The Florida Keys experienced some of the most drastic transitions from coral to macroalgae dominated states, known as phase-or regime-shifts, of any reefs in the Caribbean. Macroalgae on coral reefs lower coral recruitment by deterring coral settlement either directly through competition or indirectly by changing the chemical environment near the benthos. With evidence of species-specific interactions to coral-macroalgae competition, the type of macroalgae on a phase-shifted coral reef might be more important than just identifying a reef transition. To answer this question, I tested the effect of Laurencia intricata (a macroalgae related to the settlement inducing crustose coralline algae) and Dictyotaceae (known for its toxic or allelopathic compounds) on Porites astreoides planulae behavior, settlement and choice settlement preference, and post-settlement survival. I found that P. astreoides planulae show a positive response to chemical cues released from L. intricata, crustose coralline algae, and species in the Dictyotaceae family. However, the positive chemical cue response becomes algal-specific as larvae start probing for settlement substrate. Providing P. astreoides larvae with a choice between settlement substrates, revealed that the algal structure caused higher settlement next to L. intricata, while Dictyotaceae deterred larval settlement. It may be beneficial for larvae to settle next to L. intricata over Dictyotaceae algae. I identified that post-settlement survival was enhanced when P. astreoides larvae settled next to L. intricata while Dictyotaceae species did not enhance or deter post-settlement survival. These results indicate that coral larvae may be responding differently to a variety of chemical cues. Any chemical or physical cue from a reef may be used by coral larvae to identify and locate settlement substrate on a reef. Once they identify a reef’s location, they express a more selective behavior during settlement by avoiding Dictyotaceae macroalgae and favoring L. intricata. This suggests that the composition of a phase-shifted reef matters to coral recovery, not only that it has shifted to a dominated macroalgal state.

Recipients of present-day cochlear implants (CIs) display remarkable success with speech recognition in quiet, but not with speech recognition in noise. Normal-hearing (NH) listeners, in contrast, perform relatively well with speech recognition in noise. Understanding which speech features support successful perception in noise in NH listeners could provide insight into the difficulty that CI listeners experience in background noise. One set of speech features that has not been thoroughly investigated with regard to its noise immunity is prosody. Existing reports show that CI users have difficulty with prosody perception. The present study endeavoured to determine if prosody is particularly noise-immune in NH listeners and whether the difficulty that CI users experience in noise can be partly explained by poor prosody perception. This was done through the use of three listening experiments. The first listening experiment examined the noise immunity of prosody in NH listeners by comparing perception of a prosodic pattern to word recognition in speech-weighted noise (SWN). Prosody perception was tested in a two-alternatives forced-choice (2AFC) test paradigm using sentences conveying either conditional or unconditional permission, agreement or approval. Word recognition was measured in an open set test paradigm using meaningful sentences. Results indicated that the deterioration slope of prosody recognition (corrected for guessing) was significantly shallower than that of word recognition. At the lowest signal-to-noise ratio (SNR) tested, prosody recognition was significantly better than word recognition. The second experiment compared recognition of prosody and phonemes in SWN by testing perception of both in a 2AFC test paradigm. NH and CI listeners were tested using single words as stimuli. Two prosody recognition tasks were used; the first task required discrimination between questions and statements, while the second task required discrimination between a certain and a hesitant attitude. Phoneme recognition was measured with three vowel pairs selected according to specific acoustic cues. Contrary to the first experiment, the results of this experiment indicated that vowel recognition was significantly better than prosody recognition in noise in both listener groups. The difference between the results of the first and second experiments was thought to have been due to either the test paradigm difference in the first experiment (closed set versus open set), or a difference in stimuli between the experiments (single words versus sentences). The third experiment tested emotional prosody and phoneme perception of NH and CI listeners in SWN using sentence stimuli and a 4AFC test paradigm for both tasks. In NH listeners, deterioration slopes of prosody and phonemes (vowels and consonants) did not differ significantly, and at the lowest SNR tested there was no significant difference in recognition of the different types of speech material. In the CI group, prosody and vowel perception deteriorated with a similar slope, while consonant recognition showed a steeper slope than prosody recognition. It is concluded that while prosody might support speech recognition in noise in NH listeners, explicit recognition of prosodic patterns is not particularly noise-immune and does not account for the difficulty that CI users experience in noise. ## Ontvangers van hedendaagse kogleêre inplantings (KI’s) behaal merkwaardige sukses met spraakherkenning in stilte, maar nie met spraakherkenning in geraas nie. Normaalhorende (NH) luisteraars, aan die ander kant, vaar relatief goed met spraakherkenning in geraas. Begrip van die spraakeienskappe wat suksesvolle persepsie in geraas ondersteun in NH luisteraars, kan lei tot insig in die probleme wat KI-gebruikers in agtergrondgeraas ervaar. Een stel spraakeienskappe wat nog nie deeglik ondersoek is met betrekking tot ruisimmuniteit nie, is prosodie. Bestaande navorsing wys dat KI-gebruikers sukkel met persepsie van prosodie. Die huidige studie is onderneem om te bepaal of prosodie besonder ruisimmuun is in NH luisteraars en of die probleme wat KI-gebruikers in geraas ondervind, deels verklaar kan word deur swak prosodie-persepsie. Dit is gedoen deur middel van drie luistereksperimente. Die eerste luistereksperiment het die ruisimmuniteit van prosodie in NH luisteraars ondersoek deur die persepsie van ’n prosodiese patroon te vergelyk met woordherkenning in spraakgeweegde ruis (SGR). Prosodie-persepsie is getoets in ’n twee-alternatiewe-gedwonge-keuse- (2AGK) toetsparadigma met sinne wat voorwaardelike of onvoorwaardelike toestemming, instemming of goedkeuring oordra. Woordherkenning is gemeet in ’n oopstel-toetsparadigma met betekenisvolle sinne. Resultate het aangedui dat die helling van agteruitgang van prosodieherkenning (gekorrigeer vir raai) betekenisvol platter was as dié van woordherkenning, en dat by die laagste sein-tot-ruiswaarde (STR) wat getoets is, prosodieherkenning betekenisvol beter was as woordherkenning. Die tweede eksperiment het prosodie- en foneemherkenning in SGR vergelyk deur die persepsie van beide te toets in ’n 2AGK-toetsparadigma. NH en KI-luisteraars is getoets met enkelwoorde as stimuli. Twee prosodieherkenningstake is gebruik; die eerste taak het diskriminasie tussen vrae en stellings vereis, terwyl die tweede taak diskriminasie tussen ’n seker en onseker houding vereis het. Foneemherkenning is gemeet met drie vokaalpare wat geselekteer is na aanleiding van spesifieke akoestiese eienskappe. In teenstelling met die eerste eksperiment, het resultate van hierdie eksperiment aangedui dat vokaalherkenning betekenisvol beter was as prosodieherkenning in geraas in beide luisteraarsgroepe. Die verskil tussen die resultate van die eerste en tweede eksperimente kon moontlik die gevolg wees van óf die verskil in toetsparadigma in die eerste eksperiment (geslote- teenoor oop-stel), óf ’n verskil in stimuli tussen die eksperimente (enkelwoorde teenoor sinne). Die derde eksperiment het emosionele-prosodie- en foneempersepsie van NH en KI-luisteraars getoets in SGR met sinstimuli en ’n 4AGK-toetsparadigma vir beide take. In NH luisteraars het die helling van agteruitgang van die persepsie van prosodie en foneme (vokale en konsonante) nie betekenisvol verskil nie, en by die laagste STR wat getoets is, was daar nie ’n betekenisvolle verskil in die herkenning van die twee tipes spraakmateriaal nie. In die KI-groep het prosodie- en vokaalpersepsie met soortgelyke hellings agteruitgegaan, terwyl konsonantherkenning ’n steiler helling as prosodieherkenning vertoon het. Die gevolgtrekking was dat alhoewel prosodie spraakherkenning in geraas in NH luisteraars mag ondersteun, die eksplisiete herkenning van prosodiese patrone nie besonder ruisimmuun is nie en dus nie ’n verklaring bied vir die probleme wat KI-gebruikers in geraas ervaar nie. / Thesis (PhD)--University of Pretoria, 2014. / lk2014 / Electrical, Electronic and Computer Engineering / PhD / unrestricted

Depuis une dizaine d’années, des techniques de codage joint, exploitant les relations et les redondances entre canaux audios, ont été développées afin de réduire davantage la quantité d’information nécessaire à la représentation des signaux multicanaux. Dans cette thèse, nous étudions plus particulièrement le codage des signaux audio stéréo en l’absence d’informations à priori sur la nature des sources en présences, leur nombre et la manière dont elles sont spatialisées. Cette situation correspond à l’immense majorité des enregistrements commerciaux dans l’industrie de la musique et du multimédia de manière générale. Nous étudions des approches paramétrique et signal de la problématique de codage de ces sources, où les deux sont souvent mêlées. Dans ce contexte, trois types d’approches sont utilisés. L’approche paramétrique spatiale consiste à réduire le nombre de canaux audio de la source à coder et à recréer le nombre de canaux d’origine à partir des canaux réduits et de paramètres spatiaux, extraits des canaux d’origine. L’approche signal conserve le nombre de canaux d’origine, mais encode des canaux construits à partir de ces derniers et présentant moins de redondances. Enfin, l’approche mixte introduite dans MPEG USAC utilise un signal audio et un signal résiduel, issu d’une prédiction, et dont les paramètres sont codés conjointement. Dans cette thèse, nous analysons tout d’abord les caractéristiques d’un signal stéréo issu d’un enregistrement commercial et les techniques de production associées. Cette étude nous mène à une réflexion sur les rapports entre les modèles paramétriques d’émetteur, obtenus en analysant les techniques de production des enregistrements commerciaux, et les modèles de récepteur qui sont au coeur du codage spatial paramétrique. A partir de cette mise en perspective nous présentons et étudions les trois approches évoquées plus haut. Pour l’approche purement paramétrique, nous montrons l’impossibilité d’arriver à la transparence pour la majorité des sources audios, nous menons une réflexion sur les représentations paramétriques et proposons des techniques afin de réduire le débit de leurs paramètres et d’améliorer la qualité audio. Ces améliorations passent par une meilleur segmentation du signal audio, basée sur les transitoires, sur des caractéristiques perceptives de certains indices spatiaux et sur une meilleur estimation des indices spatiaux. L’approche mixte étant récemment standardisée dans MPEG USAC, nous l’étudions en détail, puis nous proposons une nouvelle technique de codage qui exploite au mieux l’allocation du résidu aux bandes fréquentielles, lorsque celui-ci n’est pas utilisé sur l’ensemble de la bande passante du signal. Enfin, nous concluons en évoquant l’avenir du codage audio spatial généraliste et mettons l’accent sur l’importance de développer des techniques de classification et de segmentation audio pour optimiser le rapport qualité/débit. / During the last ten years, technics for joint coding exploiting relations and redundancies between channels have been developped in order to further reduce the amount of information needed to represent multichannel audio signals.In this document, we focus on the coding of stereo audio signals where prior informations on the nature of sources in presence, their number or the manner they are spatialized is unknown. Such signals are actually the most representative in commercial records of music industry and in multimedia entertainment in general. To address the coding problematic of these signals, we study parametric and signal approaches, where both of them are often mixed.In this context, three types of approaches are used. The spatial parametric approach reduce the number of audio channels of the signal to encode and recreate the original number of channels from reduced channels and spatial parameters extracted from original channels. The signal approach keep the original number of channels, but encode mono signals, built from the combination of the original ones and containing less redundancies. Finally, the hybrid approach introduced in the MPEG USAC standard keep the two channels of a stereo signal, but one is a mono downmix and the other is a residual signal, resulting from a prediction on the downmix, where prediction parameters are encoded as side information.In this document, we first analyse the characteristics of a stereo audio signal coming from a commercial recording and the associated production techniques. This study lead us to consider the relations between the emitter parametric models, elaborated from our analysis of commercial recording production techniques, and the receiver models which are the basis of spatial parametric coding. In the light of these considerations, we present and study the three approaches mentioned earlier. For the parametric approach, we show that transparency cannot be achieved for most of the stereo audio signals, we have a reflection on parametric representations and we propose techniques to improve the audio quality and further reduce the bitrate of their parameters. These improvements are obtained by applying a better segmentation on the signal, based on the significant transient, by exploiting perceptive characteristics of some spatial cues and by adapting the estimation of spatial cues. As the hybrid approach has been recently standardized in MPEG USAC, we propose a full review of it, then we develop a new coding technique to optimize the allocation of the residual bands when the residual is not used on the whole bandwidth of the signal to encode. In the conclusion, we discuss about the future of the general spatial audio coding and we show the importance of developping new technics of segmentation and classification for audio signals to further adapt the coding to the content of the signal.

O propósito do presente estudo foi o de investigar o efeito das dicas verbais na aquisição das habilidades rebater e driblar na Educação Física Escolar (EFE), com foco de atenção para os aspectos perceptivo e motor, como conhecimento escolarizado na aprendizagem do movimento. Participaram do estudo 165 alunos de seis salas de aula de uma escola da rede pública estadual (séries iniciais do ensino fundamental, na faixa etária de 6 a 8 anos). Cada sala correspondeu a um grupo, sendo três grupos para cada habilidade: sem dicas, com dica perceptiva e com dica motora. O experimento desenvolveu-se em três fases: pré-teste, aulas de EFE e pós-teste. Na tarefa de rebater, o Grupo 2 (com dica perceptiva) apresentou melhor resultado que os demais grupos, na variável estágio do padrão de movimento. Na tarefa de driblar, o Grupo 6 (com dica motora) apresentou melhora significativa nas três variáveis analisadas: padrão de movimento, número de perdas de controle de bola e tempo de realização do percurso. Verificou-se ainda, que o efeito das dicas depende da sua relação com a especificidade da tarefa no que se refere à demanda de processamento. Também foram coletados os registros iconográficos e escritos dos alunos e os registros do diário da professora das seis salas de aula, os quais evidenciaram a relevância do uso das dicas no processo de aprendizagem na escola. Concluiu-se que a dica funcionou como um conhecimento que orienta os alunos a respeito de como melhorar a qualidade do movimento e, isso ratifica a possibilidade de sua inclusão como conteúdo de ensino da EFE / The main purpose of this study was to investigate the effects of verbal cues on dribbling and striking skills acquisition, focusing on the perceptual and motor aspects of movements learning. The sample for this study was made of 165 public school students aged between 6 to 8 years old from six classrooms in the same school. Each classroom was classified into a group, three for striking skill, three for dribbling skill and each group received a different treatment regarding the skill learning cues: no cues, perceptual cues and motor cues. The experiment was carried out in three phases: pre-test, classes with determined cues and post-test. As the result for striking skill, the Group 2 (which received perceptual cues) had better results than others as it showed an improvement in the level of movement patterns. For dribbling skill, the Group 6 (which received motor cues) showed better results in all three dependent variables: movement pattern levels, ball controlling and time of execution. Thus, it was verified that the effects of cues depend on tasks specificity in relation to the information processing demand. Also, students iconographics and writings, and teachers diary registers of six classrooms showed the importance of cues in the process of learning at school. This study concludes that the cues worked as knowledge for the student which guided them towards improvement of movement performance and it can be seen as positive evidence in favor of their inclusion as content to be taught in the Physical Education classes

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This thesis deals with the image object detection using Contour cues. The text describes methods how to train and test object detector. The main contribution of this thesis consists in creation Feature extractor for creation object detector in Java programming. The functionality of object detector was demonstrated on medical images.

Background: Promotional cues are commonly applied on online travel agency websites. The most common cues were identified to be scarcity, popularity and pricing, which are said to increase consumers’ perception of scarcity, popularity and price and following enhance consumers’ booking intention. There is an increasing interest in promotional cues’ impact on booking intention in the online booking context, however, the results are not coherent as well as previous studies have looked only into intention to book. By applying the theory of planned behavior model to measure booking intention, new theoretical insights regarding promotional cues and booking intention should be given. Furthermore, this should help hotel suppliers to increase booking intention on the own hotel’s website. Purpose: The purpose is to explain how promotional cues found on online hotel booking sites impact the relationship between (1) perceived scarcity, (2) perceived popularity, (3) perceived price and consumers’ booking intention, by using the theory of planned behavior model. Method: This study has taken a deductive approach with quantitative data collection methods. By using a between-subjects experimental design, a fictional online hotel booking scenario was created. In total, data from 379 respondents were collected with a web-based survey. Thereby, respondents were assigned to six different groups (three treatment groups and three control groups). With conducting a manipulation check, it was identified that the perceived pricing group did not show a significant difference between control group and treatment group, however, perceived scarcity and perceived popularity did. For the analysis a correlation and regression analysis were conducted. Several t tests were conducted to find significant differences between diverse variables. Conclusion: A positive moderate relationship was found between perceived scarcity and booking intention, when applying scarcity cues. Furthermore, implementing popularity cues, led also to a moderate positive relationship indicated between perceived popularity and booking intention, however, the relationship was not as strongly correlated as when applying scarcity cues. Thereby, implementing scarcity and popularity cues is an effective tool to increase bookings, however, only to a small amount. Hence, it is important to also pay attention to the other factors influencing booking intention and simply using the cues as support to increase the number of booking.

The increasing availability of modern head-mounted displays have spurred interest in social virtual reality (VR) applications, but their immersion-inducing features limit the use of important nonverbal social cues in multiuser contexts. Embodied avatars have proven useful in increasing the social affordances of real-time rendered VR applications but remain underexplored in cinematic virtual reality (CVR). In the present study, three different conditions were evaluated in co-located CVR where participants watched 360° videos together in pairs; one condition had no visual representation of the co-watcher, one condition had a translucent cone representing the co-watcher’s viewing direction, and one condition had both the cone and a set of hands representing the co-watcher. Social presence was measured through the Networked Minds Social Presence Inventory and a semantic differential scale, presence was measured through the iGroup Presence Questionnaire, and participants’ use of implicit and explicit spatial references (i.e., “there” versus “next to the blue house”) was analyzed. The results indicate that simple embodied avatars can increase presence and social presence in CVR, and lead to more face-to-face-like verbal behavior. / Intresset för sociala VR-applikationer har stigit i takt med spridningen av moderna VR-glasögon, men applikationer för två eller fler användare är svåra att realisera i och med att glasögonen blockerar viktiga ickeverbala sociala signaler. I realtidsrenderad VR har de sociala interaktionsmöjligheterna kunnat förbättras genom så kallade embodied avatars men deras effekt har hittills inte undersökts i cinematisk VR (CVR). I den här studien utforskades tre betingelser av embodied avatars i ett CVR-experiment där deltagarpar tittade på 360° filmer tillsammans i ett rum. En betingelse saknade avatar, i en betingelse representerades ens partners blickfång av en halvgenomskinlig kona, och i en betingelse representerades ens partner av både konan samt ett par virtuella händer. Social presence mättes genom the Networked Minds Social Presence Inventory och en semantic differential scale, presence mättes genom the iGroup Presence Questionnaire, och deltagarnas användning av implicita (”där”) och explicita (”bredvid det blå huset”) spatiala uttalanden analyserades. Resultaten visar att enkla embodied avatars kan öka både presence och social presence i CVR, samt leda till verbal kommunikation som liknar den vi använder i när vi interagerar ansikte mot ansikte.

While consumers are shifting towards online clothing purchases globally, South Africa, a developing economy with well-developed infrastructure, is lagging in this regard. This research highlights significant drawbacks that may jeopardise the growth of online shopping despite the multiple advantages that consumers and retailers could benefit from. The key to the issue is that a consumer is not physically present in the store, and that online consumers’ experiences are limited to the technological capabilities of existing digital platforms. Inevitably, consumers’ online experiences would be framed in terms of what they are accustomed to in physical stores, therefore, sensory-rich, captivating environments. Creating well-designed mobile phone applications, which incorporate multiple sensory cues, is consequently crucial to capture online shoppers’ attention, and to ensure online retailers’ success. Millennials, the largest generational consumer group presently worldwide, is particularly important to online clothing retailers due to their potential buying power, interest in clothing as a product category, as well as their extensive use of mobile technologies. This study was conducted in the context of an emerging economy and aimed to examine the real-time influence of visual and auditory cues - that could viably be incorporated with available technology into a custom-designed mobile phone application for a fictitious clothing retailer - on millennials’ sensory experience and purchase intentions when purchasing clothing online. Clothing is a rather complex product category where sensory cues in combination with a range of extrinsic and intrinsic product characteristics are highly relevant during product evaluation. To accommodate the realities of physical store experience, three moderating influences were examined within the chosen stimulus-organism-response (S-O-R) theoretical framework, namely, the effects of telepresence, customisation, and available clothing product information. A positivistic, quantitative, descripto-explanatory, cross-sectional study was designed, presenting a two-phase electronic survey. It presented a vignette design that exposed respondents to the capabilities of the custom-designed mobile phone application before completing a questionnaire. Convenient, online snowball sampling through social media produced a sample size of 842 millennial respondents, from the Gauteng province in South Africa. Statistical analyses included descriptive statistics, covariance-based structural equation modelling, moderation analyses, and multivariate analyses of variance. The findings confirmed the significant influence of visual and auditory cues on millennials’ online sensory experience, as well as the significant positive moderating role of telepresence and customisation respectively, in facilitating millennials’ purchase intentions when shopping online. Failure to affirm the moderating influence of product information on consumers' purchase intentions, may be ascribed to the absence of intrinsic product characteristics such as fit, feel, and comfort, which are highly relevant but can not yet be incorporated into an online platform. This elevates the importance of how existing sensory cues are presented, and how they could counteract shortcomings of online shopping encounters. Considering what has been achieved by the gaming industry, in terms of visuals and sound when playing online, retail store mobile phone applications have not yet optimised their potential. Gender differences in online shoppers’ sensory experience, purchase intention and use of product information suggest that millennial men's purchase decisions may be more rational inclined compared to their female counterparts. The study indicates how millennials’ online clothing purchase endeavours could be enhanced in developing countries like South Africa, where online shopping has not yet reached first-world levels. Empirical evidence is also provided on how online sensory experiences and effective mobile phone app designs could enhance clothing retailers’ online apps to boost online sales. / Thesis (PhD)--University of Pretoria, 2021. / Gordon Institute of Business Science (GIBS) / PhD / Unrestricted

The global stressors of ocean warming and acidification, as well as local stressors such as eutrophication, overfishing, and coastal construction, have all contributed to the severe decline in coral populations worldwide. Recovery of coral reefs depends partly on recruitment, which relies on the response of larvae to settlement cues indicative of habitat quality; however, it remains unclear whether recruitment in disturbed areas will be compromised. Specifically, as reefs become more disturbed and dominated by macroalgae, it is important to understand larval behavior in response to changes in habitat quality. In this study, we first assessed the settlement success of newly released Agaricia agariciteslarvae in response to several settlement cues, including temperature and water movement. Then, to test the Desperate Larva Hypothesis, the ability of larvae of different ages (0-7 days) to settle and discriminate between inducing and inhibitory settlement cues was assessed. Newly released larvae displayed a stronger preference for settling on crustose coralline algae (93%) than on ceramic plates in macroalgae- (30%) or conspecific-treated seawater (5%), or filtered seawater (13%) (control). Older larvae became progressively less discriminatory of settlement cues, settling even in response to inhibitory cues. This confirms that, although the absence of good settlement cues initially deters settlement, larvae become desperate as they become older and settle even on unfavorable substrates, thus contributing to recruitment in poor quality habitats.