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The Global ETD Search service is a free service for researchers
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Showing 451 to 456 of 456 (0.117 seconds)Spelling suggestions: "subject:"[een] BENCHMARK"" "subject:"[enn] BENCHMARK""
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自由語文資訊檢索資料庫系統績效評估工作量模式之研究－以傳播學網際網路資料庫為例 / Free-Text Information Retrieval Database System Benchmark Workload Model－Web Communication Databases林佳慧, Lin, Chia-Hui Unknown Date (has links)
資訊檢索(Information Retrieval)一直是資訊學界的重要研究領域，但長久以來並未能在其它的學門中發揮其重要性，然而藉由Internet的普及與網路資源的激增，以資訊檢索為基礎的網路搜尋技術，已逐漸成為Internet上相當受到重視的技術之一。雖然全文資訊檢索的技術已存在多時，然而電腦產業一直缺乏一廣泛標準的績效評估，來評估全文資訊檢索系統的產出及價格/效能比，1990年代對全文資訊檢索軟體的大量需求，極需要一個標準、一致的方法，來比較各系統間效能的差異。本研究即針對傳播中文全文資訊檢索資料庫系統為探討的主題，試圖以關連式資料庫績效評估的理論及方法，來建構其工作量模式以進行績效評估。 / Information Retrieval has been a important research domain in Information academic. But it does not play in the other domain for a long time. However the Internet search technology based on Information Retrieval has been an one of the important technologies in the Internet by the spreading of Internet and the growth of network resources. Although the Full-Text Information Retrieval or Free-Text Information Retrieval technology has existed for a long time, the computer industry was lack of a wide, standard benchmark to evaluate the throughput and price/performance of the Full-Text Information Retrieval System. The large demand for Full-Text Information Retrieval System or Free-Text Information Retrieval System software needs a standard method to compare the performance of each system in 90s. This research is focused on the Communication Free-Text Information Retrieval Database System in Chinese, and construct it’s workload model to evaluate by using the theory and method of Relational Database Benchmark.
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共同基金績效評估－個股特徵之持股比例變動法與四因子評估模型李佳樺, Lee-Chia-Hua Unknown Date (has links)
本研究考慮市場、規模、淨值市價比及前期累積報酬，這四個影響股票報酬的因子，分別以個股特徵之持股比例變動法與四因子評估模型，對共同基金風險調整後的報酬作績效評比，不但可以評估基金的選股能力與擇時能力，並進一步瞭解報酬之風險來源。最後討論這兩種評比方式的適用性，並藉由基準投資組合將市場股票區分成不同的風險類別，根據基金在各類別股票的持有比例，引伸出對基金持股風格的另一種看法。現將本篇研究結果整理如下：
1. 四因子模型對於資產的解釋能力比資本資產評價模型（CAPM）好；並且透過規模、淨值市價比、前期累積報酬之風險溢酬因子，可以瞭解報酬之不同風險來源。
2. 依照個股特徵為基準之持股比例變動法，計算出實際績效、特徵擇時、特徵選股及平均持股型態的績效。結果顯示共同基金多具有正的選股能力，擇時能力，但經過檢定，並沒有顯著的超額報酬。
3. 以四因子評價模型對共同基金績效做評估。結果發現幾乎不具有顯著的超額報酬；兩種方法的評比結果相類似。但是部份基金在規模、與前期累積報酬項有顯著異於零的結果，顯示基金在規模、量能操作上有穩定的績效表現，因此使得檢定的結果顯著。
4. 而以持股類型風格上來看，顯示部份基金會高度持有大型股、以及過去表現良好的股票，持股風險類群明顯而集中，屬於穩健、偏重長期，並配合量能操作的投資策略。
最後根據本文的實證結果，分別對投資人與基金經理人提出建議。而從持股比例計算的過程，對持股風格分析提供一個更簡易明瞭的看法，並將研究中發現的問題，一併列在建議中，提供給後續研究者作為參考。
第一章 緒論…………………………………………1
第二章 文獻回顧……………………………………4
第一節 風險調整因素……………………………4
第二節 四因子評估模型…………………………7
第三節 依個股特徵之持股比例變動法…………9
第三章 研究設計……………………………………13
第一節 研究假說…………………………………13
第二節 研究架構…………………………………14
第三節 研究範圍與期間…………………………16
第四節 變數定義與資料處理……………………18
第四章 實證結果與分析……………………………22
第一節 四因子評估模型…………………………22
第二節 共同基金績效評估………………………27
第三節 基金之持股類型比例……………………36
第五章 結論與建議…………………………………40
第一節 結論………………………………………40
第二節 建議…………………………………………41
參考文獻……………………………………………45
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Hybridization of particle Swarm Optimization with Bat Algorithm for optimal reactive power dispatchAgbugba, Emmanuel Emenike 06 1900 (has links)
This research presents a Hybrid Particle Swarm Optimization with Bat Algorithm (HPSOBA) based
approach to solve Optimal Reactive Power Dispatch (ORPD) problem. The primary objective of
this project is minimization of the active power transmission losses by optimally setting the control
variables within their limits and at the same time making sure that the equality and inequality
constraints are not violated. Particle Swarm Optimization (PSO) and Bat Algorithm (BA)
algorithms which are nature-inspired algorithms have become potential options to solving very
difficult optimization problems like ORPD. Although PSO requires high computational time, it
converges quickly; while BA requires less computational time and has the ability of switching
automatically from exploration to exploitation when the optimality is imminent. This research
integrated the respective advantages of PSO and BA algorithms to form a hybrid tool denoted as
HPSOBA algorithm. HPSOBA combines the fast convergence ability of PSO with the less
computation time ability of BA algorithm to get a better optimal solution by incorporating the BA’s
frequency into the PSO velocity equation in order to control the pace. The HPSOBA, PSO and BA algorithms were implemented using MATLAB programming language and tested on three (3)
benchmark test functions (Griewank, Rastrigin and Schwefel) and on IEEE 30- and 118-bus test
systems to solve for ORPD without DG unit. A modified IEEE 30-bus test system was further used
to validate the proposed hybrid algorithm to solve for optimal placement of DG unit for active
power transmission line loss minimization. By comparison, HPSOBA algorithm results proved to
be superior to those of the PSO and BA methods.
In order to check if there will be a further improvement on the performance of the HPSOBA, the
HPSOBA was further modified by embedding three new modifications to form a modified Hybrid
approach denoted as MHPSOBA. This MHPSOBA was validated using IEEE 30-bus test system to
solve ORPD problem and the results show that the HPSOBA algorithm outperforms the modified
version (MHPSOBA). / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)
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| 454 |
Application of the Stimulus-Driven Theory of Probabilistic Dynamics to the hydrogen issue in level-2 PSA / Application de la Stimulus Driven Theory of Probabilistic Dynamics (SDTPD) au risque hydrogène dans les EPS de niveau 2.Peeters, Agnes 05 October 2007 (has links)
Les Etudes Probabilistes de Sûreté (EPS) de niveau 2 en centrale nucléaire visent à identifier les séquences d’événements pouvant correspondre à la propagation d’un accident d’un endommagement du cœur jusqu’à une perte potentielle de l’intégrité de l’enceinte, et à estimer la fréquence d’apparition des différents scénarios possibles.<p>Ces accidents sévères dépendent non seulement de défaillances matérielles ou d’erreurs humaines, mais également de l’occurrence de phénomènes physiques, tels que des explosions vapeur ou hydrogène. La prise en compte de tels phénomènes dans le cadre booléen des arbres d’événements s’avère difficile, et les méthodologies dynamiques de réalisation des EPS sont censées fournir une manière plus cohérente d’intégrer l’évolution du processus physique dans les changements de configuration discrète de la centrale au long d’un transitoire accidentel.<p>Cette thèse décrit l’application d’une des plus récentes approches dynamiques des EPS – la Théorie de la Dynamique Probabiliste basée sur les Stimuli (SDTPD) – à différents modèles de déflagration d'hydrogène ainsi que les développements qui ont permis cette applications et les diverses améliorations et techniques qui ont été mises en oeuvre.<p><p>Level-2 Probabilistic Safety Analyses (PSA) of nuclear power plants aims to identify the possible sequences of events corresponding to an accident propagation from a core damage to a potential loss of integrity of the containment, and to assess the frequency of occurrence of the different scenarios.<p>These so-called severe accidents depend not only on hardware failures and human errors, but also on the occurrence of physical phenomena such as e.g. steam or hydrogen explosions. Handling these phenomena in the classical Boolean framework of event trees is not convenient, and dynamic methodologies to perform PSA studies are expected to provide a more consistent way of integrating the physical process evolution with the discrete changes of plant configuration along an accidental transient.<p>This PhD Thesis presents the application of one of the most recently proposed dynamic PSA methodologies, i.e. the Stimulus-Driven Theory of Probabilistic Dynamics (SDTPD), to several models of hydrogen explosion in the containment of a plant, as well as the developed methods and improvements.<p> / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished
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The Development of a Three Minute Realtime Sampling Method to Measure Social Harmony during Interactions between Parents and their Toddlers with AutismCunningham, Isabel L. 08 1900 (has links)
Training parents of a child with autism to increase the frequency of their child's social behavior may improve the quality of parent-child interactions. The purpose of this methodological study was to develop a direct observation method for rapidly sampling social harmony between parents and their toddlers with autism during parent training interactions. The current study used a pre and post probe design, with benchmark comparisons to test the discriminability of the measurement protocol across two sets of data. The first set of data came from pre and post training videos from a parent training program for children with a diagnosis of autism or at risk for a diagnosis. The second set of data came from videos of typically developing toddlers and their parents. The results of the study show that the measurement system differentiated in the level of harmonious engagement between the benchmark sample and the sample including children diagnosed with autism. The results are discussed in the context of future directions and the utility of the measurement system for behavior analytic practices in parent training and other settings where rapport and complex interactional behaviors are an intervention priority.
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The Incremental Scheme - From Method Development to Applications in ChemistryFiedler, Benjamin 15 October 2020 (has links)
In this thesis, several development steps for the incremental method are presented. At first, the extension of the incremental scheme to other quantities than the energy is advanced in terms of molecular dipole moments. In this context, a revised error correction as well as the template localization for the treatment of aromatic systems are introduced. As a second enhancement, a new implementation of the template localization ensures a higher stability of this algorithm step and, thus, of the incremental scheme. Finally, pair natural orbitals (PNOs) are utilized in the incremental method with the aim of an increased efficiency. The PNO approach is re-assessed in context of the incremental expansion leading to both small incremental and PNO local errors for reaction, intermolecular interaction and cluster binding energies. The higher efficiency due to the twofold reduction of the computational efforts by the PNO and the incremental approaches is demonstrated for molecular clusters. Additionally, the complete basis set (CBS) limit is targetted by using the efficient MP2-based focal-point approach to the incremental scheme (with and without PNOs).
Finally, based on these improvements of the performance, the PNO-based incremental scheme is applied to support a computational study regarding the modelling of the reaction mechanism for the base-catalyzed twin polymerization.
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