1,720,997 research outputs found
Integrating Ecological Flow Regimes and Environment Gradient Concept in Optimum Water Resources Management
No full text近年來針對保護河川生態的河川環境流量研究，已從以往考慮保留單一最小流量的方式，發展成為以維護「生態河川流態」為基礎的河川流量管理方式；但發展生態河川流態的難題在於如何能真正考量河川流態與河川生態系統間的關係與影響，而非僅是採用歷史流量改變度評估的替代方案。本研究提出一考量生態河川流態與魚類群聚關係的架構，以數量生態學上的梯度分析方法建立魚類豐度與台灣生態水文指標(TEIS)間的生態反應模型，引進代表合成環境梯度的虛擬變數以定義各魚種在生態水文環境梯度軸上的生態區位；這方法的優點在於(1)以河川魚類群聚為考量對象而非少數選定魚種，(2)為一基於高斯反應模型的生態模型，(3)能有效的分離眾多環境因子對生物影響的複雜合成效應。在本研究中並延伸此概念於建立基於河川流態的河川流量管理方式，以石門水庫為例建立考量人類需求與生態需求的多目標最佳化操作模式，並利用非支配排序遺傳演算II (NSGA-II)搜尋最佳蓄水歷線。研究結果顯示結合梯度分析方法與NSGA-II能幫助建立更具生態意義的河川流量管理方式，找出同時滿足人類用水需求與維持生態系統健全之水庫操作規則，以供多目標水資源管理進行決策。Investigation on environmental flow for conservation of river ecosystem has been focused on ecological flow regime approach which is more comprehensive than the traditional minimum flow management schemes that merely consider single flow value. The pivotal difficulty in developing ecological flow regime is how to take into account the interaction and relation between flow regime and river ecosystem. In this study we propose an idea of considering the relation between ecological flow regime and fish communities and then applying the gradient analysis technique in quantitative ecology theory to constructing the ecological response model. The model is built based on the fish abundance and the Taiwan Ecohydrology Indicator System (TEIS). The dummy variables for representing synthetic environment gradient could be used to identify the niche in each fish species on ecohydrological gradient axis. The main advantages of this technique are: (1)approximate the natural flow regimes that maintained the entire panoply of species, (2)based on unimodal Gaussian response model, and (3)separate the effects of explanatory environment variables. his technique is then extended herein to build the optimal operation model in Shihmen Reservoir by considering the maintenance of natural flow regimes and human needs, and the non-dominated sorting genetic algorithm II (NSGA-II) is used to optimize the multi-objective model. The results demonstrated that more meaningful manner of flow management in ecological aspect can be effectively constructed by integrating the gradient analysis technique and NSGA-II for the ecological flow regimes. Meanwhile, the method searches the optimal operation rule that can simultaneously the water demand for maintenance of ecosystem and human need provides the decision for multi-objective water resources management.摘 要 ibstract ii 錄 iv目錄 ix目錄 xi一章 緒 論 1.1 研究動機與目的 1.2 研究方法與流程 2.3 論文架構 4二章 文獻回顧 6.1 生態河川流態 6.2 梯度分析方法 8.3 模糊規劃理論 10.4 優選模式於水庫運轉操作 11.5 多目標進化式演算法 13三章 理論概述 15.1 台灣生態水文指標系統 15.1.1 自然河川流態與生態河川流態 15.1.2 水文變化指標 17.1.3 台灣生態水文指標系統之考量因子 18.1.4 台灣生態水文指標系統之介紹 21.2 梯度分析方法 23.2.1 環境梯度與生態區位 23.2.2 梯度分析方法之目的 27.2.3 梯度分析方法的分類與流程 30.2.4 梯度分析方法之雙序圖意義 33.2.5 除趨勢對應分析(DCA) 36.2.6 浄蒙地卡羅排列測試 37.2.7 典型對應分析(CCA) 38.3 模糊規劃 40.3.1 模糊集合理論 40.3.2 模糊規劃模式 41.4 遺傳演算法 45.4.1 遺傳演算法簡述 45.4.2 演算流程與基本單元 47.4.3 遺傳演算法三大運算元 49.5 非支配排序遺傳演算法II (NSGA-II) 52.5.1 多目標最佳化模式 52.5.2 NSGA-II概述及演算流程 57.5.3 非支配排序及擁擠距離 59.5.4 NSGA-II運算元 61四章 研究案例 63.1 研究區域概況 63.1.1 大漢溪流域簡介 63.1.2 大漢溪流域魚類簡介 64.1.3 石門水庫簡介 67.2 梯度分析方法結果 69.2.1 資料選取原則及限制 69.2.2 降趨對應分析DCA結果 73.2.3 DCA梯度值與水文因子逐步迴歸結果 82.2.4 浄蒙地卡羅排列測試結果 88.2.5 典型對應分析CCA結果 92.3 石門水庫操作 101.3.1 石門水庫引水系統概述 101.3.2 石門水庫操作規線 101.4 多目標最佳化模式之建立 103.4.1 人類需求目標及限制式 103.4.2 人類需求目標函數及限制式的模糊化 106.4.3 生態系統需求目標 108.4.4 多目標水庫最佳化模式 109.4.5 聯程原理與缺水指標 112五章 結果與討論 115.1 石門水庫單目標最佳操作 115.2 石門水庫多目標最佳化結果 120.3 結果與討論 125六章 結論與建議 132.1 結論 132.2 建議 134考文獻 135錄一 台灣生態水文指標系統說明 148錄二 大漢溪常見淡水魚類照片與棲所生態描述 151錄三 民國77年石門水庫操作規線最佳化結果 15
Defining the ecological hydrology of Taiwan Rivers using multivariate statistical methods
No full textThe identification and verification of ecohydrologic flow indicators has found new support as the importance of ecological flow regimes is recognized in modern water resources management, particularly in river restoration and reservoir management. An ecohydrologic indicator system reflecting the unique characteristics of Taiwan’s water resources and hydrology has been developed, the Taiwan ecohydrological indicator system (TEIS). A major challenge for the water resources community is using the TEIS to provide environmental flow rules that improve existing water resources management. This paper examines data from the extensive network of flow monitoring stations in Taiwan using TEIS statistics to define and refine environmental flow options in Taiwan. Multivariate statistical methods were used to examine TEIS statistics for 102 stations representing the geographic and land use diversity of Taiwan. The Pearson correlation coefficient showed high multicollinearity between the TEIS statistics. Watersheds were separated into upper and lower-watershed locations. An analysis of variance indicated significant differences between upstream, more natural, and downstream, more developed, locations in the same basin with hydrologic indicator redundancy in flow change and magnitude statistics. Issues of multicollinearity were examined using a Principal Component Analysis (PCA) with the first three components related to general flow and high/low flow statistics, frequency and time statistics, and quantity statistics. These principle components would explain about 85% of the total variation. A major conclusion is that managers must be aware of differences among basins, as well as differences within basins that will require careful selection of management procedures to achieve needed flow regimes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Artificial Neural Networks for Estimating Arsenic Variation in the Regional Ground Water
No full text致癌毒物－砷對環境與人類健康之影響係為社會所關切的議題，本研究架構砷濃度類神經網路推估模式，對區域內砷濃度進行推估工作，提供區域內砷濃度變化，以維護當地民眾使用地下水之安全。台灣西南沿海地區有嚴重砷污染地下水情形，水利署於民國81年至94年間於雲林沿海地區，共設置28口水質監測井，蒐集此區域水質資料作為架構模式之用，在過程中發現本區域雖有長期水質監測資料，惟資料時常發生零星遺漏情形，為解決此問題，本研究以雲林沿海地區為研究範例，架構類神經網路模式推估各水質站內遺漏砷濃度資料，並對沿海地區進行區域砷濃度推估工作。另一方面，由於本區域內水質站之資料不足，造成模式之穩定性不佳，無法建構可靠補遺推估模式，為改善此問題，首先採用交叉驗證以確認模式架構後，並採修正型目標函數搜尋模式中參數，其結果證明此兩種方法可改善模式不穩定性及過度訓練情況，擴大類神經網路之用範圍及應用領域，提供可靠砷濃度空間推估結果，對於了解此區域內砷濃度在時間與空間變化有很大助益，同時依據此結果可減少居民誤引用高濃度砷地下水之危險，達地下水有效管理及利用之目的。
With the great concern for the potential effects of aresenic on human health and the environment, there is a growing need for efficiently determining and modeling the presence and amount of aresenic in the ecohydrogeological systems. In this study,we construct the ANNs model to complete the lost aresenic data according to the relationship of the aresenic concentration of the monitoring wells in the region. The results offer the realization for the aresenic variation and keep the safe from the resident ingesting and usage of the groundwater. Blackfoot disease was once common the southwestern coast of Taiwan, especially in the alluvial fan of Chou-Shui River. In order to monitoring the aresenic concentration, the Water Resource Agency has setup twenty-eight water quality wells which distribute in coasltal area in Yun-Lin county from 1992 to 2005. However, some water quality data were lost or not record because of the man-made amd money factors. The lost data affect the development of the arsenic associate research. Therefore, we choose this region as the example to construct ANNs model to estimate the lost aresenic data.
Due to sparse and lost data, there are not steady and over-fitting problem in the process of constructing the ANNs model. To solve the problems, we first apply cross-validation to assure the architecture of the model amd adopt the modify-objective function to search the optimal weights. It is proven that these two methods can reduce the unsteady and over-fitting problems. The results have been apparently improved the realization of the spatial-temporal distribution of aresenic. Based on the results, the risk of ingesting the high aresenic groundwater can be decreased to reach the goal of efficiently controlling and usage of the groundwater
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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