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Academic literature on the topic 'Mathematical precursors'

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Published: 11 March 2023

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Journal articles on the topic "Mathematical precursors"

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Cirino, Paul T. "The interrelationships of mathematical precursors in kindergarten." Journal of Experimental Child Psychology 108, no. 4 (April 2011): 713–33. http://dx.doi.org/10.1016/j.jecp.2010.11.004.

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Nogues, Camila Peres, and Beatriz Vargas Dorneles. "Systematic review on the precursors of initial mathematical performance." International Journal of Educational Research Open 2-2 (2021): 100035. http://dx.doi.org/10.1016/j.ijedro.2021.100035.

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Guzev, Mikhail, and Vladimir Makarov. "Investigation of Deformation of Rock Samples." Key Engineering Materials 744 (July 2017): 61–65. http://dx.doi.org/10.4028/www.scientific.net/kem.744.61.

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Deformation of rock samples compressed up to failure has been studied in laboratory. A system of trustworthy deformational precursors of the failure stage has been developed. The system includes long-term, middle-term and short-term precursors, which correspond to the threshold of dilatancy, change of the specific volume deformation, and jump of the specific volume deformation increments, respectively. Proposed methods of the complex research include deformation and mathematical methods. The mathematical model of deformation in samples of rocks at uniaxial compression is founded on hypothesis of self-equilibrium stresses. The model had been successfully used for description of oscillating deformation. Good coincidence between the experimental and theoretical results has been observed.
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Sajid, Muhammad, Apu Chowdhury, Ghulam Bary, Yin Guoliang, Riaz Ahmad, Ilyas Khan, Waqar Ahmed, Muhammad Farooq Saleem Khan, Aisha M. Alqahtani, and Md Nur Alam. "Conversion of Fructose to 5-Hydroxymethyl Furfural: Mathematical Solution with Experimental Validation." Journal of Mathematics 2022 (April 29, 2022): 1–8. http://dx.doi.org/10.1155/2022/6989612.

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Conversion of fructose to furan aldehydes is a rapidly developing concept considering the emergent scenario of the replacement of fossil-derived components to biomass-derived green precursors. 5-hydroxymethyl furfural (HMF) and levulinic acid (LA) are the two most important bio-precursors with expanded downstream utilization in modern industries. Their production from biomass-derived sugars is a complex reaction due to competitive side reactions with a variety of byproducts. Therefore, their simulated optimization is an important tool that can help for process optimization in an economical way. In this article, we have developed a mathematical solution for fructose conversion, HMF production, and levulinic acid (LA) formation in a reactive environment. The accuracy of the developed model is further verified through experiments and found satisfactory with high accuracy. Therefore, the developed model can be used to simulate the reaction environment and product optimization under a given set of conditions.
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Zolotov, O. V., A. A. Namgaladze, I. E. Zakharenkova, O. V. Martynenko, and I. I. Shagimuratov. "Physical interpretation and mathematical simulation of ionospheric precursors of earthquakes at midlatitudes." Geomagnetism and Aeronomy 52, no. 3 (May 2012): 390–97. http://dx.doi.org/10.1134/s0016793212030152.

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KHAN, K. M., W. AHMAD, and K. IQBAL. "A NONTHERMAL MODEL FOR CATALYTIC SURFACE REACTION OF THE TYPE A2+B2→2AB: A MONTE CARLO SIMULATION STUDY." International Journal of Modern Physics C 14, no. 10 (December 2003): 1413–26. http://dx.doi.org/10.1142/s0129183103005492.

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The kinetics of irreversible dimer–dimer reaction of the type A2+B2→2AB has already been studied through Monte Carlo simulation via a model based on Langmuir–Hinshelwood (thermal) mechanism. The results of this study are well known. There is single transition point (yC) at yB=0.5 (where yB is partial pressure of B2 dimer in gas phase), which separates the two poisoned states from each other. Here, we have studied this reaction on the basis of a nonthermal model, which involves the precursor motion of B2 molecule. The most interesting feature of this model is that it yields a steady reactive window. The phase diagram is similar to the ZGB model. The reactive window is separated by continuous and discontinuous irreversible phase transitions. The width of the reactive window depends upon the mobility of the precursors. The dependence of production rate on partial pressure of B2 is shown by simple mathematical equations in our model. Some interesting results are observed when reaction between precursors and chemisorbed B atoms is considered.
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Bazan, Carlos. "Effect of the University’s Environment and Support System on Subjective Social Norms as Precursor of the Entrepreneurial Intention of Students." SAGE Open 12, no. 4 (October 2022): 215824402211291. http://dx.doi.org/10.1177/21582440221129105.

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In this study, we aim to understand the influence of the university’s environment and support system (ESS) on subjective social norms (SSN) as one of the precursors of the entrepreneurial intention (EI) of university students. For this, we applied a customized mathematical model of EI based on the theory of planned behavior to probe whether the university’s ESS can affect SSN and analyze the paths that this influence may follow to form the EI of students. In other words, this study argues that the university plays a critical dual role in shaping the EI of students. First, it can provide support mechanisms to help students translate their ideas into viable business models that may further translate into successful ventures. Second, it can help students gain the support of their families and friends who influence their SSN, thus affecting their EI through the mediating effects of the other two precursors of intention. We collected the data from students in a public university in Atlantic Canada via a structured non-disguised questionnaire to test the hypotheses formulated in this study. We analyzed them through partial least square-structural equation modeling of a second-order mathematical model of EI. Analysis of the data indicates that the mathematical model is appropriate for evaluating the relations among the five constructs of the mathematical model of EI. Results of this study support the hypothesis that the university’s ESS may influence students’ perceptions of the opinions of important reference people regarding their prospects of becoming entrepreneurs. Furthermore, we determined that the university’s ESS influences the EI of students mediated by the more proximal precursors of intention. The effect of the university’s ESS is such that it may positively impact the EI of students, but its importance in the mathematical model of EI is still low. These findings can help universities assess their initiatives to promote innovation and entrepreneurship on campus.
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Torresi, Sandra. "Interaction between domain-specific and domain-general abilities in math´s competence." Journal of Applied Cognitive Neuroscience 1, no. 1 (December 7, 2020): 43–51. http://dx.doi.org/10.17981/jacn.1.1.2020.08.

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This article is an approach to some viewpoints about interactions between domain-specific and general cognitive tools involved in the development of mathematical competence. Many studies report positive correlations between the acuity of the numerical approximation system and formal mathematical performance, while another important group of investigations have found no evidence of a direct connection between non-symbolic and symbolic numerical representations. The challenge for future research will be to focus on correlations and possible causalities between non-symbolic and symbolic arithmetic skills and general domain cognitive skills in order to identify stable precursors of mathematical competence.
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Polonsky, Michal, Jacob Rimer, Amos Kern-Perets, Irina Zaretsky, Stav Miller, Chamutal Bornstein, Eyal David, et al. "Induction of CD4 T cell memory by local cellular collectivity." Science 360, no. 6394 (June 14, 2018): eaaj1853. http://dx.doi.org/10.1126/science.aaj1853.

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Cell differentiation is directed by signals driving progenitors into specialized cell types. This process can involve collective decision-making, when differentiating cells determine their lineage choice by interacting with each other. We used live-cell imaging in microwell arrays to study collective processes affecting differentiation of naïve CD4+ T cells into memory precursors. We found that differentiation of precursor memory T cells sharply increases above a threshold number of locally interacting cells. These homotypic interactions involve the cytokines interleukin-2 (IL-2) and IL-6, which affect memory differentiation orthogonal to their effect on proliferation and survival. Mathematical modeling suggests that the differentiation rate is continuously modulated by the instantaneous number of locally interacting cells. This cellular collectivity can prioritize allocation of immune memory to stronger responses.
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Namgaladze, A. A., M. V. Klimenko, V. V. Klimenko, and I. E. Zakharenkova. "Physical mechanism and mathematical modeling of earthquake ionospheric precursors registered in total electron content." Geomagnetism and Aeronomy 49, no. 2 (April 2009): 252–62. http://dx.doi.org/10.1134/s0016793209020169.

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Dissertations / Theses on the topic "Mathematical precursors"

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Costa, Hiwet Mariam. "Precursors of mathematics learning: identification and intervention." Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/11005.

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2013/2014
The studies presented in this thesis contribute to the growing body of knowledge regarding the relationships between domain general precursors, domain specific precursors and mathematical learning. Given the previous inconsistent results about the link between ANS acuity and mathematical abilities (i.e. Kolkman et al., 2013) we were interested in the investigation of the relation between the ANS and early mathematics abilities in preschool years. This relationship was explored by using two different approaches: in Chapter 2 the relationship between ANS and different mathematical measures, measured concurrently, were investigated; Chapter 3 examined the possibility to improve the ANS abilities in preschool children by using intensive adaptive training over a relatively short period. Moreover, the transfer effects of the training on mathematical abilities were also examined. The second aim of this dissertation concerned the potential role played by STM and WM skills in supporting domain-specific precursors of mathematics. The few studies that considered the role of WM in simple quantity comparison abilities did not provide a strong basis for any firm conclusions on such a relationship (Mussolin, Nys, Leybaert, & Content, 2012; Soltész, Szűcs, & Szűcs, 2010) since they didn’t assess all of the WM components. Chapter 2 focuses on uncovering which specific WM component is involved in non-symbolic approximate quantity comparison processing in the preschool age. Moreover, in ordered to further explore the relationship between WM abilities and ANS, Chapter 3 investigated whether training focusing on the improvement of ANS abilities produced a far-transfer effect on WM abilities. Several studies found that WM abilities are related to overall mathematical skills (Gersten et al., 2005; Jordan et al., 2006; Passolunghi & Lanfranchi, 2012), therefore Chapter 4 investigated a possible causal relationship between domain-general working memory abilities and domain-specific numerical competence through a training study during the preschool years. The third aim of this dissertation was to explore the malleability of cognitive precursors of mathematical learning. In Chapter 3, the possibility to improve ANS abilities was investigated, whereas Chapter 4 aimed to verify and compare the effects on early numerical competence of two types of training. One type of training focused on the enhancement of domain-general precursors, working memory abilities; while the other focused on the enhancement of domain-specific precursors, early numeracy abilities. In the field of intellectual disabilities, some studies suggested that WM skills of children with neurodevelopmental disorders (like Down’s syndrome) tend to be impaired and very poor compared to typically developing children of a similar mental age (Gathercole & Alloway, 2006). In Chapter 5, the efficacy of a school-based visuo-spatial WM training on STM and WM skills for two individuals with DS was examined. The main findings emerging from overall studies and limitations, future directions and implications of the research are finally discussed in Chapter 6.
Gli studi presentati in questa tesi forniscono nuovi risultati riguardo la relazione tra precursori dominio-generali e precursori dominio-specifici dell’apprendimento matematico. Le ricerche che si sono occupate di indagare la relazione tra Approximate Numer System (ANS) e abilità matematiche finora hanno prodotto risultati contrastanti (Kolkman et al., 2013). Ci siamo quindi interessati ad approfondire lo studio della relazione tra ANS e matematica in età prescolare utilizzando due diversi approcci. Nel capitolo 2 è stato indagata la relazione tra ANS e diverse abilità matematiche, misurati contemporaneamente. Nel Capitolo 3 è stata indagata la possibilità di potenziare le abilità di ANS in bambini in età prescolare, utilizzando un training intensivo per un periodo relativamente breve. Inoltre, sono stati esaminati gli effetti del training di ANS sulle abilità matematiche. Il secondo obiettivo di questa tesi è stato quello di indagare il ruolo svolto della memoria a breve termine e della memoria di lavoro nello sviluppo dei precursori dominio-specifici dell’apprendimento matematico. I pochi studi che hanno considerato la relazione tra abilità di memoria e abilità di confronto di quantità non sono giunti a conclusioni certe su tale relazione in quanto non hanno analizzato in maniera completa il ruolo svolto da ogni componente della memoria di lavoro (Mussolin, Nys, Leybaert, & Content, 2012; Soltész, Szűcs, & Szűcs, 2010). Con lo studio descritto nel Capitolo 2 abbiamo voluto indagare quale specifica componete della memoria di lavoro sia coinvolta nel processo di comparazione di quantità in età prescolare. Inoltre, per analizzare ulteriormente tale relazione nel Capitolo 3 abbiamo indagato l’effetto, sulle abilita di memoria di lavoro, di un training focalizzato sul potenziamento delle abilità di ANS. Dato che diversi studi confermano la relazione tra memoria di lavoro e abilità matematiche (Gersten et al., 2005; Jordan et al., 2006; Passolunghi & Lanfranchi, 2012), nel capitolo 4 abbiamo esaminato la possibile relazione causale tra le capacità dominio-generali di memoria di lavoro e precursori dominio-specifici (abilità matematiche precoci) tramite uno studio di training in età prescolare. Il terzo obiettivo di questa tesi è stato quello di esplorale la malleabilità dei precursori cognitivi dell’apprendimento matematico. Nel Capitolo 3 è stata indagata la possibilità di potenziare le abilità di ANS mentre nel capitolo 4 abbiamo voluto verificare l’efficacia di due diversi tipi di training sul potenziamento della abilità matematiche in età prescolare. Il primo training era focalizzato sul potenziamento della memoria di lavoro (precursore dominio-generale) mentre il secondo training era focalizzato sul potenziamento delle abilità matematiche precordi (precursore dominio-specifico). Gli studi nel campo delle disabilità intellettive, suggeriscono che le competenze di memoria di lavoro di bambini con disturbi dello sviluppo neurologico (come la sindrome di Down) tendono ad essere compromesse e molto scarsa in confronto alle abilità di memoria di bambini con sviluppo tipico ma stessa età mentale (Gathercole e Alloway, 2006). Nel capitolo 5, è stata indagata l'efficacia di un training di memoria di lavoro visuo-spaziale sulle abilità di memoria a breve termine e di memoria di lavoro di due persone con sindrome di Down. I principali risultati della tesi, le direzioni future e le implicazioni delle ricerche sono state discusse nel Capitolo 6.
XXVII Ciclo
1987
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Grove, Dale A. III. "Mathematical model of solid state thermo-oxidative stabilization of acrylic precursors for carbon fibers : evaluation of the properties of carbon fibers produced from melt-spun pan-based fibers." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/11111.

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Neves, Neuza Maria Santos. "Formação e dispersão de ozônio na região do Recôncavo Baiano." reponame:Repositório Institucional da UFBA, 2009. http://www.repositorio.ufba.br/ri/handle/ri/11753.

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Ozônio pode afetar a saúde humana sendo a ele atribuída a responsabilidade por centenas de milhares de mortes prematuras a cada ano e por centenas de internações hospitalares adicionais, além da perda de milhões de dias de trabalho. Estes impactos na saúde são causados tanto por exposições a longo prazo (crônica) quanto a curto prazo (aguda). De forma semelhante a que ocorre atualmente próximo às grandes cidades do mundo e aos centros industriais, as concentrações ambientais de ozônio estavam ultrapassando o padrão de qualidade do ar estabelecido no Brasil, nas vizinhanças do Pólo Petroquímico de Camaçari, especialmente durante os anos de 2000 a 2003. Com o objetivo de avaliar a formação e dispersão de ozônio na região do Recôncavo Baiano, foi desenvolvido um estudo, usando modelagem matemática, para melhor compreender as principais fontes dos precursores de ozônio, bem como sua formação e dispersão na referida região. A metodologia adotada no estudo foi a elaboração de um inventário de emissões atmosféricas para as regiões urbanas e industriais e utilização do modelo matemático fotoquímico denominado STEM III – Sulfur Transport and Deposition Model, da Universidade de Iowa (USA), para simular a formação e dispersão deste poluente fotoquímico secundário na atmosfera na região do Recôncavo Baiano. Os resultados do modelo foram comparados com as concentrações medidas por uma rede de monitoramento contínuo da qualidade do ar do Pólo Petroquímico, referente a um período em abril de 2003. Concluiu-se que os resultados calculados para ozônio na região do Recôncavo Baiano, através do modelo matemático STEM são adequados, uma vez que há concordância satisfatória com os dados medidos. Os desvios encontrados ocorreram especificamente durante os episódios com baixas velocidades do vento, quando foram registrados picos de concentrações deste poluente próximo ao Pólo Petroquímico de Camaçari. Os modelos matemáticos meteorológicos não descrevem adequadamente a situação real quando a velocidade do vento é inferior a 1 m/s. ix Os resultados das simulações demonstram que a formação de ozônio ocorre em regiões situadas muito além dos locais onde estão situadas as estações de monitoramento do ar do Pólo, e atinge áreas distantes de Salvador e da região industrial, como Feira de Santana e Santo Estevão, situadas a jusante dos ventos que sopram do quadrante Este, predominantes na região. Todas as concentrações calculadas para ozônio foram inferiores ao limite de 160 µg/m3 estabelecidas pela Resolução CONAMA 003/90, para períodos horários e portanto, não deverão causar impactos na saúde humana. No entanto as concentrações encontradas até cerca de 100 a 150 Km das fontes consideradas podem afetar os ecossistemas pois as concentrações máximas simuladas estão próximas do limite de 40 ppb.h (do inglês:Accumulated Dose Over Threshold of 40 ppb.h - AOT40), na região Oeste e Noroeste do domínio estudado. O regime de formação de ozônio na região de Camaçari e de Candeias é limitado pelo NOx, e as reduções das emissões de NO2 efetuadas pelo Pólo Petroquímico à partir de 2004 resultaram na eliminação das violações dos limites de ozônio na sua região de influência. Considerando-se o atual cenário de desenvolvimento do Brasil, em dez anos as concentrações de ozônio nas áreas costeiras do Recôncavo poderão representar uma ameaça para a produtividade agrícola desenvolvida na região situada no interior da Bahia, e eventualmente poderão representar também uma ameaça para a saúde humana, a depender do aumento das emissões, particularmente veiculares.
Salvador
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Cargnelutti, Elisa. "Children and mathematics: beyond the role of cognitive abilities in early math achievement." Doctoral thesis, Università degli studi di Trieste, 2014. http://hdl.handle.net/10077/10022.

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2012/2013
The field of mathematical learning has received in recent years increasing attention in research, clinical and educational settings. The leading research line is dedicated to the investigation of the cognitive abilities fundamental for the acquisition and application of math concepts. Among general abilities, there is a wealth of evidence in favor of the recruitment of both working memory and short-term memory, despite there is no agreement concerning the involvement of the related subcomponents. Conflicting results pertain also the role of intelligence. Even major debate concerns more specific cognitive abilities, therefore those closely related to mathematics. In particular, it has not been elucidated the involvement of basic skills entailing approximate judgments about magnitudes and identified with ANS. Moreover, it is not yet clear how the recruitment of all these abilities can vary in dependence on stage of development and level of instruction. The other research line, almost independent from the previous, is dedicated to the evaluation of constructs non-cognitive in nature, for instance affective and motivational factors but also self-perceptions, in relation to academic achievement. Mainly studied are constructs such as self-efficacy and anxiety, with particular reference to a subtype of anxiety that is specific to math. Other relevant aspects are represented by constructs such as self-concept and self-esteem, but also depression. Nevertheless, this kind of studies is usually conducted on old children, typically in those attending secondary school or college, whereas less attention is dedicated to younger students. Starting from these considerations, the purpose of the current dissertation has been that of elucidating which are the factors, both cognitive and non-cognitive, that can assume a greater relevance at the beginning of schooling, i.e., in the first grades of primary school. These factors have been inspected both separately and by trying to find a possible interrelation between them. In CHAPTER 1, the topics that are object of the present work are illustrated by delineating the state-of-the-art pertinent to each of them. CHAPTER 2 is dedicated to the description of Study 1, where a broad range of cognitive abilities including memory, intelligence and ANS has been investigated just at the beginning of formal instruction and therefore in relation to early math competence. Having proved the significant involvement of all tested skills, the consequent aim was that of exploring to which extent the same are suitable in the prediction of math performance in following grades. This investigation has represented the topic of Study 2, illustrated in CHAPTER 3. In this study, children were longitudinally followed from first to third grade, observing that the tested abilities can successfully predict future math learning, but with a leading role of working memory. Once having shed light on the involvement of cognitive abilities, a second purpose was the investigation of the possible involvement in young students of non-cognitive factors. These constructs were thus assessed in Study 3, reported in CHAPTER 4. The sample was represented by second graders and more relevant aspects resulted to be self-efficacy and general anxiety. Contrary to expectations, anxiety specific to math appeared be non-significantly related to math performance. For this reason, Study 4, described in CHAPTER 5, was dedicated to an extensive evaluation of this constructs in third graders, in order to inspect when it could become relevant. Results suggested the association with math performance to establish in third grade, with particular impact of anxiety related to learning math rather than that associated to the math testing condition. The main findings emerging from overall studies and limitations, future directions and implications of the research are finally discussed in CHAPTER 6.
Negli ultimi anni, lo studio dell’apprendimento della matematica ha iniziato a ricevere crescente attenzione nel campo della ricerca, ma anche in quello clinico ed educativo. Maggiore interesse è dedicato allo studio delle abilità cognitive che sottostanno all’apprendimento e all’applicazione dei concetti matematici. Tra le abilità a carattere generale, in letteratura esiste un forte consenso sul ruolo cruciale della memoria, sia di lavoro che a breve termine, nonostante non sia del tutto chiarito il coinvolgimento relativo delle varie componenti della stessa. Dibattito sussiste anche in merito al ruolo dell’intelligenza. Ancora maggiori divergenze permangono in merito al ruolo di abilità più specifiche, ovvero strettamente pertinenti alla matematica. In particolare non c’è accordo sul ruolo di abilità molto di base, indicate come ANS, e che consistono nel fornire giudizi approssimati in merito a grandezze e quantità. In aggiunta, non è chiaro il coinvolgimento relativo delle sopraccitate abilità in relazione a determinati stadi dello sviluppo o livelli di istruzione. Il secondo filone di ricerca, perlopiù indipendente dal precedente, è rappresentato dalla valutazione di aspetti prettamente non-cognitivi, quali quelli affettivi e motivazionali, ma anche percezioni che gli individui formano in merito a se stessi e alle proprie capacità. I costrutti maggiormente indagati sono quelli dell’auto-efficacia e dell’ansia, sia generale che specifica per la matematica. Altri aspetti rilevanti sono rappresentati dal concetto di sé, dall’autostima e dalla depressione. Questi fattori sono tuttavia tipicamente valutati in studenti a partire dalla scuola secondaria, mentre minore attenzione viene dedicata a quelli frequentanti i primi anni del percorso scolastico. A partire da queste considerazioni, l’obiettivo primario del presente lavoro di tesi è consistito nella valutazione di quali fattori, sia cognitivi che non, hanno una maggiore rilevanza nell’ambito della prestazione matematica all’inizio della scolarità, più precisamente nelle prime classi della scuola primaria. Si è voluto valutare questi fattori sia indipendentemente, sia esplorandone la possibile influenza reciproca. Il CAPITOLO 1 è quindi dedicato alla discussione degli argomenti trattati in modo da fornire una panoramica sullo stato dell’arte attuale in merito alle ricerche condotte e ai relativi risultati. Il CAPITOLO 2 è centrato sulla descrizione dello Studio 1, in cui è stato testato un ampio spettro di abilità cognitive quali memoria, intelligenza e ANS, in bambini appena avviati all’istruzione formale e pertanto valutando il ruolo di queste abilità in relazione ad abilità matematiche precoci, prettamente informali. Verificato il coinvolgimento significativo di abilità tanto generali quanto specifiche all’inizio della scolarità, l’obiettivo conseguente è stato quello di verificare in che modo tali abilità siano in grado di predire l’apprendimento matematico negli anni successivi della scuola primaria. Questo obiettivo ha caratterizzato lo Studio 2, descritto nel CAPITOLO 3. Un campione di bambini è stato seguito longitudinalmente dalla classe prima alla classe terza, riscontrando che tutte le abilità indagate hanno un significativo impatto anche sull’apprendimento formale della matematica, ma con un ruolo primario assunto dalla memoria di lavoro. Una volta delineato il quadro delle abilità cognitive cruciali nei primi anni scuola, la volontà è stata quello di esplorare se anche costrutti non-cognitivi possano avere un impatto significativo. Lo Studio 3, illustrato nel CAPITOLO 4, si è quindi focalizzato anche sulla valutazione di questi aspetti in bambini di classe seconda, riscontrando un diretto coinvolgimento di auto-efficacia ed ansia generale. Contrariamente alle aspettative, l’ansia specifica per la matematica non è risultata avere alcun legame significativo con la prestazione matematica. A partire da questo risultato, l’obiettivo dello Studio 4, riportato nel CAPITOLO 5, è consistito nella valutazione più approfondita di questo costrutto in bambini di classe terza, in modo da esplorare quando lo stesso possa diventare rilevante ai fini della prestazione matematica. I risultati hanno dimostrato un ruolo significativo a questo livello, in particolare per quanto concerne l’ansia da apprendimento, piuttosto che di valutazione, della disciplina. Il CAPITOLO 6 è quindi dedicato alla discussione generale dell’elaborato in cui sono riassunti i principali risultati emersi e discusse le limitazioni, prospettive future ed implicazioni pratiche della ricerca.
XXVI Ciclo
1986
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Tang, Mingnam. "Synthesis of 2H-1-Benzthiocin: a Precursor for the Generation of the "4n+2" Pi-electron 1-Benzthiocinide Anion." [Johnson City, Tenn. : East Tennessee State University], 2001. http://etd-submit.etsu.edu/etd/theses/available/etd-0828101-115953/restricted/tangm112701b.pdf.

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Thiruchengode, Muruganandam. "Sensing and Dynamics of Lean Blowout in a Swirl Dump Combustor." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10538.

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This thesis describes an investigation on the blowout phenomenon in gas turbine combustors. The combustor primarily used for this study was a swirl- and dump-stabilized, atmospheric pressure device, which did not exhibit dynamic combustion instabilities. The first part of the thesis work concentrated on finding a sensing methodology to be able to predict the onset of approach of combustor blowout using optical methods. Temporary extinction-reignition events that occurred prior to blowout were found to be precursor events to blowout. A threshold based method was developed to identify these events in the time-resolved sensor output. The number and the average length of each event were found to increase as the LBO limit (fuel-air ratio) is approached. This behavior is used to predict the proximity to lean blowout. In the second part of this study, the blowout sensor was incorporated into a control system that monitored the approach of blowout and then actuated an alternate mechanism to stabilize the combustor near blowout. Enhanced stabilization was achieved by redirecting a part of the main fuel to a central preinjection pilot injection. The sensing methodology, without modification, was effective for the combustor with pilot stabilization. An event based control algorithm for controlling the combustor from blowing out was also developed in this study. The control system was proven to stabilize the combustor even when the combustor loading was rapidly changed. The final part of this study focused on understanding the physical mechanisms behind the precursor events. High speed movies of flame chemiluminescence and laser sheet scattering from oil droplets seeded into the reactants were analyzed to explain the physical processes that cause the extinction and the reignition of the combustor during a precursor event. A physical model for coupling of the fluid dynamics of vortex breakdown and combustion during precursor and blowout events is proposed. This model of blowout phenomenon, along with the sensing and control strategies developed in this study could enable the gas turbine combustor designers to design combustors with wider operability regimes. This could have significant payoffs in terms of reduction in NOx emissions from the combustor.
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Starr, Ariel. "From Magnitudes to Math: Developmental Precursors of Quantitative Reasoning." Diss., 2015. http://hdl.handle.net/10161/9842.

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The uniquely human mathematical mind sets us apart from all other animals. Although humans typically think about number symbolically, we also possess nonverbal representations of quantity that are present at birth and shared with many other animal species. These primitive numerical representations are thought to arise from an evolutionarily ancient system termed the Approximate Number System (ANS). The present dissertation aims to determine how these preverbal representations of quantity may serve as the foundation for more complex quantitative reasoning abilities. To this end, the five studies contained herein investigate the relations between representations of number, representations of other magnitude dimensions, and symbolic math proficiency in infants, children, and adults. The first empirical study, described in Chapter 2, investigated whether infants engage the ANS to represent the full range of natural numbers. The study presented in Chapter 3 compared infants' acuity for detecting changes in contour length to their acuity for detecting changes in number to assess whether representations of continuous quantities are primary to representations of number in infancy. The study presented in Chapter 4 compared individual differences in acuity for number, line length, and brightness in children and adults to determine how the relations between these magnitudes may change over development. Chapter 5 contains a longitudinal study investigating the relation between preverbal number sense in infancy and symbolic math abilities in preschool-aged children. Finally, the study presented in Chapter 6 investigated the mechanisms underlying the maturation of the number sense and determined which features of the number sense are predictive of symbolic math skill. Taken together, these findings confirm that number is a salient feature of the environment for infants and young children and suggest that approximate number representations are fundamental for the acquisition of symbolic math.


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LeFew, William R. "Optical Precursor Behavior." Diss., 2007. http://hdl.handle.net/10161/195.

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Osipova, Anna. "Synthesis of Diverse Polyfunctional Amides as Precursors to Potentially Interesting Peptidomimetics." Doctoral thesis, 2006. http://hdl.handle.net/11858/00-1735-0000-0006-ACB4-D.

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Kim, Hai-Young. "Characterization of the amyloid precursor of alpha-synuclein by NMR spectroscopy." Doctoral thesis, 2008. http://hdl.handle.net/11858/00-1735-0000-0006-ACB5-B.

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Books on the topic "Mathematical precursors"

1

Effler, Steven W. Origins, behavior, and modeling of THM precursors in lakes and reservoirs. Denver, Colo: Awwa Research Foundation, 2005.

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Fichera, Teresa. Archimede: Precursore di secoli e millenni. [Palermo]: A. Lombardi, 2003.

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Singer, Philip C. Impact of ozone on the removal of particles, TOC, and THM precursors. Denver, CO: The Foundation, 1989.

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Madison, Wis ). Workshop on Accident Sequence Precursors and Probabilistic Risk Analysis (1995. Proceedings of Workshop on Accident Sequence Precursors and Probabilistic Risk Analysis: Madison, Wisconsin, USA, May 24-26, 1995. College Park, Md: University Printing Services, University of Maryland, 1998.

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National Research Council (U.S.). Committee on Precursor Measurements Necessary to Support Human Operations on the Surface of Mars., National Research Council (U.S.). Aeronautics and Space Engineering Board., and National Research Council (U.S.). Space Studies Board., eds. Safe on Mars: Precursor measurements necessary to support human operations on the Martian surface. Washington, D.C.: National Academy Press, 2002.

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Dean, Colin Leslie. Juxtaposing 2 contradictory views of Freud : The apotheosis of Logic ; the undermining of the epistemological validity of logic: Freud rejects Aristotelian logic as the criteria to assess the 'truths' of psychoanalysis and thus becomes a precursor to quantum mechanics and mathematics like wise abandonment of Aristotelian logic as an epistemic condition of 'truth' in certain situations. West Geelong, Vic: Gamahucher Press, 2005.

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Stagg, Robert. Shakespeare's Blank Verse. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780192863270.001.0001.

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Abstract Shakespeare’s Blank Verse: An Alternative History is a study of both Shakespeare’s versification and its place in the history of early modern blank verse (unrhymed iambic pentameter). It ranges from the continental precursors of English blank verse in the early sixteenth century through the drama and poetry of Shakespeare’s contemporaries to the editing of blank verse in the eighteenth century and beyond. Alternative in its argumentation as well as its arguments, Shakespeare’s Blank Verse tries out fresh ways of thinking about meter—by shunning doctrinaire, almost mathematical ways of apprehending a writer’s versification, and by reconnecting meter to the fundamental literary, dramatic, and social questions that animate Shakespeare’s drama.
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Lenhard, Johannes. Calculated Surprises. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190873288.001.0001.

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In this book, Lenhard concentrates on the ways in which computers and simulation are transforming the established conception of mathematical modeling. His core thesis is that simulation modeling constitutes a new mode of mathematical modeling that is rearranging and inverting key features of the established conception. Although most of these new key features—such as experimentation, exploration, and epistemic opacity—have their precursors, the new ways in which they are being combined is generating a distinctive style of scientific reasoning. Lenhard also documents how simulation is affecting fundamental concepts of solution, understanding, and validation. He feeds these transformations back into the philosophy of science, thereby opening up new perspectives on longstanding oppositions. By combining historical investigations with practical aspects, the book is accessible for a broad audience of readers. Numerous case studies covering a wide range of simulation techniques are balanced with broad reflections on science and technology. Initially, what computers are good at is calculating—with a speed and accuracy far beyond human capabilities. Lenhard goes further and investigates the emerging characteristics of computer-based modeling, showing how this initially simple observation is creating a number of surprising challenges for the methodology and epistemology of science. These calculated surprises will attract both philosophers and scientific practitioners who are interested in reflecting on recent developments in science and technology.
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Shapiro, Stewart, and Geoffrey Hellman, eds. The History of Continua. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198809647.001.0001.

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Mathematical and philosophical thought about continuity has changed considerably over the ages. Aristotle insisted that continuous substances are not composed of points, and that they can only be divided into parts potentially; a continuum is a unified whole. The most dominant account today, traced to Cantor and Dedekind, is in stark contrast with this, taking a continuum to be composed of infinitely many points. The opening chapters cover the ancient and medieval worlds: the pre-Socratics, Plato, Aristotle, Alexander, and a recently discovered manuscript by Bradwardine. In the early modern period, mathematicians developed the calculus the rise of infinitesimal techniques, thus transforming the notion of continuity. The main figures treated here include Galileo, Cavalieri, Leibniz, and Kant. In the early party of the nineteenth century, Bolzano was one of the first important mathematicians and philosophers to insist that continua are composed of points, and he made a heroic attempt to come to grips with the underlying issues concerning the infinite. The two figures most responsible for the contemporary hegemony concerning continuity are Cantor and Dedekind. Each is treated, along with precursors and influences in both mathematics and philosophy. The next chapters provide analyses of figures like du Bois-Reymond, Weyl, Brouwer, Peirce, and Whitehead. The final four chapters each focus on a more or less contemporary take on continuity that is outside the Dedekind–Cantor hegemony: a predicative approach, accounts that do not take continua to be composed of points, constructive approaches, and non-Archimedean accounts that make essential use of infinitesimals.
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Precursor Math Concepts: The Wonder of Mathematical Worlds with Infants and Toddlers. Teachers College Press, 2021.

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Book chapters on the topic "Mathematical precursors"

1

Novik, Oleg, Feodor Smirnov, and Maxim Volgin. "Tsunami Precursors: Mathematical Model and Applications." In Electromagnetic Geophysical Fields, 35–59. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-98461-2_3.

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Kolman, Vojtěch. "Inferentialism and Its Mathematical Precursor." In From Rules to Meanings, 323–33. 1 [edition]. | New York : Routledge, 2017. | Series: Routledge studies in contemporary philosophy ; 103: Routledge, 2018. http://dx.doi.org/10.4324/9781315103587-18.

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Casazza, Peter G., and Thaddeus J. Shura. "Precursors of the Tsirelson construction." In Lecture Notes in Mathematics, 1–7. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/bfb0085268.

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Maccone, Claudio. "FOCAL mission to 1,000AU as an interstellar precursor." In Mathematical SETI, 349–60. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-27437-4_13.

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Papic, Ljubisa, Milorad Pantelic, and Joseph Aronov. "System Safety Analysis via Accident Precursors Selection." In Springer Proceedings in Mathematics & Statistics, 179–204. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-10046-3_10.

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Sijtsma, Klaas. "Theory Development as a Precursor for Test Validity." In Springer Proceedings in Mathematics & Statistics, 267–74. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-9348-8_17.

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Fukawa-Connelly, Timothy, and Sera Karahoca. "Proof in the Context of Tertiary Mathematics: Undergraduate Inquiry-Based Learning in Abstract Algebra as a Precursor to Mathematical Proof." In Research in Mathematics Education, 251–64. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-80008-6_20.

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Antos, Carolin. "Conceptions of Infinity and Set in Lorenzen’s Operationist System." In Paul Lorenzen -- Mathematician and Logician, 23–46. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-65824-3_3.

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AbstractIn the late 1940s and early 1950s, Lorenzen developed his operative logic and mathematics, a form of constructive mathematics. Nowadays this is mostly seen as a precursor of the better-known dialogical logic (Notable exceptions are the works of Schroeder-Heister 2008; Coquand and Neuwirth 2017; Kahle and Oitavem 2020.), and one might assume that the same philosophical motivations were present in both works. However, we want to show that this is not everywhere the case. In particular, we claim that Lorenzen’s well-known rejection of the actual infinite, as stated in Lorenzen (1957), was not a major motivation for operative logic and mathematics. Rather, we argue that a shift happened in Lorenzen’s treatment of the infinite from the early to the late 1950s. His early motivation for the development of operationism is concerned with a critique of the Cantorian notion of set and with related questions about the notions of countability and uncountability; it is only later that his motivation switches to focusing on the concept of infinity and the debate about actual and potential infinity.
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Ramasubramanian, K., Takao Hayashi, Clemency Montelle, and Kim Plofker. "Bhojarājā and Bhāskara: Precursors of Karaṇakutūhala algebraic approximation formulas in the Rājamṛgāṅka." In Sources and Studies in the History of Mathematics and Physical Sciences, 361–73. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6034-3_17.

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Freiman, Viktor, and Xavier Robichaud. "A Short History of Computing Devices from Schickard to de Colmar: Emergence and Evolution of Ingenious Ideas and Technologies as Precursors of Modern Computer Technology." In Computations and Computing Devices in Mathematics Education Before the Advent of Electronic Calculators, 339–64. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73396-8_13.

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Conference papers on the topic "Mathematical precursors"

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Nair, Vineeth, Gireeshkumaran Thampi, and R. I. Sujith. "Engineering Precursors to Forewarn the Onset of an Impending Combustion Instability." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-26020.

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The present study aims at arming an operator of fielded turbulent combustors with a repertoire of mathematical measures for real-time monitoring to forewarn the onset of impending combustion instability. In turbulent combustors, the route to high-amplitude, periodic, combustion-driven oscillations from conditions of low-amplitude, chaotic, combustion noise happens through an intermediate regime in flow conditions where the measured pressure fluctuations display bursts of intermittent, high-amplitude, periodic oscillations that appear in a near-random manner amidst chaotic fluctuations. This loss of chaos from combustion noise to combustion instability can be quantified to serve as a precursor to impending instability. The recurrence properties of intermittent burst oscillations can be quantified using dynamical systems theory by tracking the distribution of the aperiodic segments in the measured signals. Several statistical measures may be constructed through such recurrence quantification that provide robust early warning signals to an impending instability. Further, the transition to combustion driven oscillations leads to a collapse of the number of relevant time scales involved in the problem. This collapse in time scales can be quantified using generalized Hurst exponents which serve as an additional measure that captures the onset of an impending combustion instability well in advance. The various patent pending measures illustrated in this paper serve as precursors due to the inevitable presence of an intermittent regime of burst oscillations in turbulent combustors.
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Platenkin, Alexey, Vladimir Chernyshov, Tatyana Chernyshova, and Maxim Dutov. "Process Development for obtaining functional layers for solid oxide fuel cells from liquid precursors using plasma sputtering technology." In 2020 2nd International Conference on Control Systems, Mathematical Modeling, Automation and Energy Efficiency (SUMMA). IEEE, 2020. http://dx.doi.org/10.1109/summa50634.2020.9280767.

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Meng, Jiandong, and Yogesh Jaluria. "Numerical Simulation of GaN Growth in a MOCVD Process." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63040.

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This paper describes a model for the growth of gallium nitride in a vertical impinging metalorganic chemical vapor deposition (MOCVD) reactor. With trimethylgallium (TMGa) and ammonia (NH3) carried by hydrogen (H2) as precursors, the flow, temperature and concentration profiles are predicted by numerical modeling, which is performed using a commercial CFD software package CFD-ACE+. The growth rate is predicted based on detailed reaction mechanisms given in the literature, and related studies are carried out to verify the reliability and adaptability of the chosen chemical kinetics. A detailed mathematical model is developed first, and the complete chemical mechanisms are introduced. Then, the dependence of the growth rate and uniformity of the deposited layers on operating conditions, such as reactor operating pressure, susceptor temperature, inlet velocity and concentration of the precursors, is investigated to gain greater insight into the reactor performance and characteristics. Based on the simulation results, discussion is presented in this paper to offer the possibility of better control of the GaN film growth process, and to ultimately lead to an optimization of the process, with respect to production rate and film quality.
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Khatami, S. M. Navid, and Olusegun J. Ilegbusi. "Droplet Evaporation and Chemical Reaction in a Single Multi-Component Droplet to Synthesis Mixed-Oxide Film Using Spray Pyrolysis Method." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86382.

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This paper describes mathematical modeling of transport and chemical reaction phenomena in a single droplet on a heated substrate deposited by spray pyrolysis. The droplet contains mixed salt solution which reacts on the heated substrate to produce mixed oxides and water residue. The water is subsequently evaporated, leaving a thin film of the mixed oxides for sensor application. The droplet, containing solvent and precursors is modeled using Computational Fluid Dynamics (CFD) technique. The variety of stages is predicted of the evolution of droplet morphology associated with surface energy and evaporation. The transient distribution is also predicted of the concentration of various species in the droplet.
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Lapshin, Oleg, and Anastasya Ryabkova. "Mathematical Modeling of Mechanochemical Synthesis of Precursor Particles." In 2020 7th International Congress on Energy Fluxes and Radiation Effects (EFRE). IEEE, 2020. http://dx.doi.org/10.1109/efre47760.2020.9241995.

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Henderson, Peter B. "Discrete mathematics as a precursor to programming." In the twenty-first SIGCSE technical symposium. New York, New York, USA: ACM Press, 1990. http://dx.doi.org/10.1145/323410.319070.

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Diallo, Ousmane, and Dimitri Mavris. "A Data Analytics Approach to Failure Precursor Detection of Gas Turbine." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46019.

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In this paper, a novel approach is proposed to detect precursory events that lead to catastrophic systems failures. This approach is applied to investigating failures of heavy duty gas turbines. Current industry standards rely on either vibration sensors or gas path performance measurement sensors to identify system anomalies, but this proposed process is based on a combination of information from both type of monitoring sensors. This process is built on a systematical multi-step concept developed by assembling proven mathematical and statistical signal processing techniques to achieve a robust and more precise failure precursor detection methodology. The first step includes performing a multi-resolution analysis of gas turbines gas path performance measurement parameters, condition monitoring and vibration sensors data using wavelet packet transform to extract their signal features. Then, the probabilistic principal component analysis is utilized to fuse data of different types into a set of uncorrelated principal components. Next, a one-dimensional signal representing the multi-variable data is computed. After that a statistical process control technique is applied to set the anomaly threshold. Finally, a Bayesian hypothesis testing method is applied to the monitored signal for abnormality detection. As a proof of concept, the proposed process is successfully applied to a gas turbine compressor failure precursor detection problem.
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Lall, Pradeep, Kazi Mirza, Mahendra Harsha, Jeff Suhling, and Kai Goebel. "Method for Assessment of Prolonged and Intermittent Storage on Reliability of Leadfree Electronics Using Leading Indicators." In ASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/ipack2013-73309.

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Electronic systems may be subjected to prolonged and intermittent periods of storage prior to deployment or usage. Prior studies have shown that leadfree solder interconnects show measurable degradation in the mechanical properties even after brief exposures to high temperature. In this paper, a method has been developed for the determining equivalent storage time to produce identical damage at a different temperature. Electronics subjected to accelerated tests often have a well-defined thermal profile for a specified period of time. Quantification of the thermal profile in field deployed electronics may be often difficult because of variance in the environment conditions and usage profile. There is need for tools and techniques to quantify damage in deployed systems in absence of macro-indicators of damage without knowledge of prior stress history. Approach for mapping damage in leadfree second-level interconnects under between thermal conditions is new. High reliability applications such as avionics and missile systems may be often exposed to long periods of storage prior to deployment. Effect of storage at different temperature conditions can be mapped using the presented approach. A framework has been developed to investigate the system state and estimate the remaining useful life of solder ball subjected to a variety of isothermal aging conditions including 60°C, 75°C and 125°C for periods of time between 1-week and 4-week. Data on damage precursors has been collected and analyzed to derive physics based damage mapping relationships for aging. Mathematical relationships have been derived for the damage mapping to various thermal storage environments to facilitate determining appropriate time-temperature combination to reach a particular level of damage state. Activation energy for the leading indicators of failure is also computed. Specific damage proxies examined include the phase-growth indicator and the intermetallic thickness. The viability of the approach has been demonstrated for leadfree test assemblies subjected to multiple thermal aging at 60° C, 75°C and 125°C. Damage mapping relationships are derived from data based on the two separate leading indicators.
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Hamzah Siregar, Amir, Saharman Gea, Aditia Warman, Mahyuni Harahap, Grace Nainggolan, and Dellyansyah. "Electrospinning of Lignin as a Carbon Fibre Precursor." In The International MIPAnet Conference on Science and Mathematics (IMC-SciMath). SCITEPRESS - Science and Technology Publications, 2019. http://dx.doi.org/10.5220/0010142700002775.

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Hong, A. J., R. B. Bratvold, and G. Nævdal. "Robust Production Optimization with Capacitance-Resistance Model as Precursor." In ECMOR XV - 15th European Conference on the Mathematics of Oil Recovery. Netherlands: EAGE Publications BV, 2016. http://dx.doi.org/10.3997/2214-4609.201601840.

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