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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

Operational and environmental comparisons between left-turn bypass, diverging flow and displaced left-turn intersection designs

Unknown Date (has links)
The rapidly and significantly growth of the population in the United States has caused expansion of the urban areas to accommodate more residential facilities.. Thus, the demand for more efficient intersection designs is a high priority, as wasted fuel and travel time increases each year. A new method to solve the congestion issue is the creation of unconventional arterial intersection designs (UAID). The objective of this study is to compare the operational and environmental performance of three UAIDs called Left-turn Bypass, Diverging Flow, and Displaced Left-turn intersections. This study will evaluate the UAIDs in the isolated manner and then compare the intersections in a network using an existing corridor in the state of Florida. The microscopic simulation platform VISSIM v. 5.10 will be used to test different scenarios. The results indicated that the Displaced Left-turn consistently reports better results for average delay of less than 20 seconds per vehicle. / by Claudia Olarte. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
262

Persistência dos sintomas típicos de doença do refluxo gastroesofágico na vigência de inibidor da bomba de próton: características clínicas, endoscópicas, manométricas e de pH-metria de 24 horas / Persistent typical symptoms of gastroesophageal reflux disease on proton pump inhibitor treatment. Clinical, endoscopic, manometric and 24- hour pH-metry characteristics

Sá, Cláudia Cristina de 12 August 2009 (has links)
I NTRODUÇÃO: A refratariedade aos inibidores da bomba de prótons (IBP) tem sido o grande desafio dos gastroenterologistas. Este trabalho visa caracterizar os pacientes que persistem com sintomas típicos de doença do refluxo gastroesofágico (DRGE), em uso de inibidores de bomba de prótons em doses de, pelo menos 40mg/dia, quanto aos aspectos demográficos, clínicos e laboratoriais, determinando-se a freqüência da persistência de refluxo ácido pela pH-metria esofágica de 24h. Secundariamente procurouse determinar a freqüência da esofagite eosinofílica nessa população. MÉTODO: Foram entrevistados 110 pacientes que apresentavam persistência de sintomas de pirose e/ou regurgitação em uso de pelo menos 40 mg de IBP por pelo menos 6 semanas. Os mesmos foram submetidos à endoscopia digestiva alta (EDA) com biópsia esofágica, manometria, pHmetria esofágica de duplo canal e exames laboratoriais. RESULTADOS: Dos pacientes avaliados, 77,3% eram do sexo feminino, com média de 46 anos e predomínio de baixa escolaridade. Apenas 10,9% eram tabagistas, 55% apresentavam índice de massa corpórea (IMC) acima de 25Kg/m2, sendo o IMC médio de 27Kg/m2. Entre as comorbidades, as mais freqüentes foram: alergias (72,7%); hipertensão arterial (34,5%), asma (18,2%), depressão (29,1%) e fibromialgia (8,2%), sendo estas duas últimas maiores que a encontrada na população geral. Observou-se freqüência elevada de sintomas dispépticos (70% dos pacientes relataram epigastralgia e 70% plenitude pós-prandial), disfagia (60,9%); globus (37,3%), tosse (37,3%) e dor torácia não cardíaca (30,9%). Apenas 16,4% evidenciavam à endoscopia, lesão em corpo esofágico e 23,6% hérnia de hiato. A maioria dos pacientes (61,8%) apresentava alguma alteração à manometria esofágica. Encontrou-se, entre os pacientes estudados, 24,6% com pHmetria positiva (8,1% no canal distal e 16,45% no proximal) e 75,4% com pH-metria normal. Comparando-se os resultados desses dois grupos de pacientes (pH-metria positiva e normal), segundo as variáveis estudadas, apenas a presença de lesão no corpo esofágico à endoscopia e a elevada escolaridade evidenciaram associação com persistência de pH-metria positiva (p: 0,0061 OR: 4,11 IC: 1,43:11,84 e p: 0,0237 OR: 2,74 IC: 1,13: 6,67 respectivamente). Ao se comparar presença de sintomas atípicos com a presença de refluxo ácido (no esôfago proximal versus distal), apenas globus apresentou associação com pH-metria positiva no canal proximal. Foi diagnosticado um único caso de esofagite eosinofílica entre os pacientes com sintomas típicos de DRGE refratários ao IBP. CONCLUSÃO: DRGE refratária predomina em mulheres de meia idade, associada à alta freqüência de história de alergia, depressão, fibromialgia e sintomas dispépticos. Segundo os resultados da pH-metria, a presença de esofagite erosiva em uso do IBP ou elevada escolaridade foram os únicos fatores de risco para a persistência de refluxo ácido nos dois canais, e globus no canal proximal. Não se observou diferença entre os pacientes com pH-metria positiva ou normal quanto às demais variáveis, até mesmo sintomas dispépticos. É baixa a freqüência de esofagite eosinofílica entre pacientes com pirose e/ou regurgitação refratários ao inibidor da bomba de próton / BACKGROUND: Proton pump inhibitor (PPI) refractory patients have been a big challenge to gastroenterologists. The aim of this study was to characterize the patients that had gastroesophageal reflux disease (GERD) persistent typical symptoms, undergoing PPI medication, administered at a dose of at least 40 mg/day, according to demographic, clinical and laboratory aspects. The primary outcome was to determine the frequency of acid reflux persistence based on the 24-hour esophageal pH-metry result. The secondary outcome was to determine, the frequency of eosinophilic esophagitis in the same population. METHODS: We interviewed 110 patients that presented persistence of heartburn and/or regurgitation symptoms and were undergoing treatment with PPI at a minimum dose of 40 mg/day for at least six weeks. They underwent upper gastrointestinal endoscopy with esophageal mucosa biopsy, esophageal manometry and double probe 24- hour esophageal pH-metry, as well as laboratory tests. RESULTS: 77.3% of the evaluated patients were female, with mean age of 46 years old, and most of them with low educational level. Only 10.9% were tobacco smokers and 55% had body mass index (BMI) greater than 25Kg/m2, showing mean BMI of 27Kg/m2. The most frequent comorbidities were allergy (72.7%), arterial systemic hypertension (34.5%), asthma (18.2%), depression (29.1%) and fibromyalgia (8.2%). Comparing the general population and the group of patients, a higher frequency of depression and fibromyalgia was observed. Some symptoms were found in high frequency: dyspeptic symptoms (70% associated with epigastric pain and 70% with postprandial fullness), dysphagia (60.9%), globus and cough (37.3% each) and no-cardiac chest pain (30.9%). By endoscopy, only 16.4% showed esophageal body lesion and 23.6% hiatal hernia. Most patients (61.8%) presented some alteration in esophageal manometry. Among studied patients, 24.6% had abnormal pHmetry (8.1% in distal probe and 16.45% in the upper probe) and 75.4%, a normal result. When comparing normal to abnormal pH-metry patients according to studied variables only the presence of esophageal body lesion, observed by endoscopy, and high educational level were associated to the persistence of abnormal pH-metry (p: 0.0061; OR: 4.11; IC: 1.43:11.84; and p: 0.0237; OR: 2.74; IC: 1.13: 6.67; respectively). When comparing atypical symptoms with the presence of acid reflux (proximal versus distal esophagus) only globus was associated with abnormal upper probe pHmetry. Only one patient was diagnosed with eosinophilic esophagitis among the total sample with typical gastroesophageal reflux symptoms refractory to PPI treatment. CONCLUSION: Refractory GERD was predominant in middleaged females, associated with high frequency of previous allergy, depression, fibromyalgia and dyspeptics symptoms. The risk factors to the persistence of acid reflux in the two pH-metry probes and to the symptom of globus in the upper pH-metry probe were the persistence of erosive esophagitis in patients undergoing treatment with PPI an a higher educational level. No differences between abnormal or normal pH-metry results patients were found regarding the other variables, such as dyspeptic symptoms. The frequency of eosinophilic esophagitis was low in heartburn and/or regurgitation in PPI refractory patients
263

Projeto de sinais de excitação para identificação multivariável de plantas industriais. / Excitation signal for multivarible plant identification.

Kuramoto, André Seichi Ribeiro 08 November 2012 (has links)
Neste trabalho são discutidos e avaliados métodos de construção de conjuntos de sinais de excitação para identificação de sistemas. Esse estudo é realizado tendo como objetivo aplicações na indústria de processos, particularmente no refino de petróleo. As restrições operacionais da indústria de refino de petróleo estão cada vez mais severas em virtude do aumento da demanda energética, qualidade de derivados, variações de preço de petróleo, concorrência no mercado de derivados e outros fatores econômicos, ambientais e de eficiência energética. Nesse cenário, é crescente o uso de técnicas de controle preditivo por modelos e, consequentemente, a demanda por identificação de plantas de processamento. As características particulares das plantas de processamento e de sua operação impõem restrições ao projeto e à aplicação de sinais de excitação. Vários métodos de construção de sinais encontrados na literatura e outros três propostos neste trabalho são avaliados e comparados com referência ao atendimento a essas restrições. Uma das principais restrições para a aplicação de sinais de excitação para identificação é relativa ao tempo disponível para excitação da planta. Assim, para o bom uso desse período, faz-se necessário garantir o sucesso de um experimento previamente à sua realização. Na literatura, encontram-se várias medidas de desempenho de sinais de excitação possíveis de serem obtidas previamente ao experimento de identificação. Neste trabalho, s~ao propostas duas novas medidas que complementam essas na avaliação dos conjuntos de sinais previamente ao experimento. A eficácia dos métodos de construção e das medidas de desempenho de sinais de excitação é avaliada por meio de simulação de identificação multivariável de duas plantas típicas de refinarias. As conclusões deste trabalho apresentam em síntese essas avaliações, como também sugestões de trabalhos futuros que visam à continuidade da pesquisa desenvolvida aqui. / In this work methods for generating sets of excitation signals for system identification are discussed and evaluated. This study is focused on applications in the process industries, particularly in oil refining. The operational constraints of the oil refining industry are becoming increasingly severe due to increased energy demand, quality of products, oil price variations,market competition and other economic, environmental and energy efficiency factors. In this scenario the use of model predictive control techniques is increasing, thus the demand for plant identification as well. The particular characteristics of the processing plants impose restrictions to the project and application of excitation signals. Various methods for generating signals accessible in the literature and three new others proposed in this work are compared with reference to these restrictions. One of the main constraints for applying excitation signals for identification is relative to the period available for excitation of the plant. Thus, for the proper use of this time interval, it is necessary to ensure the success of an experiment prior to its implementation. In the literature there are several performance measurements for evaluation of sets of excitation signals prior to the experiment. This work proposes two new measures to complement the evaluation. The effectiveness of the generating methods and performance measurements for excitation signals is evaluated by simulation of multivariable identification of two typical oil refining plants. The conclusions of this work briefly present these evaluations, as well as some suggestions of future work for the continuity of the current research.
264

Using Ballistocardiography to Perform Key Distribution in Wearable IoT Networks

Witt, Alexander W 20 May 2017 (has links)
A WIoT is a wireless network of low-power sensing nodes placed on the human body. While operating, these networks routinely collect physiological signals to send to offsite medical professionals for review. In this manner, these networks support a concept known as pervasive healthcare in which patients can be continuously monitored and treated remotely. Given that these networks are used to guide medical treatment and depend on transmitting sensitive data, it is important to ensure that the communication channel remains secure. Symmetric pairwise cryptography is a traditional scheme that can be used to provide such security. The scheme functions by sharing a cryptographic key between a pair of sensors. Once shared, the key can then be used by both parties to encrypt and decrypt all future messages. To configure a WIoT to support the use of symmetric pairwise cryptography a key distribution protocol is required. Schemes for pre-deployment are often used to perform this distribution. These schemes usually require inserting key information into WIoT devices before they can be used in the network. Unfortunately, this need to manually configure WIoT devices can decrease their usability. In this thesis we propose and evaluate an alternative approach to key distribution that uses physiological signals derived from accelerometer and gyroscope sensors. The evaluation of our approach indicates that more study is required to determine techniques that will enable ballistocardiography-derived physiological signals to provide secure key distribution.
265

Les heuristiques dans le luxe : la psychologie de l'utilisation des signaux liés au luxe / The status heuristic : on the psychology of using status signals

Rezaee Vessal, Saeedeh 09 July 2018 (has links)
Cette recherche s'intéresse à la façon dont les modes de pensée influencent les préférences des consommateurs pour les produits de luxe. Dans une série d'expérimentation, nous montrons que lorsque les consommateurs sont plus susceptibles de pensée de manière intuitive, ils utilisent davantage le signal lié au luxe dans leur processus de décision. Afin de montrer l'effet de ce signal comme indicateur heuristique, le mode de pensée des consommateurs a été manipulé. Dans un mode de pensée intuitif, les individus ont tendance à utiliser significativement plus le signal lié au luxe comme un signal heuristique dans la prise de décision. / In this research, we discuss consumers’ preference for status products which is affected by their mode of thinking. In a series of experiments, we show that when consumers are more likely to rely on intuitive system thinking, they use status signal more often as a cue in their decision making process. In order to show the effect of the status signal as a heuristic cue, we manipulate consumers’ mode of thinking. Using an online questionnaire, we show that being in intuitive mode of thinking leads individuals to disproportionately rely on status signals as a heuristic cue in their decision making process.
266

Sinalização elétrica de longa distância pós-irrigação em plantas de girassol sob déficit hídrico / Long-distance electrical signaling after irrigation in sunflower plants under drought

Daneluzzi, Gabriel Silva 09 November 2016 (has links)
Uma propriedade fundamental dos seres vivos é a condução de sinais elétricos através de seus tecidos. Mas esse fato pouco é lembrado quando se trata de organismos vegetais. Outro item fundamental é a geração de sinais que possam transmitir informações entre os tecidos e órgãos para um ajuste fino do metabolismo. Nas plantas esses sinais podem ser de natureza química, hidráulica e elétrica. Nesse último caso são conhecidos potenciais de ação (PA), de variação (PV), de ferimentos (WP) e sistêmicos (SP), cada um com sua particularidade quanto à amplitude, velocidade e rotas de propagação, bem como seu papel no metabolismo. Os sinais elétricos podem afetar a respiração, fotossíntese, absorção de água, ativação de genes e fechamento de folhas de plantas insetívoras. PAs podem se propagar com velocidade relativamente constante e sem decréscimo. Eles seguem a lei do tudo-ou-nada, ou seja, todo estímulo que desencadeia um PA deve atingir um limiar de excitação para desencadear o sinal. Assim que o limiar é atingido o sinal se autoperpetua ao passo que estímulos supra limiares desencadeiam PAs de amplitude constante. A via de propagação do PA é o vaso do floema. O objetivo do presente trabalho foi avaliar a sinalização elétrica em resposta à irrigação em plantas de girassol sob déficit hídrico e caracterizar esse sinal quanto à amplitude, duração, velocidade e direção de propagação. Para tanto 37 plantas foram avaliadas por meio de eletrodos extracelulares. Elas foram monitoras eletrofisiologicamente durante um período em que eram irrigadas e em um período sob déficit hídrico. Desse montante, onze responderam à irrigação pela geração de potenciais de ação (PA), ou seja, 30% delas. Oito delas geraram PAs em direção ao ápice (propagação acrópeta) enquanto duas geraram na direção basípeta. Uma delas gerou nos dois sentidos. O PA foi gerado também pós-irrigação mesmo com a planta não tendo passado por déficit hídrico, porém só aconteceu em uma das onze plantas. Os sinais se propagaram no caule, pecíolo e nervura central das folhas. O potencial de ação é gerado após irrigação em plantas de girassol com maior frequência quando elas passam por período de déficit hídrico e se propagam por toda a planta. Isso evidencia o papel do PA na sinalização de longa distância nos vegetais. / A fundamental property in the leaving beings is the conduction of electrical signals through their tissues. However, this fact is not always remembered when it comes to plant organisms. Another key process is the generation of signals that can transmit information among tissues and organs to a fine-tuning of the metabolism. In plants, these signals can be chemical, hydraulic and electrical. Concerning the last one, action potentials (AP), variation potentials (VP), wound potentials (WP) and system potentials (SP) are known; each one with its particularity regarding amplitude, velocity and propagation routes as well as its role in metabolism. The electrical signals may affect respiration, photosynthesis, water uptake, activation of genes and leaf closure in insectivorous plants. APs can spread with relatively constant speed and no decrement. They follow the all-or-nothing law, in another words, every stimulus that triggers an AP must reach a threshold to trigger the signal. Once the threshold is reached, the signal is self-perpetuating while stimuli above threshold trigger APs with constant amplitude. The propagation path of the AP is the phloem vessel. The aim of this work was to evaluate the electrical signaling in response to irrigation in sunflower plants under water deficit and characterize the AP regarding its amplitude, duration, velocity and propagation direction. Thirty seven plants were analyzed using extracellular electrodes. They were electrophysiologically monitored during a period when irrigated and in a period under drought. Eleven plants generated AP after irrigation, i.e. 30%. Eight of them generated AP that propagated acropetally while two generated in basipetal direction. One generated in both directions. The action potential was also generated in a plant that was not under drought stress, however it just happened in one of the eleven plants. The signals propagated in the stem, petiole and midrib of the leaves. The action potential is generated after irrigation in sunflower plants more frequently when they go through a period of water deficit and propagate throughout the plant. This highlights the role of AP in long-distance signaling in plants.
267

Detecção de vazamentos em redes sob pressão baseada na análise dos sinais de pressão e vazão com um sistema de reconhecimento de padrões / Leak detection in water networks based on the analysis of flow and pressure signals by a pattern recognition system

Gamboa Medina, Maria Mercedes 29 July 2013 (has links)
O controle de perdas em sistemas de distribuição de água para abastecimento é uma preocupação constante, e uma tarefa fundamental para a solução do problema é a detecção rápida e confiável dos vazamentos que frequentemente iniciam em qualquer ponto da rede. Uma abordagem promissória é a detecção de vazamentos baseada na análise de sinais adquiridos pelo monitoramento das redes durante sua operação, e dentro dela se enquadra este trabalho. É desenvolvido um sistema de reconhecimento de padrões para análise de sinais de pressão e vazão que permite identificar se durante a aquisição do sinal aconteceu um vazamento ou não. Para a conformação desse sistema diversas técnicas são exploradas, incluindo a extração de características no domínio do tempo (energia, entropia, número de cruzamentos por zero) e na decomposição wavelet (distribuição da energia nas componentes). Também é explorado o uso de algoritmos para classificação de diferentes tipos (vizinhos mais próximos, árvore de decisão, regra de decisão, Naive Bayes, máquina de vetor suporte e rede neural artificial com funções de base radial). Sinais são adquiridos junto ao circuito hidráulico experimental, que permitiu a simulação da ocorrência de um vazamento na rede, para constituir uma amplia base de dados com sinais de exemplo. Além da revisão bibliográfica e os conceitos relativos às metodologias exploradas, são apresentadas neste documento as análises que conduzem à criação do sistema de reconhecimento de padrões mais apropriado para o problema. Das análises dos diferentes métodos considerados é definido o sistema de reconhecimento de padrões, em suas etapas de segmentação e padronização, extração de características e classificação. A avaliação do sistema proposto mostra um desempenho totalmente satisfatório, com reconhecimento acertado de sinais vinculados ou não a um vazamento em mais de 95% dos testes. / Control of losses in water supply systems is a constant concern, and a key to the solution of this problem is the rapid and reliable detection of leaks that often begin anywhere on the network. A promising approach to solve the problem is the leak detection based on the analysis of signals acquired by monitoring the network in operation, and this research fits with that approach. Its developed a pattern recognition system for the analysis of pressure and flow signals, which identifies whether a leak happened during signal acquisition. Several techniques are exploited for forming this system, including the feature extraction in the time domain (energy, entropy, zero crossings count) and in the wavelet decomposition (energy distribution in the components). Also, the use of different types of algorithms for classification (nearest neighbors, decision tree, decision rule, Naive Bayes, support vector machine and artificial neural network with radial basis functions) is explored. Signals are acquired from the experimental hydraulic circuit, allowing the simulation of the onset of a leak in the network, to form a big database of example signals. Besides the literature review and the concepts relating to the considered methods, in this document are shown the analyses leading to the creation of the pattern recognition system most appropriate for the problem. The analysis of the methods considered allows defining the pattern recognition system, which is composed by segmentation and standardization, feature extraction and classification. The evaluation of the proposed system shows a completely satisfactory performance, recognizing rightly the signals as linked or not to a leak in more than 95% of the tests.
268

Using Metering Signals at Roundabouts with Unbalanced Flows to Improve the Traffic Condition : The Case Study of Kannik Area in Stavanger / Using Metering Signals at Roundabouts with Unbalanced Flows to Improve the Traffic Condition : The Case Study of Kannik Area in Stavanger

Mosslemi, Marjan January 2008 (has links)
In some roundabouts, just relying on the "right of way" regulations results in long queues forming along the approaches. This usually happens when a roundabout suffers from unbalanced flow patterns (one or two of the approaches convey much heavier traffic compared to the others). There is an idea that signalization of roundabouts can be useful as a countermeasure for such a problem, especially during peak hours. In that case, signal operation can come in many forms, including full-time control, part-time control, or metering. One problem that seems to be facing engineers when signalizing roundabouts is lacking a general set of patterns or guidelines to choose an appropriate form of signalization and apply it efficiently in different situations. There is also a need for a comprehensive review over the available literature concerning signalization of roundabouts. In this thesis, a review of literature regarding signalization of roundabouts is carried out. Moreover, a roundabout in Stavanger with unbalanced traffic flows is studied in order to find an appropriate signalization scenario which can improve the traffic situation. The network is modeled and simulated in AIMSUN.
269

Improving routing performance of underwater wireless sensor networks

Ayaz, Beenish January 2016 (has links)
In this research work we propose a 3D node deployment strategy by carefully considering the unique characteristics of underwater acoustic communication as well as 3D dynamic nature of UWSN. This strategy targets 3D UWSN and not only improves the routing protocol performance significantly in terms of end to end delay and energy consumption but also provides reliability in data transmission. This strategy has been developed step by step from a single line of vertical communication to an effective 3D node deployment for UWSN. Several simulation experiments were carried out after adding different features to the final design to observe their impact on the overall routing performance. Finally, it is verified that this design strategy improves the routing performance, provides reliability to the network and increases network lifetime. Furthermore, we compared our results to the random node deployment in 3D, which is commonly used for analysing the performance of UWSN routing protocols. The comparison results verified our effective deployment design and showed that it provides almost 150% less end-to-end delay and almost 25% less energy consumption to the random deployment. It also revealed that by increasing the data traffic, our 3D node deployment strategy has no loss of data due to several back-up paths available, which is in contrast to random node deployment, where the packet loss occurs by increasing the data traffic. Improving the routing performance by carefully analysing the impact of 3D node deployment strategy and ensuring full sensing, transmission and back-up coverage in a highly unpredictable underwater environment, is a novel approach. Embedding this strategy with any networking protocol will improve its performance significantly.
270

Context, cognition and communication in language

Winters, James Richard January 2017 (has links)
Questions pertaining to the unique structure and organisation of language have a long history in the field of linguistics. In recent years, researchers have explored cultural evolutionary explanations, showing how language structure emerges from weak biases amplified over repeated patterns of learning and use. One outstanding issue in these frameworks is accounting for the role of context. In particular, many linguistic phenomena are said to to be context-dependent; interpretation does not take place in a void, and requires enrichment from the current state of the conversation, the physical situation, and common knowledge about the world. Modelling the relationship between language structure and context is therefore crucial for developing a cultural evolutionary approach to language. One approach is to use statistical analyses to investigate large-scale, cross-cultural datasets. However, due to the inherent limitations of statistical analyses, especially with regards to the inadequacy of these methods to test hypotheses about causal relationships, I argue that experiments are better suited to address questions pertaining to language structure and context. From here, I present a series of artificial language experiments, with the central aim being to test how manipulations to context influence the structure and organisation of language. Experiment 1 builds upon previous work in iterated learning and communication games through demonstrating that the emergence of optimal communication systems is contingent on the contexts in which languages are learned and used. The results show that language systems gradually evolve to only encode information that is informative for conveying the intended meaning of the speaker - resulting in markedly different systems of communication. Whereas Experiment 1 focused on how context influences the emergence of structure, Experiments 2 and 3 investigate under what circumstances do manipulations to context result in the loss of structure. While the results are inconclusive across these two experiments, there is tentative evidence that manipulations to context can disrupt structure, but only when interacting with other factors. Lastly, Experiment 4 investigates whether the degree of signal autonomy (the capacity for a signal to be interpreted without recourse to contextual information) is shaped by manipulations to contextual predictability: the extent to which a speaker can estimate and exploit contextual information a hearer uses in interpreting an utterance. When the context is predictable, speakers organise languages to be less autonomous (more context-dependent) through combining linguistic signals with contextual information to reduce effort in production and minimise uncertainty in comprehension. By decreasing contextual predictability, speakers increasingly rely on strategies that promote more autonomous signals, as these signals depend less on contextual information to discriminate between possible meanings. Overall, these experiments provide proof-of-concept for investigating the relationship between language structure and context, showing that the organisational principles underpinning language are the result of competing pressures from context, cognition, and communication.

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