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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Investigation of Inverted and Active Pedagogies in Introductory Statistics

Abbasian, Reza O., Czuchry, Mike 01 January 2020 (has links)
In this paper, we will introduce partial results from our 3-year NSF funded grant titled “Inverted and Active Learning Pedagogies (IALP) for Student Success.” We will present our results comparing student achievement between inverted (flipped) classrooms and traditional lecture formats in statistics classes at Texas Lutheran University. Included are a brief introduction, the study design, data gathering, faculty and students’ surveys, and the methodology used for the study. We will share results from instruments that were developed to measure different levels of cognitive understanding across multiple sections of the same introductory statistics classes. We will also examine grades, withdrawals, potential professor effects, student characteristics, class size effects, video saturation, accountability of students for watching videos, and student evaluations of various activities in the classroom.
12

A numerical method for describing the inverted load duration curve as a sum of two normal probability distributions

Dickson, John S. January 1985 (has links)
No description available.
13

Analysis, Design, and Operation of a Spherical Inverted-F Antenna

McDonald, Jacob J. 2009 May 1900 (has links)
This thesis presents the analysis, design, and fabrication of a spherical inverted-F antenna (SIFA). The SIFA consists of a spherically conformal rectangular patch antenna recessed into a quarter section of a metallic sphere. The sphere acts as a ground plane, and a metal strip shorts the patch to the metallic sphere. The SIFA incorporates planar microstrip design into a conformal spherical geometry to better meet the design constraints for integrated wireless sensors. The SIFA extends a well-established technology into a new application space, including microsatellites, mobile sensor networks, and wireless biomedical implants. The complete SIFA design depends on several parameters, several of which parallel planar design variables. A modified transmission line model determines the antenna input impedance based on the sphere's inner and outer radii, the patch length and width, short length and width, and feed position. The SIFA can be tuned to the desired frequency band by choosing the proper outer radius, after which the antenna can be matched by tuning the short characteristics, patch dimensions, and feed position. The fabricated design was chosen to operate at the MICS band (402-405 MHz), a popular band for biomedically implanted devices. An initial design was constructed with Styrofoam (epsilon r approximately equal to 1) and copper tape. Simulation in HFSS corroborates that SIFA operation incorporates the MICS band, with resonant frequency of 404 MHz and 32 MHz (7.9%) bandwidth. The fabricated prototype performs similarly, with a resonant frequency of 407 MHz and 19 (4.7%) MHz bandwidth. Following fabrication, several modifications were implemented to miniaturize the SIFA and introduce additional functionality. Slot loading and dielectric coating were implemented to achieve SIFA miniaturization. Multiple elements were also introduced to achieve dual band operation and beam steering. A miniaturized SIFA was investigated in several biological media, and a lossy coating implemented to maintain impedance match in several different media, with the goal of retaining a matched impedance bandwidth in the MICS band.
14

A band-suppression UWB suspended planar antenna incorporating a slotted spiral resonator

See, Chan H., Abd-Alhameed, Raed, Hraga, Hmeda I., Excell, Peter S., Jones, Steven M.R., Noras, James M. 19 November 2012 (has links)
No / A novel miniaturized planar inverted F-L antenna assembly is considered for UWB radio operations. The antenna design utilizes the electromagnetic coupling between an air dielectric planar inverted-F antenna (PIFA) and a parasitic planar inverted-L (PIL) element, with broadband feeding from a rectangular plate. To improve the functionality of the channel, a simple notch filter has been introduced through a local modification to the broadband feed plate, this takes the form of a simple slotted rectangular spiral resonator which is etched directly onto the plate. This allows the proposed antenna to maintain its full band UWB coverage, with the HYPERLAN/2 band centered at 5.35 GHz to be effectively rejected over the sub-band 5.15–5.725 GHz, without the need for substantial re-optimization of its principal structure parameters. The impedance bandwidth operates over the full UWB band, with VSWR better than 2, this performance is not degraded by the presence of the band rejection. The observed gains, radiation patterns, and group delay confirm that the antenna has appropriate characteristics for short range wireless applications.
15

Design of Planar Double Inverted-F Antenna for Ultra-Wideband Applications

See, Chan H., Abd-Alhameed, Raed, Zhou, Dawei, Excell, Peter S. 2010 September 1922 (has links)
yes / A novel miniaturized planar double inverted-F antenna is presented. The antenna design is based on the electromagnetic coupling of two air dielectric PIFA antennas, combined with a broadband rectangular plate feed structure to achieve ultra-wideband characteristics. The computed and experimental impedance bandwidths show good agreement over an UWB frequency band from 3.1 GHz to 10.6 GHz for |S11| < -10dB. The antenna is electrically small, with size 0.31 x 0.16 x 0.09 wavelengths at 3.1 GHz and 1.06 x 0.55 x 0.31 wavelengths at 10.6 GHz. The simulated and measured gain and radiation patterns show acceptable agreement and confirm that the antenna has appropriate characteristics for short range wireless applications. / MSCRC
16

SemIndex: Semantic-Aware Inverted Index

Chbeir, Richard, Luo, Yi, Tekli, Joe, Yetongnon, Kokou, Raymundo Ibañez, Carlos Arturo, Traina, Agma J. M., Traina Jr, Caetano, Al Assad, Marc, Universidad Peruana de Ciencias Aplicadas (UPC) 10 February 2015 (has links)
carlos.raymundo@upc.edu.pe / This paper focuses on the important problem of semanticaware search in textual (structured, semi-structured, NoSQL) databases. This problem has emerged as a required extension of the standard containment keyword based query to meet user needs in textual databases and IR applications. We provide here a new approach, called SemIndex, that extends the standard inverted index by constructing a tight coupling inverted index graph that combines two main resources: a general purpose semantic network, and a standard inverted index on a collection of textual data. We also provide an extended query model and related processing algorithms with the help of SemIndex. To investigate its effectiveness, we set up experiments to test the performance of SemIndex. Preliminary results have demonstrated the effectiveness, scalability and optimality of our approach.
17

O movimento quântico em potencial de um oscilador invertido / The quantum motion in a inverted oscillator potential

Macêdo, Edmilson dos Santos 21 May 2013 (has links)
Esta dissertação descreve o movimento quântico de uma partícula numa barreira de potencial parabólica, condicionalmente este sistema é chamado de oscilador invertido. Determinamos estados quânticos semiclássicos como família de estados coerentes generalizados (ECG), sendo construídos através da adaptação do trabalho de Malkin e Man´ko, determinando-se um operador que seja integral do movimento, parametrizado por algumas constantes e reconhecido como operador de aniquilação, cujos auto-estados tem características dos estados comprimidos. Discutimos suas propriedades e observamos que é possível comparar ECG do oscilador invertido com ECG da partícula livre e oscilador harmônico obtidos na literatura. Também é feito um estudo do movimento puramente quântico (tunelamento) nas barreiras de potenciais do oscilador invertido e oscilador invertido truncado, por meio das soluções estacionárias exatas e aproximadas (JWKB), comparando os resultados obtidos em cada situação. / This dissertation describes the motion of a particle in a quantum potential barrier parabolic, this system is conditionally called inverted oscillator. Determined quantum states semi-classics like family generalized coherent states (GCS), being constructed by adapting work Malkin\'s and Man\'ko, determining an operator who is integral of the motion, parameterized for some constants and recognized as annihilation operator, whose eigenstates have characteristics of squeezed states. We discuss its properties and note that it is possible to compare the GCS of inverted oscillator with GCS the particle free and harmonic oscillator obtained in the literature. Also made a study of the movement purely quantum (tunneling) in the barriers potential inverted oscillator and truncated inverted oscillator by means of exact and approximate stationary solutions (JWKB), comparing the results obtained in each situation.
18

Clinico-pathological characteristics of sinonasal inverted papilloma. Are they unique in Hong Kong?.

January 2012 (has links)
Introduction: Sinonasal inverted papilloma (SNIP) is an uncommon benign tumor with a high recurrence rate, significant malignant potential and unknown etiology. The population in Hong Kong is unique in its high population density and having a majority of Chinese people who are ethnically and geographically predisposed to certain cancers. Research on the etiology, pathogenesis, diagnosis and treatment of the neoplasm and comparison with reported findings from other parts of the world may contribute to management of the condition in terms of prevention, staging and treatment. / Aims: The aim of the thesis is to describe the common and unique clinico-pathological characteristics of SNIP in Hong Kong and compare these with reported characteristics in populations from other geographical areas and in other races with the expectation of attaining new insights into the diagnosis and management of SNIP in Hong Kong patients. / Methods: Four studies designed to evaluate the risk factors, viral associations, cell-cycle protein expression, radiological features, clinical features, treatment approaches and treatment outcomes were conducted. The findings of these studies were compared with those reported from different geographical areas of the world. Study 1: Evaluation of the risk factors associated with SNIP by a case-controlled epidemiological study of 50 patients with SNIP and 150 matched control patients. Study 2: Evaluation of the prevalence of human papillomavirus (HPV), Epstein-Barr virus (EBV), p21 and p53 expression in SNIP and comparison with reports from the literature. In a case-control study, 73 SNIP, 48 nasal polyps (NP) and 85 hypertrophied turbinates (HT) specimens were examined by polymerase chain reaction (PCR) for HPV. Seventy-three SNIP, 30 NP and 32 HT specimens were examined by in-situ hybridization (ISH) for EBV and by immunohistochemistry (IHC) for p21 and p53. SNIP results were compared with those of NP and HT (as controls). Study 3: Evaluation of the radiological signs, accuracy of prediction of tumor origin and extent, and accuracy of preoperative staging of SNIP of plain computed tomography by an observational study of plain CT scans and operative findings from 30 patients with SNIP. Study 4: Evaluation of the clinico-pathological features and treatment outcomes of SNIP in 56 patients seen between 1990 and 2008 with follow-up of more than 2 years and comparison with the results of the literature. / Results and conclusions: There are certain unique clinico-pathological features of sinonasal inverted papilloma (SNIP) in Hong Kong which are related to its predominantly Chinese population, high population density, heavy pollution and, accessible and efficient specialist services. Concordant with the results of another case-control study in the literature, the study described herein demonstrated that occupational chemical exposure, but not smoking, is a risk factor for SNIP. This is the first case-control study demonstrating that alcohol intake, allergic rhinitis, nasal polyposis, sinusitis, non-sinonasal papilloma and non-sinonasal malignancy are not risk factors for SNIP. The low prevalence of HPV in non-malignant sinonasal inverted papillomas (NMIPs) in Hong Kong suggests that it does not play a significant pathogenic role. The absence of EBV in SNIPs in Hong Kong concurs with most reports that EBV is not a causative agent. The high p21 and low p53 expression in SNIPs compared with the average values reported from other studies further support the presence of a non-p53-dependent p21 regulatory pathway. The higher prevalence of both HPV and p53 in malignant sinonasal inverted papilloma (MIP) than in NMIP agrees with other reports that both could be markers of malignant transformation. However, their inverse relation suggests they are independent factors. Although most plain CT signs are the same as those previously reported and not pathognomonic for SNIP, the high predictive value of the “pedunculation sign and absence of intra-tumor calcification are unique to Hong Kong patients. Concordant with other reports, “bony strut or focal hyperostosis is highly accurate in predicting the site of SNIP origin. This is the first report on the accuracy of preoperative CT staging, which is slightly lower than that of preoperative MRI staging (80% versus 86%). The estimated incidence of SNIP (2.4/1,000,000/year) is low but may be an underestimation as the number from the private sector is undetermined. The male:female ratio of SNIP patients in both Hong Kong and Asia is low, suggesting a geographic or racial influence on sex predilection. The absence of extrasinonasal extension, low rates of cellular atypia, dysplasia and synchronous malignancy in the Hong Kong SNIPs may reflect less aggressive tumor behavior as well as accessibility to efficient specialist services. The distribution of tumor origins, presenting symptoms and presenting stages of the Hong Kong SNIPs are similar to those reported elsewhere. The higher recurrence rate in the Hong Kong series is related to inadequate treatment of the tumor origin and inadequate conversion to combined external approaches in the early cases. Contrary to previously reported statistics, combined extranasal approaches were used more often in secondary cases than in primary cases. As in previously reported series, the recurrence rate in secondary cases tended to be higher than that in primary cases. Concordant with previous reports from the endoscopic era, most recurrences in Hong Kong occurred at the original tumor site and were discovered within the first 2 years after surgery. The average time of diagnosis of the first recurrence was much shorter than that of the pre-endoscopic era (1.2 years vs. 4.3 years). As reported elsewhere, about one-third of recurrences required combined external approaches for salvage. This is the first report comparing 2-, 5- and 10-year-follow-up results, and suggesting a minimum of 2 years’ follow-up before reporting results to avoid underestimation of recurrences. / Sham, Cheuk-lun. / Thesis (M.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 215-237). / CHAPTER 1 / Introduction / Chapter 1.1 --- Sinonasal inverted papilloma --- p.1 / Chapter 1.1.1 --- Nomenclature and classification --- p.1 / Chapter 1.1.2 --- Etiology and pathogenesis --- p.4 / Chapter 1.1.3 --- Gross and histological pathology --- p.9 / Chapter 1.1.4 --- Site of tumor attachment and extension --- p.10 / Chapter 1.1.5 --- Association with malignancy --- p.11 / Chapter 1.1.6 --- Incidence and demographics --- p.11 / Chapter 1.1.7 --- Clinical features --- p.12 / Chapter 1.1.8 --- Radiological features --- p.13 / Chapter 1.1.9 --- Staging --- p.14 / Chapter 1.1.10 --- Treatment modalities --- p.16 / Chapter 1.1.11 --- Treatment outcomes, recurrence and residual disease --- p.17 / Chapter 1.2 --- Unique characteristics of the Hong Kong population --- p.19 / Chapter 1.3 --- Research aims, areas and hypotheses --- p.22 / Chapter 1.3.1 --- Research aims --- p.22 / Chapter 1.3.2 --- Research areas and hypotheses --- p.23 / Chapter 1.4 --- Research plan and methodology --- p.25 / Chapter 1.5 --- Summary of Chapter 1 --- p.28 / CHAPTER 2 / Risk factors associated with SNIP / Chapter 2.1 --- Background --- p.29 / Chapter 2.2 --- Hypothesis --- p.29 / Chapter 2.3 --- Patients and methods --- p.30 / Chapter 2.4 --- Results --- p.35 / Chapter 2.5 --- Discussion --- p.39 / Chapter 2.6 --- Summary of Chapter 2 --- p.45 / CHAPTER 3 / Evaluation of the prevalence of HPV, EBV, p21 and p53 expression in SNIP in Hong Kong and comparison with results reported in the literature / Chapter 3.1 --- Background --- p.46 / Chapter 3.2 --- Hypothesis --- p.48 / Chapter 3.3 --- Patients and methods --- p.48 / Chapter 3.4 --- Results --- p.55 / Chapter 3.4.1 --- Overall results --- p.55 / Chapter 3.4.2 --- Comparison of the results of HPV studies --- p.57 / Chapter 3.4.3 --- Comparison of the results of EBV studies --- p.68 / Chapter 3.4.4 --- Comparison of the results of p21 studies --- p.71 / Chapter 3.4.5 --- Comparison of the results of p53 studies --- p.74 / Chapter 3.5 --- Discussion --- p.79 / Chapter 3.5.1 --- HPV and SNIP --- p.79 / Chapter 3.5.2 --- EBV and SNIP --- p.95 / Chapter 3.5.3 --- p21 and SNIP --- p.98 / Chapter 3.5.4 --- p53 and SNIP --- p.103 / Chapter 3.6 --- Summary of Chapter 3 --- p.115 / CHAPTER 4 / Evaluation of the radiological signs, accuracy of prediction of tumor origin and extent, and accuracy of preoperative staging of SNIP by plain computed tomography / Chapter 4.1 --- Background --- p.117 / Chapter 4.2 --- Hypothesis --- p.118 / Chapter 4.3 --- Patients and methods --- p.118 / Chapter 4.4 --- Results --- p.120 / Chapter 4.5 --- Discussion --- p.135 / Chapter 4.6 --- Summary of Chapter 4 --- p.142 / CHAPTER 5 / Evaluation of the clinico-pathological features and treatment outcomes of SNIP and comparison with results reported in the literature / Chapter 5.1 --- Background --- p.143 / Chapter 5.2 --- Hypothesis --- p.144 / Chapter 5.3 --- Patients and methods --- p.144 / Chapter 5.4 --- Results --- p.148 / Chapter 5.4.1 --- Incidence --- p.148 / Chapter 5.4.2 --- Demographics --- p.150 / Chapter 5.4.3 --- Presenting symptoms --- p.154 / Chapter 5.4.4 --- Site of tumor origin --- p.156 / Chapter 5.4.5 --- Rate of association with malignancy --- p.158 / Chapter 5.4.6 --- Staging of disease (Krouse system) and recurrence rate --- p.163 / Chapter 5.4.7 --- Treatment approaches and recurrence rates --- p.165 / Chapter 5.4.8 --- Comparison between patients with and without previous surgery --- p.167 / Chapter 5.4.9 --- Time and site of recurrence --- p.170 / Chapter 5.4.10 --- Surgical approaches used in salvage surgery --- p.175 / Chapter 5.4.11 --- Complication rate --- p.176 / Chapter 5.5 --- Discussion --- p.178 / Chapter 5.5.1 --- Incidence --- p.178 / Chapter 5.5.2 --- Demographics --- p.179 / Chapter 5.5.3 --- Present symptoms and duration --- p.180 / Chapter 5.5.4 --- Sites of tumor origin --- p.181 / Chapter 5.5.5 --- Association with malignancy --- p.182 / Chapter 5.5.6 --- Disease stages (Krouse system) and recurrence rate --- p.184 / Chapter 5.5.7 --- Treatment approaches and recurrence rates --- p.186 / Chapter 5.5.8 --- Comparison between patients with and without previous surgery --- p.187 / Chapter 5.5.9 --- Time and site of recurrence --- p.189 / Chapter 5.5.10 --- Surgical approaches used in salvage surgery --- p.191 / Chapter 5.5.11 --- Complication rate --- p.192 / Chapter 5.5.12 --- Management principles based on clinico-pathological features --- p.193 / Chapter 5.6 --- Summary of Chapter 5 --- p.197 / CHAPTER 6 / Summary of thesis and future perspective --- p.201 / REFERENCES --- p.215 / APPENDIX / Questionnaire for study of risk factors of SNIP --- p.238
19

Biomimetic Studies of Oxidation Reactions by Metalloporphyrins through Ligand Effect and Kinetic Studies of Photo-Generated Porphyrin-Iron(Iv)- Oxocompound II Models

Patel, Dharmesh J 01 April 2018 (has links)
High-valent iron(IV)-oxo porphyrins are the central oxidizing species in hemecontaining enzymes and synthetic oxidation catalysts. Many transition metal complexes have been extensively studied as models of the ubiquitous cytochrome P450 enzymes to probe the sophisticated oxygen atom transfer (OAT) mechanism as well as to invent enzyme-like oxidation catalysts. In this work, two metalloporphyrin complexes have been successfully synthesized, and spectroscopically characterized. A new photochemical entry to porphyrin-iron(IV)-oxo derivatives, commonly referred to as compound II models, was also investigated in two porphyrin ligands that differ in electronic and steric environments. As determined by their distinct UV-vis spectra and kinetic behaviors, iron(IV)-oxo porphyrins [FeIV(Por)O] were successfully produced by visible light irradiation of highly photo-liable porphyrin-iron(III) bromates. The iron(IV)-oxo porphyrins investigated in this study include 5,10,15,20- tetra(pentafluorophenyl)porphyrin-iron(IV)-oxo (4a), and 5,10,15,20-tetra(2,6- difluorophenyl)porphyrin-iron(IV)-oxo (4b).
20

Flippad matematik : Elevers uppfattningar av det inverterade klassrummet / Flipped mathematics : Student perceptions of the inverted classroom

Fors, Rickard January 2012 (has links)
I det inverterade klassrummet flyttas genomgångarna från klassrummet till videofilmer som eleverna ser på hemma. Lektionerna ägnas till stor del åt sådant som annars hade utgjort hemarbete för eleven. I denna studie analyseras gymnasieelevers uppfattning av denna undervisningsmodell i matematikämnet med fokus på videogenomgångarna och förändringar i hem- och skolarbete. Det framkommer att elevernas uppfattningar av videogenomgångarna kan kategoriseras utifrån deras grad av aktivitet under videogenomgången samt deras beroende av relationen mellan elev och lärare. I en jämförelse mellan enkla filmer, digitala animationer och klassrumsgenomgångar framhålls de enkla filmernas tydlighet och fokus på matematik, samt klassrumsgenomgångarnas flyktiga natur. Dessa resultat diskuteras utifrån en kognitiv modell för överbelastning av arbetsminnet. Eleverna uppfattar att deras arbetsbelastning är lägre i det inverterade klassrummet än i ett traditionellt klassrum eftersom det finns mer tid för egen räkning i klassrummet. Dessutom uppfattas videogenomgångar som mer effektiva än klassrumsgenomgångar trots att de är betydligt kortare. Den tid som frigörs när klassrummet inverteras har inte förändrat elevernas sätt att arbeta inom matematikämnet. Elevers respons på förändrade undervisningsvillkor analyseras med hjälp av en kognitiv teori för elevers reglering av sitt eget lärande. Utifrån denna teori diskuteras hur lärare kan ta tillvara på de ökade tidsresurserna och förändra elevers tänkande om matematik och deras lärande.

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