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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Application of HHT to temperature variations at the thermal outlet of Third Nuclear Power Station

Wu, Wei-lih 22 March 2005 (has links)
Nan Wan is a half-closed embayment in the most southern part of Taiwan. While facing the Luzon Strait, it also connects to the Pacific Ocean in its southeast, and is adjacent the Taiwan Strait and the South China Sea . In view of general oceanic circulation, Nan Wan Bay happens to lie to the rim of South China Sea circumfluence and Kuroshio where a variety of water mass exchange has taken place, causing saline intrusion and mixed of water. Seasonal variation and tidal fluctuations also contribute to the exchange of water masses. The Third Nuclear Power Station of Taiwan Power Company is located in Nan Wan with its thermal discharge outlet adjacent to Maobitou to the west of the bay in order to minimize the effect of warm water discharge on the local marine ecology and coral . A long-term monitoring program on water temperature and other environmental factors has been set up implemented .this research report will first describe the archives regarding the hydrology in Nan Wan in support of monitoring the process in temperature variation . Previous research efforts are found somehow unable reveal precisely the physical mechanism leading to water temperature variations in the bay, due to limited facilities, short of information or poor analytical tools. This report adopts 14 records of water temperature at the thermal outlet of the Third Nuclear Power Station for signal analysis. As to non-linear and unstable data analysis, it is based on the Hilbert-Huang Transform. HHT includes Empirical Mode Decomposition, EMD which could decompose the raw data into numerous Intrinsic Mode Function, IMF. It is allowed to comprehend the main causes for the rising and dropping of water temperature based on the variation of spectroscopy by transferring through Hilbert and analyzing via IMF. Furthermore, the characteristic of each quantity could be developed according to the quantities acquired from the former method of HHT. The analytical report of water temperature covers 14 records dating from 1999 to 2003. In light of the analytical report, tide and wind account for the main cause of the temperature variation in waters while demanding information to ensure whether it is influenced by other factors like internal waves, water masses or landforms, etc. In addition, the report compares the difference in the same of data between FFT and HHT and moreover concludes the advantages and disadvantages as reference for researches.
62

none

Wu, Wan-jung 26 July 2008 (has links)
none
63

Rethinking Constitutionalism in Late 19th and Early 20th Century China

Zhao, Hui January 2012 (has links)
In the tenets of Western political science, “limited government” is usually seen as the touchstone of modern constitutionalism. Yet significant issues can arise when one applies this framework to East Asia. By studying the origin of constitutionalism in China and Japan, my dissertation reexamines the idea that “limited government” is the core of modern constitutionalism. I argue that constitutionalism, as it was introduced in Meiji Japan and late Qing China, focused on strengthening the government rather than limiting it. Many might feel this affirms the popular belief in an inherent affinity for authoritarianism in the Chinese mind, but this dissertation disagrees, finding such a conclusion to be unfairly reductive, and dangerous to achieving a true cross-cultural understanding. It argues instead that Chinese constitutionalism’s desire to strengthen the state was not the manifestation of a cultural predisposition toward authoritarianism, but was instead consciously adopted and constructed in response to the chaotic realities of late 19th and early 20th century China. By studying the constitutional thought of Aristotle, Cicero, Machiavelli, Hobbes, the early English constitutionalists, Locke, Montesquieu, the American founding fathers, and others, I shine light on a dilemma that was as critical to late Qing China constitutionalism as it was to Aristotle’s ancient Greece, Machiavelli’s Renaissance Florence, and Lincoln’s splitting 19th century America: to achieve the delicate balance between a strong state and the limiting principles of a Republic. My argument calls for a reevaluation not only of Chinese constitutional thought, but also of current liberal constitutional theory, which tends to define the goal of constitutionalism simply as the limiting of governmental power. My research shows that the essential goal of constitutionalism, whether it takes place in the East or the West, in the present or the past, is not to move closer to one pole of authoritarianism or the other of limited government, but to strike an ideal balance between the two, depending on the specific context of a state’s time and place in history. / East Asian Languages and Civilizations
64

The transition from foraging to farming and the origin of agriculture in China /

Lu, Tracey Lie Dan. January 1999 (has links)
Texte remanié de: Thesis--Australian national university. / Bibliogr. p. 145-158.
65

Experimental investigations of two-phase flow measurement using ultrasonic sensors

Abbagoni, Baba Musa January 2016 (has links)
This thesis presents the investigations conducted in the use of ultrasonic technology to measure two-phase flow in both horizontal and vertical pipe flows which is important for the petroleum industry. However, there are still key challenges to measure parameters of the multiphase flow accurately. Four methods of ultrasonic technologies were explored. The Hilbert-Huang transform (HHT) was first applied to the ultrasound signals of air-water flow on horizontal flow for measurement of the parameters of the two- phase slug flow. The use of the HHT technique is sensitive enough to detect the hydrodynamics of the slug flow. The results of the experiments are compared with correlations in the literature and are in good agreement. Next, experimental data of air-water two-phase flow under slug, elongated bubble, stratified-wavy and stratified flow regimes were used to develop an objective flow regime classification of two-phase flow using the ultrasonic Doppler sensor and artificial neural network (ANN). The classifications using the power spectral density (PSD) and discrete wavelet transform (DWT) features have accuracies of 87% and 95.6% respectively. This is considerably more promising as it uses non-invasive and non-radioactive sensors. Moreover, ultrasonic pulse wave transducers with centre frequencies of 1MHz and 7.5MHz were used to measure two-phase flow both in horizontal and vertical flow pipes. The liquid level measurement was compared with the conductivity probes technique and agreed qualitatively. However, in the vertical with a gas volume fraction (GVF) higher than 20%, the ultrasound signals were attenuated. Furthermore, gas-liquid and oil-water two-phase flow rates in a vertical upward flow were measured using a combination of an ultrasound Doppler sensor and gamma densitometer. The results showed that the flow gas and liquid flow rates measured are within ±10% for low void fraction tests, water-cut measurements are within ±10%, densities within ±5%, and void fractions within ±10%. These findings are good results for a relatively fast flowing multiphase flow.
66

Don't Believe a Word I Say: Metafiction in Contemporary Chinese Literature / Metafiction in Contemporary Chinese Literature

Kaiser, Marjolijn, 1984- 06 1900 (has links)
ix, 106 p. / This thesis focuses on the metafictional elements in selected works of the contemporary Chinese authors Gao Xingjian, Huang Jinshu, and Wang Xiaobo. I define metafiction as both a formal feature inherent in the text and the result of an approach towards that text. I argue that metafiction confronts us with the (postmodern) issues of 1) the ontological status of the text, 2) the figure of the author and reader, and 3) the (ambiguous) relationship between fiction and reality. Simultaneously, it accepts and celebrates this self-conscious and ambiguous character, encouraging readers to do the same. By combining elements from the indigenous literary tradition and international literary movements, contemporary Chinese metafiction is a valuable contribution to the study of metafiction. Ultimately, it shows what it means to write and read in a Chinese as well as in a global context. / Committee in charge: Prof. Alison Groppe, Chairperson; Prof. Maram Epstein, Member; Prof. Xiaoquan Raphael Zhang, Member
67

PART I. COMPREHENSIVE STUDY OF HERBAL MEDICINE FORMULA SHUANG HUANG LIAN BY UNTARGETED PROFILING WITH UHPLC-QTOF-MS AND NETWORK PHARMACOLOGYPART II. DEVELOPMENT OF UHPLC-MS/MS-BASED ASSAY FOR CARDIOLIPIN, A BIOMARKER OF HUMAN DISEASES

Xu, Gang 11 June 2019 (has links)
No description available.
68

Experimental analysis of thermal mixing at reactor conditions

Bergagio, Mattia January 2016 (has links)
High-cycle thermal fatigue arising from turbulent mixing of non-isothermal flows is a key issue associated with the life management and extension of nuclear power plants. The induced thermal loads and damage are not fully understood yet. With the aim of acquiring extensive data sets for the validation of codes modeling thermal mixing at reactor conditions, thermocouples recorded temperature time series at the inner surface of a vertical annular volume where turbulent mixing occurred. There, a stream at either 333 K or 423 K flowed upwards and mixed with two streams at 549 K. Pressure was set at 72E5 Pa. The annular volume was formed between two coaxial stainless-steel tubes. Since the thermocouples could only cover limited areas of the mixing region, the inner tube to which they were soldered was lifted, lowered, and rotated around its axis, to extend the measurement region both axially and azimuthally. Trends, which stemmed from the variation of the experimental boundary conditions over time, were subtracted from the inner-surface temperature time series collected. An estimator assessing intensity and inhomogeneity of the mixing process in the annulus was also computed. In addition, a frequency analysis of the detrended inner-surface temperature time series was performed. In the cases examined, frequencies between 0.03 Hz and 0.10 Hz were detected in the subregion where mixing inhomogeneity peaked. The uncertainty affecting such measurements was then estimated. Furthermore, a preliminary assessment of the radial heat flux at the inner surface was conducted. / <p>QC 20161116</p>
69

Fully coupled 1D model of mobile-bed alluvial hydraulics: application to silt transport in the Lower Yellow River

Huybrechts, Nicolas 10 September 2008 (has links)
The overall objective is to improve the one-dimensional numerical prediction of the fine and non-cohesive bed material load in alluvial rivers, especially during high intensity episodes during which sediment beds are strongly remobilized. For this reason, we attempt to reduce the major inaccuracy sources coming from the alluvial resistance and bed material load relations needed to close the mathematical system. Through a shared parameter called the control factor m, the interactions occurring in alluvial rivers are incorporated more deeply into the mathematical model and more particularly into the closure laws: bed material load (SVRD, Suction-Vortex Resuspension Dynamics) and the energy slope (Verbanck et al. 2007). The control factor m is assumedly related to the Rossiter resonance modes of the separated flow downstream the bed form crest. <p><p>To further improve the representation of the flow-sediment-morphology interactions, a fully coupled model approach has been naturally chosen. In this work the terminology fully coupled means that the three equations forming the system are solved synchronously and that the terms often neglected by more traditional decoupled models are kept. <p><p>The feasibility of the new closure methodology has been drawn up by reproducing numerically the silt-flushing experiment conducted by the Yellow River Conservancy Commission (Y.R.C.C.) in the Lower Yellow River (LYR) in Northern China. The objective of the silt flushing experiment is to reverse the aggradation trend of the Lower Yellow River which, in the last decades, has become a perched river. The numerical simulation specifically reproduces the silt-flush effects in a reach of LYR located in the meandering part of the river. This reach (around 100 km) is delimited by Aishan and Luokou hydrometric stations.<p><p>Since the SVRD formulation has been developed from flume observations, the law has first been confronted to river datasets. The confrontation has revealed that the SVRD law becomes less suitable for fine sediment fluxes (ratio of water depth over median particle size > 5000). Therefore, a modified equation SVRD-2 has been built to enlarge the validity range.<p><p>The suitability of the SVRD-2 equation to predict fine sediment fluxes has been tested on data available from several hydrometric stations located in the meandering reach of the LYR: historical observations and measures collected during the flushes. The SVRD-2 has also been compared with relations specifically calibrated for this configuration. The comparison has pointed out that the performance of the two formulas is similar, which is encouraging for the SVRD-2 approach as it has not been calibrated on those data. <p><p>The closed equation system has been written on its quasi-linear form and is solved by a Finite Volume Method combined with a linearized Riemann algorithm. The numerical model has been checked up on two test cases: deposition upstream of a dam and the aggradation experiment conducted by Soni 1975. <p><p>As it is not yet possible to predict dynamically the value of the control factor m, a possible solution would be to extract its value from the measured data at the inlet cross section. Unfortunately, the necessary data are not measured locally. Moreover, a uniform value of the control factor m may not suffice to reproduce the flow along the whole reach. Therefore, it has been proposed to work temporarily in the reverse way. <p><p>From the comparison between the numerical results and the experimental data, a time evolution of the control factor m has effectively been extracted and it has been shown that it varies along the reach. At Aishan, the evolution of the control factor m corresponds to the evolution expected from the data analysis previously conducted on other data sets: the value of the control factor m decreases during the flush as it tries to reach the optimal value m=1. The time evolution at Luokou behaves differently to the one at Aishan, but remains in agreement with m evolution patterns observed historically for the river section flowing round Jinan City walls. For Luokou, the highlighted differences may come from three dimensional effects coming from the meander bend upstream the station.<p><p>Generally, the results obtained for the hydraulics, the sediment transport and bed adaptation are encouraging but still need improvements and additional feeding from the experimental data. The results for the concentration and therefore the bed elevation are very sensitive to the value of the control factor m as it influences most of the terms of the bed material load equation (SVRD-2). <p><p>The major remaining difficulties are, firstly, to deal with the rapid transients for which the model is less suitable and, secondly, to improve the prediction of the value of control factor m. Before paying more attention into the transients, enhancements concerning the flow along the reach (initial condition and discharge rates during the first days of the flush) must be conducted in priority. Indeed as the prediction of the bed or the cross section evolutions depend directly on the quality of the prediction of the sediment concentration and the hydraulics, one should first improve these aspects. To perform this study, more information about the water levels or sediment concentrations is necessary at some intermediate stations. One solution is to lengthen the studied reach, upstream to Sunkou and downstream to Lijin, totaling a river length of 456 Km.<p><p>A more entire signal of the energy slopes and the associated bed configurations at different stations would enlighten how the control factor m evolves along the reach during the silt-flush events. <p><p> / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished
70

Zur Reduzierung des mehrwegebedingten GNSS-Trägerphasenmessfehlers durch Anwendung der Hilbert-Huang-Transformation auf Signalqualitätsparameter

Hirrle, Angelika 29 May 2017 (has links) (PDF)
Die Positionsbestimmung von Verkehrsteilnehmern basiert häufig auf der Auswertung von Signalen globaler Navigationssatellitensysteme (GNSS). Dabei werden die Laufzeiten der Signale und darauf beruhend die Entfernungen zwischen den Satelliten und dem Verkehrsteilnehmer ermittelt. Die Positionsbestimmung erfolgt dann nach dem Prinzip der Trilateration. Bei hohen Anforderungen an die Genauigkeit der Position wird hierfür insbesondere die Phase des Trägersignals ausgewertet. Eine besondere Herausforderung stellt dabei die Mehrwegeausbreitung der Signale dar. Hervorgerufen wird diese durch Objekte, wie Bäume, Gebäude oder Fahrzeuge in der Umgebung des Verkehrsteilnehmers. Durch die Mehrwegeausbreitung werden die Laufzeiten der Signale und somit die Position fehlerhaft bestimmt. Es ist daher von großer Bedeutung, die mehrwegebedingten Fehleranteile zu detektieren und sie zu reduzieren. In dieser Arbeit wird dafür der Zusammenhang zwischen dem Trägerphasenmessfehler und der Signalqualität genutzt. Durch Anwendung einer im Rahmen dieser Arbeit entwickelten adaptierten Hilbert-Huang-Transformation auf die aus dem Signalqualitätsparameter des Signal-zu-Rauschleistungsdichte-Verhältnis abgeleiteten Signalamplituden können Mehrwegesignale detektiert und der durch sie verursachte Trägerphasenmessfehler berechnet werden. Anhand der Auswertung eines Experimentaldatensatzes sowie Daten von GNSS-Referenzstationen des SAPOS-Netzes kann der Erfolg des Einsatzes der adaptierten Hilbert-Huang-Transformation nachgewiesen werden.

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