To see the other types of publications on this topic, follow the link: HFTC.
Dissertations / Theses on the topic 'HFTC'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'HFTC.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Dung, Tran BA Viet, and n/a. "Teaching listening skills to students of commerce at Hanoi Foreign Trade College." University of Canberra. Education, 1989. http://erl.canberra.edu.au./public/adt-AUC20060706.122222.
Full textAbstract:
There is a great need for competent teaching of Business
English in tertiary institutions in Vietnam.
At the Hanoi Foreign Trade College (HFTC) alone, about 150
students per year seek training to equip them to work in export
and import organizations, banks for foreign trade and customs
departments.
In teaching such students, one problem is the provision of
interesting and relevant materials. This study addresses the
question of selection of materials and techniques for teaching
business English listening skills.
This Field Study Report consists of five chapters. Chapter 1
describes the purposes and aims of study, the background to
this study, dealing with students, the teaching and the
curriculum.
Chapter 2 looks at the general theory about listening and in
particular listening in business. The chapter also describes
listening requirements for business graduates from the HFTC.
Chapter 3 discusses criteria for selection of textbooks for
language teaching in general and for teaching listening skills
in business English in particular.
Chapter 4 surveys the teaching of business English in two
institutes of Technical and Further Education in the Australian
Capital Territory (ACT).
The final chapter makes suggestions for priorities to improve
the teaching of business English.
This Field Study Report should be regarded as an exploratory
attempt in choosing classroom techniques and materials for
teaching listening skills to students of commerce at the Hanoi
Foreign Trade College.
2
HE, ZHENG. "HFTS AND NON-HFTS ALONG THE LIMIT ORDER BOOK." OpenSIUC, 2020. https://opensiuc.lib.siu.edu/dissertations/1857.
Full textAbstract:
Using NASDAQ high frequency trading (HFT) and minute-by-minute Limit Order Book (LOB) data over 120 sample stocks in 10 weeks between 2008-2010, including the week of the Lehman Brothers crisis, we study how trading activities of HFTs, NHFTs (Non-HFTs) and their order placements interact, and affect overall market quality. We capture order placements via the depth (step) and the height (price) dimensions along the LOB. We first document that HFTs are active not only at the top of the LOB, but their orders are placed along the LOB with an average around the 5th step, slightly ahead of NHFTs who on average are close to the 6th step. Generally, both HFTs and NHFTs are more aggressive in order placement with large stocks and hidden orders and HFT orders are further ahead during the crisis week, though price-wise they all back off somewhat with more conservative placements by NHFTs. In market turmoil, whenever HFTs see NHFTs trade among themselves, they become less aggressive in order placement. However, when HFTs trade, other HFT orders become more aggressive by moving ahead. On the contrary, NHFTs generally become more aggressive when other NHFTs supply liquidity in trading, and more conservative when HFTs are the supplier. We find mixed results on the impact of HFTs order placements and trading activities on market quality by different measures, but aggressive orders by HFTs and NHFTs both are related with decreases in short-term market volatility. Our findings highlight the importance of not only studying HFTs and NHFTs activities along the LOB, but also in both depth and height dimensions, instead of only at the market inside quotes.
3
Johansson, Daniel. "Slutväxel HFT : Konstruktionskoncept för banddriven skotare." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-72675.
Full textAbstract:
Sveriges samlade skogsindustriföretag förutspår en förlust av marknadsandelar, eftersom man inte lyckas hålla samma tempo på produktionen som många andra länder. En orsak till detta är att skogsmaskinerna är för långsamma. Skotarna, vars uppgift är att förflytta virket från avverkningsplatsen till en uppsamlingsplats, bär en stor del av skulden. De hinner inte transportera virket tillräckligt snabbt. För att råda bot på detta ska en ny typ av skotare utvecklas, vars plattform inspireras av försvarsteknologi. Tack vare sin långa erfarenhet av banddrivna fordon har BAE Systems Hägglunds i Örnsköldsvik fått i uppdrag att konstruera en prototyp, som baseras på deras framgångsrika bandvagn, BvS10.[A] Skotaren går under namnet Hybrid Forestry Truck (HFT), och är en banddriven skotare med fyra larvband. Framdrivningen är av seriehybridtyp, vilket betyder att en generator drivs av en dieselmotor. Dieselmotorn förser sedan fyra elmotorer, en i varje bandställ, med ström. Detta examensarbete går ut på att utveckla länken mellan elmotorn och drivhjulen till banden. Tre designkoncept presenteras och analyseras. Den, i författarens åsikt, mest ideala lösningen utvecklas sedan vidare mer detaljerat. Många andra examensjobb, samt interna analyser av Hägglunds själva, har gjorts på HFT. Detta innebär att många kraftsituationer och belastningsfall redan är uträknade, samt att de flesta komponenterna till slutväxeln är utvalda.
4
Fan, Haibo. "HfC structural foams synthesized from polymer precursors." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Dissertation/FAN_HAIBO_30.pdf.
Full text
5
Björkman, Jonas, and Johan Durling. "The impact of high-frequency trading on the Swedish stock market – based on liquidity and volatility." Thesis, Linköpings universitet, Nationalekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148882.
Full textAbstract:
This paper studies how high-frequency trading (HFT) affects the Swedish stock market quality based on volatility and liquidity measures. Previous studies show ambiguous results where a few propose that HFT deteriorates market quality by increasing volatility and decreasing liquidity while some studies point in the opposite direction.By setting up a simultaneous equations system with instrumental variables and estimating the parameters with Generalized Methods of Moments (GMM), this paper finds that in the majority of the investigated stocks high-frequency trading activity reduces bid ask spreads and therefore increases liquidity, i.e. enhancing market quality. Additionally, the results also show that the volatility decreases through high-frequency trading activity. Hence, both measures are indicating that the market quality is positively affected by high-frequency trading.However, interesting is the analysis and discussion on whether high-frequency trading strategies such as spoofing and layering potentially can contribute to false liquidity. This would mean that the market quality is impaired due to HFT. This paper also examines the reversed relationship, how the liquidity and volatility affect HFT activity and conclude that HFT is not affected by how liquid or volatile the market is.
6
Wheeler, Mark R. "The adsorption of HFC-134a onto zeolite Na-13X." Thesis, Brunel University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307487.
Full text
7
Neilson, Martin M. "The bulk and surface properties of HFC replacement refrigerants." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312801.
Full text
8
Sålder, Christofer, and Andreas Callander. "Fast or furious : Högfrekvenshandelns påverkan på privata aktiesparare." Thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-16192.
Full text
9
Narasimhan, Anirudhan. "Commercialization of HFAC Electronic Nerve Block Technology to Treat Chronic Post Surgical Pain." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1290641992.
Full text
10
Yan, Yu. "Performance optimisation of HFC refrigerants by experimental and mathematical methods." Thesis, University of Strathclyde, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248796.
Full text
11
Costa, Isac Silveira da. "High frequency trading (HFT) em câmera lenta: compreender para regular." reponame:Repositório Institucional do FGV, 2018. http://hdl.handle.net/10438/20720.
Full textAbstract:
Submitted by Isac Costa (isac.costa@gmail.com) on 2018-03-29T03:00:24Z
No. of bitstreams: 1
COSTA, Isac. HFT - Compreender para Regular (2018).pdf: 2204316 bytes, checksum: 34d586d9b8bca337d4f2631f417e7c8d (MD5)Rejected by Katia Menezes de Souza (katia.menezes@fgv.br), reason: Prezado Isac, Para que possamos aprovar seu trabalho são necessários alguns ajustes conforme norma ABNT/APA. ESTRUTURA: Capa (obrigatório) – No final da página a informação “2018” deverá constar abaixo da frase “São Paulo” e não ao lado como consta atualmente. Ficha catalográfica – Excluir a informação “presente trabalho foi realizado com apoio da Fundação Getúlio Vargas, Por meio da bolsa Mário Henrique Simonsen de Ensino e Pesquisa” Folha de aprovação- Não deverá conter a ata e sim um modelo anexo. Outra situação que detectamos é que no espaço de uma página para outra a algumas folhas em branco, favor exclui-las. Após os ajustes excluir o pdf já postado e submete-lo novamente para analise e aprovação. Qualquer dúvida estamos à disposição, Att. on 2018-04-02T20:20:05Z (GMT)
Submitted by Isac Costa (isac.costa@gmail.com) on 2018-04-03T11:41:00Z No. of bitstreams: 1 COSTA, Isac. HFT - Compreender para Regular (2018).pdf: 1858992 bytes, checksum: 4c53e5c7b819d28a0f2d41fdf22fdd62 (MD5)
Approved for entry into archive by Katia Menezes de Souza (katia.menezes@fgv.br) on 2018-04-03T12:03:00Z (GMT) No. of bitstreams: 1 COSTA, Isac. HFT - Compreender para Regular (2018).pdf: 1858992 bytes, checksum: 4c53e5c7b819d28a0f2d41fdf22fdd62 (MD5)
Approved for entry into archive by Suzane Guimarães (suzane.guimaraes@fgv.br) on 2018-04-03T12:21:35Z (GMT) No. of bitstreams: 1 COSTA, Isac. HFT - Compreender para Regular (2018).pdf: 1858992 bytes, checksum: 4c53e5c7b819d28a0f2d41fdf22fdd62 (MD5)
Made available in DSpace on 2018-04-03T12:21:35Z (GMT). No. of bitstreams: 1 COSTA, Isac. HFT - Compreender para Regular (2018).pdf: 1858992 bytes, checksum: 4c53e5c7b819d28a0f2d41fdf22fdd62 (MD5) Previous issue date: 2018-03-05
High frequency trading (HFT) é uma técnica de negociação baseada em algoritmos que pode implementar estratégias variadas, das quais resultam um elevado número intradiário de mensagens enviadas aos sistemas de negociação das bolsas. High frequency traders (HFTs) são protagonistas no mercado secundário em termos de número de ofertas e negócios. Neste texto, procuramos definir os contornos deste já não tão novo fenômeno e os riscos a ele associados. Investigamos os objetivos pretendidos pela regulação, as regras aplicáveis e as dificuldades associadas a cada um delas. Assim, podemos avaliar se, no direito brasileiro, é necessário editar uma nova norma ou atualizar normas existentes e discutir qual poderia ser o seu conteúdo. A formulação de respostas regulatórias toma como ponto de partida os pressupostos teóricos do funcionamento do mercado de capitais, suas funções econômicas e o modo pelo qual o direito pode contribuir para que estas funções sejam desempenhadas adequadamente. Um estudo crítico dos HFTs nos permite examinar os riscos associados à sua atividade e à negociação algorítmica de um modo geral, bem como repensar o funcionamento do mercado, os objetivos da sua regulação e como estes podem ser alcançados. É imprescindível que seja realizado um esforço para a compreensão adequada de novas tecnologias que chegam ao mercado, avaliando seus riscos antes que seja disseminado um discurso de alarde ou medo. Este estudo também procura oferecer uma descrição atualizada do funcionamento do mercado secundário de capitais e como as tecnologias mais recentes influenciaram a dinâmica das negociações.
High frequency trading (HFT) is a kind of algorithmic trading which implements several strategies that result in a high number of intraday messages that are sent to exchanges and other trading venues. High frequency traders (HFTs) are key players in secondary markets given the number of orders and trades they generate. In this text, we explore the boundaries of this phenomenon and the associated risks. We investigate the regulation goals, the mechanisms to achieve such goals and the obstacles ahead. Then we evaluate whether it is necessary to create new rules or update the existing ones in Brazilian law – and what these new rules could be. The formulation of regulatory responses start with the analysis of a theoretical framework for the dynamics of capital markets, its economic functions and how Law can play a key part in this scenario. A critical study of HFTs enables us to assess its risks along with the risks of algorithmic trading in general, and, in addition, it is an invitation to rethinking how the market works, the goals that regulation can pursue and how they can be achieved. Understanding new technologies that emerge in capital markets is paramount before any risk assessment discussions in order to prevent hype and panic. This work also aims to provide an up to date description of the secondary market dynamics and how state-of-art trading technologies reshaped it.
12
Boisselier, Guilhaume. "Dépôt chimique en phase vapeur de carbures de chrome, de silicium et d'hafnium assisté par injection liquide pulsée." Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0064/document.
Full textAbstract:
Des revêtements céramiques sont obtenus par un procédé de dépôt chimique en phase vapeur assisté par injection liquide pulsée (DLICVD) de précurseurs organométalliques. Des dépôts de carbure de chrome (CrCx) sont élaborés dans un réacteur tubulaire à paroi chaude à partir d’une solution de bis(benzène) chrome dans du toluène pour des températures de 475 °C et sous pression partielle d’azote (pression totale 50 Torr). Une couche d’accroche pouvant être nécessaire pour revêtir des pièces métalliques, tels des aciers et alliages, par un revêtement céramique non-oxyde de type CrCx, des couches de chrome métallique (Cr) et des carbures mixtes Cr-Si-C ont également été élaborées par ce procédé DLICVD. Ainsi, l’ajout d’un additif à base de chlore ou de soufre (par exemple l’hexachlorobenzène ou le thiophénol) dans la solution BBC/toluène permet la déposition de films de chrome métallique (Cr) à 475 °C. De plus, l’utilisation d’une solution de précurseur contenant simultanément du Si et du Cr tel que le tetrakis(trimethylsilylmethyl)chromium dans du toluène mène au dépôt d’un carbure mixte Cr-Si-C pouvant jouer le rôle d’interphase dans des assemblage céramique-métal. Des films de carbure de silicium (SiC) sont obtenus à partir de deux précurseurs (1,3 disilabutane et polysilyléthylène) injectés purs ou en solution également dans du toluène. Les dépôts sont faits dans une gamme de température comprise entre 700 et 800 °C, sous pression partielle d’azote (pression totale 50 Torr). Les films obtenus sont des films amorphes de SiC contenant une faible quantité d’hydrogène (provenant du mécanisme de décomposition des précurseurs) : a-SiC:H. Les films sont stœchiométriques dans le cas de l’injection de précurseur pur, et quasi stœchiométrique lorsque les précurseurs sont dilués dans du toluène. Les films amorphes tels que déposés deviennent nanocristallins en présentant la structure cubique du SiC après recuit sous vide à 1000 °C. L’influence du solvant (toluène) sur la composition, la morphologie et la vitesse de croissance des dépôts est discutée en fonction des systèmes chimiques étudiés et des conditions expérimentales, en particulier les conditions locales dans le réacteur DLICVD telles que les gradients de température et de concentration. Des films de carbure de hafnium (HfC) sont également élaborés par le même procédé à partir d’une solution de bis(cyclopentadiényl)diméthyl hafnium dans du toluène après avoir testé plusieurs précurseurs. Une température de 750 °C est utilisée et l’utilité d’une pression partielle de dihydrogène dans le gaz vecteur azote est démontrée (pression totale 50 Torr, 423 sccm de N2 et 77 sccm de H2). Tels que déposés, ces films sont riches en carbone (C-rich HfCx) et ont une structure quasi-amorphe. Ils deviennent nanocristallins après recuit sous vide à 1000 °C. Enfin, la mise en œuvre de films multicouches céramiques par DLICVD à paroi chaude est mise en évidence par l’élaboration de revêtements multicouches HfC/SiC à 750 °C, sous pression partielle d’un mélange de gaz vecteur N2/H2. Le contrôle du procédé permet une nano structuration de ces revêtements multicouches jusqu’à une bi-période de 100 nm (empilement de 100 couches d’environ 50 nm chacune). La stabilité thermique de ces architectures et des tests préliminaires de résistance à l’oxydation à haute température des films de SiC et HfC/SiC sont discutésCeramic coatings are made from metalorganic precursors by a chemical vapour deposition process assisted by pulsed liquid injection (DLICVD). Chromium carbide (CrCx) films are grown in a tubular hot wall reactor from a solution of bis(benzene)chromium in toluene under partial pressure of nitrogen at 475 °C (total pressure set at 50 Torr). Bonding layers are useful on metallic components, such as steels and alloys, with non-oxide ceramic films such as CrCx, to that purpose metallic chromium (Cr) and mixed carbides Cr-Si-C have been made by DLICVD. Furthermore, adding a chlorinated or sulfur based additive (e.g. hexachlorobenzene or thiophenol) in the BBC/toluene solution allows depositing metallic chromium (Cr) at 475 °C. Moreover, using a precursor containing Si and Cr as tetrakis(trimethylsilylmethyl)-chromium in toluene leads to the deposition of Cr-Si-C mixed carbide. Silicon carbide films are made from two precursors (1,3-disilabutane and polysilylethylene) that have been injected either pure or diluted in toluene. A temperature range of 700 to 800 °C has been used under a partial pressure of nitrogen (total pressure of 50 Torr). SiC films are amorphous and contain a small quantity of hydrogen (hydrogen comes from precursor pyrolysis mechanism): a-SiC:H. Films are stoichiometric when pure precursors are injected, and quasi stoichiometric when precursors are diluted in toluene. As deposited coatings are amorphous and become nanocristalline (cubic SiC structure) after annealing at 1000 °C under vacuum. The influences of the solvent (toluene) on the composition, morphology and growth rate are discussed as a function of the chemical system and experimental conditions, in particular reactor gradient conditions such as temperature and precursors concentration in gas phase. Hafnium carbide films are also made using a solution of bis(cyclopentadiényl)diméthyl hafnium in toluene by the same process. Temperature is set to 750 °C and hydrogen partial pressure has been shown useful (total pressure of 50 Torr, 423 sccm of N2 and 77 sccm of H2). As-deposited films are C-rich HfCx and quasi amorphous. They become nanocristalline after annealing at 1000 °C under vacuum. Finally, ceramics multilayer HfC/SiC coatings were deposited by DLICVD at 750 °C under a partial pressure of a mixture of N2/H2. The process allows a good control of the multilayer nanostructure. Thermal stability and high temperature oxidation preliminary tests on SiC and HfC/SiC films are discussed
13
Loan, Nguyen Kim, and n/a. "Listening comprehension tests for intermediate students at Hanoi Foreign Languages College." University of Canberra. Education, 1989. http://erl.canberra.edu.au./public/adt-AUC20060818.141820.
Full textAbstract:
In Vietnam today there is an urgent demand for well-designed tests
of listening comprehension. Little attention has been given to this
problem. This field study is intended to provide guidance on the
design of listening comprehension tests and in particular for
intermediate level students at the Hanoi Foreign Language College
(HFLC).
The Field Study Report consists of six chapters. Chapter One gives a
brief introduction which covers the problem, aims, subjects
(testees) and the background of the Field Study Report.
Chapter Two deals with the purposes of testing in some detail,
setting this in the framework of the teaching-testing link, teachers
and testing, and students and testing. Test characteristics are
considered and the problem of sampling for test content is addressed.
Chapter Three concerns test items for listening comprehension. The
chapter begins with a short description of listening comprehension
and is followed by a survey of theorists on listening comprehension
together with the test items for listening that they suggest. Some
commonly-used standardised tests and their listening items are
discussed.
The chapter ends with a checklist of selected listening items
suitable for students at HFLC in Vietnam.
Chapter Four discusses the designing and trialling of test items for
listening comprehension, such as multiple choice, completion of a
taped talk, matching pictures with statements etc. The chapter
presents the results of the trialling of sample items and also deals
with correlations between the sample tests used.
Chapter Five deals with test design and development in general. It
clarifies the bases for test design and provides a checklist of
steps in the development of tests. In addition, the chapter includes
a resources inventory for listening test items.
Chapter Six presents the conclusions of the Field Study Report.
14
Chen, De-Kang. "Flashing flow of refrigerant HFC-134a through a diabatic capillary tube." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25924.pdf.
Full text
15
Scholz, B. [Verfasser]. "Untersuchung an TaC-HfC-Hartstoffen mit und ohne Bindemetall / B. Scholz." Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/1187252808/34.
Full text
16
Tumbalobos, Cubas Brenda Jackeline. "Estudio del diseño de servicio IPTV con tecnología HFC y FTTH." Bachelor's thesis, Pontificia Universidad Católica del Perú, 2016. http://tesis.pucp.edu.pe/repositorio/handle/123456789/6860.
Full textAbstract:
En la presente tesis se estudia el diseño del servicio IPTV para brindar una
solución a la digitalización de la televisión en el mundo IP. Se plantea dos
propuestas de tecnología para el servicio de IPTV: HFC y FTTH, logrando así la
interactividad entre la televisión y el usuario.
En el capítulo 1 se detalla el origen IP, IP multicast, las aplicaciones de IP, IPTV en
el mercado mundial, las aplicaciones de IPTV, comparación entre IPTV y CATV, el
marco problemático y los objetivos. En el capítulo 2 se muestra el servicio de IPTV
en tecnología HFC y FTTH, así como también las tecnologías FTTH y HFC con
sus elementos de red.
En el capítulo 3 se analiza los diseños de la cabecera IPTV y su transporte
mediante tecnología HFC y FTTH. Finalmente, en el capítulo 4 se detallan los
presupuestos del servicio IPTV, así como la comparación de calidad del servicio
entre ambas tecnologías.
Comparando los resultados de ambas tecnologías, se recomendará la mejor para
el despliegue del servicio IPTV.Tesis
17
Bruna, Paez Eduardo Andrés. "Modelo preventivo de morosidad temprana de clientes HFC mediante clasificación bayesiana." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/112522.
Full textAbstract:
Magíster en Gestión de OperacionesEste proyecto, formó parte del plan de mitigación de clientes morosos implementado por una empresa de telecomunicaciones en el año 2009, dónde una de las líneas de acción estaba enfocada en disminuir la morosidad de los nuevos clientes en su primera factura. Se propuso un modelo que clasifique a los nuevos clientes en pagadores y no pagadores, permitiendo con ello, reorientar recursos y realizar acciones preventivas de morosidad de manera más focalizada y efectiva, las cuales estaban siendo hasta ese momento aplicadas al universo total de nuevos clientes. El éxito de este proyecto requería el compromiso del área de cobranzas, usuaria del modelo, por esto, la elección del modelo consideró aspectos tanto teóricos como prácticos. La simpleza y la fácil ejecución del modelo, idealmente programable, eran variables deseables y decidoras del éxito de éste. Se ejecutó basado en Clasificación Bayesiana por su forma simple de utilizar y presentar una confiabilidad aceptable [17]. Los métodos de inducción bayesiana han demostrado ser una clase de algoritmos tan competitivos como los métodos árboles de decisión y redes neuronales [29], que permiten implementar algoritmos en Wolfram Mathematica 6.0 cuyas sentencias de programación son muy similares al lenguaje C++, permitiendo su programación posterior. El modelo se confeccionó con 42.087 clientes, contratantes entre el 15 de julio y el 15 de octubre del 2009, de estos, 40.087 formaron la base de aprendizaje para calibrar y realizar los cálculos de probabilidades, y 2.000 como base de testing. Los clientes a clasificar en pagadores y no pagadores correspondieron a 9.328, quienes ingresaron a la empresa entre el 16 de Octubre y el 15 de Noviembre del 2009. En base a establecer una probabilidad a priori, se plantea en valores estimados de corte probabilístico basado en la experiencia o un método de clasificación [19], por una probabilidad de corte de 0,4 para clasificar a un cliente pagador por la necesidad que enfrenta la empresa de mejorar el % de clientes morosos en su primera boleta y a la vez reducir los costos actuales involucrados en la cobranza. El modelo clasificó a 2.910 clientes como no pagadores, 2.179 de ellos efectivamente no cancelaron su boleta al vencimiento (75%). Este resultado es compatible con el esperado en el análisis teórico, debido a la eficiencia de los estimadores estimados, como también, el tamaño de los set de datos empleados que en forma teórica respalda los resultados obtenidos con un 80% de confiabilidad. Como trabajo futuro, resulta interesante evaluar el aporte del modelo en la reducción real del porcentaje de clientes morosos al permitir reorientar recursos y focalizarse en ciertos clientes, como a su vez, actualizar la base de aprendizaje de tal forma ir considerando la actualidad al modelo.
18
Reilly, Michael Anthony. "Characterisation of HFC-134a by gas chromatography-mass spectrometry and chemometrics." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/14268.
Full textAbstract:
1,1,1,2-tetrafluoroethane (HFC 134a) is one of the major replacement compounds for chlorofluorocarbons and is therefore of great industrial importance. This work describes a method of characterisation for HFC 134a. The method profiled the levels of synthesis by-products present in samples of HFC 134a using gas chromatography (GC) with detection by flame ionisation detector (FID) or electron capture detector (ECD). The principal method for identification of the by-products was EI GC-mass spectrometry. The multi-variate data produced by the profiling of samples were analysed using chemometric techniques. A training set of samples of HFC 134a, with known origins of production, was analysed by both GC-FID and GC-ECD. This training data set was used to investigate the different methods of chemometric analysis as applied to the raw data, normalised data and principal component analysed data. K-means clustering and Hierarchical clustering were investigated to find the optimum methods for the identification of samples' origins of production based on their chromatographic profiles. The FID chromatographic traces could be correctly identified by applying a two step principal component analysis (PCA) using a hierarchical clustering method to classify the samples. The ECD chromatographic data could be correctly identified by applying a PCA followed by classification using a hierarchical clustering method. The two classification techniques were used to identify further samples of HFC 134a into clusters belonging to the known origins of production or into new clusters representing samples of unknown origin. Classification of samples using the ECD data required the least amount of operator interpretation and provided the least amount of ambiguity in sample identification.
19
Alalwan, Mahmood A. "In Vitro Evaluation oF Aerosol Drug Delivery With And Without High Flow Nasal Cannula Using Pressurized Metered Dose Inhaler And Jet Nebulizer in Pediatrics." Digital Archive @ GSU, 2012. http://digitalarchive.gsu.edu/rt_theses/14.
Full textAbstract:
Background: HFNC system is a novel device used with aerosol therapy and seems to be rapidly accepted. Although there are some studies conducted on HFNC and vibrating mesh nebulizer, the effect of HFNC on aerosol delivery using jet nebulizer or pressurized metered-dose inhaler (pMDI) has not been reported. In an effort to examine the effect of HFNC on aerosol deposition, this study was conducted to quantify aerosol drug delivery with or without a HFNC using either pMDI or jet nebulizer.
Methodology: The SAINT model, attached to an absolute filter (Respirgard II, Vital Signs Colorado Inc., Englewood, CO, USA) for aerosol collection, was connected to a pediatric breathing simulator (Harvard Apparatus, Model 613, South Natick, MA, USA). To keep the filter and the SAINT model in upright position to collect aerosolized drug, an elbow adapter was connected between the absolute filter and the breathing simulator. An infant HFNC (Optiflow, Fisher & Paykel Healthcare LTD., Auckland, New Zealand) ran at 3 l/min O2 was attached to the nares of the SAINT model. Breathing parameters used in this study were Vt of 100 mL, RR of 30 breaths/min, and I:E ratio of 1: 1.4. Aerosol drug was administered using: 1) Misty-neb jet nebulizer (Allegiance Healthcare, McGaw Park, Illinois, USA) powered by air at 8 l/min using pediatric aerosol facemask (B&F Medical, Allied Healthcare Products, Saint Louis, MO, USA) to deliver albuterol sulfate (2.5 mg/3 mL NS), and 2) Four actuations of Ventolin HFA pMDI (90 μg/puff) (GlaxoSmithKline, Research Triangle Park, NC, USA) combined with VHC (AeroChamber plus with Flow-Vu, Monaghan Medical, Plattsburgh, NY, USA). Aerosol was administered to the model with and without the HFNC and another without (n=3). Drug was collected on an absolute filter, eluted and measured using spectrophotometry. Independent t tests were performed for data analysis. Statistical significance was determined with a p value of <0.05.
Results: The mean inhaled mass percent was greatest for pMDI with (p = 0.0001) or without HFNC (p = 0.003). Removing HFNC from the nares before aerosol treatment trended to increase drug delivery with the jet nebulizer (p = 0.024), and increased drug delivery by 6 fold with pMDI (p = 0.003).
Conclusions: Aerosol drug may be administered in pediatrics receiving HFNC therapy using either jet nebulizer or pMDI. However, using pMDI, either with or without HFNC, is the best option. When delivering medical aerosol by mask, whether by jet nebulizer or pMDI, removing HFNC led to an increase in inhaled mass percent. However, the benefit of increased aerosol delivery must be weighed against the risk of lung derecruitment when nasal prongs are removed.
20
Grénar, Milan. "Implementace pokročilé filtrace s klasifikací paketů pro bezdrátové sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-218953.
Full textAbstract:
The diploma thesis addresses facility of QoS control with GNU/Linux tools iptables and iproute. An attention is focused especially on HTB and HFSC traffic shaping methods with regard to utilization in wireless networks. The paper also includes a simulation of ensuring QoS in wireless network with 802.11e amendment.
21
Wolff, Rojas Patricio. "Diseño e Implementación de un Curso de Servicios Sobre Redes HFC de Nueva Generación." Tesis, Universidad de Chile, 2009. http://repositorio.uchile.cl/handle/2250/103626.
Full textAbstract:
Las redes híbridas de fibra óptica y cable coaxial, HFC, fueron implementadas en
un principio por operadores de TV Cable, los que posteriormente incluyeron servicios
como Video-on-Demand, Pay-Per-View, etc. Con el avance de la tecnología, las redes
de TV Cable fueron capaces de ofrecer otros servicios multimedia como telefonía y
acceso a Internet de Banda Ancha. Para esto, modificaron las mismas redes existentes,
transformándose en Operadores Multi-Servicio, MSO. La red sufrió modificaciones
importantes, pasando de ser una red prácticamente unidireccional a ser una red
bidireccional desbalanceada.
En la discusión actual sobre telecomunicaciones se encuentran habitualmente términos
como convergencia IMS (IP Multimedia Subsystem) y Redes de Nueva Generación, NGN
(Next Generation Networking). HFC representa un bloque fundamental en la comprensión
de estos conceptos. Un factor clave para el éxito de los operadores de cable que pretenden
adecuar sus redes para la próxima generación de arquitecturas de comunicaciones, será
la capacidad del personal técnico para evaluar las diversas opciones disponibles. Por otro
lado, los MSO, se enfrentan a otras consideraciones como el manejo de la compatibilidad
de las diversas normas de próxima generación con las arquitecturas existentes y cómo
determinar el momento óptimo para realizar este cambio.
El objetivo de esta memoria fue diseñar un curso teórico y práctico sobre servicios
soportados por redes HFC de nueva generación, basándose en los atributos de
escalabilidad y disponibilidad que esta tecnología presenta frente a otras. Para guiar el
desarrollo de este proyecto se utilizó una metodología que consiste en la recopilación de
información sobre tecnología HFC en la etapa inicial, seguido de un análisis de los datos
obtenidos. Con esta información se generó un programa docente y una planificación que
permitió desarrollar el curso.
En este proyecto de título se diseñó e implementó un curso de servicios teórico y
práctico. En lo teórico se cubren temas como: Broadcasting de TV, Internet/Datos, Telefonía,
IPTV, eTV, Video-on-Demand, Pay-Per-View, VoIP, videoconferencias y Juegos On Line. En
lo práctico, se presenta una propuesta preeliminar de laboratorio docente, que contempla
una red HFC a escala y guías prácticas sobre la evaluación de servicio y la vía de retorno.
El curso se diseñó para hacer uso de recursos docentes presenciales e interactivos a través
de Internet.
Este curso representa un aporte, tanto fuera como dentro del Departamento de
Ingeniería Eléctrica de la Universidad de Chile, al tratar temáticas actuales con un enfoque
orientado a la industria de los servicios ofrecidos por los MSO. El curso diseñado es una
propuesta orientada a completar la instrucción de un ingeniero civil electricista.
22
Hamza, Haval Rawf. "The impacts of high-frequency trading on the financial markets’ stability." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1428416050.
Full text
23
Molander, Lukas, and Shih Jung Yape. "Toxicity Levels of Stock Markets : Observing Information Asymmetry in a Multi-Market Setting." Thesis, KTH, Matematisk statistik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209791.
Full textAbstract:
The presence of toxic order ow and predatory HFT strategies in a multi-market setting are scarcely researched in the academic world. This thesis studies the toxicity levels of a set of markets by examining unconsolidated quote data and firm specific trade data. A method for deducing the markets toxicity levels is presented along with proxies for toxic order ow, namely: changes in spread and quoted volume, following a trade in a given market. We find both signs of toxicity and different toxicity levels between the markets. However, the results are lacking in statistical significance but they show that this field is of great interest for further research. Also, the methods proposed for deducing the toxicity levels are rudimentary but could serve well as a premise for further development.Närvaron av toxic order flow och predatoriska HFT-strategier i en flermarknadsmiljö är föga studerat i den akademiska världen. Denna avhandling studerar detta på en uppsättning marknader genom att undersöka okonsoliderad quote data och firma specifika trades, och på så vis ta fram marknadernas toxicity-nivåer. En metod för att fastställa marknadernas toxicity-nivåer presenteras tillsammans med proxys för toxic order flow, mer specifikt: förändringar i spread och quotad volym, efter en handel på en given marknad. Vi finner både tecken på toxicity och olika toxicityniv åer mellan marknaderna. Resultaten saknar dock statistisk signifikans men de visar ändå på att detta område är av stort intresse för ytterligare forskning. De metoder som föreslås för att fastställa toxicity-nivåerna är rudimentära, men kan tjäna som en utgångspunkt för vidare utveckling.
24
Yu, Yingzhong. "Approche générique des modes d'émissions de HFC-134a des systèmes de climatisation automobile." Phd thesis, École Nationale Supérieure des Mines de Paris, 2008. http://pastel.archives-ouvertes.fr/pastel-00004889.
Full textAbstract:
Les paramètres physiques à la base des fuites du fluide frigorigène HFC-134a dans les systèmes de climatisation automobile ne sont pas encore pleinement compris. Le but de ce travail de recherche est d'établir une méthode de mesures des débits de fuite de fluide frigorigène des systèmes de climatisation automobile ainsi que des composants de ces systèmes, et aussi de développer une approche générique de prévision de ces émissions. Dans la thèse, les fuites chroniques des différents composants des systèmes de climatisation automobile sont évaluées et hiérarchisées. Une méthode d'essais de laboratoire, basée sur la mesure de concentration dans un volume d'accumulation, est présentée pour déterminer les débits de fuite de systèmes et de composants. La précision de la mesure est aussi justifiée. Des mesures en régime permanent et pour plusieurs températures contrôlées sont effectuées afin de comparer le débit de fuite de l'ensemble du système et la somme des débits de fuite de tous les composants. Les simulations de la variation de température permettent de prédire les impacts des conditions climatiques annuelles quel que soit le climat. Les essais en régime dynamique sont également traités pour analyser la contribution du temps de fonctionnement du système aux émissions annuelles du système. Afin de vérifier la méthode d'essai en laboratoire, des opérations de récupération du fluide frigorigène ont été effectuées sur une quarantaine de véhicules avec une précision de +0 / -1 g. Sur la base des résultats des essais en laboratoire et de ceux obtenus sur la flotte de véhicules, un facteur de corrélation a été établi pour corréler les tests en laboratoire aux émissions mesurées sur le terrain. Les prévisions des émissions de tuyauteries flexibles utilisées dans les systèmes de climatisation automobile ont été développées en prenant en compte les effets de la température et de la pression. Les joints toriques typiques sont étudiés et deux modes de fuite: la perméation à travers des matériaux polymères et l'écoulement du gaz dans les micro-canaux sont distingués. Les performances d'étanchéité d'un joint torique radial sont étudiées en utilisant la méthode des éléments finis. Le comportement non-linéaire des déformations des polymères est pris en compte. L'analyse des facteurs principaux tels que la contrainte, la pression de contact maximale et le contact est basée sur les résultats de simulations numériques. Les deux modes de fuites permettent de comprendre les phénomènes clés des émissions et donc d'améliorer les performances d'étanchéité. En résumé, le débit de fuite d'un système de climatisation automobile est la somme des débits de fuite de toutes les sources de fuites. Ces sources sont de deux types: la perméabilité du gaz dans les polymères et l'écoulement du gaz dans les micro-canaux existant entre les joints et les parties métalliques des raccords. Pour chaque mode d'émission, une loi de comportement a été développée et les modèles prédictifs permettent de prévoir les débits de fuite avec un nombre limité de mesures.
25
MATTOS, ANA BEATRIZ VIEIRA DE. "HFT INVESTOR S IMPACT ON PRICE FORMATION IN THE BRAZILIAN FOREIGN EXCHANGE MARKE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=24313@1.
Full textAbstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
As mudanças tecnológicas e regulatórias foram facilitadores para o surgimento dos investidores de alta frequência, HFTs, no mix de participantes do mercado financeiro. Como classe, estes investidores não constituem uma entidade coerente e seu impacto e contribuição para a formação do preço não é clara. Esse trabalho analisou 10 categorias de investidores, que se diferenciam por suas características de latência, a partir de uma base de dados composta por todas as ordens enviadas para o book de dólar futuro com vencimento em 1 de agosto de 2013, da Bolsa de Valores e Mercadorias e Futuros (BMFBovespa). Dentre toda as categorias de instidores testadas, a categoria HFT 1, a mais rápida de todas, foi a que apresentou o maior coeficiente de impacto no preço, 20 por cento, e a maior medida de contribuição relativa para a volatilidade fundamental, 10 por cento.
Technological and regulatory changes were facilitators for the emergence of high frequency traders, HFTs, in the mix of financial market participants. As a class, these investors do not constitute a coherent entity and its impact and contribution to the price formation are not clear. This study analyzed 10 categories of investors, who are distinguished by their latency characteristics from a database comprised of all orders sent to the book of future dollar maturing on August 1, 2013, in the Brazilian Stock Exchange and Commodities and Futures Exchange (BMFBovespa). Among all the categories of investors tested, the HFT 1, the fastest of all, was the one that had the highest coefficient of impact on price, 20 per cent, and a larger measure of relative contribution to fundamental volatility, 10 per cent.
26
Moosavi, Atena, Sven Osterland, Dominik Krahl, Lutz Müller, and Jürgen Weber. "Numerical prediction and experimental investigation of cavitation erosion of hydraulic components using hfc." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71096.
Full textAbstract:
Hydraulic devices play an essential role in mechanical engineering due to their high-power density, good controllability, flexible application and high robustness, which expose innovative methods of energy transmission. However, in applications where there is an increased risk of fire or explosion, the commonly used combustible mineral oils represent an unacceptable safety hazard. In such cases, fireresistant, water-based hydraulic fluids are in demand. A special feature of these liquids is their high cavitation tendency and the associated strong erosion wear. The aim of this research is to predict the cavitation behaviour of HFC and the subsequent erosion phenomena using numerical methods and to validate the results with experiments. Additionally, experimental results for HFC were compared with HLP. The findings help to implement further developments to decrease the erosive effect of cavitation in high-pressure differences in hydraulic components. For this purpose, flow geometries of typical hydraulic components, e.g. valve and pump, are used for experimental and numerical investigation. The large-eddy simulation (LES) turbulent modelling is used with Zwart-Gerber cavitation model. The cavitation aggressiveness is quantified by cavitation erosion indices according to Nohmi.
27
Fouley, Aurélie. "Evaluation prédictive de la toxicité et de l'écotoxicité des principaux HCFC et HFC." Caen, 1996. http://www.theses.fr/1996CAEN4055.
Full text
28
Alanazi, Norah. "CALIBRATION OF THE HEAVY FLAVOR TRACKER (HFT) DETECTOR IN STAR EXPERIMENT AT RHIC." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1448026418.
Full text
29
Alruwaili, Manal Abluk. "PERFORMANCE OF THE HEAVY FLAVOR TRACKER (HFT) DETECTOR IN STAR EXPERIMENT AT RHIC." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1448032801.
Full text
30
Remes, J. (Janne). "The development of laser chemical vapor deposition and focused ion beam methods for prototype integrated circuit modification." Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514281403.
Full textAbstract:
Abstract
In this work the LCVD of copper and nickel from the precursor gases Cu(hfac)tmvs and Ni(CO)4 has been investigated. The in-house constructed LCVD system and processes and the practical utilisation of these in prototype integrated circuit edit work are described. The investigated process parameters include laser power, laser scan speed, precursor partial pressure and the effect of H2 and He carrier gases. The deposited metal conductor lines have been examined by LIMA, AFM, FIB secondary electron/ion micrography, and by electrical measurements.
Furthermore, the study of experimental FIB circuit edit processes is carried out and discussed with particular emphasis on ion beam induced ESD damages. It is shown how the LCVD and FIB methods can be combined to create a novel method to carry out successfully circuit edit cases where both methods alone will fail. The combined FIB/LCVD- method is shown to be highly complementary and effective in practical circuit edit work in terms of reduced process time and improved yield. Circuit edit cases where both technologies are successfully used in a complementary way are presented. Selected examples of some special circuit edit cases include RF- circuit editing, a high resolution method for FIB-deposited tungsten conductor line resistance reduction and large area EMI shielding of IC surfaces. Based on the research it was possible for a formal workflow for the combined process to be developed and this approach was applied to 132 circuit edit cases with 85% yield. The combined method was applied to 30% of the total number of edit cases. Finally, the developed process and constructed system was commercialized.
31
Ericson, Monica. "Börsrobotar och marknadsmanipulation : En rättsanalys av algoritmisk högfrekvenshandel i ljuset av MAR och MiFID II." Thesis, Stockholms universitet, Juridiska institutionen, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-194670.
Full textAbstract:
The landscape of equity trading changed when computer algorithms commenced to analyse large volumes of stock market data faster than a fraction of a second. Advances in technology have enabled trading algorithms to initiate, route, and execute orders on aspects of market timing, optimising order quantity, and deciding price parameters with limited human intervention. The distinctive features of high-frequency trading are low latency, high order to trade ratio, co-location, and short holding periods. Besides contributing to profitability, cost efficiency, and competitiveness, it has also amplified issues such as systemic risk and market disruption. European legal frameworks – in particular the Markets in Financial Instruments Directive II (MiFID II) and the Market Abuse Regulation (MAR) – have been and still are a response to this fairly new proprietary trading paradigm. This thesis interprets and analyses the risk mitigation and market manipulation requirements in order to clarify whether the legislation regarding high-frequency trading is compliant with the underlying appropriateness of MiFID II, MAR, and the Swedish Securities Act. The following two chapters provide an overview of the capital market with its participating actors and an outline of requirements for high-frequency trading investment firms. The ban on market manipulation is thereafter examined, systemised, and exemplified vis-à-vis fictitious transactions through manipulative schemes. Lastly, a case law analysis is conducted in respect of market abuse and defective trading algorithms. This thesis finds plausible causation between defective trading algorithms, investor confidence, and market manipulation. Nevertheless, high-frequency trading per se is not considered to meet the necessary prerequisites for market manipulation stated in MAR. Information provision is one of the foremost tools to mitigate risk linked to systemic events and disruptive markets. However, too extensive requirements can potentially inhibit innovation and infringe legal rights related to inter alia, intellectual property, exempli gratia, trade secrets.
32
Padilla, Gomez Miguel David. "Experimental study of third (HFC) and fourth generation (HFO) refrigerants during flow boiling in singularities." Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00715788.
Full textAbstract:
The refrigerant charge reduction in HVAC\R systems is an important issue because it falls within environmental policies regarding refrigerants contributions to the greenhouse effect. A way to move toward charge reduction is to increase the compactness of heat exchangers, which means more complex designs of the evaporators. Nevertheless, while a large amount of studies have has been published on the thermal and hydraulic analysis of flow boiling of refrigerants in horizontal tubes, very little attention has been given to flow boiling in geometries different from straight tubes. This PhD thesis aims at studying the flow boiling characteristics of third generation (HFC) and fourth generation fluids such as HFO-1234yf in geometries which modify the fluid dynamics and two-phase flow with respect to horizontal straight tubes. To achieve this goal, an experimental test facility was specifically designed and built to conduct refrigerant evaporation experiments. This test facility allowed to perform flow regimes visualizations and pressure drop measurements in singularities (such as sudden contractions and return bends). First, two-phase flow regimes visualizations have been carried out using HFO-1234yf, R-134a and R-410A either in straight tubes or in singularities. A qualitative analysis of the flow behavior and also several comparisons to flow pattern prediction methods from the literature were conducted. The second objective of this work was to characterize the flow disturbances caused by singularities such as sudden contractions and return bends, and to study their effects on the hydrodynamic performance (e.g. pressure drop) of refrigerants.Lastly, pressure drop databases for third and fourth generation refrigerants are presented.
33
Mattarredona, Edgar Antonio Costa. "Dos parametros de degradação do canal de retorno em redes hibridas fibra/coaxial (HFC) interativas." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261905.
Full textAbstract:
Orientador : Evandro ConfortiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-07-28T20:05:53Z (GMT). No. of bitstreams: 1 Mattarredona_EdgarAntonioCosta_M.pdf: 1277176 bytes, checksum: 86ae5ea6da667f07e5225456194a3d3e (MD5) Previous issue date: 2001
Mestrado
34
Yaddanapudi, Satvik Janardhan. "Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822762/.
Full textAbstract:
This study aims to experimentally investigate the spray cooling characteristics for active two-phase cooling of automotive power electronics. Tests are conducted on a small-scale, closed loop spray cooling system featuring a pressure atomized spray nozzle. Two types of refrigerants, HFC-134a (R-134a) and HFO-1234yf, are selected as the working fluids. The test section (heater), made out of oxygen-free copper, has a 1-cm2 plain, smooth surface prepared following a consistent procedure, and would serve as a baseline case. Matching size thick film resistors, attached onto the copper heaters, generate heat and simulate high heat flux power electronics devices. The tests are conducted by controlling the heat flux in increasing steps, and recording the corresponding steady-state temperatures to obtain cooling curves. The working fluid is kept at room temperature level (22oC). Performance comparisons are made based on heat transfer coefficient (HTC) and critical heat flux (CHF) values. Effects of spray characteristics and liquid flow rates on the cooling performance are investigated with the selected coolants. Three types of commercially available nozzles that generate full-cone sprays with fine droplets are utilized in the tests. Effect of liquid flow rate is evaluated varying flow rates at 2, 3, 4 ml/s. The experimental results obtained from this study provide a framework for spray cooling performance with the current and next-generation refrigerants aimed for advanced thermal management of automotive power electronics.
35
Chen, Chih Hsin, and 陳志欣. "The Characteristics of HfTaO and HfTiO High-K Layers Deposition by Reactive Sputtering of HfTa and HfTi Binary Target." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/97690042782218477066.
Full textAbstract:
碩士長庚大學
電子工程學研究所
96
Abstract As the dimensions of integrated circuits are being scaled down, the physical thickness of SiO2 has been aggressively scaled for high performance and low power complementary metal-oxide-semiconductor (CMOS) logic devices applications, but it will results in an increase of gate leakage current due to the direct tunneling effect. One solution for this issue is to replace SiO2 with high dielectric constant (high-K) materials as gate dielectrics, which provides a physically thicker film for the same electrically equivalent oxide thickness (EOT). Therefore, direct tunneling of carriers can be effectively suppressed. In this study, in order to further increase the crystallization temperature and dielectric constant of the most promising high-k gate dielectric, HfO2. The HfTa and HfTi binary target was prepared to form the HfTaO and HfTiO thin films as the gate dielectrics, for the first time. The gate dielectrics with different gas sources post deposition annealing such as N2, O2 and N2O at different annealing temperature were discussed electrically and physically. The HfTaO and HfTiO gate dielectric shows the higher crystallization temperature and dielectric constant, respectively. The hysteresis voltage and frequency dispersion of HfTaO and HfTiO MOS capacitors were effectively improved by post deposition annealing treatments. Moreover, the frequency dispersion will be further improvement by incorporating nitrogen in the gate dielectrics. A physical model of dipole structures was proposed explaining the nitrogen incorporation phenomenon.
36
陳志瑋. "Study on fault rcover for HFC networks." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/63197608496986589388.
Full text
37
Guo, Xin-Feng, and 郭欣峰. "Timestamp Media Access Control for HFC Network." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/69237624756684255531.
Full textAbstract:
碩士義守大學
資訊工程學系
90
Providing QoS guarantees in Hybrid Fiber Coaxial (HFC) networks is a very important and challenging problem. Medium Access Control (MAC) protocol and upstream channel scheduling algorithm are two key mechanisms that will affect the degree of QoS guarantees of HFC networks. Due to the long round-trip propagation delay, uncertain request access delay, and resource reservation without time information, the upstream channel scheduler in the headend cannot obtain the real cell arrival time at the stations. Thus, with the same input traffic, the cell transmission order in HFC networks would be different to the order in traditional switching networks. Therefore, this thesis proposes a new MAC protocol, called Time-stamp General-Contention Resolution Algorithm (TG-CRA), to provide the cell arrival time information to the upstream scheduler in the headend. In order to reduce the overhead of the time information, a linear offset scheme is used to stamp the arrival time information of new arrival cells on the request. Compare to the G-CRA algorithm, simulation result shows that the TG-CRA algorithm can yield better performance in reducing the uncertain request delay and cell access delay. The variance of cell access delay is also reduced, thus the TG-CRA algorithm can provide better mean delay jitter.
38
YUAN, CHENG YING, and 袁成英. "HFT spoofing strategy 、performance and stock volatility." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/t57n9v.
Full textAbstract:
碩士國立中山大學
財務管理學系研究所
102
I analysis a spoofing strategy in which high frequency trading spoof and mislead the investors through placing large orders with little chance of being executed to cause an order imbalance. And at the same time high frequency trading trade opposite with less transaction cost. Using the complete intraday order and trade data of the Taiwan Exchange in a custom data set identifying individual accounts, I find that spoofing strategy is used often especially a dealer(Proprietary trader) use it sixty-nine times each day. To spoof and mislead the other traders ,high frequency trading place orders between the best third and fourth bid/ask which are little chance of being executed but will be disclosed in the order book .With the large negative orders, high frequency trading sometimes can cause a serious order imbalance which reduce the effectiveness of the order-disclosure rule obviously. What’s more, with the use of spoofing strategy, high frequency trading can achieve substantial extra profits and increase the intraday stock volatility.
39
Lee, Mike Y. J., and 李耀中. "Evolution and emerging trends in HFT research." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/mbfxts.
Full textAbstract:
博士國立政治大學
資訊管理學系
107
In this research, the evolution and emerging trends of High Frequency Trading (HFT) research is conducted by examining papers published in the Web of Science (WOS) from 1993 to 2017. A total of 241 papers are included, and 1876 keywords from these articles were extracted and analyzed. For tracing the dynamic changes of the HFT Research, the whole 24 years are further separated into three consecutive periods: 1993-2002, 2003-2012, and 2013-2017. The Ucinet is adopted to get keywords network, or knowledge network, to study the relationship of each research theme. NetDraw is applied to visualize network. The social network analysis (SNA) technique is used to reveal patterns and trends in the research by measuring the association strength of terms representative of relevant publications produced in HFT field. Results indicate that HFT research has been strongly influenced by these keywords: “market”, “prices”, “finance”, “liquidity”, “statistics”, “financial markets”, “stock”, “stochastic”, “model” and “trades” as shown in Table 3, which represent some established research themes. These are major focuses and the bridges connecting to other research themes in HFT. The detailed analysis in “Discussions and implications” provides an overview of evolution and emerging trends in HFT Research. It concludes that “market performance” related keywords, which represent some established research themes, have become the major focus in HFT research. It also changes rapidly to embrace new themes. Especially, this research may make contribution to enlarge research method in that there is no SNA research in HFT research before.
40
lee, Chun-Hong, and 李俊弘. "MAC Protocols over HFC in Interactive CATV Network." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/52059938727494676679.
Full textAbstract:
碩士國立交通大學
資訊科學學系
86
To provide residential users with multimedia interactive services, ahigh bandwidth access network solution is required. In this work, we focus on using existing CATV networks to provide high bandwidth interactive services. We first introduce the HFC(Hybrid FiberCoax) architecture of CATV network adnd idscuss the problems in providingtwo way communication over HFC. Second, we discuss the important issues in upstream channel protcol design: 1) overlapping the collision resolution anddata transmission to archive best usage of bandwidth, in which we examine how to arrange the request mini-slots and data transmission; 2) resolving collision, in which we discuss several traditional collision algorithms; 3)resolving the synchronization problem, in which we propose our solution to getthe RTC(Round Trip Correction) parameter. Third, we introduce several proposed IEEE 802.14 protocols for upstream channel and compar these protocols.
41
Wu, Hui-Chun, and 吳慧君. "Best Selection of Refrigerant Compressor with HFC-245fa." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/ub4vrn.
Full textAbstract:
碩士國立臺北科技大學
能源與冷凍空調工程系碩士班
101
The study intends to select from the market a compressor that meets the operation specifications of HFC-245fa refrigerant, and use the compressor to achieve effectiveness of HFC-245fa. After experiments are conducted, the study employs theoretical analysis and actual compression system to compare the difference among refrigerating and heating capacities, COPL and COPH under different evaporation temperatures and condensing temperatures. Research results show that HFC-134a refrigerant is most similar to HFC-245fa refrigerant. The study conducts actual simulation tests and measurement of these 2 refrigerants under 9 conditions (TYPE 1 ~ TYPE 9) that use 3 different condensing temperatures 7.2oC, 12.2oC, 17.2oC (HFC-134a) and 49oC, 55oC, 60oC (HFC-245fa) and 3 different evaporator temperatures 35oC, 45oC, 55oC (HFC-134a) and 80oC, 92oC, 103oC (HFC-245fa). Test results show that CAPH, CAPL, COPH and COPL of HFC-245fa are 74%~85% of those of HFC-134a. As to compressor, compressor power loss actually produced by HFC-245fa is 110~112% of that of HFC-134a. These results show that overall efficiency in terms of COP can reach as high as 80%; power loss of compressor increases by 10%; and its operating state was close to that of HFC-134a. Therefore, the compressor can be selected to load HFC-245fa.
42
Wu, Chia-Jen, and 吳加任. "A HFC MAC Protocol for Interactive CATV Networks." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/48903837986033878154.
Full textAbstract:
碩士國立交通大學
資訊科學學系
84
While ATM (Asynchronous Transfer Mode) serves as the backbone of our NII (National Information Infrastructure), the prevailing cable TV networks may serve as the NII community networks that span the infrastructure into the homes. However, in order to support these services to the residential users, the community cable TV networks have to be redesigned to support 2-way interactive communication. In this work, we propose PCUP (Pipelined Cyclic Upstream Protocol) as the upstream MAC (Medium Access Control) protocol for HFC (Hybrid Fiber Coax) community access network. PCUP is designed with the intention of pipelining the upstream channel. This is achieved by proper station positioning, which measures the station propagation offset from the headend, and transmission scheduling, which assigns each station the transmission starting time and duration in a cycle. By taking into account the propagation offsets and the transmission times, transmitted cells can appear back-to-back, i.e. pipelined, at the headend. Since only the active stations are scheduled to transmit in a cycle, a membership control mechanism, which runs a contention-based tree walk algorithm, is executed periodically to allow the stations to join or leave. We evaluate the behavior of our protocol through simulations to show the effectiveness with respect to loss ratio, throughput, delay, and setup latency. Comparisons with R-ALOHA (Reservation Slotted ALOHA) and CSMA/CD are also made. The results confirm PCUP's excellent performance.
43
Wong, J. K., and 翁佳愷. "DWDM EDFA Design and Implementation for HFC Systems." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/83976018519519490964.
Full textAbstract:
碩士國立交通大學
電信工程系
87
In this thesis, we have designed and implemented EDFAs for HFC networks applications. We first studied the properties of EDFA, especially the gain model and gain dynamics. Finally, we designed and implemented two kind of EDFAs, one for power amplifiers in the head end and another one is suitably used with DWDM techniques.
44
Břenek, Roman. "Automatické rozpoznávání zpěvu ptáků." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-178596.
Full textAbstract:
This master thesis deals with methods of automatic recognition of bird species by their voices. In first, I defined the database of records and created a reference data by handmade evaluation. The next step is to find the optimal features for describing a bird singing. I use a Human Frequency cepstral Coefficients (HFCC). For the best accuracy of recognition is necessary to correctly classify a bird's vocalization from a non-vocalization segments. The VAD system is based on an algorithm k-Nearest Neighbours. The last step describes the system based on Hidden Markov Models which allows to recognize the concrete bird species from the parts of bird's singing.
45
Lin, Chin Feng, and 林晉鋒. "Dynamic Two-Way Data Communications Study over HFC Networks." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/73513168651531686339.
Full text
46
Lai, Hung-Chang, and 賴宏昌. "Adaptive contention period for performance improvement in HFC networks." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/82134790061873933830.
Full text
47
Tseng, Chih-Yuan, and 曾志遠. "Two-Step Growth of MOCVD Copper Using Cu(hfac)2 as the Precursor." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/67277989140551696758.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
90
The purpose of this paper is to investigate the two-step growth of MOCVD copper using Cu(hfac)2 as the precursor. In the first step, we pre-deposit Cu2O films with water as the additive because precursor’s partial pressure is unstable during deposition without water additive. In contrast to H2, H atoms which are produced due to dehydrogenation reaction of ethanol alcohol can be used to reduce Cu2O films at lower temperatures and enhance the reaction rate .The Cu atom in Cu2O films(24％) is the catalyst. The mixture of ethanol alcohol and water can be used to increase Cu atoms in Cu2O films (50％). More Cu atoms in the Cu2O films can cause the increase of nucleation sites, decrease of grain size, and then increase of grain density.
48
Chang, Wen-Hao, and 張文豪. "HFTG Feature Extraction for Metaheuristic HW/SW-Partitioning：An H.264 encoder case study." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/85593873064635690482.
Full textAbstract:
碩士聖約翰科技大學
電機工程系碩士班
99
The decision accuracy of hardware/software partitioning is now playing a key role towards success for an embedded system design. Recently, meta-heuristic algorithms such as GA or PSO are often exploited for solving the decision problems. Unfortunately, the use of single fitness value for the algorithm is difficult to present the design quality that concerned the factors of performance, cost, power consumption, communication latency and chip area, etc. So that bad decisions are often obtained. In this paper, we proposed a novel Hot Function Task Group (HFTG) feature extract algorithm to improve the decision efficiency of meta-heuristic algorithms. The goal is originally to avoid the trap of decision and then reduce the complexity of design space. First, we explore the call-graph structure for the functions in a system. Next, we modify fitness function based-on the cost of interface communications to extract groups. Then delete the decision points that have high communication cost to them. Finally, the control-data-flow-graph (CDFG) of the rest functions and the features are delivered to the meta-heuristic algorithms for hardware-software partitioning. For testing the efficiency of the algorithm, a JM-code of H.264 encoder, the advanced video coding standard, is employed as the study case. While extracting 79 functions from 163 functions of H.264, it results in obtaining six groups of HTFGs which occupying more than half of the system execution time. It revealed that HTFG feature extraction method chooses the blocks with high complexity and relatively simple interfaces for accelerating and avoids un-proper hardware-software calling style. The HTFG method that can do correct partition and implementation for functions in a system is proved to be valuable in the field of hardware/software co-design.
49
Chien, Chih-Ching, and 簡誌慶. "Study of hflC and related genes in tellurite reduction in Pseudomonas sp. TeU." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/22618206184562580129.
Full textAbstract:
碩士元智大學
生物科技與工程研究所
99
A Pseudomonas strain TeU resistant to tellurite (TeO32-) and cadmium (Cd2+) ions was isolated from heavy-metal contaminated sediments by enrichment. Transposon mutagenesis of strain TeU resulted in mutants exhibiting Cd2+ sensitivity (Strain BU21) and one with decreased ability to reduce tellurite (strain AU08). Genes encoding an HflKC complex and an putative metallopeptidase were identified to be associated with the bacterium’s ability for tellurite reduction and cadmium resistance, respectively. We have cloned and sequenced the hflC and metallopeptidase gene of strain TeU. Metallopeptidase gene of strain TeU was cloned and expressed in E. coli in order to investigate if the protein could improve the bacterium’s ability to resist cadmium.Transmission electron microcopy was also employed for to observe metal precipoitation when strain TeU grown in the medium containing tellurite.
50
Nitinkumar, D. Banker. "Development Of An Activated Carbon+ HFC 134a Adsorption Refrigeration System." Thesis, 2006. http://hdl.handle.net/2005/443.
Full textAbstract:
The demands facing the refrigeration industry are minimal usage of conventional energy sources for compression and avoidance of ozone depleting substances. One of the approaches to combat these issues is the use of thermally driven solid sorption compression with non-ozone depleting refrigerant. In this context, the research work presented in this thesis is devoted to a comprehensive thermodynamic analysis and development of a laboratory model of an activated carbon+ HFC 134a adsorption refrigeration system. The cooling load catered to by the laboratory model is 2-5 W, mainly for thermal management of electronics.
A complete thermodynamic analysis is carried out for the desorption temperatures varying from 75 to 90 oC, evaporating temperatures from -20 to 15oC and adsorption/condensing temperatures from 25 to 40 oC. A program on MatLab platform is developed for theoretical modeling. A new concept of thermal compression uptake efficiency (u) which is analogous to volumetric efficiency of a positive displacement compressor is introduced to consider the effect of void volume. The thesis also covers an investigation of two-stage and hybrid (thermal+ mechanical) cycle compression systems. It is possible to identify the conditions under which a two-stage gives a better performance than a single-stage one. It also shows that hybrid cycle system gives the best performance and saves ~40% of power compared to operation under the same conditions run with a single-stage mechanical compression refrigeration system.
A heat transfer analysis of the thermal compressor is carried out to evaluate non-uniformities in bed temperature. As a part of it, the thermal conductivity of the bed under adsorbed state has been calculated.
A laboratory model of activated carbon+ HFC 134a adsorption refrigeration system is fabricated to meet a 2-5 Watts cooling load based on the results from theoretical calculations. Experimental results show a fair match in the trends for the COP with analysis. The main aim of the research was to examine how effective the adsorption refrigeration system is in reducing the temperature rise of the heater used to simulate the electronic component. The heater that would have stabilized at 81, 97, 103 and 112 oC without any cooling for heat inputs of 3, 4, 4.4 and 4.9 W, respectively, would attain a cyclic steady state around 24, 26, 28, 31 oC. The influence of cycle time on the performance of the systems is also investigated.
It is concluded that an activated carbon+ HFC 134a adsorption refrigeration system can be a good supplement to conventional compression refrigeration systems. In situations where heat recovery imminent this system could be a good choice. For waste heat recovery and suppression of infrared signatures of electronic components, it is ideally suited where COP becomes immaterial.