Дисертації з теми "Generation of negative triples"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Generation of negative triples.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Generation of negative triples".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Vitiello, Adriana. "Generation and characterization of HSV-1 based oncolytic viruses towards an innovative therapeutic approach for TNBC." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3422208.
Анотація:
BACKGROUND
Immunotherapy, mainly based on checkpoint inhibitors or Chimeric Antigen Receptor (CAR) T cells, is providing a major breakthrough in the pharmacological therapy of cancer. However, many solid tumors surrounded by an immunosuppressive tumor microenvironment (TME), like triple negative breast carcinoma (TNBC), do not have a cytotoxic T lymphocyte infiltrate that can be activated by checkpoint inhibitors (“cold” tumors). Oncolytic viruses (OVs) are able to selectively replicate in cancerous cells, which are often defective in antiviral response pathways. OVs provide a powerful proinflammatory stimulus in the TME, thus subverting its immunosuppressive features. Therefore, OVs are very promising agents for the immunotherapeutic treatment of immunologically “cold” tumors. At the same time, OVs can be “armed” to express therapeutic molecules that enhance their efficacy. Herpes simplex virus type 1 (HSV-1) proved to be a suitable platform for the generation of OVs, due to its large dsDNA genome, which allows extensive manipulation and insertion of therapeutic genes, to its lytic activity and good safety profile. HSV-1 derived OVs usually carry deletions of the γ34.5 gene, which is essential for neurovirulence. The HSV-1 based talimogene laherparepvec (T-VEC) is the only OV approved for clinical use (metastatic melanoma) in the EU and the USA so far.
METHODS Bacterial artificial chromosome (BAC) mutagenesis in an appropriate strain of Escherichia coli, that is characterized by the inducible expression of a recombinase system, was adopted for the manipulation of the HSV-1 genome. In particular, mutagenesis was performed on a previously available Δγ34.5 HSV-1 BAC. Viral stocks were then reconstituted by lipofectamine transfection of purified BAC DNA into 293T cells. We tested the selectivity and the replicative capacity of the recombinant viruses in a panel of human mammary cancer cell lines as well as in both tumoral and non-tumoral murine mammary organoids. The efficiency of expression of transgenes was also evaluated by different methods.
RESULTS AND CONCLUSIONS The Us12 gene, encoding the ICP47 protein, was succesfully deleted from the parental BAC. The Us12 deletion enhances MHC-I antigen presentation by infected cells, and shifts the expression kinetics of the Us11 gene from late to immediate early, boosting viral replication without affecting safety. First of all a recombinant virus was generated by the insertion within the UL55-UL56 intergenic region of the enhanced green fluorescent protein (EGFP) gene. The recombinant virus showed specificity for tumoral organoids and efficiently killed cancer cells. Based on these findings, two additional recombinant viruses were developed by replacing the EGFP gene with a sequence encoding either i) a single chain antibody (scAb) targeting C-C Chemokine Receptor Type 4 (CCR4) or ii) the solubile Programmed cell Death-1 (sPD1) protein. Both recombinant viruses efficiently replicated in the tested cell lines. Exogenous genes were also expressed. To address the immunological complexity of the TME, we are inserting further therapeutic genes, including human IL-12, and FMS-like tyrosine kinase 3 ligand (Flt3L) in the Δγ34.5/ΔUs12 BAC. Next steps will be a deep in vitro characterization of the developed OVs and testing viral therapeutic efficacy on an appropriate mouse model.
2
Vougiouklis, Pavlos. "Neural generation of textual summaries from knowledge base triples." Thesis, University of Southampton, 2019. https://eprints.soton.ac.uk/428045/.
Анотація:
Most people need textual or visual interfaces in order to make sense of Semantic Web data. In this thesis, we investigate the problem of generating natural language summaries for structured data encoded as triples using neural networks. We propose an end-to-end trainable architecture that encodes the information from a set of triples into a vector of fixed dimensionality and generates a textual summary by conditioning the output on this encoded vector. In order to both train and evaluate the performance of our approach, we explore different methodologies for building the required data-to-text corpora. We initially focus our attention on the generation of biographies. Using methods for both automatic and human evaluation, we demonstrated that our technique is capable of scaling to domains with challenging vocabulary sizes of over 400k words. Given the promising results of our approach in biographies, we explore its applicability in the generation of open-domain Wikipedia summaries in two under-resourced languages, Arabic and Esperanto. We propose an adaptation of our original encoder-decoder architecture that outperforms a set of strong baselines of different nature. Furthermore, we conducted a set of community studies in order to measure the usability of the generated content by Wikipedia readers and editors. The targeted communities ranked our generated text close to the expected standards of Wikipedia. In addition, we found that the editors are likely to reuse a large portion of the generated summaries, thus, emphasizing the usefulness of our approach to the involved communities. Finally, we extend the original model with a pointer mechanism that enables it to jointly learn to verbalise in a different number of ways the content from the triples while retaining the ability to generate regular words from a fixed target vocabulary. We evaluate performance with a dataset encompassing the entirety of English Wikipedia. Results from both automatic and human evaluation highlight the superiority of the latter approach compared to our original encoder-decoder architecture and a set of competitive baselines.
3
Islam, Md Kamrul. "Explainable link prediction in large complex graphs - application to drug repurposing." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0203.
Анотація:
De nombreux systèmes complexes du monde réel peuvent être représentés par des graphes, où les nœuds représentent des entités et les liens des relations entre les paires de nœuds. La prédiction de liens (LP) est l'un des problèmes les plus intéressants et les plus anciens dans le domaine de l'exploration de graphes ; elle prédit la probabilité d'un lien entre deux nœuds non connectés. Cette thèse étudie le problème LP dans les graphes simples et les graphes de connaissances (KGs). La première partie de cette thèse se concentre sur le problème LP dans les graphes simples. Dans la première étude, des approches basées sur la similarité et sur l'encastrement sont évaluées et comparées sur des graphes simples de différents domaines. L'étude a également identifié la difficulté de fixer le seuil du score de similarité pour calculer la métrique de précision des approches basées sur la similarité et a proposé une nouvelle méthode pour calculer la métrique. Les résultats ont montré la supériorité attendue des approches basées sur l'intégration. Cependant, chaque approche basée sur la similarité s'est avérée compétitive sur des graphes aux propriétés spécifiques. Nous avons pu vérifier expérimentalement que les approches basées sur la similarité sont explicables mais manquent de généralisation, tandis que les approches basées sur l'encastrement sont générales mais non explicables. La deuxième étude tente de surmonter la limitation de l'inexplicabilité des approches basées sur l'encastrement en découvrant des connexions intéressantes entre elles et les approches basées sur la similarité. La troisième étude démontre comment les approches basées sur la similarité peuvent être assemblées pour concevoir une approche LP supervisée explicable. Il est intéressant de noter que l'étude montre des performances LP élevées pour l'approche supervisée sur différents graphes, ce qui est très satisfaisant. La deuxième partie de la thèse se concentre sur les LP dans les KGs. Un KG est représenté comme une collection de triplets RDF, (head,relation,tail) où les entités head et tail sont reliées par une relation spécifique. Le problème de LP dans un KG est formulé comme la prédiction de la tête ou de la queue manquante dans un triplet. La LP basée sur l'incorporation de KG est devenue très populaire ces dernières années, et la génération de triplets négatifs est une tâche importante dans les méthodes d'incorporation. La quatrième étude traite d'une nouvelle méthode appelée SNS pour générer des triplets négatifs de haute qualité. Nos résultats montrent une meilleure performance LP lorsque SNS est utilisé que lorsque d'autres méthodes d'échantillonnage négatif sont utilisées. La deuxième étude traite d'une nouvelle méthode d'extraction de règles neuro-symboliques et d'une stratégie d'abduction pour expliquer les LP par une approche basée sur l'intégration en utilisant les règles apprises. La troisième étude applique notre LP explicable pour développer une nouvelle approche de repositionnement des médicaments pour COVID-19. L'approche apprend un ensemble d'enchâssements d'entités et de relations dans un KG centré sur COVID-19 pour obtenir un meilleur enchâssement des éléments du graphe. Pour la première fois à notre connaissance, des méthodes de criblage virtuel sont ensuite utilisées pour évaluer les prédictions obtenues à l'aide des embeddings. L'évaluation moléculaire et les chemins explicatifs apportent de la fiabilité aux résultats de prédiction et sont de nouvelles méthodes complémentaires et réutilisables pour mieux évaluer les molécules proposées pour le repositionnement. La dernière étude propose une architecture distribuée pour l'apprentissage des KG embeddings dans des environnements distribués et parallèles. Les résultats révèlent que l'apprentissage dans l'environnement distribué proposé, par rapport à un apprentissage centralisé, réduit considérablement le temps de calcul des méthodes d'incorporation KG sans affecter les performances des LPMany real-world complex systems can be well-represented with graphs, where nodes represent objects or entities and links/relations represent interactions between pairs of nodes. Link prediction (LP) is one of the most interesting and long-standing problems in the field of graph mining; it predicts the probability of a link between two unconnected nodes based on available information in the current graph. This thesis studies the LP problem in graphs. It consists of two parts: LP in simple graphs and LP knowledge graphs (KGs). In the first part, the LP problem is defined as predicting the probability of a link between a pair of nodes in a simple graph. In the first study, a few similarity-based and embedding-based LP approaches are evaluated and compared on simple graphs from various domains. he study also criticizes the traditional way of computing the precision metric of similarity-based approaches as the computation faces the difficulty of tuning the threshold for deciding the link existence based on the similarity score. We proposed a new way of computing the precision metric. The results showed the expected superiority of embedding-based approaches. Still, each of the similarity-based approaches is competitive on graphs with specific properties. We could check experimentally that similarity-based approaches are fully explainable but lack generalization due to their heuristic nature, whereas embedding-based approaches are general but not explainable. The second study tries to alleviate the unexplainability limitation of embedding-based approaches by uncovering interesting connections between them and similarity-based approaches to get an idea of what is learned in embedding-based approaches. The third study demonstrates how the similarity-based approaches can be ensembled to design an explainable supervised LP approach. Interestingly, the study shows high LP performance for the supervised approach across various graphs, which is competitive with embedding-based approaches.The second part of the thesis focuses on LP in KGs. A KG is represented as a collection of RDF triples, (head,relation,tail) where the head and the tail are two entities which are connected by a specific relation. The LP problem in a KG is formulated as predicting missing head or tail entities in a triple. LP approaches based on the embeddings of entities and relations of a KG have become very popular in recent years, and generating negative triples is an important task in KG embedding methods. The first study in this part discusses a new method called SNS to generate high-quality negative triples during the training of embedding methods for learning embeddings of KGs. The results we produced show better LP performance when SNS is injected into an embedding approach than when injecting state-of-the-art negative triple sampling methods. The second study in the second part discusses a new neuro-symbolic method of mining rules and an abduction strategy to explain LP by an embedding-based approach utilizing the learned rules. The third study applies the explainable LP to a COVID-19 KG to develop a new drug repurposing approach for COVID-19. The approach learns ”ensemble embeddings” of entities and relations in a COVID-19 centric KG, in order to get a better latent representation of the graph elements. For the first time to our knowledge, molecular docking is then used to evaluate the predictions obtained from drug repurposing using KG embedding. Molecular evaluation and explanatory paths bring reliability to prediction results and constitute new complementary and reusable methods for assessing KG-based drug repurposing. The last study proposes a distributed architecture for learning KG embeddings in distributed and parallel settings. The results of the study that the computational time of embedding methods improves remarkably without affecting LP performance when they are trained in the proposed distributed settings than the traditional centralized settings
4
Genz, Adrian P. "Operational Amplifier Bandwidth Extension Using Negative Capacitance Generation." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1383.pdf.
5
Thilleul, Olivia. "Negative lift generation in a tidal device structure." Thesis, Cranfield University, 2009. http://dspace.lib.cranfield.ac.uk/handle/1826/8292.
Анотація:
Becoming aware of the impact of global warming, all countries of the European Union have agreed to produce 20% of their electricity from renewable energy by 2020. Hence, a new market emerged to develop more efficient technologies of sustainable power production.
Cranfield University has been involved since 2006 in wave and tidal energy design projects through various government agencies funded partnerships with the emerging industry of marine renewable energy. This thesis is based on one of these projects called “DeltaStream” which was developed by Tidal Energy Ltd (TEL).
The tidal stream turbine is one of the most efficient concepts in marine renewable energy, because of the high predictability of tidal streams compared to wave and wind energy. Many devices are currently being developed in the UK. Most of them are moored to the seabed using traditional methods used in the offshore oil industry, which means drilling the sea floor.
The goal of this work is to avoid drilling the seabed by adding hydrofoils on the structure. Indeed, by setting a hydrofoil in the tidal stream, the goal is to prove that a downward lift force is created and is efficient enough to maintain the structure at its location, avoiding mooring costs and ecological issues relative to drilling the sea floor.
Computational Fluid Dynamics (CFD) models have been performed, studying the sensitivity of mesh size compared to results quality, and testing then different hydrofoils to get the best downward lift force in local conditions. The main characteristics of the simulation are unsteady and one phase. The chosen geometry is a “quasi-2D” domain in order to minimize computational requirements.
A validation case has been first performed on a well-known geometry of a circular cylinder, to compare analytical results and CFD data. Small variations between results validated the model to enable us to use the model on a less-known simulation such as a hydrofoil. Different parameters influencing the efficiency of the hydrofoil in terms of lift production and drag reduction have been tested. These results have been compared with tank tests undertaken by the OENA Group in June-July 2009 in IFREMER (France). And complementary studies have been performed to compare these results and CFD results.
6
McLenaghan, Joanna Siân. "Negative frequency waves in optics : control and investigation of their generation and evolution." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6532.
Анотація:
This thesis is concerned with various methods for the control and investigation of pulse dynamics in a Photonic Crystal Fibre (PCF) and of the radiation driven by a short pulse. In particular the focus is on pulses in the anomalous dispersion region which would form solitons in the absence of higher order effects. Several different types of radiation can be driven by such pulses if they are perturbed by higher order dispersive and non-linear effects - for example Resonant Radiation (RR) and Negative Resonant Radiation (NRR) two dispersive waves which gain energy at the expense of the pulse. The feature of NRR which is of particular importance is that it is the first observed example of a coupling between positive and negative frequencies in optics. This has only been possible due to recent advances in fields such as PCFs, lasers and analogue systems. As with many scientific discoveries, NRR was found by bringing together ideas and techniques from these different fields. Both the pulse and the driven radiation are investigated using a number of different pulse and PCF parameters. These include power, chirp, polarisation and PCF dispersion. These are used to vary the wavelengths at which the driven radiation occurs as well as its generation efficiency. Furthermore the power and chirp are used to vary where in the PCF the driven radiation is generated by controlling where the driving pulse compresses and spectrally expands. This property is used to investigate different stages in the evolution of the pulse and driven radiation as well as to optimise the generation efficiency of the driven radiation.
7
Kharazi, Alexandra. "Generation and molecular analysis of dominant negative alleles of anthrax lethal factor in Drosophila." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p1453196.
Анотація:
Thesis (M.S.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed July 8, 2008). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 26).
8
Duvvury, Rolan Shawn. "Potential negative effects of wind turbines on the ear." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44927.
Анотація:
This thesis presents investigations on the potential negative effects of wind turbine noise on the human ear from a sound point source (i.e. wind farm). In Chapter 2, the tectorial membrane, which is a crucial gelatinous structural matrix located within the cochlea of the inner ear, is considered to have a similar constitutive stress-strain relationship to that of an elastomer (rubber) in tension. The tectorial membrane appears to stretch when subjected to constant heavy sound stimulation. The tectorial membrane is modeled as a simply-supported beam with an external load Pext applied at midspan. A virtual work approach is used to balance the external work at midspan Pextδz of the tectorial membrane with the internal strain energy from its hysteresis loops. These hysteresis loops quantify the amount of damage that the tectorial membrane undergoes due to an applied external loading. Normalized damage tables are presented at the end of the chapter to suggest safe distances away from the wind turbines to limit damage to the tectorial membrane. Chapter 3 considers a hypothetical autonomous village constructed in South Pretoria, South Africa. This village accommodates approximately 2000 people (~500 families) and receives electricity for hot water from a nearby 2.5 MW wind farm. The design process for the village is discussed from an architectural and design standpoint. The wind farm specifications, specifically the number of 2.5 MW wind turbines needed to provide electricity for hot water, are established. Results from Chapter 2 are used to suggest minimum safe distances between the wind farm and the autonomous village in the context of limiting damage to the tectorial membrane.
9
Agee, Elisha R. "The relationship between second-generation antipsychotic medication adherence and negative symptoms in first-episode schizophrenia." Thesis, Pepperdine University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3716463.
Анотація:
Adherence to psychotropic medication is a critical aspect of treatment for the management of psychotic disorders. While the literature on the need for medication adherence is extensive, little research has explored the relationship between the negative symptoms of psychosis and medication adherence. Since negative symptoms are enduring, stable, and strongly correlated with poor outcome, it is vitally important for research to explore the role of negative symptoms in regards to adherence to psychotropic medication. Given its potentially significant consequences for treatment interventions, the purpose of this study was to contribute to the exceedingly limited body of research exploring the relationship between the negative symptoms seen in psychosis and medication adherence. This study examined if there is a relationship between the two and whether causality could be determined should a significant relationship exist between medication adherence and negative symptoms. This study utilized data previously collected at the UCLA Aftercare Research Program for studies examining aspects of outpatient psychiatric treatment. The 148 participants had a mean age of 22.5 years and were in the midst of their first psychotic episode upon study entry. Data from the Brief Psychiatric Rating Scale, Scale for the Assessment of Negative Symptoms, and medication adherence ratings were collected over the course of 12 months. Analyses revealed a significant relationship between the presence of negative symptoms and medication nonadherence. Analyses examining the temporal relationship between the two variables revealed that initial medication nonadherence was significantly associated with subsequent negative symptoms. However, once the impact of positive symptoms was controlled for as a potential mediating variable, the strength of the relationship between medication adherence and negative symptoms dissipated. After controlling for the role of reality distortion, the only negative symptoms significantly associated with medication nonadherence were the BPRS Negative Symptom Factor, BPRS Emotional Withdrawal, and BPRS Self-Neglect. Consequently, it appears that negative symptoms are more strongly associated with positive symptoms than with medication adherence. Replication of these findings and further research exploring the relationship between positive and negative symptoms as they relate to medication adherence is needed in order to improve treatment interventions focused on medication adherence.
10
Nordeman, Emil. "Generation of Doxycycline-Inducible Cell Lines Expressing Dominant-Negative DNA Polymerase γ and Mitochondrial Helicase Twinkle Variants". Thesis, Umeå universitet, Biomedicinsk laboratorievetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184253.
11
Moscrip, Amanda Nicole. "Generation Z's Positive and Negative Attributes and the Impact on Empathy After a Community-Based Learning Experience." UNF Digital Commons, 2019. https://digitalcommons.unf.edu/etd/908.
Анотація:
Generation Z, also known as the iGeneration, iGenners, GenZ, and Generation Now, consists of those born in the mid-1990s through the late 2010s. Historical events important for this generation have influenced their perception of safety as well as how they interact with others. As compared to previous generations, technological advances (i.e., Smartphones, social media) changed how GenZ communicates, socializes, and receives information. Unique experiences and attributes influenced Generation Z’s empathy because living through these events and seeing their impact changes how they can understand and take the perspective of others. The relation between three factors was examined across University students who are members of Generation Z; intensity of the CBL activity (high versus low), sex, and empathy (empathy assessment index, basic empathy scale, ethnocultural empathy scale). It is hypothesized that freshmen students would exhibit higher gains in empathy due to their developmental period. As hypothesized, there was a consistent main effect for sex in multiple subscales across the Honors Colloquium and Interdisciplinary late-teen sample indicating that females were higher in initial pretest scores and remained higher on post-scores on empathy as compared to males. These findings hold implication for instructors aiming to provide effective CBL experience for their students. Faculty may consider how students may be differentially receptive to CBL experiences on multiple demographic and personality variables, and while this study only examined sex and intensity of experience, it provides a good representation of the diversity of outcomes that can be evidenced.
12
Popov, A. K., I. S. Nefedov, S. A. Myslivets, M. I. Shalaev, and V. V. Slabko. "Nonlinear-optical Negative-index Metamaterials: Extraordinary Properties and Applications." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35381.
Анотація:
The principles of nanoengineering of metamaterials which support optical electromagnetic and elastic
waves with negative group velocity are described. Extraordinary properties of nonlinear-optical energy
transfer between contra-propagating short pulses of electromagnetic and elastic waves are investigated
and prospective unique photonic devices are discussed.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35381
13
Ho, Shuk-wai Amy. "Generation and characterization of transgenic mice expressing dominant negative osmotic response element binding protein (OREBP) in the brain neurons /." View the Table of Contents & Abstract, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38348068.
14
Pookhao, Naruekamol. "Statistical Methods for Functional Metagenomic Analysis Based on Next-Generation Sequencing Data." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/320986.
Анотація:
Metagenomics is the study of a collective microbial genetic content recovered directly from natural (e.g., soil, ocean, and freshwater) or host-associated (e.g., human gut, skin, and oral) environmental communities that contain microorganisms, i.e., microbiomes. The rapid technological developments in next generation sequencing (NGS) technologies, enabling to sequence tens or hundreds of millions of short DNA fragments (or reads) in a single run, facilitates the studies of multiple microorganisms lived in environmental communities. Metagenomics, a relatively new but fast growing field, allows us to understand the diversity of microbes, their functions, cooperation, and evolution in a particular ecosystem. Also, it assists us to identify significantly different metabolic potentials in different environments. Particularly, metagenomic analysis on the basis of functional features (e.g., pathways, subsystems, functional roles) enables to contribute the genomic contents of microbes to human health and leads us to understand how the microbes affect human health by analyzing a metagenomic data corresponding to two or multiple populations with different clinical phenotypes (e.g., diseased and healthy, or different treatments). Currently, metagenomic analysis has substantial impact not only on genetic and environmental areas, but also on clinical applications. In our study, we focus on the development of computational and statistical methods for functional metagnomic analysis of sequencing data that is obtained from various environmental microbial samples/communities.
15
Drury, R. G. "Trajectory generation for autonomous unmanned aircraft using inverse dynamics." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/5583.
Анотація:
The problem addressed in this research is the in-flight generation of trajectories for
autonomous unmanned aircraft, which requires a method of generating pseudo-optimal
trajectories in near-real-time, on-board the aircraft, and without external intervention.
The focus of this research is the enhancement of a particular inverse dynamics direct
method that is a candidate solution to the problem. This research introduces the
following contributions to the method.
A quaternion-based inverse dynamics model is introduced that represents all
orientations without singularities, permits smooth interpolation of orientations, and
generates more accurate controls than the previous Euler-angle model.
Algorithmic modifications are introduced that: overcome singularities arising from
parameterization and discretization; combine analytic and finite difference expressions
to improve the accuracy of controls and constraints; remove roll ill-conditioning when
the normal load factor is near zero, and extend the method to handle negative-g
orientations. It is also shown in this research that quadratic interpolation improves the
accuracy and speed of constraint evaluation.
The method is known to lead to a multimodal constrained nonlinear optimization
problem. The performance of the method with four nonlinear programming algorithms
was investigated: a differential evolution algorithm was found to be capable of over
99% successful convergence, to generate solutions with better optimality than the quasi-
Newton and derivative-free algorithms against which it was tested, but to be up to an
order of magnitude slower than those algorithms. The effects of the degree and form of
polynomial airspeed parameterization on optimization performance were investigated,
and results were obtained that quantify the achievable optimality as a function of the
parameterization degree.
Overall, it was found that the method is a potentially viable method of on-board near-
real-time trajectory generation for unmanned aircraft but for this potential to be realized
in practice further improvements in computational speed are desirable. Candidate
optimization strategies are identified for future research.
16
Iwai, Akinori. "Linear and Nonlinear Functions of Plasmas in Electromagnetic Metamaterials." Kyoto University, 2019. http://hdl.handle.net/2433/242471.
17
Ojiambo, Melina. "Exploring political intolerance in a post-apartheid generation of South Africans : the role of intergroup threat and negative intergroup emotion." Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/14568.
Анотація:
Includes bibliographical references (leaves 83-89).This study extends Gibson and Gouws ' (2003) work on threat and intolerance as well as Kuklinski, Riggle, Ottati, Schwarz and Wyer's (1991) work on the influence of emotion on people's tolerance judgements. Method: Participants were randomly assigned to two experimental groups.
18
Malhotra, Kyle. "CHARACTERIZATION OF TWO GENES INVOLVED IN THE GENERATION OF A NEGATIVE SIGAL GENERATED BY THE PU-43 STRAIN OF PSEUDOMONAS CEDRELLA." Thesis, The University of Arizona, 2009. http://hdl.handle.net/10150/192519.
19
Röhrs, Susanne [Verfasser], and Gerd [Akademischer Betreuer] Sutter. "A neuraminidase-negative variant of highly pathogenic avian influenza virus H5N1 : generation, characterization and use as a model for early onset of immunity / Susanne Röhrs. Betreuer: Gerd Sutter." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1065610890/34.
20
Franco, Marla A. "Effects of Negative Climate for Diversity on Cognitive Outcomes of Latina/o College Students Attending Selective Institutions| A Comparison by Students' Gender, First-Generation College Status, and Immigrant Status." Thesis, Azusa Pacific University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10608460.
Анотація:
Latinas/os are the fastest-growing racial minority group in the United States, yet there is a lack of parity between their increased population and their participation rates in higher education. The economic strength and vitality of the nation require a college-educated workforce; therefore, the need to improve educational environments that support increased degree attainment among Latinas/os is imperative. Despite the disproportionately low enrollment of Latina/o college students at selective U.S. higher education institutions, research has suggested that attending these types of institutions uniquely and positively influences students’ educational and socioeconomic outcomes (Hearn & Rosinger, 2014). Using Astin’s (1991) Inputs-Environments-Outcomes (I-E-O) model, this study examined Latina/o college students’ cognitive development over time, their experiences related to perceived climate for diversity, and the effects of negatively-perceived climates for diversity on their cognitive development based on students’ gender, first-generation college status, and immigrant status. A quantitative design using the 2014 University of California Undergraduate Experience Survey (UCUES) was employed, of which system-wide data from 4,299 junior and senior level Latino/a college students were used. Inferential and regression analyses were used to examine the effects of perceived negative climate for diversity on students’ cognitive outcomes. Results indicated that Latina/o students attending selective institutions benefitted greatly in their cognitive skills development, although unique differences were found when students’ outcomes were examined by their gender, first-generation college status, and immigrant status. Perceived negative climates for diversity varied depending on students’ gender, first-generation college status, and immigrant status. Examination of the effects of students’ background characteristics and college experiences on their cognitive outcomes also varied based on their gender, first-generation college status, and immigrant status. In particular, perceived negative climates for diversity were found to have mixed effects on Latina/o college students’ GPA, yet demonstrated little to no effect on students’ cognitive skills development.
21
Perricone, Margherita <1987>. "Characterization of Philadelphia-negative Chronic Myeloproliferative Neoplasms: identification of novel biomarkers by Next Generation Sequencing and study of interactions between hematopoietic stem cell and the inflammatory cell micro-environment." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8358/1/PhD%20Thesis_MPerricone_final.pdf.
Анотація:
Myeloproliferative Neoplasms (MPN) are a heterogeneous group of hematological malignancies, consisting in clonal disorders of the hematopoietic stem/progenitor cell (HSC/PC). Molecular alterations and inflammatory microenvironment represent the two main etiopathogenic factors of MPN.
The aim of this study was the molecular characterization of MPN patients and the study of interactions between HSC/PC and the inflammatory cell micro-environment.
We investigated young (<40 years at diagnosis) ET and early-PMF patients, and patients with a JAK2V617F allele burden (AB) <3%, demonstrating that its determination is relevant both at diagnosis and during follow up. Indeed, it allows to prove the presence of a clonal hematopoiesis and, also, to predict clinical outcome. Of note, an AB≥0,8% always corresponds to an overt MPN phenotype. In this context, coordinating a network of 19 Italian laboratories, we identified the ipsogen JAK2 MutaQuant kit as the most sensitive and efficient assay for the quantification of samples with different mutation loads (in particular those with AB≤1%). With regard to the role of inflammatory microenvironment in the pathogenesis of MF, IL-1β and TIMP-1 seemed to confer a survival advantage to MF-derived HSPCs, enhancing their proliferation and in vitro migration, as well as their clonogenic ability. Finally, in this study we tested three different gene panels for mutations detection, obtaining promising results in terms of coverage analysis (more than 95% of target regions with depth greater than 500X) and identifying gene variants with very low mutation load (<1%) in all patients.
In conclusion, this study set the basis for the standardization of molecular techniques for the determination of JAK2V617F AB, and for the validation of a robust NGS approach to be translated into a diagnostic setting. Moreover, IL-1β and TIMP-1 emerged as novel promoting factors of the in vitro maintenance of MF-derived HSPC, which may be exploited as potential targets of therapy.
22
Ring, Josh. "Novel fabrication and testing of light confinement devices." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/novel-fabrication-and-testing-of-light-confinement-devices(51572720-0c49-482e-8523-e44ca877117f).html.
Анотація:
The goal of this project is to study novel nanoscale excitation volumes, sensitive enoughto study individual chromophores and go on to study new and exciting self assemblyapproaches to this problem. Small excitation volumes may be engineered using light con-finement inside apertures in metal films. These apertures enhance fluorescence emissionrates, quantum yields, decrease fluorescence quenching, enable higher signal-to-noiseratios and allow higher concentration single chromophore fluorescence, to be studied byrestricting this excitation volume. Excitation volumes are reported on using the chro-mophore's fluorescence by utilising fluorescence correlation spectroscopy, which monitorsfluctuations in fluorescence intensity. From the correlation in time, we can find the res-idence time, the number of chromophores, the volume in which they are diffusing andtherefore the fluorescence emission efficiency. Fluorescence properties are a probe ofthe local environment, a particularly powerful tool due to the high brightness (quantumyield) fluorescent dyes and sensitive photo-detection equipment both of which are readilyavailable, (such as avalanche photodiodes and photomultiplier tubes). Novel materialscombining the properties of conducting and non-conducting materials at scales muchsmaller than the incident wavelength are known as meta-materials. These allow combi-nations of properties not usually possible in natural materials at optical frequencies. Theproperties reported so far include; negative refraction, negative phase velocity, fluorescenceemission enhancement, lensing and therefore light confinement has also been proposed tobe possible. Instead of expensive and slow lithography methods many of these materialsmay be fabricated with self assembly techniques, which are truly nanoscopic and otherwiseinaccessible with even the most sophisticated equipment. It was found that nanoscaled volumes from ZMW and HMMs based on NW arrays wereall inefficient at enhancing fluorescence. The primary cause was the reduced fluorescencelifetime reducing the fluorescence efficiency, which runs contrary to some commentatorsin the literature. NW based lensing was found to possible in the blue region of the opticalspectrum in a HMM, without the background fluorescence normally associated with a PAAtemplate. This was achieved using a pseudo-ordered array of relatively large nanowireswith a period just smaller than lambda / 2 which minimised losses. Nanowires in the traditionalregime lambda / 10 produced significant scattering and lead to diffraction, such that they werewholly unsuitable for an optical lensing application.
23
Erlach, Berit [Verfasser], George [Akademischer Betreuer] Tsatsaronis, and Mats [Akademischer Betreuer] Westermark. "Biomass upgrading technologies for carbon-neutral and carbon-negative electricity generation : techno-economic analysis of hydrothermal carbonization and comparison with wood pelletizing, torrefaction and anaerobic digestion / Berit Erlach. Gutachter: George Tsatsaronis ; Mats Westermark." Berlin : Technische Universität Berlin, 2014. http://d-nb.info/1067387064/34.
24
Bateman, Samuel. "Hollow core fibre-based gas discharge laser systems and deuterium loading of photonic crystal fibres." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648951.
Анотація:
Research towards the development of a gas-discharge fibre laser using noble gases, with target emission wavelengths in the mid-IR. Additional and separate work on gas treatment methods for managing the formation of photo-induced defects in silica glass.
25
Thomas, Fernandez. "CONTRIBUTION A L'EVALUATION DE LA TECHNIQUE DE GENERATION D'HARMONIQUE PAR FAISCEAU LASER POUR LA MESURE DES CHAMPS ELECTRIQUES DANS LES CIRCUITS INTEGRES (EFISHG)." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2009. http://tel.archives-ouvertes.fr/tel-00997396.
Анотація:
Ce travail contribue à l'évaluation de la technique de génération de seconde harmonique induite par un champ électrique quasi statique, ou technique EFISHG, appliquée au domaine de la microélectronique. Une description du principe de la technique EFISHG, basé sur l'optique non linéaire, permet d'appréhender l'origine physique de cette méthode. Un état de l'art a permis d'identifier deux champs d'applications liés à la microélectronique : l'analyse de défaillance, via la mesure en temps réelle des variations de champs électriques internes dans les circuits intégrés, et la fiabilité par l'étude du piégeage de charges à l'interface Si/SiO2 et de la dégradation dite de " Negative Bias Temperature Instability " ou NBTI. Ce manuscrit présente les différentes étapes qui ont permis l'élaboration d'un banc de test en vue de l'évaluation de l'applicabilité de la technique EFISHG à ces problématiques. Les résultats expérimentaux obtenus avec ce montage ont permis de mettre en avant les possibilités qu'offre la technique EFISHG à caractériser et à accélérer le vieillissement NBTI.
26
Efendy, Komala Inggarwati. "The nature of intra-familial conflict in large-scale privately-held family businesses in Indonesia." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/60936/1/Komala_Efendy_Thesis.pdf.
Анотація:
This thesis is a qualitative study aimed at better capturing the complexity of conflict in family businesses. An inductive content analysis revealed two important issues: the dynamics of intergenerational conflicts and the escalation process of conflicts. The results demonstrated that conflicts are more likely to be intergenerational than intra-generational due to the role of senior members in daily business operations, generational differences, and a perception gap that exist between generations concerning each other’s competencies in doing the business. Furthermore, the set of factors contributing to conflict escalation is related to how family members handle the conflict, how they manage their emotions, and how they are able to avoid non-family employee involvement. These findings provide a foundation for taking preventative actions, implementing strategies for managing conflicts or devising effective solutions for resolving conflicts before they become more destructive.
27
Fernandez, Thomas. "Contribution à l'évaluation de la technique de génération d'harmonique par faisceau laser pour la mesure des champs électriques dans les circuits intégrés (EFISHG)." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13846/document.
Анотація:
Ce travail contribue à l’évaluation de la technique de génération de seconde harmonique induite par un champ électrique quasi statique, ou technique EFISHG, appliquée au domaine de la microélectronique. Une description du principe de la technique EFISHG, basé sur l’optique non linéaire, permet d’appréhender l’origine physique de cette méthode. Un état de l’art a permis d’identifier deux champs d’applications liés à la microélectronique : l’analyse de défaillance, via la mesure en temps de réelle des variations de champs électriques internes dans les circuits intégrés, et la fiabilité par l’étude du piégeage de charges à l’interface Si/SiO2 et de la dégradation dite de « Negative Bias Temperature Instability » ou NBTI. Ce manuscrit présente les différentes étapes qui ont permis l’élaboration d’un banc de test en vue de l’évaluation de l’applicabilité de la technique EFISHG à ces problématiques. Les résultats expérimentaux obtenus avec ce montage ont permis de mettre en avant les possibilités qu’offre la technique EFISHG à caractériser et à accélérer le vieillissement NBTIThis work concerns the elaboration of an industrial method for Single Event Effect (SEE) sensitivity testing on integrated circuits. The concerned SEEs are those produced by heavy ions and are mainly Single Event Upset (SEU) and Single Event Latchup (SEL). The original test approach chosen in this study relies on the use of infrared laser pulses striking the backside of the tested device. Laser pulse and heavy ion interaction with semiconductor materials are described and a presentation of the particle accelerator test and some former laser test methods is also given. Advantages and drawbacks of those two techniques are discussed. The developed experimental setup uses a near infrared fiber coupled Neodyme/YAG pulsed laser. Its different elements are described. Using this tool to characterise the SEU sensitivity of several modern SRAMs has allowed to define a test methodology. Its efficiency is discussed and illustrated by different experimental results
28
Kowalczyk, Piotr Jozef. "Validation and application of advanced soil constitutive models in numerical modelling of soil and soil-structure interaction under seismic loading." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/275675.
Анотація:
This thesis presents validation and application of advanced soil constitutive models in cases of seismic loading conditions.
Firstly, results of three advanced soil constitutive models are compared with examples of shear stack experimental data for free field response in dry sand for shear and compression wave propagation. Higher harmonic generation in acceleration records, observed in experimental works, is shown to be possibly the result of soil nonlinearity and fast elastic unloading waves. This finding is shown to have high importance on structural response, real earthquake records and reliability of conventionally employed numerical tools. Finally, short study of free field response in saturated soil reveals similar findings on higher harmonic generation.
Secondly, two advanced soil constitutive models are used, and their performance is assessed based on examples of experimental data on piles in dry sand in order to validate the ability of the constitutive models to simulate seismic soil-structure interaction. The validation includes various experimental configurations and input motions. The discussion on the results focuses on constitutive and numerical modelling aspects. Some improvements in the formulations of the models are suggested based on the detailed investigation.
Finally, the application of one of the advanced soil constitutive models is shown in regard to temporary natural frequency wandering observed in structures subjected to earthquakes. Results show that pore pressure generated during seismic events causes changes in soil stiffness, thus affecting the natural frequency of the structure during and just after the seismic event. Parametric studies present how soil permeability, soil density, input motion or a type of structure may affect the structural natural frequency and time for its return to the initial value. In addition, a time history with an aftershock is analysed to investigate the difference in structural response during the earthquake and the aftershock.
29
Kowalczyk, Piotr Jozef. "Validation and application of advanced soil constitutive models in numerical modelling of soil and soil-structure interaction under seismic loading." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/275675.
Анотація:
This thesis presents validation and application of advanced soil constitutive models in cases of seismic loading conditions.
Firstly, results of three advanced soil constitutive models are compared with examples of shear stack experimental data for free field response in dry sand for shear and compression wave propagation. Higher harmonic generation in acceleration records, observed in experimental works, is shown to be possibly the result of soil nonlinearity and fast elastic unloading waves. This finding is shown to have high importance on structural response, real earthquake records and reliability of conventionally employed numerical tools. Finally, short study of free field response in saturated soil reveals similar findings on higher harmonic generation.
Secondly, two advanced soil constitutive models are used, and their performance is assessed based on examples of experimental data on piles in dry sand in order to validate the ability of the constitutive models to simulate seismic soil-structure interaction. The validation includes various experimental configurations and input motions. The discussion on the results focuses on constitutive and numerical modelling aspects. Some improvements in the formulations of the models are suggested based on the detailed investigation.
Finally, the application of one of the advanced soil constitutive models is shown in regard to temporary natural frequency wandering observed in structures subjected to earthquakes. Results show that pore pressure generated during seismic events causes changes in soil stiffness, thus affecting the natural frequency of the structure during and just after the seismic event. Parametric studies present how soil permeability, soil density, input motion or a type of structure may affect the structural natural frequency and time for its return to the initial value. In addition, a time history with an aftershock is analysed to investigate the difference in structural response during the earthquake and the aftershock.
30
Radovich, Milan. "DECODING THE TRANSCRIPTIONAL LANDSCAPE OF TRIPLE-NEGATIVE BREAST CANCER USING NEXT GENERATION WHOLE TRANSCRIPTOME SEQUENCING." Thesis, 2012. http://hdl.handle.net/1805/2745.
Анотація:
Indiana University-Purdue University Indianapolis (IUPUI)Triple-negative breast cancers (TNBCs) are negative for the expression of estrogen (ER), progesterone (PR), and HER-2 receptors. TNBC accounts for 15% of all breast cancers and results in disproportionally higher mortality compared to ER & HER2-positive tumours. Moreover, there is a paucity of therapies for this subtype of breast cancer resulting primarily from an inadequate understanding of the transcriptional differences that differentiate TNBC from normal breast. To this end, we embarked on a comprehensive examination of the transcriptomes of TNBCs and normal breast tissues using next-generation whole transcriptome sequencing (RNA-Seq). By comparing RNA-seq data from these tissues, we report the presence of differentially expressed coding and non-coding genes, novel transcribed regions, and mutations not previously reported in breast cancer. From these data we have identified two major themes. First, BRCA1 mutations are well known to be associated with development of TNBC. From these data we have identified many genes that work in concert with BRCA1 that are dysregulated suggesting a role of BRCA1 associated genes with sporadic TNBC. In addition, we observe a mutational profile in genes also associated with BRCA1 and DNA repair that lend more evidence to its role. Second, we demonstrate that using microdissected normal epithelium maybe an optimal comparator when searching for novel therapeutic targets for TNBC. Previous studies have used other controls such as reduction mammoplasties, adjacent normal tissue, or other breast cancer subtypes, which may be sub-optimal and have lead to identifying ineffective therapeutic targets. Our data suggests that the comparison of microdissected ductal epithelium to TNBC can identify potential therapeutic targets that may lead to be better clinical efficacy. In summation, with these data, we provide a detailed transcriptional landscape of TNBC and normal breast that we believe will lead to a better understanding of this complex disease.
31
Chen, Yu-Hsiang. "Multi-Modality Plasma-Based Detection of Minimal Residual Disease in Triple-Negative Breast Cancer." Diss., 2019. http://hdl.handle.net/1805/20202.
Анотація:
Indiana University-Purdue University Indianapolis (IUPUI)Triple-negative breast cancers (TNBCs) are pathologically defined by the absence of estrogen, progesterone, and HER2 receptors. Compared to other breast cancers, TNBC has a relatively high mortality. In addition, TNBC patients are more likely to relapse in the first few years after treatment, and experiencing a shorter median time from recurrence to death. Detecting the presence of tumor in patients who are technically “disease-free” after neoadjuvant chemotherapy and surgery as early as possible might be able to predict recurrence of patients, and then provide timely intervention for additional therapy. To this end, I applied the analysis of “liquid biopsies” for early detection of minimal residual disease (MRD) on early-stage TNBC patients using next-generation sequencing. For the first part of this study, I focused on detecting circulating tumor DNA (ctDNA) from TNBC patients after neoadjuvant chemotherapy and surgery. First, patient-specific somatic mutations were identified by sequencing primary tumors. From these data, 82% of the patients had at least one TP53 mutation, followed by 16% of the patients having at least one PIK3CA mutation. Next, I sequenced matched plasma samples collected after surgery to identify ctDNA with the same mutations. I observed that by detecting corresponding ctDNA I was able to predict rapid recurrence, but not distant recurrence. To increase the sensitivity of MRD detection, in the second part I developed a strategy to co-detect ctDNA along with circulating tumor RNA (ctRNA). An advantage of ctRNA is its active release into the circulation from living cancer cells. Preliminary data showed that more mutant molecules were identified after incorporating ctRNA with ctDNA detection in a metastatic breast cancer setting. A validation study in early-stage TNBC is in progress. In summary, my study suggests that co-detection of ctDNA and ctRNA could be a potential solution for the early detection of disease recurrence.
2021-08-05
32
Chen, Yi-Chun, and 陳儀君. "Generation of a zebrafish xenograft model of triple-negative breast cancer for evaluating the therapeutic efficacy of Tilapia piscidin 4 (TP4)." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/88652006096495512283.
Анотація:
碩士臺灣大學
漁業科學研究所
103
Among the breast cancer subtypes, triple negative breast cancer (TNBC) (ER/PR/HER2) is particularly challenging and difficult-to-treat. Combinations of surgery, hormone, irradiation, and targeted therapies are not usually effective to TNBC patients but chemotherapy was shown good therapeutic efficacy. However, failure in TNBCs treatment by chemotherapy is the cause of multidrug-resistant (MDR) cancer cell developed and healthy cells are disrupted, causing adverse side-effects. Therefore, identifying the molecular targets underlying chemotherapy could contribute to the development of novel cytotoxic agents as well as the improvement of TNBC killing selectivity. Cationic antimicrobial peptides (CAPs) are cytotoxic to certain cancer types, but are less toxic to normal cells. Nile Tilapia piscidin 4 (TP4) is a CAP derived from Nile tilapia (Oreochromis niloticus). Synthetic TP4 was shown to inhibit gram-positive/negative bacteria; however, its role in BC toxicity has not been investigated. In this study, three BC cell lines were used for evaluating the therapeutic efficacy of TP4 in vitro. Transcriptome study was carried out to explore the potential therapeutic factors induced by TP4 in TNBC cell. In addition, zebrafish xenograft model was developed to investigate the therapeutic efficacy of TP4 in vivo. Cell viability assay showed that synthetic TP4 selectively damages to BC cells (MDA-MB-231/MDA-MB-453/MCF-7) but is less toxic to normal cells (M10/HDF). Microarray study identified FOS family proteins were affected by TP4 treatment in TNBC cells and that overexpression of a FOS family protein, FOSB, caused dramatically TNBC cell death. In addition, we observed TNBC xenotransplantation caused significant zebrafish death in vivo; however, TP4 prolongs the survival in TNBC xenograft zebrafish under a safe dosage. In this study, we confirmed that synthetic TP4 shows selective cytotoxicity to TNBC cell and good therapeutic efficacy. We also identified FOSB as a probable prognostic factor among effective TNBC treatment.
33
劉家銘. "Online Generation of Association Rules by Negative Correlation." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/82169915037430124598.
34
Weng, Chiao-Ling, and 翁巧苓. "The Study on Generation Method of Environmental Negative Air Ions." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/35686423700688946572.
Анотація:
碩士國立臺灣大學
環境工程學研究所
93
According to many research reports, the air ions in the atmosphere would affect the health of the human body. The concentration of air ions can reflect the degree of the air pollution directly in the present environment. The relative literatures indicate that the negative air ions (NAIs) have the positive effect on the human health. The in-situ monitor of air ion concentrations in the urban area is performed in this study. The concentrations of the positive and negative air ions in the fountain area are analyzed to obtain the relative information. On the other hand, the NAIs are generated from the mechanism of the breakup of water droplets by the lab atomizer in this study. The relationship between the concentration of NAIs and the operating condition is investigated. There are four monitoring sites for the measurement of background air ions in the fountain-containing area, including the first floor of Taipei County Government building, the open space of Yungho Jen-AI park, the back door of Taipei Metro Mall, and the cross section of Song-Shou and Keelung Roads. The average concentration of NAIs in these background sites is between 641 and 1131 ions/cm3. The concentration of the positive air ions (PAIs) is greater than that of NAIs with the concentration ratio of PAIs/NAIs of 1.1 in the traffic region due to the heavy vehicle transportation and human activities. However, the concentration of NAIs is higher than that of PAIs in the open space of Yungho Jen-AI park due to less air pollution sources. The concentration of NAIs is about 3.7 times that of PAIs with the concentration ratio of PAIs/NAIs of 0.27. The four sampling points of the fountain scenes includes the indoor waterfall in the building of Taipei County Government, the outdoor waterfall in Yungho Jen-AI park, the fountain in front of Taipei Metro Mall, and the fountain near the cross section of Xinyi and Keelung Roads. The average concentration of NAIs around the fountain scenes is between 38,320 ~ 263,863 ions/cm3. Among all, the concentration of NAIs near the fountain in front of Taipei Metro Mall is highest. The atomization system is employed to simulate the generation of NAIs by the breakup of water droplets in the laboratory. There are two atomized water sources and three different pressures. The results show that the concentration of NAIs is higher when the water source is clearer. The NAIs generated from the atomization of pure water is about 3.4 ~ 16.4 times that of tap water. The concentration of NAIs increases with the pressure of atomization. For example, the concentration of NAIs generated at the atomization pressure of 30 PSI is higher as 3.6 to 8.7 times that of 20 PSI.
35
Lin, Chin-Chieh, and 林瑾杰. "Effect of Carbon-Nanotubes Mass on the Generation of Negative Air Ions." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/76058877874917099843.
36
Cumbo, Chiara, Pasquale Rullo, and Annamaria Canino. "A techinique for automatic generation of rule-based text classifiers exploiting negative information." Thesis, 2014. http://hdl.handle.net/10955/499.
37
Hsu, Meng-Tsung, and 徐孟琮. "The traits of carbon-nanotubes affect generation of negative air ions by electric discharging." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/64157284559370434726.
Анотація:
碩士國立臺灣大學
環境工程學研究所
96
This study investigated the traits of carbon-nanotubes (CNTs) affect generation of negative air ions (NAIs) by negative electric discharging, and investigated the feasibility of developing a microscale air cleaner. The research investigated the effect of the discharging voltage about CNTs on the one and two dimension metal substrate, the aspect ratio of CNTs, aligned CNTs, single-walled and multi-walled CNTs, metal material, metal aspect ratio, metal needle-point curvature, the stability and the effective distance of NAIs which were generated by negative electric discharging, dectecting ozone concentration. Because electrons can gather on need-point of one dimension substrate to make electrons excite easilier, the discharging voltage of CNTs on the one dimension metal substrate gets lower than other on the two dimension metal substrate. The enhanced field emission gets bigger and the discharging voltage gets lower when the aspect ratio of CNTs gets bigger. Beacause CNTs array align regularly, it can reduce screening effect and the discharging voltage effectively. Because of bigger aspect ratio and better conductivity the discharging voltage of Single-walled CNTs gets lower than the one of multi-walled CNTs. At the same discharging voltage, the stability of NAIs which were generated by negative electric discharging gets better when the aspect ratio of CNTs gets bigger. The NAIs concentration decreased when the distance increased, and The NAIs concentration and the distance indicated logarithmic linear relationship. The NAIs concentration of CNTs on copper and silver electrode which was used as the negative electrode to generate NAIs can reach detecting limit range when the discharging voltage was about 1.6 kV and 1.4 kV, and there was no generation of ozone. When the discharging voltage was about 3.0 kV, ozone concentration which was generated by CNTs on copper and silver electrode was about 0.5 ppb and 0.6 ppb, and ozone concentration increased fast when the discharging voltage increased.
38
Liao, Gong-Pu, and 廖弓普. "Development of Microscale Air Ionizer -- Generation of Negative air Ions by Carbon-nanotube Electric Discharging." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/75637050061553359015.
Анотація:
碩士國立臺灣大學
環境工程學研究所
95
This study investigated the operational factor and the base property of the negative air ions (NAIs) which were generated by negative electric discharge. This study also investigated the characteristics of carbon nanotubes which was used to generate negative air ions to develop a microscale air cleaner (MAC). First, this research investigated the influence of the initial discharging voltage about needle-point curvature, electrode diameter, electrode material, and the characteristics of carbon nanotubes. Second, it studied the effective distance of NAIs, stability of NAIs generator. NAIs were generated by the negative electric discharge method. The results show that the initial discharging voltage gets lower when the electrode needle-point curvature gets bigger. At the same needle-point curvature, the initial discharging voltage is lower when the electrode diameter is shorter. For different electrode material, when needle-point curvature and diameter are constant, copper had the lowest initial discharging voltage and followed by silver, graphite, lead, iron, tungsten, aluminum. The initial discharging voltage of carbon nanotubes which was used as the negative electrode to generate NAIs can be under 0.2 kV that was much lower than the initial discharging voltage of the experimental metal electrode. At relative humidity 40%, ozone was generated at 0.5 ppb when NAI concentration was about 6.3*105 ion/cm3. At relative humidity 70%, ozone was generated at 0.5 ppb when NAI concentration was about 9*105 ion/cm3. The NAI concentration decreased with the distance. The regression analysis of NAI concentration and distances from the discharge electrode indicated a logarithmic linear relationship. Additionally, more stable NAIs were generated by carbon nanotubes than other by metal electrodes when voltage was increased.
39
Tzeng, Xian-Yau, and 曾顯堯. "Generation Negative Air Ions by Carbon Nanotube Directly Grown on Carbon Cloth by Chemical Vapor Deposition." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/55285148954345519264.
Анотація:
碩士國立臺灣大學
環境工程學研究所
102
The purpose of this study is to produce a portable negative air ion (NAI) generator. NAI generated by corona discharge. In order to be portable, voltage which produces air ions needed should be reduced. This study attempts to replace the different electrode to reduce the voltage required to produce NAI. In this study chose carbon nanotubes directly (CNTs) grown on carbon cloth as the discharge electrode. It has lower resistance than the CNTs stick to the substrate. In this study, CNT have six terms, they are doped nitrogen (CNT-N) or not (CNT), growing time that is 5min, 10min, 15min. In this study measures starting voltage, stability of discharging and steady concentration of NAI in RH=0%, 20%, 40%, 60%, 80%,. The result of experiment reveal CNT-N is easier gathering than CNT. Growing time of CNT in 5min, 10min, 15min that their starting voltage is 2.3kV、1.93kV、2.06kV; Growing time of CNT-N in 5min, 10min, 15min that their starting voltage is 3.23 kV、1.86 kV、2.33 kV. It revels CNT have lower staring voltage in 5min and 15min. CNT-N in 10min have lower starting voltage. Measuring six different CNTs in relative humidity is 0%, 20%, 40%, 60%, 80%, the average value of starting voltage is 2.22±0.43kV、1.67±0.38kV、1.63±0.38kV、1.63±0.36kV、1.67±0.37kV, showing in 20%~60% has lower starting voltage. Testing in stability with humidity 40% and 2.5kV, growing time of CNTs-blank in 5min, 10min, 15min their coefficient of variation is 5.50%、64.98%、10.75%, growing time of CNT-N 5min, 10min, 15min their coefficient of variation is 20.78%、63.26%、8.84%, they reveal growing in 5min and 15min have better stability. Four electrode with higher stability : growing time of CNTs-N in 5min, 15min and growing time of CNTs-blank in 5min, 15min. Chose the steady concentration of NAI is higher than 200×103ions/cm3 and growing time of CNT in 15min (CNT-15) which starting voltage is the lowest electrode as the best electrode. Observing the relation of distance, humidity and concentration of NAI which generated by CNT-15. The result reveal when the longer distance between detector and generator the lower concentration of NAI. And continuous discharging electricity in 30 min, detecting concentration of ozone is 1.5ppb、2.1ppb、0.8ppb、1.8ppb、2.4ppb、1.6ppb, lower 0.06ppm in air quality law, in the course, producing ozone is not enough to endanger human body. Starting voltage of CNT-15 between 1.9~2.0kV. Coefficient of variation is 10.75%, average of concentration of NAI is around 773×103ions/cm3 , while CNT-15 discharge at -2.5kV and R.H.=40%. CNT 15 is most suitable CNTs to producing NAI in this study. Compare CNT-15 with research of 林(2009) stick carbon nanotubes on iron substrate (Fe-CNT), Fe-CNT has lower starting voltage(0.5kV). Fe-CNT can produce NAI only for 3 min. Consider the produce time of NAI, CNT-15 is better than Fe-CNT.
40
Lu, Shan-Jen, and 盧宣任. "The effect of field emission traits of carbon-nanotubes on the generation of negative air ions." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/38403545768069636163.
Анотація:
碩士國立臺灣大學
環境工程學研究所
97
This study investigated the traits of field emission effect of carbon-nanotubes (CNTs) on generation of negative air ions (NAIs) by negative electric discharging, and the feasibility of developing a microscale air cleaner. The research evaluated the effect of the aspect ratio of CNTs, density of the CNTs, single-wall and multi-wall CNTs and double-wall CNTs, metal material, metal aspect ratio, and metal needle-point curvature on the discharging voltage of CNTs. It also evaluated the stability and the effective space of the generation of NAIs by using CNTs with negative electric discharging, and studied the possible generation of ozone. The results show that enhanced field emission gets bigger when the aspect ratio of CNTs increased, so that discharging voltage gets lower. The limited voltage value of multi-wall CNTs(aspect ratio ranged from 1666.66 to 5000) required only 0.5 kV when they used as discharging electrode. That was the first time the value lower than 1.0 kV. CNTs array can reduce screening effect because of regular alignment and also reduce discharging voltage effectively. The field emission from CNTs array could be optimized with the inter-tube distance of 10th of the height(CNTs array with density of 1~2×109 CNTs/cm2). No matter the number of layers of CNTs, the CNTs with greater aspect ratio have lower discharging voltage. At same discharging voltage, the stability of NAIs by negative electric discharging gets higher when the aspect ratio of CNTs increases. And we find out that the stability of generate NAIs by imitate pulsed corona is much better than continued discharging. If we close the electric field for 30sec and restart it for 1 minutes. We could keep the concentration of NAIs over than 4.0×105ions/cm3 for 30minutes. The NAIs concentration did not change with increasing space. CNTs on copper electrode can reach detecting limit range of NAIs at discharging voltage of 0.5kV without generation of ozone. At discharging voltage of 2.5 kV, CNTs on copper electrode begin to generate ozone at 0.2 ppb, this value is much lower than the Indoor Air Quality value (0.03 ppm), so we don’t have to worry about the problem of ozone pollution.
41
Kjellberg, Marcus, and Barry Spaan. "Sustainability advertisements : The effects of negative and positive appeals on generation Y’s attitudes towards sustainable concerns." Thesis, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-73036.
42
Chen, Yi Liu, and 劉辰宜. "Candidates’ Appearance Attractiveness, Gender, and Positive/Negative Appeals on the Political Advertising Attitude:A Case of Young Generation." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/w45eb6.
Анотація:
碩士輔仁大學
企業管理學系管理學碩士班
103
The purpose of this study is to discuss the impacts under candidates’ appearance attractiveness (high attractiveness / low attractiveness), candidates’ gender (male/ female) and political advertising (positive appeals /negative appeals) on the advertising effectiveness. A total of 234 respondents participated in this study. An experimental method was used in this study, and data were analyzed by performing 3-way ANOVA. There are some findings in this study:(1) High attractiveness candidates have better advertising attitude than low attractiveness candidates;(2) Positive appeals advertisements have better advertising attitude than negative appeals advertisements;(3) High attractiveness candidates use negative appeals advertisements have better advertising attitude than low attractiveness candidates use negative appeals advertisements.
43
Seymore, Reyno. "The competitiveness effects of electricity generation taxes : a computable general equilibrium analysis." Thesis, 2011. http://hdl.handle.net/2263/28732.
Анотація:
The South African Government, in the Budget Review of 2008, proposed to impose a 2c/kWh tax on the sale of electricity generated from non-renewable sources, to be collected at source by the producers/generators of electricity. This tax will create distortions in the South African economy. The research study aims to identify measures that can be taken to negate the negative competitiveness impact of the tax. In the first part of the study, we applied the Global Trade Analysis Project (GTAP) model, which is coordinated by the Centre for Global Trade Analysis at Purdue University. The GTAP model is the pre-eminent modelling framework for the analysis of trade and environmental issues across countries. GTAP is a multi-region CGE model designed for comparative-static analysis of trade policy issues. Various versions were constructed and the closure was changed to reflect the South African reality more accurately. After the national as well as international economic and environmental impacts were analysed, we considered Border Tax Adjustments (BTAs) as a possible remedy to negate the negative competitiveness impact of the tax. Utilising theoretical Heckscher-Ohlin methodology, as well as the GTAP model, we showed that BTAs will not negate the adverse economic impact of an environmental tax. Instead, reversed BTAs, through gains of trade, could reverse the negative economic impact of an electricity generation tax, while enabling an economy to retain most of the environmental benefits of the tax. We also considered the impact of an integrated approach, consisting of an electricity generation tax and a demand side policy, on the welfare of households. To analyse this, we used the University of Pretoria General Equilibrium Model (UPGEM). The model was extended to reflect Equivalent Variation values and we updated the database to include import tariffs. It was then shown that reversed BTAs could be used to offset the regressiveness of the electricity generation tax. Policy implications from the study will be useful for macroeconomic policies, international trade negotiations and environmental policies to increase the welfare of society.Thesis (DCom)--University of Pretoria, 2011.
Economics
unrestricted
44
Kan, Li-Hsing, and 甘力行. "High energy pulse generation in large negative-dispersion mode-locked Er-doped fiber laser with long cavity length." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/63481228711128143870.
Анотація:
碩士國立交通大學
顯示科技研究所
99
In this thesis, we experimentally demonstrate a passive mode-locked Erbium-doped fiber laser with large net round trip anomalous dispersion and nonlinearity through about 400m cavity length. The laser can output optical pulse trains at the low repetition rate around 500kHz and with the high pulse energy larger than 120nJ directly from the laser output. By adjusting the polarization controllers (PCs) and the pump power level, high energy pulses with square profile and nanosecond pulse-width without pulse breaking can be observed. Finally, we study the characteristic parameters of our pulses for further compressing the pulse-width to attain the short pulse-width and high peak power.
45
Neill, Joanna C., Samuel Barnes, Samantha Cook, Ben Grayson, Nagi F. Idris, Samantha L. McLean, S. Snigdha, Lakshmi Rajagopal, and Michael K. Harte. "Animal models of cognitive dysfunction and negative symptoms of schizophrenia: focus on NMDA receptor antagonism." 2010. http://hdl.handle.net/10454/8461.
Анотація:
YesCognitive deficits in schizophrenia remain an unmet clinical need. Improved understanding of the neuro- and psychopathology of these deficits depends on the availability of carefully validated animal models which will assist the development of novel therapies. There is much evidence that at least some of the pathology and symptomatology (particularly cognitive and negative symptoms) of schizophrenia results from a dysfunction of the glutamatergic system which may be modelled in animals through the use of NMDA receptor antagonists. The current review examines the validity of this model in rodents. We review the ability of acute and sub-chronic treatment with three non-competitive NMDA antagonists; phencyclidine (PCP), ketamine and MK801 (dizocilpine) to produce cognitive deficits of relevance to schizophrenia in rodents and their subsequent reversal by first- and second-generation antipsychotic drugs. Effects of NMDA receptor antagonists on the performance of rodents in behavioural tests assessing the various domains of cognition and negative symptoms are examined: novel object recognition for visual memory, reversal learning and attentional set shifting for problem solving and reasoning, 5-Choice Serial Reaction Time for attention and speed of processing; in addition to effects on social behaviour and neuropathology. The evidence strongly supports the use of NMDA receptor antagonists to model cognitive deficit and negative symptoms of schizophrenia as well as certain pathological disturbances seen in the illness. This will facilitate the evaluation of much-needed novel pharmacological agents for improved therapy of cognitive deficits and negative symptoms in schizophrenia.
46
JHANG, JING-YU, and 張競宇. "The Influence of Negative Electronic Word-of-Mouth on Consumer Switching Behavior : Take Next-Generation Video Game Consoles for Example." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/yd9vfe.
Анотація:
碩士國立臺灣科技大學
企業管理系
95
This research is to investigate electronic negative word-of-mouth and the influence on consumer switching behavior. Electronic negative word-of-mouth is that through web-based consumer opinion platforms, customers can share their opinions on, and dissatisfied experiences with, goods or services with a multitude of other consumers and suggest others not to purchase this goods or services. This research is to discuss the impact of the strength of electronic negative word-of-mouth, the disseminator’s expertise and the strength of relationship on consumer switching behavior, and this study also discusses how swatching cost play as a moderator on the negative effect. On the research approach, this research regards internet network user as the research object, and choose the next-generation video game consoles to fill out and answer the products as the questionnaire. The analysis used hierarchical regression analysis to analyze variables influence on consumer switching behavior in the model. The results reveal that the strength of electronic negative word-of-mouth, the disseminator’s expertise and the strength of relationship would affect the consumer switching behavior. Swatching cost will weaken the strength of relationship impact on consumer switching behavior.
47
Hansen, Kristy Lee. "Effect of leading edge tubercles on airfoil performance." Thesis, 2012. http://hdl.handle.net/2440/79211.
Анотація:
This thesis provides a detailed account of an experimental investigation into the effects of leading edge sinusoidal protrusions (tubercles) on the performance of airfoils. The leading edge geometry was inspired by the morphology of the Humpback whale flipper, which is a highly acrobatic species. The aim of this study is to investigate the potential advantages and disadvantages of incorporating tubercles into the leading edge of an airfoil. Specific parameters have been varied to identify an optimum tubercle configuration in terms of improved lift performance with minimal drag penalties. The investigation has shown that for all tubercle arrangements investigated, increased lift performance in the post-stall regime comes at the expense of degraded lift performance in the pre-stall regime. However, it has also been noted that through optimizing the amplitude and wavelength of the tubercles, pre-stall lift performance approaches the values attained by the unmodified airfoil and post-stall performance is much improved. In general, the configuration which demonstrates the best performance in terms of maximum lift coefficient, maximum stall angle and minimum drag has the smallest amplitude and wavelength tubercles. A new alternative modification has also been explored, whereby sinusoidal surface waviness is incorporated into the airfoil, giving a spanwise variation in local attack angle. Results indicate that optimisation of this configuration leads to similar performance advantages as the best-performing tubercle configuration. It is believed that the flow mechanism responsible for performance variation is similar to tubercles. The deterioration in pre-stall performance for airfoils with tubercles in the current study has been explained in terms of Reynolds number effects and also the relatively weak spanwise flow in the boundary layer. In swept and tapered wings such as the Humpback whale flipper, spanwise flow occurs along the entire span, so the effect of tubercles can be expected to be much larger. Surface pressure measurements have indicated that the region of separation and reattachment for airfoils with tubercles is restricted to the trough between the tubercles rather than extending across the entire span. Hence, leading-edge separation is initiated at the troughs but occurs at a higher angle of attack for other locations, leading to a delayed overall stall for airfoils with tubercles. In addition, integration of the surface pressures along the airfoil chord has indicated that lift, and hence circulation, varies with spanwise position, providing suitable conditions for the formation of streamwise vorticity. A spanwise variation in circulation is also predicted for the wavy airfoil since the relative angle of attack varies along the span. Counter-rotating streamwise vortices have been identified in the troughs between tubercles using particle image velocimetry in a series of cross-streamwise, crosschordwise planes which have not been investigated previously using this technique. The associated peak primary vorticity and circulation have been found to increase with angle of attack for a given measurement plane. This provides an explanation for the effectiveness of tubercles post-stall since an increased primary vortex strength leads to a greater boundary layer momentum exchange. The results show that the magnitude of the circulation generally increases in the streamwise direction, except when there exist secondary vortex structures of opposite sign on the flow side of the primary vortices. A proposed mechanism for this increasing circulation of the primary vortices is the entrainment of secondary vorticity which is generated between the adjacent primary vortex and the airfoil surface. It is postulated that this process of entrainment alternates between the primary vortices in an unsteady fashion. Leading edge tubercles have also been found to mitigate tonal noise associated with the NACA 0021 and the NACA 65-021 at all angles of attack in a novel investigation. Elimination of the tonal noise occurred for the majority of modified airfoils and in many cases the broadband noise level was also reduced for certain frequency ranges. It is believed that tonal noise elimination is facilitated by the presence of the streamwise vortices and that the spanwise variation in separation location is also an important factor. Both characteristics modify the stability characteristics of the boundary layer, altering the frequency of velocity fluctuations in the shear layer near the trailing edge. This affects the coherence of the vortex generation downstream of the trailing edge, hence leading to a decrease in trailing edge noise generation.Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2012
48
Comeau, Kathryn Marie. "Generation of both an shRNA-resistant MEF2A over expression construct and a dominant negative construct in adenovirus for rescue and knockout experiments in muscle." Thesis, 2015. https://hdl.handle.net/2144/14021.
Анотація:
The Myocyte Enhancer Factor-2, or MEF2, transcription factor family is necessary for the differentiation and regeneration of both skeletal and cardiac muscle tissue. The transcription factors in this family are responsible for the activation of many muscle specific growth factor-induced and differentiation genes. There are four individual isoforms of MEF2; MEF2A, -B, -C, and –D, and the roles of these individual transcription factors are not completely understood. Knockdowns of these individual isoforms revealed that a MEF2A knockdown mouse model displays severe myofibrillar defects in cardiac muscle. This knockdown also has shown that MEF2A is required for myogenesis in vitro, where the other 3 isoforms, -B, -C, and –D, are not necessary for this process. One method of knocking down MEF2A to study its roles further is through the use of short hairpin RNAs (shRNA). The purpose of my research was two-fold. First, in order to test the specificity of this shRNA method, an shRNA-resistant MEF2A over expression construct in an adenoviral vector was created to perform rescue experiments. Second, to compare individual MEF2 isoform knockouts to a complete knockout of the entire MEF2 family, a dominant negative construct was created in an adenoviral vector. In both cases, a pShuttle-CMV adenoviral vector was used. The results of this experiment can be used to further investigate the roles of MEF2A in both regeneration and differentiation of skeletal and cardiac muscle tissue.
49
Venkataraman, Anusha. "Self-assembled nanoelectronic networks with tunable molecule-nanoparticle ratios: experiment, modeling, and applications." Thesis, 2021. http://hdl.handle.net/1828/13442.
Анотація:
Replacing electronic components with molecule-sized analogs or hybrids is often seen as a promising alternative to further miniaturization of conventional electronics in the effort to achieve functional nanoscale circuit elements. In this thesis, electronic transport through self-assembled networks with tunable thiolated (alkane(di)thiol and benzenedithiol) molecule-to-colloidal gold (Au) nanoparticle ratios (1:5–50:1) is studied using a combination of broad area and scanning probe microscope-based measurements. The electronic transport paths through the network can be altered by adjusting the (di)thiol molecule–gold nanoparticle ratio and/or type of molecules in the network. Resistance can be controllably tuned by several orders of magnitude (~105 to 1011 ohms for the Au-thiolated structures studied). Two-terminal current–voltage (I-V) measurements of the Au-thiolated networks display linear behavior at low bias. High bias measurements in case of benzenedithiol networks show nonlinear negative differential resistance (NDR) and hysteresis behavior for different benzenedithiol concentrations, which can be attributed to a combination of field-assisted tunneling and charge trapping occurring in the nanoscale networks. Circuit simulations that account for different network morphologies, tunable via molecule-to-nanoparticle ratio, and defects show good agreement with the experiment and provide a guide to engineer network properties using different molecules. In addition, electronic transport properties of nanoscale networks, which are composed of Au metal clusters interconnected with thiolated molecules (benzene/alkanedithiol) and connected in linear chains and branched extended networks, are examined via first-principles density functional theory-based simulations. Calculated I-V characteristics of the metal-molecular networks exhibited nonlinearities and rectification with NDR peaks that became more pronounced with increasing chain length. The transmission spectra of the linear chains and branched networks showed an increase in the number and width of transmission peaks near the Fermi energy, as the structures were extended, indicating enhanced transmission. Peak-to-valley current NDR ratios as large as ~ 500 and rectification ratios of ~ 10 (0.25 V) were shown for linear and branched circuit elements, respectively, illustrating how charge transport through molecular-scale devices could be controlled with precision by modifying the structure and geometry of molecule-nanoparticle networks. These experimental and simulation results are utilized to propose molecular-scale circuits in applications such as memory, switching, and hardware security. The metal nanoparticle molecular electronic networks presented in this thesis provide an avenue for engineering electronics at the molecular level.Graduate
50
Alibakhshikenari, M., B. S. Virdee, L. Azpilicueta, M. Naser-Moghadasi, M. O. Akinsolu, C. H. See, B. Liu, et al. "A comprehensive survey of "metamaterial transmission-line based antennas: design, challenges, and applications"." 2020. http://hdl.handle.net/10454/18129.
Анотація:
YesIn this review paper, a comprehensive study on the concept, theory, and applications of composite right/left-handed transmission lines (CRLH-TLs) by considering their use in antenna system designs have been provided. It is shown that CRLH-TLs with negative permittivity (ε <; 0) and negative permeability (μ <; 0) have unique properties that do not occur naturally. Therefore, they are referred to as artificial structures called “metamaterials”. These artificial structures include series left-handed (LH) capacitances (C L ), shunt LH inductances (L L ), series right-handed (RH) inductances (LR), and shunt RH capacitances (CR) that are realized by slots or interdigital capacitors, stubs or via-holes, unwanted current flowing on the surface, and gap distance between the surface and ground-plane, respectively. In the most cases, it is also shown that structures based on CRLH metamaterial-TLs are superior than their conventional alternatives, since they have smaller dimensions, lower-profile, wider bandwidth, better radiation patterns, higher gain and efficiency, which make them easier and more cost-effective to manufacture and mass produce. Hence, a broad range of metamaterial-based design possibilities are introduced to highlight the improvement of the performance parameters that are rare and not often discussed in available literature. Therefore, this survey provides a wide overview of key early-stage concepts of metematerial-based designs as a thorough reference for specialist antennas and microwave circuits designers. To analyze the critical features of metamaterial theory and concept, several examples are used. Comparisons on the basis of physical size, bandwidth, materials, gain, efficiency, and radiation patterns are made for all the examples that are based on CRLH metamaterialTLs. As revealed in all the metematerial design examples, foot-print area decrement is an important issue of study that have a strong impact for the enlargement of the next generation wireless communication systems.
This work was supported in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER, UE) under Grant RTI2018-095499-B-C31, in part by the Innovation Programme under Grant H2020-MSCA-ITN-2016 SECRET-722424, and in part by the financial support from the U.K. Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/E022936/1.