Дисертації з теми "The quality factor"
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1
Jacinto, Gutarra Jorge Lorenzo, and Baldeon Luis Ricardo Agüero. "Aplicación de factores de inversión: value, volatility, quality y momentum en la Bolsa de Valores de Lima." Master's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/626323.
Повний текст джерелаАнотація:
En la presente tesis de aplicación de Factores de Inversión: Value, Volatility, Quality y Momentum en la Bolsa de Valores de Lima (BVL), se utilizó como Benchmark el Índice General de la Bolsa de Valores de Lima (IGBVL), conformada por 39 valores, que mediante filtros de liquidez y tiempo de cotización en la Bolsa quedaron 27, por falta de datos se llegó finalmente a 25 valores.
Luego, se definen las variables de cada factor. Para el Factor Value: PER y PBV (Price to Book). Para el Factor Momentum la variable momento de los precios. Para el Factor Quality la variable ROE. Para el Factor Volatility la variable Volatilidad total. Seguidamente, se aplican procedimientos para analizar las variables de los cuatro factores a los datos para escoger aquellos que puedan superar al Benchmark.
Finalmente, se demuestra que en los últimos diez años que el portafolio, con valores que tengan un ratio PER (Variable del Factor Value) inferior al promedio de la Bolsa y actualizando la cartera de manera trimestral, tiene un mejor rendimiento que el Benchmark y el portafolio conformado por empresas con ratio PER superior al promedio de la Bolsa. Los resultados han sido enmarcados en un nivel de confianza al 95%.In this thesis of application of Investment Factors: Value, Volatility, Quality and Momentum in the Lima Stock Exchange (BVL), the General Index of the Lima Stock Exchange (IGBVL) was used as Benchmark, consisting of 39 values, which by means of liquidity filters and time of quotation in the Stock Exchange were 27, due to lack of data, finally 25 values were reached. Then, the variables of each factor are defined. For the Value Factor: PER and the Price to Book. For the Momentum Factor the price momentum variable. For the Quality Factor, the variable ROE. For the Volatility Factor the variable Total Volatility. Next, procedures are applied to analyze the variables of the four factors to the data to choose those that can surpass the Benchmark. Finally, it is shown that in the last ten years that the portfolio, with values that have a PER (Variable Value Factor) ratio lower than the average of the Exchange and updating the portfolio quarterly, has a better performance than the Benchmark and the portfolio made up of companies with a PER ratio higher than the average of the Stock Exchange. The results have been framed at a 95% confidence level.
Trabajo de investigación
2
Kramer, Miriam. "The human factor in Total Quality Management." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50154.
Повний текст джерелаАнотація:
Thesis (MBA)--Stellenbosch University, 2004.The nature of work and its organisation has interest managers, economists and social scientists for as long as people have been employed by others to engage in productive activity. Managers have largely been interested in maximising output from available resources. During the last decade one approach has risen to outstanding popularity in this context: Total Quality Management. Total Quality Management is regarded as an approach which combines the technical and managerial side of management. Whereas the technical side of quality management is very much dependant on statistical control processes, the managerial side is more concerned with the people involved. A main focus point of this research report is the human side of quality management. By conducting an in depth literature review the author found that the human aspect of quality management had a great impact on the successful of quality assurance programmes. In this context the variable of motivation and satisfaction are reviewed in detail. It was discovered that the success of a business is largely dependent upon the ability of leaders to motivate workers to achieve the highest results. All leaders should understand motivation theory so that they can help ensure the success of their workplace. Only by taking into account the human aspects of an organisation and especially in the context of quality management programmes, the success of an organisation in the rapidly changing and extremely demanding times can be assured.
3
Zicarelli, Natasha. "Fluency in interpreting: a native-like quality factor." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10757/.
Повний текст джерелаАнотація:
Lo studio si occupa di fluency e analizza alcuni aspetti che la definiscono (pause vuote, pause piene, segnali discorsivi, riformulazioni).
Si analizzano frequenza e durata di tali fenomeni, attraverso due corpora di produzioni orali di due gruppi di parlanti della lingua inglese: gli studenti italiani del corso di Mediazione Linguistica Interculturale della Scuola di Lingue, Letterature, Interpretazione e Traduzione di Forlì, Università di Bologna, e partecipanti britannici di un programma radiofonico. Si è ritenuto utile comparare le produzioni orali di studenti della lingua inglese a quelle di oratori pubblici madrelingua. Si è cercato di bilanciare i due corpora in termini di genere.
Sono stati utilzzati i software Praat, per identificare la morfologia e la durata delle variabili, e Notetab Light, per l'annotazione dei corpora.
I risultati della ricerca mostrano che le differenze maggiori tra i due gruppi risiedono nella durata delle pause vuote e nella frequenza, durata e e varietà di suoni delle pause piene, oltre a sillabe aggiuntive, sillabe allungate e riformulazioni. Le sillabe aggiuntive appaiono tipiche della produzione orale degli studenti italiani, in quanto, per la maggior parte, le parole della lingua italiana terminano con un suono vocalico. E' inoltre emersa una questione di genere. Le parlanti di sesso femminile, in entrambi i corpora, impiegano maggiormente le variabili della fluency prese in esame, rispetto ai parlanti di sesso maschile.
Sulla base di questa ricerca e ricerche future si potranno ideare moduli di insegnamento dell'inglese basati sulla fluency come fattore primario di competenza linguistica.
Il Capitolo 1 introduce lo studio. Il Capitolo 2 presenta lo stato dell'arte sul tema. Il Capitolo 3 presenta la metodologia dello studio. Il Capitolo 4 è dedicato a illustrare e discutere i risultati della ricerca. Il Capitolo 5 presenta considerazioni conclusive e future prospettive per l'insegnamento dell'inglese e per la ricerca.
4
Fayers, Peter Michael. "Causal variables in quality of life measurement." Thesis, Open University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388438.
Повний текст джерела
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Li, Shyi-Shyang. "Comparing the ability of subjective quality factor and information theory to predict image quality /." Online version of thesis, 1994. http://hdl.handle.net/1850/11880.
Повний текст джерела
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Xiao, Chenyang. "The coherence of public concern for the environment a conceptual and methodological analysis /." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Dissertations/Summer2004/c%5Fxiao%5F072104.pdf.
Повний текст джерела
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Surendra, Kanchana. "Modeling and Design of a Three-dimensional Inductor with Magnetic Core." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/34565.
Повний текст джерелаАнотація:
As the demand for portable electronic devices increase, the need to replace off-chip discrete devices with on-chip devices is imperative. Inductors are one such passive device that is widely used in low noise amplifiers, oscillators, etc. Current on-chip spiral inductors suffer from large parasitics and area for a meager value of inductance and quality factor. The need to overcome these issues has led to the development inductors with new geometries housing magnetic cores that show an enhanced inductance compared to the air core coil.
In this thesis, we discuss the design of a three-dimensional spiral inductor with a Co-Fe nanoparticle core that will be fabricated as per the process rules set by VT MT SPL. The changes in the value of the inductance, resistance, quality factor and parasitics are studied for varying number of turns of the coil, thickness of the coil, spacing between turns and different materials used as the coil. An optimum design incorporating the least parasitics and reasonable inductance is proposed.Master of Science
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Zhang, Hanzhen 1974. "Quality factor enhanced coupled inductor structures and their RF applications." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82647.
Повний текст джерелаАнотація:
This thesis is concerned with one of the key passive components in RFIC design, namely on-chip inductors. Complete design equations, EM simulation and data processing procedures have been established and demonstrated for 0.18um and 0.13um CMOS technologies. Following these procedures, several inductors have been designed and fabricated. A low noise amplifier (LNA) working at 6 GHz has been implemented using the TSMC 0.18 standard CMOS technology, and the prototype chip was successfully tested.As an attempt to build higher performance on-chip inductors, a new quality factor enhanced coupled inductor structure is proposed and discussed. Through intertwining and coupling two inductors, and making use of the positive mutual inductance built up between them, a 56% increase in quality factor has been achieved. Detailed design guidelines and methodologies are presented. Measurement and simulation results of the fabricated prototypes demonstrated the accuracy and effectiveness of the work proposed.
VCO and LNA designs using the coupled structures are presented. Simulation results also demonstrate the performance improvement resulting from using coupled structures, compared to using optimized standard inductors. (Abstract shortened by UMI.)
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Castonguay, Francois. "Increasing the quality factor of microcantilevers in a fluid environment." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96942.
Повний текст джерелаАнотація:
The need to improve the quality factor of Atomic Force Microscopy cantileversimmersed in fluid has been demonstrated in great length, especially in the caseswhere samples need to be in their natural liquid environment. For that reasona series of low pressure chemical vapor deposited silicon nitride cantilevers werecreated based on a series of defined parameters. Each cantilever had a fixed surfacearea of 5600μm2, comparable with the rectangular cantilever of dimension of 140μmby 40μm used as a reference. A procedure to fabricate these levers in a clean roomenvironment, as well as issues that came up during the fabrication, is explained indetail. Each measurement was done on our in-house setup. The main componentsof this apparatus are a focussed laser, a sample holder and a split photodiode. Theresults obtained were not as impressive as we had hope although some cantileversshowed a significant decrease in the quality factor, helping us direct future workon the subject. One cantilever (#9) did however show equivalent performance withrespect to the reference cantilever and even slightly increasing the quality factor ratioin the second mode.Le besoin criant d'augmenter le facteur de qualité de micros-levier immergée dans un fluide utilisé en microscopie de force atomique a été démontré a mainte reprise, plus particulièrement dans le cas ou les échantillons devais être dans leur environnent liquide naturelle. C'est pour cette raison qu'une série de micro-levier ont été crée sur une basse de paramètre prédéfini et avec un dépôt de nitrure de silicium chimique en phase vapeur sous pression réduite. Chaque micros-leviers a une aire de surface de 5600μm2, pouvant ainsi être comparé avec le micro-levier de référence ayant pour dimension 140μm par 40μm. Une procédure pour fabriquer c'est micros-leviers dans un environnent de salle blanche, ainsi que les méthodes utiliser pour contrevenir aux problèmes encourus durant la fabrication, sont expliqués en détail. Chaque prise de mesure a été effectué sur notre appareil fait maison ayant comment composante principale un laser focalisé, un porte échantillon et une photodiode divisée. Les résultats obtenu n'ont pas été a la hauteur de nos attentes, néanmoins certain micros-leviers ont démontrés une réduction significative de leur facteur de qualité, nous aidant donc à diriger le travail futur sur le sujet. Un microlevier (#9), a par contre démontré une performance équivalente par rapport au micro-levier de référence augmentant même le ratio de facteur de qualité pour le 2e mode d'opération.
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Qi, Yazhi. "On the Forecasting Quality of the Combining Forecast Factor Models." Thesis, Uppsala universitet, Statistiska institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-385483.
Повний текст джерела
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Shao, Peng. "Microscale hemispherical shell resonating gyroscopes." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/54266.
Повний текст джерелаАнотація:
MEMS gyroscopes are electromechanical devices that measure rate or angle of rotation. They are one of the fastest growing segments of the microsensor market. Advances in microfabrication technologies have enabled the implementation of chip scale monolithic gyroscopes (MEMS gyroscopes) with very small form factor that are lightweight and consume little power. Over the past decade, significant amount of research have been directed towards the development of high performance and very small size MEMS gyroscopes for applications in consumer electronics such as smart phones. In this dissertation, high aspect-ratio hemispherical shell structure with continuously curved surface is utilized as the high Q resonator. Being an axial symmetric structure, the 3D hemispherical shell is able to achieve low frequency (3 ~ 5 kHz) within 2 mm X 2mm die area. Detailed analysis on energy dissipation also shows its potential to achieve ultra-high quality factor with the selection of high Q material and proper design of support structure. This dissertation presents, for the first time, the analysis, design, fabrication and characterization of a micro-hemispherical resonating gyroscope (μHRG) that has the potential to be used as a whole angle micro-gyroscope. A three-dimensional high aspect-ratio poly- and single crystalline silicon (3D HARPSS) process is developed to fabricate free-standing, stem-supported hemispherical shell with self-aligned deep electrodes for driving, sensing and quadrature control of the gyroscope. This monolithic process consists of seven lithography steps and combines 3D micro-structure with curved surfaces with the HARPSS process to create capacitive electrodes with arbitrary gaps around the micro-hemispherical shell resonator (μHSR). Polysilicon is utilized as the structural material due to its isotropic mechanical properties and the potential of achieving high quality factor. The fabrication is demonstrated successfully by prototypes of polysilicon μHRG with diameter of 1.2 mm and thickness of 700 nm. Frequency response and gyro operation are electronically measured using the integrated electrodes. Quality factor of 8,500 is measured with frequency mismatch of 105 Hz. Electronic mode matching and alignment are successfully performed by applying tuning voltages and quadrature nulling voltages. An open loop rate sensitivity scale factor of 4.42 mV/°/s was measured. Design and process optimization of the support structure improved the quality factor to 40,000. Further improvement of quality factor will enable the demonstration of high performance RIG using polysilicon μHRG.
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Harvey, Malia. "The Quality Factor and Tunability Optimization of a Novel BST Varactor Design." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1596455377781046.
Повний текст джерела
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Xu, Yue. "Modeling and Evaluation of Personal Displacement Ventilation System for Improving Indoor Air Quality." Scholarly Repository, 2007. http://scholarlyrepository.miami.edu/oa_theses/106.
Повний текст джерелаАнотація:
This research aims at evaluating a new ventilation concept: personal displacement ventilation (PDV) for improving indoor air quality. The new ventilation method combines room displacement ventilation with task ventilation, the latter being directed at controlling air quality and comfort in the microenvironment where the building occupant is working, with the premise that such directed ventilation will maintain air quality where it matters. This approach could lead to improved ventilation system design that could even provide individual control of indoor microclimate. The effectiveness of PDV was studied by using computational fluid dynamics (CFD) modeling and rigorous validation experiments. First, a small office setup was built in a controlled environmental chamber. Three PDV cases with different locations of contaminant source and one general displacement ventilation (DV) case were investigated. Spatial distributions of airflow, temperature, and hypothetical pollutant distributions were measured. The measured data were then used to evaluate the performance of PDV against defined indoor air quality and thermal comfort criteria, and to validate the CFD model. The validated CFD program was further used to study PDV under various conditions. This study found that basic equipped PDV acts no different from DV from airflow pattern?s point of view. Due to the lack of heat generation around occupant?s legs, local buoyancy effect is not strong enough to attract supply air, which is generated from diffuser nearby, to join in the plume around occupant. However, auxiliary activities adjusting the direction of supply air and adding high panels around person can improve the fraction of supply air to join the plume around person or decrease the average contaminant concentration in breathing zone.
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Clark, Colin William. "Digital control techniques for power quality improvements in power factor correction applications." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42799.
Повний текст джерелаАнотація:
The prevalence of standards and recommended practices to meet harmonic current limits has gained, and continues to gain, momentum over recent years. To meet these requirements, power electronic rectification devices are necessitated along with their specialized control techniques. A popular power electronic circuit to obtain low-harmonic input current is the boost power factor correction (PFC) converter, and with the advent of digital control, powerful control techniques to meet these harmonic current limits are possible.
The first contribution is a detailed guide to the conversion of an analog IC-controlled boost PFC converter to a digitally controlled equivalent. Design of the voltage and current sensing networks, compensator, overview of the critical interrupt service routines, and the control implementation in a digital signal processor (DSP) is presented. The existing boost PFC converter modified for digital control is successful, and provides a flexible prototyping test bench for further use.
The second contribution is a novel DSP-based discontinuous conduction mode (DCM) detection method for application to the boost PFC converter. The proposed detection method is computationally simple, and requires little or no modification to existing digitally controlled boost PFC converters using DSPs with on-board comparators. An experimental boost PFC converter verifies the effectiveness of the proposed detection method over traditional zero current detection and DCM detection techniques, enabling advanced control techniques for power quality improvements.
The final contribution is a new adaptive mixed conduction mode (MCM) control technique for the boost PFC converter. This MCM control technique applies the proposed DSP-based DCM detection method to realize higher power factor and decreased total harmonic distortion (THD) over a commercially available analog controller and a conventional digital controller. Using a boost PFC converter operating in MCM with the proposed adaptive control method, THD improvements of up to 4.55% at light loads and power factor improvements of up to 17.4% are provided over the analog and conventional digital controller.
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Strauss, Hencharl Johan. "Correlations between the standard and alternative definitions of the beam quality factor." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/16619.
Повний текст джерелаАнотація:
Thesis (MSc)--University of Stellenbosch, 2005.ENGLISH ABSTRACT: The beam quality factor (M2) of a laser is important because it describes both the quality of a laser beam as well as its propagation. Particular applications require that the beam radii (from which the M2 factor is determined) be defined in a specific way. The International Standards Organisation (ISO) recently standardised the theoretically correct, but practically difficult second moment definition of the beam radius. This thesis aims to establish correlations between the second moment definition and other more practical definitions. Chapter 2 presents a systematic introduction of moment theory for general beams. Beam centre and radius definitions as well as beam classification are derived by means of second and mixed moments. In Chapter 3 simple laser beams are modelled by means of a resonator approach. The infinite number of solutions of this model is called Gaussian solutions, which are found to be different for rectangular and cylindrical symmetric resonators. The zero order solution for both symmetries is identified as the ideal solution to which all others can be compared to for quality determinations. Chapter 4 presents different beam scanning devices, beam radius definitions and correlations between these definitions. The theoretical basis for a new correlation theory is also given. Chapter 5 describes programs and computations used to verify existing correlation methods and to calculate correlation factors for a newly proposed theory. Chapter 6 presents the results of the computations for both circular and rectangular symmetric beams. The ISO’s correlation theories are tested first. Newly proposed correlation functions between the second moment and alternative definitions as well as theoretical error graphs are given for various beams. A novel method to correlate several important beam subclasses is also presented. Chapter 7 describes the experimental setup, automation software and post processing techniques that were used to characterise a modified CO2 TEA laser. It is further shown how the theory developed in previous chapters could be applied to the experimental data. Chapter 8 presents the experimental results of the beam characterisation measurements performed on two different beams that emanated from the CO2 TEA laser. Existing and newly developed correlation theories are applied to the experimental data and the corresponding results are compared. In Chapter 9, conclusions and suggestions with respect to the initial aims identified in the first chapter are made. Several suggestions for future work are also made.
AFRIKAANSE OPSOMMING: Die bundel kwalitietsfaktor (M2) is baie belangrik omdat dit beide die kwaliteit en voortplanting van ‘n laser bundel beskryf. Bundel radiusse (waarvan die M2 faktor bepaal word) word verskillend gedefinieer vir spesifike toepassings. Die teoreties korrekte, maar minder praktiese tweede moment definisie is onlangs deur die Internasionale Standaard Organisasie (ISO) gestandariseer. Hierdie tesis se hoofdoel is om die tweede moment definisie en ander meer praktiese definisies te korreleer. Hoofstuk 2 stel die moment teorie van bundels sistematies bekend. Dit word gewys hoe die senter en radius van ‘n bundel deur tweede en gemengde momente gedefinieer kan word. In Hoofstuk 3 word laser bundels gemodeleer deur middel van resonator aanslag. Die oneindige aantal oplossings wat verkry word heet Gaussiese oplossings en is verskillend vir reghoekige en silindriese simmetriese resonators. Dit word gewys dat die ideale bundel, waarmee alle ander bundels vergelyk word, die zero orde oplossing van beide simmetrieë is. Hoofstuk 4 stel verskillende bundel skanderings apparaat, bundel radius definisies en korrelasies tussen die definisies bekend. Die teoretiese basis vir ‘n nuwe korrelasie teorie word ook gegee. Hoofstuk 5 beskryf die rekenaarprogramme en berekeninge wat gebruik word om huidige korrelasie teorie mee te toets asook om nuwes mee te skep. Hooftuk 6 gee die resultate van die berekeninge van die rekenaarprogramme vir beide reghoekig en silindriese simmetrie. Die ISO se korrelasies word eerste getoets voordat nuwe teorieë bekend gestel word. In Hoofstuk 7 word die eksperimentele opstelling, outomisasie sagteware en postprosessering tegnieke gewys wat gebruik was om ‘n aangepaste CO2 TEA laser te karakteriseer. Verder word dit gewys hoe die teorie wat in voorafgaande hoofstukke ontwikkel is op eksperimentele data toegepas kan word. Hoofstuk 8 gee die eksperimentele resultate van die bundel karakterisering van twee verskillende bundels vanaf die CO2 TEA laser. Bestaande en nuwe korrelasie metodes word gebruik om die bundels te korreleer en die resultate van elke metode word dan met mekaar vergelyk. In Hoostuk 9 word afleidings gemaak. Daar word ook voorstelle gemaak vir potensiële toekomstige werk.
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Peters, Joshua 1981. "Design of a high quality factor spiral inductors in RF MCM-D." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32105.
Повний текст джерелаАнотація:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 79-82).
This thesis studies the design and fabrication of spiral inductors for use in Radio Frequency (RF) applications. A design methodology is developed to search an inductor design space efficiently using existing simulation software. The methodology allows designers to specify a desired inductance, total area, and frequency of operation instead of the geometrical parameters required by most design software. An implementation of the methodology that finds devices with optimal quality factor at a given frequency is presented. Several inductor designs are generated using this implementation, and the devices are fabricated in the Draper Laboratory, Inc. Multichip Module-Deposited (MCM-D) process. Simulated characteristics of the devices are verified using experimental measurements, and deviations from predicted performance are discussed.
by Joshua Peters.
M.Eng.
17
Thompson, Ryan Wayne. "Soybean Quality and Market Factor Influence on North Dakota Origin Basis Values." Thesis, North Dakota State University, 2020. https://hdl.handle.net/10365/31850.
Повний текст джерелаАнотація:
In North Dakota, origin soybean basis values place risk on market participants involved with trading the commodity. Researchers study market factors that influence origin basis values in order to better understand basis movements. Quality is an important component of basis values, but soybean quality in the form of crude protein and essential amino acid content may be implicitly reflected in the basis rather than explicitly in the flat price. A panel data set is created comprised of ten years of data ranging from 2009-2018 and across eight North Dakota agricultural statistics districts. This thesis utilizes principal component analysis to identify principal components among essential amino acid variables. Panel regression models using fixed effects are employed to identify the influence soybean quality and other market factors have on origin soybean basis values in North Dakota. Results indicate that essential amino acids and protein implicitly influence North Dakota origin soybean basis values.
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Abdallah, Zeina. "Microwave sources based on high quality factor resonators : modeling, optimization and metrology." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30267/document.
Повний текст джерелаАнотація:
La technologie photonique-RF offre une alternative intéressante à l'approche purement électronique dans différents systèmes micro-ondes pour des applications militaires, spatiales et civiles. Un composant original, l'oscillateur optoélectronique (OEO), permet la génération de signaux RF stables et à haute pureté spectrale. Il est basé sur une liaison photonique micro-onde utilisée comme boucle de rétroaction et comportant soit une fibre longue, soit un résonateur à fort coefficient de qualité. Différentes études ont été menées au cours de cette thèse afin d'optimiser et d'améliorer la performance en termes de stabilité et de bruit de phase pour le cas de l'OEO à résonateur. La caractérisation fine et la modélisation des résonateurs est une première étape de la conception globale du système. La métrologie du résonateur optique est réalisée par une technique originale, dite de spectroscopie RF. Les résultats expérimentaux ont révélé que cette technique permet d'une part d'identifier le régime de couplage du résonateur et d'autre part de déterminer avec une grande précision tous les paramètres d'un dispositif résonant, comme les facteurs de qualité interne et externe ou les facteurs de couplage. Une deuxième étude a été orientée vers l'implémentation d'un modèle non-linéaire fiable du dispositif. Dans un tel modèle, la photodiode rapide nécessitait une description plus précise, dans le but de contrôler la conversion du bruit d'amplitude optique en bruit de phase de l'OEO. Un nouveau modèle non-linéaire d'une photodiode hyperfréquence a été développé sous un logiciel commercial: Agilent ADS. Ce nouveau modèle rend effectivement compte de cette conversion de bruit. Une puissance optique optimale à l'entrée de la photodiode a été déterminée, pour laquelle la contribution de RIN du laser au bruit de phase RF pourrait être négligeable. La performance de l'OEO est affectée par diverses perturbations entrainant un décalage en fréquence entre la fréquence du laser et la fréquence de résonance du résonateur. Il est donc important d'utiliser un système de stabilisation pour contrôler cette différence de fréquence. Des séries d'expériences et de tests ont été menées pour étudier la possibilité, d'une part, de remplacer l'électronique commerciale utilisée auparavant pour le système de verrouillage en fréquence (boucle de Pound-Drever-Hall) par une électronique faible bruit et, d'autre part, d'utiliser un laser à semi-conducteur. Un bilan de ces approches est présentéRF photonics technology offers an attractive alternative to classical electronic approaches in several microwave systems for military, space and civil applications. One specific original architecture dubbed as optoelectronic oscillator (OEO) allows the generation of spectrally pure microwave reference frequencies, when the microwave photonic link is used as a feedback loop. Various studies have been conducted during this thesis on the OEO, especially the one that is based on fiber ring resonators, in order to optimize and improve its phase noise performance and its long-term stability. Precise characterization and modeling of the optical resonator are the first step towards overall system design. The resonator metrology is performed using an original approach, known as RF spectral characterization. The experimental results have demonstrated that this technique is helpful for the identification of the resonator's coupling regime and the accurate determination of the main resonator parameters such as the intrinsic and extrinsic quality factors or the coupling coefficients. A second study was directed toward implementing a reliable nonlinear model of the system. In such a model, the fast photodiode require an accurate description, in order to reduce the conversion of the optical amplitude noise into RF noise. A new nonlinear equivalent circuit model of a fast photodiode has been implemented in a microwave circuit simulator: Agilent ADS. This new model is able to describe the conversion of the laser relative intensity noise (RIN) into microwave phase noise at the photodiode output. An optimal optical power at the photodiode's input has been identified, at which the contribution of the laser RIN in RF phase noise is negligible. When it comes to practical applications, the desired performance of an OEO is threatened by various disturbances that may result in a frequency shift of both the laser frequency and the transmission peak of the resonator, which causes a malfunction of the OEO. Therefore it is desirable to use a stabilization system to control the difference between the laser frequency and the resonator frequency. A series of tests and experiments have been carried out to investigate the possibility, on one hand, to replace the commercial servo controller that was used up until now in the Pound-Drever-Hall loop, with a low noise homemade one and, on the other hand, to use a semiconductor laser to reduce the system size. A detailed review of these approaches is presented
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Remenaric, Hajak Mateja. "Study of ribonucleoprotein particle biogenesis and quality control by a novel technique using bacterial Rho factor as a tool." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2013/document.
Повний текст джерелаАнотація:
Chez les eucaryotes, l’information génétique est transcrite en ARN messager qui subit plusieurs étapes de maturation et évènements d’assemblage avant d’être exporté hors du noyau. Ces modifications du transcrit sont effectuées par de nombreux facteurs protéiques recrutés au transcrit naissant, formant ainsi une particule ribonucléoprotéique (mRNP). La biogenèse du mRNP est étroitement liée avec la transcription et le contrôle qualité afin d’assurer l’efficacité et l’exactitude de la production de mRNPs matures. Des études récentes suggèrent que les membres du complexe THO-Sub2 pourraient être des facteurs cruciaux dans le couplage de la transcription, de la biogénèse du mRNP et de l’export. Dans notre groupe, nous avons mis en oeuvre un essai novateur pour étudier la biogénèse du mRNP et le contrôle qualité, basé sur l’expression du facteur Rho bactérien dans Saccharomyces cerevisiae. Rho interfère avec l’assemblage adéquat du mRNP et génère des transcrits aberrants qui sont dégradés par la machinerie de dégradation nucléaire. Dans cette étude, nous avons utilisé le système expérimental Rho pour mieux comprendre Rrp6 et l’implication de l’exosome dans la dégradation des transcrits liée au contrôle qualité, ainsi que pour mieux caractériser le rôle et la fonction du complexe THO-Sub2 dans le processus de biogénèse du mRNP. Les résultats obtenus révèlent une différence intéressante dans le comportement des membres du complexe THO sous l’action de Rho et dévoilent leur dépendance à la liaison à l’ARN, ce qui n’aurait pas pu être observé avec d’autres techniques expérimentales. Cela confirme le potentiel attendu du système expérimental basé sur Rho dans l’étude des facteurs protéiques impliqués dans la biogénèse et le contrôle qualité du mRNPIn eukaryotes, the genetic information is transcribed into messenger RNA which undergoes various processing and assembly events prior to its export from the nucleus. These transcript modifications are performed by numerous protein factors recruited to the nascent transcript, thus making a messenger ribonucleoprotein particle (mRNP). mRNP biogenesis is tightly interconnected with both transcription and quality control to ensure efficiency and accuracy in production of mature mRNPs. Recent findings suggest that members of THO-Sub2 complex might be crucial factors in coupling transcription, mRNP biogenesis and export. In our group, we have implemented an innovative assay to study mRNP biogenesis and quality control, based on the expression of the bacterial factor Rho in Saccharomyces cerevisiae. Rho interferes with proper mRNP assembly and generates aberrant transcripts degraded by the nuclear degradation machinery. In this study, we use Rho experimental system to expand our findings on Rrp6 and exosome involvement in quality control degradation of transcripts, as well as to better characterize the role and function of THO-Sub2 complex in the process of mRNP biogenesis. Obtained results reveal an interesting difference in behavior of THO complex members upon Rho action and disclose their dependence on binding to the RNA, which could not be observed by other experimental techniques. This substantiates the expected potential of Rho-based experimental system in the study of protein factors involved in mRNP biogenesis and quality control
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Smith, Suzanne J. A. "Evaluating health-related quality of life assessment instruments in severe migraine a confirmatory factor analysis /." Ohio : Ohio University, 2003. http://www.ohiolink.edu/etd/view.cgi?ohiou1082129153.
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Hutcherson, Sarne Makel. "Theoretical and Numerical Studies of the Air Damping of Micro-Resonators in the Non-Continuum Regime." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4871.
Повний текст джерелаАнотація:
Micromechanical resonators are used in a variety of sensing and filtering applications. In these applications, the accurate performance of micro resonators depends on the sensitivity of these devices to a particular resonance frequency. This sensitivity is measured using the quality factor Q, which is the ratio of the total input energy into the device to the energy dissipated within a vibration cycle. A higher quality factor indicates a smaller resonance bandwidth, which makes the micro-resonator more effective in identifying a desired signal. Higher Q values result from reductions in dissipation losses. Dissipation losses occur through damping by the ambient fluid, anchor losses, thermoelastic damping, and other sources. The squeeze-film effect is of particular interest in micro-resonators as the fluid enclosed between the resonating components can provide significant dissipation.
This work covers investigations into the air damping of oscillating micromachined resonators that operate near a fixed wall, which is parallel to the oscillating surface. The main portion of this work focuses on the theoretical and numerical investigation of the air damping of micromachined resonators when the surrounding gas (air) is in the Free-Molecule regime. Errors and limitations of previous theoretical models have been found and corrected. A molecular dynamics simulation code that is suitable to handle a more general class of resonators has been developed. This code has been used to find the quality factor of a microbeam resonator. The results from the code were compared to existing experimental results, and were found to have very good agreement in the free molecular regime. The simulation was then used to investigate the effects of the oscillation mechanics on the energy dissipation and quality factor.
The second part of this work focuses on the region between the bottom surface of a laterally-oscillating disk resonator and the substrate. The compressibility effects of a 1 micron thick film of air on a laterally-oscillating disk resonator were investigated. The pressure perturbation for this case was found to be minimal, which means that the compressibility effects of the fluid film will negligible.
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Klimek, Pawel. "Search for Charginos and Sleptons in ATLAS and Identification of Pile-up with the Tile Calorimeter." Licentiate thesis, Stockholms universitet, Fysikum, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-100026.
Повний текст джерелаАнотація:
The Large Hadron Collider (LHC) located at the European Organization for Nuclear Research (CERN) is the most powerful particle accelerator in the world in terms of collision energy and luminosity. This thesis presents a search for supersymmetric particles in proton-proton collision data recorded by the ATLAS experiment. A search for direct production of chargino and slepton pairs in a final state characterised by the presence of two leptons and missing transverse momentum is presented. This analysis is done using L = 20 fb-1 proton-proton collisions at √s = 8 TeV collected in 2012. No significant excess over background is observed. Exclusion limits at 95% confidence level on chargino, neutralino and slepton production are set. In 2011-12 the LHC was providing collisions every 50 ns. This puts very strong requirements on the energy measurement in presence of energy deposits from different collisions in the same read-out window and in the same calorimeter channel (pile-up). A quality factor computed offline for each collision and for each channel in the ATLAS Tile Calorimeter (TileCal) is studied. It is shown that the quality factor can be used to select channels that need a special treatment to account for large energy deposition from pile-up. Efficient criteria to detect pile-up in TileCal channels are proposed.
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Mehdi, Hadi Abidalsajad-Kamel, and Yin-tsu Lin. "Evaluation of Information Quality in Business Intelligence as a key success factor for using Decision Support System." Thesis, Uppsala universitet, Informationssystem, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-163186.
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Adolfsson, Teodor, and Henrik Domellöf. "Factor Investing on the Swedish Stock Market : A Quantitative Study of a Model Based on Quality and Value." Thesis, Umeå universitet, Företagsekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149715.
Повний текст джерелаАнотація:
Investors and fund managers have, since the start of financial markets, always been on the lookout for new ways of beating the market. However, researchers of the Efficient Market Hypothesis have shown that markets are usually highly efficient, implying that there are few possibilities of earning returns that are higher than the market returns, on a risk adjusted basis. Prevailing theories, such as the Capital Asset Pricing Model, has shown that increased return must stem from taking on higher risk. Though, this model’s explanatory power has been challenged by numerous researchers who propose different factors, other than market risk, which could hold explanatory power when it comes to returns in the stock market. This area of research is called factor investing, and has shown that factors such as momentum, size, and value, all can lead to outperforming the market.This study examines how a model based on two common factors, quality and value, would have performed on the Swedish stock market. The study is based on five portfolios chosen by the quality and value factors, each one held for 5 years, examined over a 25-year time span and uses the capital asset pricing model as a tool to measure whether or not the selected factors outperform the market. The study has taken a quantitative approach to examining the research question, using a positivistic and objectivistic view.The results of the study show evidence that the quality and value factors can lead to significant outperformance relative to the market index. Both total returns and risk adjusted returns were higher than the market index for some of the portfolios created using the quality and value factors. Furthermore, statistical evidence was found of that CAPM not fully explains all returns, and thus, that the returns are in part explained by the quality and value factors. The findings led to the conclusion that the quality and value factors does, in fact, hold explanatory power beyond that of CAPM. Purchasing quality companies at a reasonable price is shown to be a sound investment strategy, and that a portfolio created using the quality and value factors has good chances of outperforming the market index.
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Xu, Hongjiang. "Critical success factors for accounting information systems data quality." University of Southern Queensland, Faculty of Business, 2003. http://eprints.usq.edu.au/archive/00001526/.
Повний текст джерелаАнотація:
Quality information is critical to organisations’ success in today’s highly competitive environment. Accounting information systems (AIS) as a discipline within information systems require high quality data. However, empirical evidence suggests that data quality is problematic in AIS. Therefore, knowledge of critical factors that are important in ensuring data quality in accounting information systems is desirable. A literature review evaluates previous research work in quality management, data quality, and accounting information systems. It was found that there was a gap in the literature about critical success factors for data quality in accounting information systems. Based on this gap in the literature and the findings of the exploratory stage of the research, a preliminary research model for factors influence data quality in AIS was developed. A framework for understanding relationships between stakeholder groups and data quality in accounting information systems was also developed. The major stakeholders are information producers, information custodians, information managers, information users, and internal auditors. Case study and survey methodology were adopted for this research. Case studies in seven Australian organisations were carried out, where four of them were large organisations and the other three are small to medium organisations (SMEs). Each case was examined as a whole to obtain an understanding of the opinions and perspectives of the respondents from each individual organisation as to what are considered to be the important factors in the case. Then, cross-case analysis was used to analyze the similarities and differences of the seven cases, which also include the variations between large organisations and small to medium organisations (SMEs). Furthermore, the variations between five different stakeholder groups were also examined. The results of the seven main case studies suggested 26 factors that may have impact on data quality in AIS. Survey instrument was developed based on the findings from case studies. Two large-scale surveys were sent to selected members of Australian CPA, and Australian Computer Society to further develop and test the research framework. The major findings from the survey are: 1. respondents rated the importance of the factors consistent higher than the actual performance of those factors. 2. There was only one factor, ‘audit and reviews’, that was found to be different between different sized organisations. 3. Four factors were found to be significantly different between different stakeholder groups: user focus, measurement and reporting, data supplier quality management and audit and reviews. 4. The top three critical factors for ensuring data quality in AIS were: top management commitment, education and training, and the nature of the accounting information systems. The key contribution of this thesis is the theoretical framework developed from the analysis of the findings of this research, which is the first such framework built upon empirical study that explored factors influencing data quality in AIS and their interrelationships with stakeholder groups and data quality outcomes. That is, it is now clear which factors impact on data quality in AIS, and which of those factors are critical success factors for ensuring high quality information outcomes. In addition, the performance level of factors was also incorporated into the research framework. Since the actual performance of factors has not been highlighted in other studies, this research adds new theoretical insights to the extant literature. In turn, this research confirms some of the factors mentioned in the literature and adds a few new factors. Moreover, stakeholder groups of data quality in AIS are important considerations and need more attention. The research framework of this research shows the relationship between stakeholder groups, important factors and data quality outcomes by highlighting stakeholder groups’ influence on identifying the important factors, as well as the evaluation of the importance and p erformance of the factors.
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Bochkova, Elena. "Concepts avancés de métamatériaux pour l'électromagnétisme et la photonique." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS441/document.
Повний текст джерелаАнотація:
Les méta-surfaces permettent de contrôler efficacement es rayonnements électromagnétiques en manipulant la phase, l'amplitude et la polarisation des ondes. Pour de nombreuses applications, telles que des fonctions d’agilité, de commutations et de détection, des surfaces de haute performance sont nécessaires. L’objectif de cette thèse est d'explorer des méthodes innovantes permettant d'améliorer les facteurs de qualité des méta-surfaces dans les domaines micro-ondes et optique. La limitation des méta-surfaces est généralement liée aux pertes par rayonnement et à l'absorption non radiative. L'étude se concentre sur des solutions permettant la suppression des pertes de rayonnement en utilisant des concepts de mode sombre et de résonance de Fano. Un mécanisme d'excitation direct de mode sombre dans un résonateur individuel basé sur l’adaptation de symétrie est proposé. La possibilité d'améliorer l'efficacité de la réponse magnétique en optique est présentée. L'analyse de l'excitation par résonance de Fano dans un système de résonateurs couplés identiques est également réalisée sur la base du formalisme de la théorie des modes couplés. Deux configurations générales correspondant à l'arrangement spatial symétrique et énantiomères des résonateurs sont considérées. Dans le premier cas, le système de cavité formé par les méta-surfaces très proches fournit des caractéristiques spectrales très étroites et une sensibilité efficace élevée par rapport aux cavités Fabry-Perot conventionnelles. Dans le second cas, les caractéristiques de conception permettent de contrôler la suppression des pertes de rayonnement, permettant d'augmenter considérablement le facteur de qualité de la résonance de FanoMetasurfaces allows an effective control of electromagnetic radiation by manipulating phase, amplitude and polarization of electromagnetic waves. For numerous applications including tunable, switchable and sensing functionalities, high performance metasurfaces are required. The goal of this thesis is to explore innovative methods enabling to improve the quality factors of metasurfaces in microwave and optical domains. The limitation of metasurfaces is generally related to radiation losses and non-radiative absorption. The study is focused on solutions allowing the suppression of radiative losses by using concepts of dark mode and Fano resonance. A direct dark mode excitation mechanism in individual resonator based on symmetry matching is proposed. The possibility to enhance magnetic response efficiency in optical frequency range is presented. Analysis of Fano resonance excitation in a system of identical coupled resonators is also performed on the basis of coupled mode theory formalism. Two general configurations are considered corresponding to symmetric and enantiomeric space arrangement of resonators. In the first case, cavity system formed by near-field coupled metasurfaces provides sharp spectral characteristics and high efficient sensitivity compared to conventional Fabry-Perot cavities. In the second case the design features enables to control suppression of radiation losses, allowing to considerably increase Fano resonance quality factor
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Villa, Margarita Maria. "Tailoring the Geometry of Micron Scale Resonators to Overcome Viscous Damping." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32333.
Повний текст джерелаАнотація:
Improving the quality factor of the mechanical oscillations of micron scale beams in a viscous fluid, such as water, is an open challenge of direct relevance to the development of future technologies. We study the stochastic dynamics of doubly-clamped micron scale beams in a viscous fluid driven by Brownian motion. We use a thermodynamic approach to compute the equilibrium fluctuations in beam displacement that requires only deterministic calculations. From calculations of the autocorrelations and noise spectra we quantify the beam dynamics by the quality factor and resonant frequency of the fundamental flexural mode over a range of experimentally accessible geometries. We carefully study the effects of the grid resolution, domain size, linear response, and time-step for the numerical simulations. We consider beams with uniform rectangular cross-section and explore the increased quality factor and resonant frequency as a baseline geometry is varied by increasing the width, increasing the thickness, and decreasing the length. The quality factor is nearly doubled by tripling either the width or the height of the beam. Much larger improvements are found by decreasing the beam length, however this is limited by the appearance of additional modes of dissipation. Overall, the stochastic dynamics of the wider and thicker beams are well predicted by a two-dimensional approximate theory beyond what may be expected based upon the underlying assumptions, whereas the shorter beams require a more detailed analysis.Master of Science
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Smith, Suzanne. "Evaluating health-related quality of life assessment instruments in severe migraine: A confirmatory factor analysis." Ohio University / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1082129153.
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Becnel, Audrey R. "Land Use and Water Quality Correlations in Miami-Dade, Florida." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1549.
Повний текст джерелаАнотація:
South Florida continues to become increasingly developed and urbanized. My exploratory study examines connections between land use and water quality. The main objectives of the project were to develop an understanding of how land use has affected water quality in Miami-Dade canals, and an economic optimization model to estimate the costs of best management practices necessary to improve water quality. Results indicate Miami-Dade County land use and water quality are correlated. Through statistical factor and cluster analysis, it is apparent that agricultural areas are associated with higher concentrations of nitrogen, while urban areas commonly have higher levels of phosphorous than agricultural areas.
The economic optimization model shows that urban areas can improve water quality by lowering fertilizer inputs. Agricultural areas can also implement methods to improve water quality although it may be more expensive than urban areas. It is important to keep solutions in mind when looking towards future water quality improvements in South Florida.
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Dhurup, Manilall. "Consumer perceptions of supermarket service quality : scale development, measurement and validation / Manilall Dhurup." Thesis, North-West University, 2003. http://hdl.handle.net/10394/2414.
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31
Vennström, Fredrika. "Architecture, Home & Daylight, -The openings affection on the quality of a space." Thesis, KTH, Ljusdesign, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-241477.
Повний текст джерелаАнотація:
This thesis investigates how the opening in the envelope of a typical Swedish commercial residential project could be treated differently from today. Instead of using the openings only to create a unique facade or to reach a certain daylight factor I try to find out how the openings could be treated in a manner affecting the perception of the interior space. Conscious use of qualities related to the opening, such as daylight and view has been used as a design tool. This project is not to be seen as a traditional design project but as an investigation about daylight and openings in commercial residential architecture in Sweden today. Also the project is looking into the industry’s relation to the subject of daylight.
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Abbatemarco, Carla. "Heating behavior and quality factor retention in canned foods as influenced by thermal processing in a rotary autoclave." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69673.
Повний текст джерелаАнотація:
Heat penetration data were obtained for a canned food model (gelatinized waxy maize starch) during processing in an agitating retort under various conditions to evaluate the effect of process variables on the heat penetration parameters (f$ sb{ rm h}$ and j$ sb{ rm ch}$) and resulting process lethality (F$ sb{ rm o}$) and cook value (C$ sb{ rm o}$). Overall heat transfer coefficient (U$ sb{ rm o}$), Hunter L, a and b values were determined. The study indicated that f$ sb{ rm h}$, j$ sb{ rm ch}$, F$ sb{ rm o}$, C$ sb{ rm o}$ and U$ sb{ rm o}$ were influenced (p $<$ 0.05) by all process variables except can headspace. Retention percentage of thiamin, ascorbic acid and chlorophyll at each process condition was estimated using the heat penetration data and documented D and z values for each quality factor. Results confirm better retention of quality factors at higher temperatures and higher rotation speeds.Rheological changes associated with the starch were evaluated in relation to different factors and were well described by the Power law model. Apparent viscosity of the processed product was related to the cook value of the process.
Fresh vegetables were canned and subjected to end-over-end rotation. Heating times were adjusted to give approximately the same process lethality (F$ sb{ rm o}$ = 10 minutes). Processing under higher temperatures and higher rotation speeds resulted in better retention (p $<$ 0.01) of vegetable texture, while only temperature (higher the better) had a desirable effect on color.
Buffered aqueous mixtures of ascorbic acid and thiamin were sealed in glass vials and cans. At each temperature, rotation speed did not have a significant effect on the retention of either vitamin. Processing at 110$ sp circ$C yielded significantly lower retention (p $<$ 0.01) of both vitamins than at 120$ sp circ$C and 130$ sp circ$C. Estimated ascorbic acid and thiamin retention using experimental time-temperature data and published kinetic parameters showed fairly good agreement with experimental data.
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Hung, Tak-fung Anchor. "A community study on the factor associated with quality of life of people with epilepsy in Hong Kong." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40687454.
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Stephens, Melissa Ketring Scott A. "Marital adjustment as a mediating factor between symptom distress and therapeutic alliance in couples therapy." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/STEPHENS_MELISSA_44.pdf.
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PINTO, REGIANE de S. "Laser de Nd:YAG de alta potência, estabilidade e qualidade de feixe." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11798.
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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2014-11-10T11:16:04Z
No. of bitstreams: 0Made available in DSpace on 2014-11-10T11:16:04Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Lin, Jyun-Han, and 林均翰. "Factor Investing: Can Quality Factor Outperform the Taiwan Stock Market?" Thesis, 2018. http://ndltd.ncl.edu.tw/handle/yvmb6t.
Повний текст джерелаАнотація:
碩士國立中興大學
財務金融學系所
106
This study is based on the research by Asness, Frazzini, and Pedersen(2014), who define quality which includes profitability, growth, safety and payout as characteristics that investors should be willing to pay a higher price for. Therefore, we take the factors they create and adding Sharpe ratio to construct portfolio to apply in the Taiwan stock market. We take the stock of companies which have once existed in 1997 to 2017 in the Taiwan stock market as examples. The empirical result shows that the four main factors and quality factor can outperform the Taiwan stock market no matter what performance measure index which includes Sharpe ratio, Sortino ratio and Jensen’s alpha we take. In addition, we also find that with the increase in assets, the return and volatility of portfolio are both decreasing. The positive correlation reflects that there is a trade-off between return and risk. However, some portfolios we construct show that the Sharpe ratio and the number of stocks are both increasing in the same time. It means that the portfolio’s decreasing level of return is smaller than the portfolio’s decreasing level of volatility, which shows that we do not have to pay higher cost for diversification.
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Campagner, Michele. "Quality dimension in equity factor investing." Master's thesis, 2021. http://hdl.handle.net/10362/133438.
Повний текст джерелаАнотація:
This paper investigates and define the Quality dimension in Equity Factor Investing, as it lacks a common definition within the economic literature. Several accounting-based factors are studied in different geographical areas, such as Accruals, Profitability, Leverage, Pay-out, Growth, and Investment. The text aims to study and recognize which of these factors lead to the true composition of the Quality dimension through a portfolio (Long/Short) implementation. In addition, the thesis recreates a systematic investment strategy that aims to optimize the Sharpe ratio of the Quality portfolio, to enhance the performance, and integration, of the Factors in a true portfolio scenario.
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Sung, Hui-Ching, and 宋惠卿. "Quality-Factor Improvment Designs for Spiral Inductors." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/37376433106176642331.
Повний текст джерелаАнотація:
碩士華梵大學
電子工程學系碩士班
95
Among the wireless communication circuits, the spiral inductor is play an important elements in radio frequency integrated circuits (RFICs). Improvement of the quality factor (Q-factor) of inductors is important issue. Since the Q-factor is the main determine that the loss of the metal strip and substrate, much research has been devoted to improve the Q-factor by reducing the metal or substrate loss. In this work, by reducing the metal loss improved the Q-factor.We will make use of an analytical formula is developed to efficiently determine the line width in the variable line-width inductor design. the formula can characterized by an equivalent series resistance Rs, an analytical formula expression of the series resistance for a spiral inductor is first derived. Nevertheless, Rs can be decomposed into the ohmic resistance Rohm and the eddy-current resistance Reddy. By minimizing Rs, an analytical formula for determining the proper line width (Wopt) of the n-th coil is then formulated. One method approach is the variable line width layout design. this technique modifies a conventional spiral inductor with fixed line width that is decreasing from the outer to the inner turns. By narrowing the width of the inner coils, can be alleviated the loss due to induced current by the time-varying magnetic flux passing through the metal lines in the inner coils. Although this technique is effective and can be easily implemented Q-factor by original technologies, it is generally difficult to find the proper line width of each metal coil. With the obtained analytical formula, the variable line width design can be a very efficient and user-friendly method for improving the inductor performance. We have been make use of several spiral inductors tested,by EM numerical and measurement shows that the conspicuous can improve Q-factor .
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Lin, ChingYi, and 林靜怡. "Service Quality Factor for Mobile Banking System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/94383784735228590956.
Повний текст джерелаАнотація:
碩士國立宜蘭大學
應用經濟與管理學系經營管理碩士班
100
In recent years, due to the increasing popularity of mobile phones users, the quality of mobile trading services has been attracting increasing attention. By referring to the four dimensions of E-S-QUAL (E-core service quality) developed by Parasuraman et al. (2005) as well as relevant literature, this study summarizes 13 service quality contents that affect M-banking trading and design the formal ANP questionnaire. A total of 10 academic and industrial experts with more than 10 years of experience were invited to fill in the questionnaire. The data were analyzed using the Analytic Network Process (ANP) to calculate weights and build the entire model. This study found that the top three factors (in order) are: (1) M-banking trading should be able to execute designated transactions and ensure the accuracy of the transmitted information; (2) the M-banking transaction process should be secure and safe; (3) M-banking should protect the personal data and transaction information of all users. User confidence in and intention for the future use of M-banking transaction systems can be improved by enhancing the service quality of these three factors. M-banking operators should concentrate on improving their service quality by following the principles of having sound business operations and appropriately updating their systems and services, in order to increase the number of M-banking business items and create M-banking transaction platforms that users can trust.
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Lin, Yu-Hsien, and 林育賢. "Exceptional Quality Factor in Single-Walled Carbon Nanotubes." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/23596488600995136562.
Повний текст джерелаАнотація:
碩士國立清華大學
材料科學工程學系
94
In this work, we discover that single-walled carbon nanotubes (SWNTs) exhibit exceptionally high quality factor in ac circuit. We find that SWNTs not only play the role as a dielectric material to contribute the capacitance to an ac circuit, but also contribute the inductance to the circuit due to the helical current arisen in itself. For the contribution of SWNTs, the circuit performs extra high quality factor compared to traditional material. In the end of this chapter, we will discuss the electrical behavior and the main mechanism of SWNTs in a RLC circuit. In addition, we illuminate the SWNTs device by laser in order to find the relationship between the photocurrent and the electrical characteristics. When the device illuminate by laser, the resistance decreases and the quality factor increase as well. In addition to the quality factor, the resonant frequency is also changed after illuminating.
41
Cai, Dong-Po, and 蔡東坡. "Pulley-Type Microring Resonator with High Quality Factor." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/58574007607735030658.
Повний текст джерелаАнотація:
博士國立中央大學
光電科學與工程學系
103
In this thesis, the microring resonators have been studied to propose the guidelines to design the high Q-factor microring resonators. First, by wrapping the curved waveguide around the microring to form the pulley coupler, the bending loss can be effectively decreased. The longer interaction length of coupling region such as the concentrically curved waveguides is helpful to decrease the radiation loss of microring to improve the Q-factor of resonator. Second, the large difference of propagation constant between the microring and the bus waveguide can maintain the propagating light in the microring. Third, the critical coupling can be optimized by adjusting the bus waveguide width to increase the Q-factor. The reasons mentioned above and the obtained results by comparing the performance of the different type ring resonators show that the pulley-type microring can provide higher Q-factor. Besides, in order to define the coupling length of the pulley coupler, the conformal transformation method based on Helmholtz equation is employed to estimate the coupling length of the concentrically curved waveguides. The coupling length obtained by the method proposed in this thesis has a good agreement with the finite-difference time-domain method. For demonstrating the performance of the designed high Q microring resonator, the pulley-microring resonator and the grating coupler are fabricated on the silicon-on-insulator substrate by using the E-beam lithography and the reactive-ion etching. The grating coupler is adopted to guide the light into the pulley-type microring resonator. The Q-factor can be obtained as high as 173000. In the literature, the microring resonator with the radius of 20 um constructed by the pulley coupler, such that pulley-type microring resonator can provide the high Q-factor from 20000 to 600000 by using the reflow process or covering the cladding layer. However, the radius of microring resonator is too long. In this thesis, the pulley-type microring resonator with high Q-factor of 173000 and with the smaller radius of 4.43 um is proposed and demonstrated. The high Q-factor pulley-type microring resonator is obtained by adjusting the bus waveguide width. This indicates that the pulley-type microring resonator is suitable for the miniaturization of the optical integrated circuit.
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Liu, Shu-Hui, and 劉淑蕙. "Study on Preparation and Factor of Quality of Pancake." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/19189498920286371676.
Повний текст джерелаАнотація:
碩士國立中興大學
食品科學系
93
Pancake is one of the favorite and popular desserts in Taiwan. It is made up of wheat flour, leavening agent, powder of sugar and water , use the protein of wheat and leavening agent to emerge the good cereal baking product in the appearance, quality and sensory overall acceptability. This study was to research into the effect of different ingredient and baking conditions (Beating temperature and time) on the qualities. On the other hand, response surface methodology experiment design was used to determine optimum produce conditions for preparation of pancake. The results were as follows. The protein, hardness and elasticity and Hunter L value of wheat flour was increased, and the moisture content a value and b value decrease. A kind of the leaven agent and ratio was different; the factor of the volume, color, hardness and elasticity affected the quality in the pancake. Using the single leaven agent, the ammonium bicarbonate made the large volume, loose and soft. The sodium bicarbonate caused the Hunter L value and the sensory overall acceptability was lower than others; mixed the acidity agent counteracted to over alkalinity, let the product was near the commerce leaven agent in the sensory evaluation parameter. The baking conditions were important factors that would influence the pancake. With the baking temperature and time increased, the vent number, volume, hardness and elasticity. The high temperature and long time treatment might cause the water and gas run off and it might cause the observation and texture like the sponge. With baking times increased, Hunter L value descended and both of a value and b value increased. Response surface methodology experiment design was used to determine optimum produce conditions for preparation of pancake in this study. The results of this part showed that the optimum produce conditions of pancake were water addation 110-120 %, baking temperature 200℃and baking time 140 sec.
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Tu, Chin-hao, and 塗謹豪. "Development of a High Quality-factor Micro Spiral Inductor." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/41563035899587585640.
Повний текст джерелаАнотація:
碩士國立中山大學
電機工程學系研究所
103
In order to reduce the power consumption of portable electronic devices, this thesis aims to develop a high quality-factor micro spiral inductor for DC-DC converter applications. According to the published literatures, the quality-factor of conventional spiral inductor is only about 2~4.5 as it operated at low frequency (e.g. 100 kHz~1 MHz). Such low quality-factor will result in high power consumption. In this research, the influence of five geometric parameters of the proposed micro spiral inductor on the quality-factor are investigated and a high quality-factor (Q&;gt;6) can be achieved utilizing ANSYS Maxwell commercial simulation software and micro-electro-mechanical systems (MEMS) technology. The simulated inductance and resistance of the proposed micro spiral inductor are increased and decreased respectively as the diameter and thickness are increased, therefore, the quality-factor can be effectively increased. Besides of the diameter and thickness parameters, the influence of the coil width, coil space and number of turns on the quality-factor of the proposed micro spiral inductor also will be discussed. A maximum simulated quality-factor (Q=6.92) can be obtained in this work as the five geometric parameters are optimized. After three thin-film deposition and one photolithography fabrication processes, fifteen micro spiral inductors with different geometry designs are implemented and characterized. In this thesis, a high quality-factor (Q=6.07) measured at 1 MHz can be demonstrated as the presented micro spiral inductor with 5000 μm-diameter, 74.45 μm-thickness, 60 μm-coil width, 10 μm-coil space and 15-coil turns. All of the simulated and measured results are match very well with the theoretical prediction.
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Chen, Shaio-Mei, and 陳曉玫. "The Discussion of Consumption Factor Service Quality and Price Factor: An Example of Hairdressing Business." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/g2df5h.
Повний текст джерелаАнотація:
碩士南華大學
企業管理學系管理科學碩博士班
103
As a result of large chain hair salons’ rapid expansion and medium-sized hair salons’ transformation towards providing diverse services, the survival and development of Taiwan’s small-sized hair salons in the future is to encounter tons of challenges. Due to their small business scale, small hair salons are short of information about the latest trends and have less perfect quality of services and image. However, in sync with the aesthetic culture which is taking root, the hair salon market in Taiwan is bristling with fashionable hair salons with diverse styles or the second expertise and knowhow. For contemporary customers, a trip to a hair salon is more than getting the hair washed, trimmed or permed. Enjoying a hair salon’s quality of service and atmosphere is also a very important element for customers’ spending decisions. Strictly speaking, a hair salon’s quality of service and atmosphere which are cultivated by the hair salon’s managers are also important elements which affect customers’ spending decisions. With research problems which expend from the three aspects including elements which affect hair salon customers spending decisions, quality of services, and service charges, this study employed literature review and the questionnaire survey method, chose customers of hair salons in Northern Taiwan and Central Taiwan as objects of study, handed out a total of 350 questionnaire copies, collected 325 out of the 350 distributed questionnaire copies, made a 94% questionnaire return rate, and used SPSS and IPA as instruments to perform statistical analysis and analyze sample data’s reliability.
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Bauer, Andrew M. "Internal Control Quality as an Explanatory Factor of Tax Avoidance." Thesis, 2011. http://hdl.handle.net/10012/6359.
Повний текст джерелаАнотація:
Internal control disclosures mandated by section 404 of the Sarbanes-Oxley Act (SOX) are designed to provide information about a firm’s financial reporting quality and in doing so may offer information on firm-specific tax planning activities. Internal control weaknesses disclosed under SOX are frequently related to a firm’s tax function (Ge and McVay, 2005; Gleason, Pincus and Rego, 2010) and thus raise the question of whether or not these frequent problems affect corporate tax avoidance.
In this thesis, I test hypotheses that tax-related disclosures, particularly those that contain company-level internal control weaknesses (ICWs), provide information with respect to long-run tax avoidance. Furthermore, I test hypotheses that the combination of internal control quality and aggressive tax avoidance aid in assessing shareholder returns. To conduct these tests, I collect and construct firm-level SOX disclosure data from 2004 to 2006 across 1,286 publicly-owned corporations. I begin with an empirical analysis of the association between tax avoidance and firm-level ICWs and generally find that the presence of tax ICWs and company-level tax ICWs constrain long-run tax avoidance. For firms with low cash constraints however, company-level tax ICWs appear to lead to an increase in tax avoidance. Nevertheless, subsequent analysis of monthly abnormal returns implies that the stock market reacts negatively to the disclosure of company-level tax ICWs, regardless of whether or not tax aggressiveness is also present.
This thesis contributes to the literature by documenting the first evidence that internal control disclosures provide information regarding firm-level tax planning. Although the number of internal control weakness disclosures is decreasing over time, the availability of these SOX disclosures represents a previously unavailable opportunity to examine and further understand internal governance mechanisms within the firm and their influence on tax planning. In addition, this thesis further corroborates prior literature that argues for the importance of the pervasiveness of internal control weaknesses by showing that the pervasive, company-level tax internal control weaknesses are associated with tax avoidance and lower shareholder returns.
Finally, my dissertation implies that the presence of tax internal control weaknesses constrains tax avoidance and thus a focus on improving internal controls could help improve the tax planning function. However, my firm-level analysis also implies that effective tax planning is a sustainable process and thus a firm and its stakeholders may require several periods before the full benefits of these improvements are realized.
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Chih, Yeh-Chien, and 葉建志. "The Study of Diversified Calibration Factor for PET Image Quality." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/61409902327467414006.
Повний текст джерелаАнотація:
碩士義守大學
電子工程學系碩士班
98
The accuracy of PET (Positron Emission Tomography) affects the disease diagnosis。 This research is to focus on PET physics difference analysis and find out the possible influence factor to PET imaging quality in order to increase imaging reliability and establish an evaluation form、research data and method. At first, using calibration source and Phantom to establish experiment group data。 Second, using PET to gain image analysis。 Third, using Xeleris to collect data。 Forth, using statistic analysis software ( Minitab、Matlab and EXCEL) to verify data. The result shown: 1. when used Ge68 standard source at different collimator position for 15 times, we acquired PMT Energy Peak 144.83±0.71、RMS Peak error 0.736﹤2 which matched to system regulation。 2. after calibration procedure was completed, selected high count rate and smooth waveform from Collimator Position 10(P10) then received WCC Factor as well as SUVbw as group analysis by using Regression, and it shown propotional linear Relationship。 3. the correlation analysis of calibration factor influence the imaging quality。 We put 15 group of recombination Flood Phantom out of same activity (30MBq) of WCC Factor group and analyze Flood Phantom signal-to-noise (SNR) by using Matlab software then receive highest SNR 47.873 from Collimator Position 10th imaging。 4. The influence evaluation of WCC factor to clinical human body imaging。 Using statistical method (T-test) to calculate the distribution tolerance of SUVbw and setting up clinical image of SUVbw 0.63523 as expected value. The result shown: Firstly,no obvious and direct influence from single photon to image quality；Secondly, On the procedure of 2D Normalization Correction at PET, we found obviously difference between bed and bed imaging overlap, Non-Normalization group has less 35% SNR. We examined the difference from Flood Phantom imagingm, the SUVbw value differ only 0.02, thus there’s no difference on image identification ; Thirdly, on the procedure of Calibrate the Collimator , we examined on 15 Collimator Position by using Matlab software, we obtain optimum uniformity of Flood Phantom from Collimator Position 10th (P10)。 Fourthly, WCC experiment procedure proved that the WCC will be influenced by collimator position, data from P10 are the most stable one, it won’t affect SUVbw reading. If we compare two group data from same WCC Dose (before and after calibration) by using Regression and analyze the difference between SUVbw and WCC factor, it shown that new calibration factor revised PET system error。 To conclude above calibration processes, we learn that the major influence to the PET imaging quality will be Collimator Position. When collimator position was at optimum position of receiving photon energy, it will be the opposite position of BGO photon receiver (for which we call crystal central) and also has the optimum optical sensitivity. When BGO photon receiver working at its highest value and highest efficiency, the variation of FDG calibration activity to WCC factor will be at smallest influence level, therefore, the correct Collimator Position is able to revise image artifact efficiently and also reduce SNR.
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Lin, Jia-yi, and 林佳儀. "An on-chip spiral inductor design with enhanced quality factor." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/34646163993582943142.
Повний текст джерелаАнотація:
碩士國立高雄第一科技大學
電子工程研究所
100
In the recent years, the needs of low-cost, low power consumption and the high density integrated circuit of wireless communication rapidly grow. The development of RFIC (radio frequency integrated circuits, RFICs) required for passive components and circuits have become considerable important to research topics. In those passive components required for RF1Cs, chip spiral inductors (on-chip spiral inductors) are more complex, due to its electrical characteristic performance, than other passive components (such as chip capacitors, resistors). Therefore, the design of the chip inductors is usually difficult. Currently, there are a few popular research topics of chip inductors, the development of miniaturization inductance circuit design, high accuracy and scalable equivalent broadband inductor circuit model, and inductor quality factor (quality factor, Q-factor) improvement. Because of the current spiral inductor quality factor is not good enough, particular the silicon substrate chip type, it causes the trouble designing application circuit (such as an amplifier or oscillator circuit). Therefore, improving the inductor quality factor may be one of the most concern issues in the current chip inductor design. In this thesis, the use of inductor test key successfully verifies that the new layout improves the inductor quality factor. This new design deliberately applies grooving design in the inner traditional spiral metal coil to reduce the resistance of metal line and level up the inductor performance. In addition, the inductor geometry chooses square and round shape. Square inductor measuring result proves that the improved inductor design in this study significantly raises the inductor quality factor, while not affecting the sense of the value of performance. The quality factors of square tradition and carved inductor trough in the 1.8GHz were 4.376 and 5.920, through in 2.4GHz were 5.236 and 6.767, respectively. The percentages of improvement were 35.28% and 29.24% respectively. The circular tradition inductor provides better symmetry, so there is less parasitic resistance, and higher quality factor compared with the inductance of the square type. Circular traditions and carved inductor through in the 1.8 GHz, their quality factor were 8.998 and 9.990. Through in 2.4 GHz, they were 9.660 and 10.612. The percentages of improvement were 11.02% and 9.86% respectively. This thesis applies improved square carved inductor to high-performance oscillator design, with the best inductive quality frequency between 1.8 GHz and 2.4 GHz. So this high-performance oscillator is designed in GSM / CDMA / WCDMA communication frequency band. The oscillator core is cross coupling by PMOS, with PMOS transistor current source. The oscillator core uses three bits group symmetry switching capacitor array as the coarse adjustment of the frequency, synchronizing increasing in the frequency tuning range. Circuit phase noise optimization design process is described in detail in the thesis. Under the DC bias of 1.5 V, the oscillator core consumes power only 4.485 mW, of which the frequency operating range from 1.499 to 1.874-GHz (tunable percentage of 22.24%). When the oscillator is operating at 1.874-GHz, the phase noise are -124.35 and -141.47 dBc / Hz while frequency shifting at 1-MHz and 10-MHz. Corresponding to FOM is 183.29 in the 1-MHz frequency shift. According to the literature, this oscillator substantially reduces DC power consumption which is able to enhance the portability of communication goods. In addition, base on improved round carved inductance measurement results, through the open de-embedding method to the parasitic of the metal pad, we get the deduction results to design the oscillator. We found in the DC bias of 1.5 V, oscillator core power consumption is only 4.5 mW, of which the frequency operating range is 1.511 to 2.423-GHz (tunable percentage of 46.7934%). When the oscillator operating in the 2.423GHz, the phase noises are -126.418 and -146.656 dBc / Hz while frequency shifting at 1-MHz and 10-MHz respectively. Corresponding to FOM is 187.58 dB. The proposed modified groove inductors only modify the layout of the metal coil, and it can be conducted directly in the standard circuit process. Do not need to do additional circuit manufacturing processing. Hence, its excellent application value can even be extended to fully symmetric planar spiral inductor layout studies and improve the consumption of the chip area.
48
張筑程. "Factor Analysis of Water Quality in Li-Yu-Tan Reservoir." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/88838991501339317179.
Повний текст джерелаАнотація:
碩士逢甲大學
水利工程與資源保育學系
101
This study analyzed routine water quality monitoring data from Liyutan Reservoir. Data for the 19 years between 1994, the year the reservoir began operation, and 2012 were obtained from the Environmental Protection Administration, Executive Yuan, and analyzed on 18 dimensions, including the CTSI, clarity, chlorophyll-a, and phosphorous concentration. The residuals and ND values were calculated to determine the effects that hydrology and water diversions from Daan River have on water quality. Statistical testing was also performed to analyze the effect that cross-watershed diversion has on water quality. Factor analysis was conducted to identify the variation in water quality before and after water diversions, and to propose reasons for water diversions causing variations in reservoir water quality. Principal component analysis was employed to select three or four factors with variances greater than 68% and Kaiser-Meyer-Olkin values higher than 0.5 for factor analysis. A comparison of rotations for handling residuals and ND values indicated that Promax rotation with factor loadings of 0.7 resulted in load factors with the highest eigenvalues. The factor analysis results showed that before cross-watershed diversion, phosphorus supply and algae factors were present (i.e., nutrient salts), and the reservoir contained non-point source pollution. After cross-watershed diversion, the greatest changes in reservoir water quality were observed for the reservoir capacity and algae factors. This suggests that cross-watershed diversion increased the storage capacity and discharge flow. The CTSI of reservoir water quality declines annually, which is the primary reason for the improving water quality of Liyutan Reservoir.
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Chun-LinHuang and 黃俊霖. "Fabrication of high-quality WDM with a high isolation factor." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/v79736.
Повний текст джерелаАнотація:
碩士國立成功大學
微電子工程研究所
105
The purpose of this thesis is to fabricate a particular 1590/1950 nm Wavelength Division Multiplexing (WDM) with high channel isolation, low insertion loss, low excess loss. So that the structure can support large light energy such as Q-switch laser and high power CW laser. we let light energy transfer in fused biconical-taper single-mode fiber couplers to divide different light wavelength frequency. Advantages of fused biconical-taper structure is low energy consumption, Low cost and High damage threshold, it is able to achieve our purpose. We used a torch hydroxide and pulling stage to make single-mode fiber elongated tapered. We have improved the two issues that can only detect a single wavelength and short wavelength detection bandwidth. we make dual-wavelength system to improve the issues ；Using MATLAB control two Photo-detector and laser source. Use the dual-wavelength system we can get two wavelengths instant energy changes. We use this dual-wavelength system to discuss changes in the pulling speed and knots volume changes and make particular 1590/1950 nm Wavelength Division Multiplexing (WDM) components.
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Li, Ching-Jen, and 李清仁. "Study of environmental risk factor in semen quality of male." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/6z82y9.
Повний текст джерелаАнотація:
博士臺北醫學大學
公共衛生學系暨研究所
104
Semen quality is a key indicator of the male reproductive ability. The decline in semen quality has been debated for several decades. However, this decline might be inconsistent given factors such as geographical area, ethnicity, environmental exposure, and lifestyle changes. Taiwan is an urbanized and industrialized island, where pollution is a pressing problem. In addition, lifestyle-related factors, such as dietary patterns and obesity, have changed tremendously in recent years. This study aimed to provide information on the semen quality of Taiwanese men by analyzing semen parameters between 2001 and 2010. In addition, we evaluate the levels of heavy metals and reproductive hormones in the blood to clarify the relationship between these factors and semen quality or subfertilty. Objective: 1. To understand the status and trends of semen quality from 2000 to 2010 in North Taiwan men. 2. To understand the relationship between lead and low semen quality. 3. To understand the relationship among metal, semen parameters, and fertility, and determine the values of suitable sperm parameters for Taiwanese men. Method: We recruited 7187 male participants between 2001 and 2010 from a reproductive medical center to provide information on the semen quality of Taiwanese men. In cross-sectional study, we collected demography information and measured the levels of metals and reproductive hormones in the blood. To determine the association between blood lead levels and low semen quality. In case-control study, we examined the blood lead (Pb) levels and semen quality in the fertile and subfertile men. In addition, receiver operating characteristic (ROC) curve analysis was used to determine the cutoff values of suitable sperm parameters for Taiwanese men to achieve spontaneous pregnancy. Result: Increasing age (per year) was significantly and negatively associated with semen volume, progressive sperm motility, rapid progressive sperm motility, and sperm with normal morphology. In addition, all semen parameters were reduced with year by year of recruitment. We observed that the increased blood Pb levels were significantly and positively associated with low semen quality. High blood Pb levels ( 5 g/dL) had an 11-fold risk of low semen quality. Our data also suggest that low percentages of total and progressively motile sperms were significant risk factors for subfertility. In addition, the percentage of sperms with normal morphology had a higher ROC curve area (0.87), and the new cutoff point for the percentage of sperms with normal morphology was determined to be 65% and those having <65% of sperms with normal morphology had an 11.35-fold higher risk of subfertility. Disscision and Conclusion: In this study, age and cohort effect on reduced the progressive and rapid progressive sperm motility. Even blood Pb levels lower than the reference level of the CDC and FSH levels were within the normal recommended range, we observed that the increased blood Pb levels were significantly and positively associated with low semen quality. In addition, low percentages of total and progressively motile sperms were significant risk factors for subfertility. Moreover, the new cutoff point for the percentage of sperms with normal morphology (65%) should be determinated with larger sample size in future. This information will be of use in clinical practice and public health investigations of the male reproductive health.