效益的京津冀城市群土地利用优化配置情景分析

京津冀城市群作为影响我国经济发展的重要区域,具有多重战略意义。然而,快速的城市扩张在提高社会、经济水平的同时,伴随着资源供求矛盾加深、耕地被侵占、生态退化,以及水、大气环境污染等众多突出问题,如何优化调整城市空间结构与布局,实现社会、经济发展与生态环境保护等多目标的协同优化是京津冀规划管理与决策的关键。从土地覆盖/利用数量和空间布局两个重点方面出发,通过多目标优化模型和CLUE-S模型的构建,提出了多目标权衡下的土地扩张优化情景预案,以期为京津冀城市群扩张布局与土地利用优化配置规划与管理提供科学参考。结果表明:一方面,利用多目标遗传算法(MOGA)可以很好地实现对京津冀土地利用结构优化配置及其与社会、经济及生态效益等多目标的定量化求解,为决策人提供满足不同权衡目标的多种选择,并通过与CLUE-S模型相结合,实现京津冀城市群土地利用格局的空间优化配置情景模拟;另一方面,研究结果表明,综合考虑了社会、经济和生态效益的优化方案中,林地的增加可以相对满足政策要求,增幅较大,耕地较未优化方案减幅放缓,符合耕地保有量的要求,同时,也从空间上减少了对重要生态用地的侵占。本研究的方法与结果可为京津冀城市群土地利用规划与生态安全格局建设提供理论与应用参考。

ATAM方法及其在C^4ISR系统体系结构评价中的应用

ATAM(ArchitectureTradeoffAnalysisMethod)方法是一种评价信息系统体系结构级设计的方法,它通过对诸如性能、可更改性、可靠性、安全性等多个质量属性的分析来确定体系结构设计中的折衷点,从而降低设计风险。介绍了ATAM方法的基本概念、步骤,并给出了该方法在C4ISR系统体系结构评价中的一个应用实例。

武器系统采购费与维修费权衡的依据分析

根据武器系统寿命周期费用的理论和方法,建立了系统的费用模型,依据数学分析和优化理论,在已知可用武器系统目标数的前提下,建立了费用优化条件,确定了采购费与维修费的比例限值,用以确定武器系统采购费和维修费的最优比例,从而对系统方案确定的权衡分析提供量化依据.

可靠性与维修性指标综合权衡

本文首先采用定量与定性相结合的方法，分别建立了费用、效能与可靠性、维修性的关系式。然后通过费用－效能分析的方法，把可靠性、维修性综合权衡问题转化为二元非线性规划问题。通过连续变化费用，最后得到最优组合曲线，根据最优组合曲线权衡出可靠性、维修性指标。

基于场景的两种软件体系结构评估方法

基于场景的软件体系结构评估方法通过场景将系统的质量需求转换为风险承担者与系统的交互活动,通过低代价的事前评估活动降低软件的质量风险。SAAM及ATAM两种方法在具体的实际评估活动中,它们在场景的生成、风险承担者的商业动机的表述、软件体系结构的描述等方面存在着很大的不同,两种评估方法各有特长,其评估方法在具体的场景执行环节上具有不确定性,将定量的度量方法与定性场景结合是提高评估的有效途径。

燕山-太行山区生态系统服务价值权衡/协同关系的多尺度分析

基于生态系统服务价值评估模型测算了燕山-太行山区生态系统服务价值,进而系统分析了其动态变化过程,最后对比了生态系统服务价值权衡/协同关系在不同尺度(县域、乡镇、网格)下的空间演变规律。结果表明:(1)燕山-太行山区生态系统服务价值呈持续增加趋势,由2000年的2 985.09亿元增加至2019年的3 171.01亿元。生态系统服务价值在空间上呈东高西低、北高南低的分布特征。(2)各类生态系统服务价值中调节服务占比最高,其后依次为支持、供给和文化服务。各类用地中,林地生态系统服务价值占比最高,其后依次为草地、耕地、湿地、水域和荒漠。(3)协同关系为燕山-太行山区生态系统服务之间的主导关系,权衡关系存在于供给服务与其他3项服务中。不同研究尺度下权衡/协同关系具有差异,县域尺度仅表现出协同关系,而乡镇和网格尺度下协同/权衡关系并存。研究结果对准确把握不同尺度下生态系统服务价值和权衡/协同关系具有重要意义,可为燕山-太行山集中连片特困区生态环境恢复提供科学依据,进而为实现贫困区经济发展与生态保护双赢奠定基础。

运用寿命周期成本分析方法优化设备系统选型

通过对寿命周期成本分析理论的阐述和运用费用效率法的工程实例,系统地总结了提高费用效率的5种途径,以求得费用效率最大化,来指导具体工作实践,寻找在设备系统选型时,设置费和维持费之和为最小的平衡点.

基于物质平衡原则的工业碳排放效率评估

考虑物质平衡原则,采用数据包络分析法构建了一个新的碳排放效率指标,并应用于分析1997~2012年间中国工业部门的CO2排放效率、减排潜力,以及排放与成本之间的权衡。结果表明,中国工业部门的CO2排放效率和成本效率均较低,且具有较大的省际差异;在现行技术下,全国平均的成本节约和排放削减存在潜力。成本有效和排放有效之间存在权衡关系,虽然可以通过征税或者补贴等措施来同时达到这两种目标,但由此产生的额外成本巨大,在经济上不可行。比较而言,成本有效是现行市场条件下更为合理的选择。

2006年诺贝尔经济学奖得主菲尔普斯理论评介

本文介绍了2006年诺贝尔经济学奖得主埃德蒙.菲尔普斯的主要理论贡献。他在宏观经济政策跨期权衡分析、“黄金律”与经济增长、宏观经济政策的“短期—长期”分析、“自然率”、构建宏观经济学的微观基础,以及结构性萧条与繁荣等诸多领域进行了开创性的研究。菲尔普斯的理论和主张对西方经济理论和经济政策的研究都有十分重大的影响。