Journal of Environmental Systems最新文献

Estimating Probability Distributions from Complex Models with Bifurcations: The Case of Ocean Circulation Collapse 从带分岔的复杂模式估计概率分布:以海洋环流崩溃为例

Journal of Environmental Systems Pub Date : 2007-07-01 DOI: 10.2190/A518-W844-4193-4202

M. Webster, Jeffery R. Scott, A. Sokolov, P. Stone

{"title":"Estimating Probability Distributions from Complex Models with Bifurcations: The Case of Ocean Circulation Collapse","authors":"M. Webster, Jeffery R. Scott, A. Sokolov, P. Stone","doi":"10.2190/A518-W844-4193-4202","DOIUrl":"https://doi.org/10.2190/A518-W844-4193-4202","url":null,"abstract":"Studying the uncertainty in computationally expensive models has required the development of specialized methods, including alternative sampling techniques and response surface approaches. However, existing techniques for response surface development break down when the model being studied exhibits discontinuities or bifurcations. One uncertain variable that exhibits this behavior is the thermohaline circulation (THC) as modeled in three dimensional general circulation models. This is a critical uncertainty for climate change policy studies. We investigate the development of a response surface for studying uncertainty in THC using the Deterministic Equivalent Modeling Method, a stochastic technique using expansions in orthogonal polynomials. We show that this approach is unable to reasonably approximate the model response. We demonstrate an alternative representation that accurately simulates the model’s response, using a basis function with properties similar to the model’s response over the uncertain parameter space. This indicates useful directions for future methodological improvements.","PeriodicalId":376487,"journal":{"name":"Journal of Environmental Systems","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125070007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Alternative Forms of Aggregation in the Analytic Hierarchy Process: Ordered Weighted Averaging Operators 层次分析过程中聚合的替代形式:有序加权平均算子

Journal of Environmental Systems Pub Date : 2007-07-01 DOI: 10.2190/3272-5507-6531-8352

P. Smith

{"title":"Alternative Forms of Aggregation in the Analytic Hierarchy Process: Ordered Weighted Averaging Operators","authors":"P. Smith","doi":"10.2190/3272-5507-6531-8352","DOIUrl":"https://doi.org/10.2190/3272-5507-6531-8352","url":null,"abstract":"The analytic hierarchy process (AHP) methodology was introduced by Thomas Saaty and has had numerous applications in a wide range of contexts. In a common three-level hierarchy, AHP involves the aggregation of criterion importance weights (or priorities) and the performance scores (or priorities) of alternatives as the sum of the products of weights and scores for each alternative. The multiplicative AHP (MAHP) involves the multiplicative aggregation of performance scores raised to the power of the criterion weights and has been seen by many individuals (notably, Freerk Lootsma and John Barzilai) as an alternative more desirable structure. It is suggested that alternative forms of aggregation of performance scores and criterion weights might be more useful, in particular the ordered weighted averaging (OWA) operator introduced by Ronald Yager. The choice of weights in an OWA operator may be guided by a linguistic quantifier involving the importance weights associated with each criterion. The geometric ordered weighted averaging (GOWA) operator is also considered as a possibility for aggregation in the MAHP. An example is given relating to the location of a Green Bridge Link (for public transport and non-motorized modes of transport) in Brisbane, Queensland, Australia. The four approaches (alternatives) to the identified site of the Green Bridge (Dutton Park) are a Full Busway, Boggo Road, Cornwall Street, and Kent Street.","PeriodicalId":376487,"journal":{"name":"Journal of Environmental Systems","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128243494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Economies of Scale Can Be Implemented by Cooperative Game: The Chain Model Case 规模经济可以通过合作博弈实现:链式模型案例

Journal of Environmental Systems Pub Date : 2007-07-01 DOI: 10.2190/G103-37W5-311K-9318

Hung-Ming Wu, K. Willett

引用次数: 1

A Risk Based, Multi-Component Model to Identify Contaminant Loadings and Transport through Groundwater Systems Under Uncertainty 一个基于风险的多组分模型来识别不确定条件下地下水系统中的污染物负荷和运输

Journal of Environmental Systems Pub Date : 2007-07-01 DOI: 10.2190/2406-3212-6V40-3820

Todd A. Wang, W. Mcternan

引用次数: 0

Waste Disposal and Groundwater Quality in Owerri, Nigeria 尼日利亚奥韦里的废物处理和地下水质量

Journal of Environmental Systems Pub Date : 2007-07-01 DOI: 10.2190/Q4G4-MV32-65TN-82H6

C. O. Owuama, A. Uzoije

引用次数: 5

Dilutions of Glucose and Glutamic Acid Analyzed as Multi-Order BOD Reactions 葡萄糖和谷氨酸的多级生化需氧量稀释分析

Journal of Environmental Systems Pub Date : 2007-07-01 DOI: 10.2190/8712-651M-0783-6M26

Trieu Le, D. Adrian

引用次数: 2

Public attitudes toward forest management in an Illinois National Forest. 公众对伊利诺伊州国家森林管理的态度。

Journal of Environmental Systems Pub Date : 2004-07-01 DOI: 10.2190/A5J1-1JAB-Q7F5-CA9D

Joanne Vining

引用次数: 7

Comparison of two techniques to promote recycling: block leader versus reward 促进回收的两种技术的比较:区块领导与奖励

Journal of Environmental Systems Pub Date : 2004-07-01 DOI: 10.2190/80XY-MBQ0-YKX5-QBBU

G. Meneses

引用次数: 6

GROUNDWATER-SURFACE WATER INTERACTION AS A COMPONENT OF THE ECOHYDROLOGY OF SEMI-ARID REGIONS 半干旱区地下水-地表水相互作用作为生态水文的组成部分

Journal of Environmental Systems Pub Date : 2004-07-01 DOI: 10.2190/F74V-HERH-PGL5-2N8F

J. Diiwu

引用次数: 6

SIMPLIFIED DEVELOPMENT OF OXYGEN SAG MODEL 氧凹陷模型的简化发展

Journal of Environmental Systems Pub Date : 2004-07-01 DOI: 10.2190/283A-2C4U-BBX7-2VKC

Trieu Le, E. M. Roider, D. Adrian

{"title":"SIMPLIFIED DEVELOPMENT OF OXYGEN SAG MODEL","authors":"Trieu Le, E. M. Roider, D. Adrian","doi":"10.2190/283A-2C4U-BBX7-2VKC","DOIUrl":"https://doi.org/10.2190/283A-2C4U-BBX7-2VKC","url":null,"abstract":"A dissolved oxygen sag equation is developed by use of the Laplace transform and the convolution integral for a stream in which the biochemical oxygen demand (BOD) deoxygenation rate is described as a second-order reaction. The Laplace transform method simplifies the mathematical solution of the model equation by avoiding difficult-to-evaluate integrals. The dissolved oxygen sag equation incorporates exponential integral functions which are calculated by exact or approximate series. The time at which the minimum dissolved oxygen concentration occurs is calculated numerically. The dissolved oxygen sag model is applied using BOD data collected from Douglas Fir needles in stream water. The Douglas Fir needles had a small reaction rate constant which results in the stream being able to carry a BOD load without exhausting its dissolved oxygen supply. The model is useful in calculating Total Maximum Daily Loads (TMDL) of streams. INTRODUCTION Water quality modeling in a river has developed from the pioneering work of Streeter and Phelps [1], who developed a balance between the dissolved oxygen *Financial support was provided by a Louisiana State University Board of Regents fellowship to the senior author.","PeriodicalId":376487,"journal":{"name":"Journal of Environmental Systems","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125950187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4