Studying newborns in the first days of life prior to experiencing the world provides remarkable insights into the neurocognitive predispositions that humans are endowed with. First, it helps us to improve our current knowledge of the development of a typical brain. Secondly, it potentially opens new pathways for earlier diagnosis of several developmental neurocognitive disorders such as Autism Spectrum Disorder (ASD). While most studies investigating early cognition in the literature are purely behavioural, recently there has been an increasing number of neuroimaging studies in newborns and infants. Electroencephalography (EEG) is one of the most optimal neuroimaging technique to investigate neurocognitive functions in human newborns because it is non-invasive and quick and easy to mount on the head. Since EEG offers a versatile design with custom number of channels/electrodes, an ergonomic wearable solution could help study newborns outside clinical settings such as their homes. Compared to adult EEG, newborn EEG data are different in two main aspects: 1) In experimental designs investigating stimulus-related neural responses, collected data is extremely short in length due to the reduced attentional span of newborns; 2) Data is heavily contaminated with noise due to their uncontrollable movement artifacts. Since EEG processing methods for adults are not adapted to very short data length and usually deal with well-defined, stereotyped artifacts, they are unsuitable for newborn EEG. As a result, researchers manually clean the data, which is a subjective and time-consuming task. This thesis work is specifically dedicated to developing (semi-) automated novel signal processing methods for noise removal and for extracting reliable neural responses specific to this population. The solutions are proposed for both high-density EEG for traditional lab-based research and wearable EEG for clinical applications. To this end, this thesis, first, presents novel signal processing methods applied to newborn EEG: 1) Local Outlier Factor (LOF) for detecting and removing bad/noisy channels; 2) Artifacts Subspace Reconstruction (ASR) for detecting and removing or correcting bad/noisy segments. Then, based on these algorithms and other preprocessing functionalities, a robust preprocessing pipeline, Newborn EEG Artifact Removal (NEAR), is proposed. Notably, this is the first time LOF is explored for EEG bad channel detection, despite being a popular outlier detection technique in other kinds of data such as Electrocardiogram (ECG). Even if ASR is already an established artifact real algorithm originally developed for mobile adult EEG, this thesis explores the possibility of adapting ASR for short newborn EEG data, which is the first of its kind. NEAR is validated on simulated, real newborn, and infant EEG datasets. We used the SEREEGA toolbox to simulate neurologically plausible synthetic data and contaminated a certain number of channels and segments with artifacts commonly manifested in developmental EEG. We used newborn EEG data (n = 10, age range: 1 and 4 days) recorded in our lab based on a frequency-tagging paradigm. The chosen paradigm consists of visual stimuli to investigate the cortical bases of facelike pattern processing, and the results were published in 2019. To test NEAR performance on an older population with an event-related design (ERP) and with data recorded in another lab, we also evaluated NEAR on infant EEG data recorded on 9-months-old infants (n = 14) with an ERP paradigm. The experimental paradigm for these datasets consists of auditory stimulus to investigate the electrophysiological evidence for understanding maternal speech, and the results were published in 2012. Since authors of these independent studies employed manual artifact removal, the obtained neural responses serve as ground truth for validating NEAR’s artifact removal performance. For comparative evaluation, we considered the performance of two state-of-the-art pipelines designed for older infants. Results show that NEAR is successful in recovering the neural responses (specific to the EEG paradigm and the stimuli) compared to the other pipelines. In sum, this thesis presents a set of methods for artifact removal and extraction of stimulus-related neural responses specifically adapted to newborn and infant EEG data that will hopefully contribute to strengthening the reliability and reproducibility of developmental cognitive neuroscience studies, both in research laboratories and in clinical applications.

No description available.

Researchers perform multivariate techniques MANOVA, discriminant analysis and factor analysis. The most common applications in social science are to identify and test the effects from the analysis. The use of this multivariate technique is uncommon in investigating the effects of power usage and Province in South Africa on the amounts of the five power modes. This dissertation discusses this issue, the methodology and practical problems of the three multivariate techniques. The author examines the applications of each technique in social public research and comparisons are made between the three multivariate techniques. This dissertation concludes with a discussion of both the concepts of the present multivariate techniques and the results found on the use of the three multivariate techniques in the energy household consumption. The author recommends focusing on the hypotheses of the study or typical questions surrounding of each technique to guide the researcher in choosing the appropriate analysis in the social research, as each technique has some strengths and limitations. / Statistics / M. Sc. (Statistics)

This study investigated the relationship between capital structure, performance and replacement of chief executive officer in firms listed on the Nairobi Securities Exchange (NSE). Data was collected from a sample of 37 firms listed on the NSE over a period of 23 years, from 1990 to 2012. The analysis was conducted at three stages. The canonical correlation technique was employed to investigate the bi-directional relationship between capital structure and performance and to select competing indicators of performance and capital structure. Second, the general linear model (GLM) procedure was used to test the effect of performance and ownership structure and to test the effect of capital structure and ownership structure. Lastly, the generalised estimating equation (GEE) was used to assess effects of performance, capital structure and ownership structure on change in CEO. The results revealed that a bidirectional relationship exists between capital structure and debt capital. The indicators found to be useful in examining the relationship between performance and capital structure are asset turnover ratio and total debt to the total asset ratio. The findings support the efficiency hypothesis but not the franchise hypothesis. The results also indicated that firms with a low asset turnover are with a low asset turnover are 3.045 times likely to change CEO compared to firms with a high asset turnover. The results also indicated that firms with high leverage (debt) are he results also indicated that firms with high leverage (debt) are 3.430 times likely to change CEO compared to firms in low leverage, while the firms with medium leverage are are are are 6.491 times likely to change CEO. Therefore managers should not be passive when it comes to choosing between equity and debt capital played a disciplinary role on firms listed on the NSE. / Business Management / DCom (Business Management)

國中基測實施迄今已十年，但是各種多元管道仍以國中基測量尺分數作為分發篩選之重要參據，多元能力評量參採比重偏低，國中學生升學競爭壓力未得緩解。本研究透過數學與統計分析的工具，尋找採用學生在校成績的方法，希望能找出更好的方式來代表學生在校三年的學習現況與學習成果，以做為免試升學採計在校成績的參考與依據。 本研究主要目的是要探討如何取決各科在校成績的權重(也就是在每個科目的分數之前乘上一個加權比重係數)，以求得一個新的合成變量(由數個科目分數組成的線性組合)，並用這個新合成變量做為學生在校的“綜合學科能力表現分數”，代表學生在校三年的基本學習能力及程度。 研究方法運用主成份分析與典型相關分析的觀念，但因限制條件設定的範圍與傳統主成分分析及典型相關分析的要求不一致，因此，我們便將所用的研究方法命名為「類主成分分析」與「類典型相關分析」。 研究中，方法主要在比較「類主成分分析」、「主成分分析」、「類典型相關分析」、以及「典型相關分析」四種方法與一般學校常用的「等加權比重」算平均成績的方法之分別；了解這些不同加權機制對同一所學校內學生的學科加權平均分數之成績排名百分比結果，以及與基測排名結果的差異。 「類主成份分析」研究結果發現，各科學科成績中變異數大的科目將獲得較大的權重比例，成為主導學生加權平均成績中舉足輕重的科目。另外；運用「類典型相關分析法」所求得的典型相關係數，其結果與傳統典型相關分析法以及使用最佳數值分析軟體(GAMS)所得的典型相關係數完全相同。 本研究最重要的貢獻之一，是我們在「類典型相關分析法」中證明並推導出一個求得各科權重的公式，只要使用此公式代入簡單的MATLAB程式，其所得的權重結果與最佳化數值分析軟體(GAMS)所得的結果完全相同，但花費的計算時間及成本卻遠少於GAMS所需，是一個求權重極便捷的方法，讀者可以在本論文附錄7.5.2或政大應數系網站上下載此程式。本研究最後結論也發現，類主成份分析的變異解釋率是所有方法中較高的；與基測總分結果較相近的則是類典型相關分析所得的權重機制；而等加權方法所得的排名結果則與基測排名結果差異最小。 / The BCTEST (Basic Competence Test) for junior high school students has been implemented for ten years, however, the screenings for a variety of entrance programs are still based on the scale scores of the BCTEST with a low proportion of multi-intelligence. Hence, the competitive entrance pressure for junior high school students remains un-relieved. In view of this, via mathematics and statistics, this study is to explore an alternative approach which can not only reflect students' in-school grade, their learning situations and achievements but also represent a reference for entering senior high schools and junior colleges without entrance examinations. The purpose of this study is to determine the different weightings of five learning subjects (that is, multiply the score of each subject by a weighted coefficient) and acquire a new composite variable from the linear combinations of five learning subjects. Then, use this new composite variable as the synthetic score of students' in-school academic performance. Principal Component Analysis and Canonical Correlation Analysis are used in this study. Due to inconsistent restraints, the other two approaches we use are based on the concept of previously mentioned methodologies and denominated Principal Component Type of Analysis and Canonical Correlation Type of Analysis. In the study, we compare with the different results of Principal Component Analysis, Principal Component Type of Analysis, Canonical Correlation Analysis, Canonical Correlation Type of Analysis and identical weighted method to realize how these different weighted schemes affect the rankings of students from the same school on both their weighted in-school grade and scores of the BCTEST (Basic Competence Test). The outcomes of Principal Component Type of Analysis show that subjects with greater variance acquire larger weightings and play a dominant role in weighted in-school grade. Moreover, the correlation coefficients of Canonical Correlation Type of Analysis are completely the same as the ones of Canonical Correlation Analysis and GAMS. One of the most important contributions in this study is we have proven and derived a formula to acquire different weightings of five learning subjects by using Canonical Correlation Type of Analysis. The acquired weightings are completely the same as the ones of GAMS with less time consuming. Readers can download this program in appendix 7.5.2 or from the website of Department of Mathematical Sciences, National Chengchi University(NCCU). We have also found that, the explanation rate of variance obtained from Principal Component Type of Analysis is the highest; the weighted scheme of Canonical Correlation Type of Analysis is more similar to the scores of the BCTEST; the difference of the rankings between identical weighted method and the BCTEST is the smallest.

本研究探討服務設計、展覽體驗、體驗價值、顧客滿意度與推薦意願之關聯，以2010年台北國際花卉博覽會為例。主要研究目的是想了解花博園區的服務設計內容，是否會使前往花博的顧客有不同的體驗經驗，間接增加體驗價值，進一步使滿意度增加，進而願意推薦親朋好友前往參觀？也想了解是否因為顧客個人因素的不同，導致不同的體驗價值與顧客滿意度？ 本研究有效紙本問卷有136份，有效網路問卷有461份，全部問卷共597份。利用典型相關與迴歸分析，發現良好的服務設計將會帶給花博顧客正向的展覽體驗；良好的展覽體驗提高體驗價值；較高的體驗價值使顧客對此次花博擁有較高的滿意度進而使推薦意願提高。接著透過MANOVA、ANOVA、多重比較與T檢定，發現參觀花博的時間不同，對於體驗價值與顧客滿意度有所差異；而第一次參觀花博月份的不同，使滿意度有所差異；累計參觀花博次數不同，對於體驗價值與滿意度也會有所差異。 / In this study serive design, exhibition experience, experiential value, customer satisfication and recommendation are used to investigate the 2010 Taipei Flora Expo. The main purpose is to understand how the host organization service design used in the Flora Expo, caused tourists to have different experiences, increased experiential values, satisfication and recommendation. The study will also investigate whether different personal factors will cause different experiential values and satisfication. There are 136 subjects from paper questionnaire and 461 subjects from on-line questionnaire. Total subjects are 597. Using Canonical Correlation, Regression, MANOVA, ANOVA, Post Hoc and T test the resulting data is as follows： 1. Service design had a positive correlation to experiential marketing. 2. Experiential marketing had a positive correlation to experiential value. 3. Experiential value had a positive correlation to satisfaction. 4. Satisfaction had a positive correlation to recommendation. 5. Different visiting days (weekday, weekend, both) had different experiential value and satisfication 6. During the month (11-12, 1-2, 3-4) of people visting for the first time had different level of satisfication. 7. The amout of times (1, 2, above 3 times) visiting the expo had different experiential values and satisfication.

En raison de la demande croissante de services de communication sans fil et de la limitation des ressources de spectre, la radio cognitive (CR) a été initialement proposée pour résoudre la pénurie de spectre. CR divise les systèmes transmetteurs-récepteurs de communication en deux catégories : les Utilisateurs Principaux (PU) et les Utilisateurs Secondaires (SU). PU a le droit légal d'utiliser la bande spectrale, tandis que SU est un utilisateur opportuniste qui peut transmettre sur cette bande chaque fois qu'elle est vacante afin d'éviter toute interférence avec le signal de PU. De ce fait, la détection des activités de PU devient une priorité principale pour toute CR.Le Spectrum Sensing devient ainsi une partie importante d’un système CR, qui surveille les transmissions de PU. En effet, le Spectrum Sensing joue un rôle essentiel dans le mécanisme du fonctionnement du CR en localisant les canaux disponibles et, d'autre part, en protégeant les canaux occupés des interférences de la transmission SU. En fait, Spectrum Sensing a gagné beaucoup d'attention au cours de la dernière décennie, et de nombreux algorithmes sont proposés. Concernant la fiabilité de la performance, plusieurs défis comme le faible rapport signal sur bruit, l'incertitude de bruit (NU), la durée de détection du spectre, etc. Cette thèse aborde les défis de la détection du spectre et apporte quelques solutions. De nouveaux détecteurs basés sur la détection des caractéristiques cyclo-stationnaires et la densité spectrale de puissance (PSD) du signal de PU sont présentés. Un algorithme de test de signification de corrélation canonique (CCST) est proposé pour effectuer une détection cyclo-stationnaire. CCST peut détecter la présence des caractéristiques cycliques communes parmi les versions retardées du signal reçu. Ce test peut révéler la présence d'un signal cyclo-stationnaire dans le signal de mélange reçu. Une autre méthode de détection basée sur la PSD cumulative est proposée. En supposant que le bruit est blanc (sa PSD est plate), la PSD cumulative s'approche d'une droite. Cette forme devient non linéaire pour les signaux de télécommunication. Distinguer la forme cumulative PSD peut donc conduire à diagnostiquer l'état du canal.La radio cognitive Full-Duplex (FD-CR) a également été étudiée dans ce manuscrit, où plusieurs défis sont analysés en proposant de nouvelles contributions. Le fonctionnement FD permet au CR d'éviter la période de silence pendant la détection du spectre. Dans le système CR classique, le SU cesse de transmettre pendant la détection du spectre afin de ne pas affecter la fiabilité de détection. Dans FD-CR, SU peut éliminer la réflexion de son signal transmis et en même temps réaliser le Spectrum Sensing. En raison de certaines limitations, le résidu de l'auto-interférence ne peut pas être complètement annulé, alors la crédibilité de la détection du spectre est fortement affectée. Afin de réduire la puissance résiduelle, une nouvelle architecture de récepteur SU est élaborée pour atténuer les imperfections du circuit (comme le bruit de phase et la distorsion non linéaire de l'amplificateur à faible bruit du récepteur). La nouvelle architecture montre sa robustesse en assurant une détection fiable et en améliorant le débit de SU. / Due to the increasing demand of wireless communication services and the limitation in the spectrum resources, Cognitive Radio (CR) has been initially proposed in order to solve the spectrum scarcity. CR divides the communication transceiver into two categories: the Primary (PU) or the Secondary (SU) Users. PU has the legal right to use the spectrum bandwidth, while SU is an opportunistic user that can transmit on that bandwidth whenever it is vacant in order to avoid any interference to the signal of PU. Hence the detection of PU becomes a main priority for CR systems. The Spectrum Sensing is the part of the CR system, which monitors the PU activities. Spectrum Sensing plays an essential role in the mechanism of the CR functioning. It provides CR with the available channel in order to access them, and on the other hand, it protects occupied channels from the interference of the SU transmission. In fact, Spectrum Sensing has gained a lot of attention in the last decade, and numerous algorithms are proposed to perform it. Concerning the reliability of the performance, several challenges have been addressed, such as the low Signal to Noise Ratio (SNR), the Noise Uncertainty (NU), the Spectrum Sensing duration, etc. This dissertation addresses the Spectrum Sensing challenges and some solutions are proposed. New detectors based on Cyclo-Stationary Features detection and the Power Spectral Density (PSD) of the PU are presented. CanonicalCorrelation Significance Test (CCST) algorithm is proposed to perform cyclo-stationary detection. CCST can detect the presence of the common cyclic features among the delayed versions of the received signal. This test can reveal the presence of a cyclo-stationary signal in the received mixture signal. Another detection method based on the cumulative PSD is proposed. By assuming the whiteness of the noise (its PSD is at), the cumulative PSD approaches a straight line. This shape becomes non-linear when a telecommunication signal is present in the received mixture. Distinguishing the Cumulative PSD shape may lead to diagnose the channel status.Full-Duplex Cognitive Radio (FD-CR) has been also studied in this manuscript, where several challenges are analyzed by proposing a new contribution. FD functioning permits CR to avoid the silence period during the Spectrum Sensing. In classical CR system, SU stops transmitting during the Spectrum Sensing in order to do not affect the detection reliability. In FD-CR, SU can eliminate the reflection of its transmitted signal and at the same time achieving the Spectrum Sensing. Due to some limitations, the residual of the Self Interference cannot be completely cancelled, then the Spectrum Sensing credibility is highly affected. In order to reduce the residual power, a new SU receiver architecture is worked out to mitigate the hardware imperfections (such as the Phase Noise and the Non-Linear Distortion of the receiver Low-Noise Amplifier). The new architecture shows its robustness by ensuring a reliable detection and enhancing the throughput of SU.

This study investigated the relationship between capital structure, performance and replacement of chief executive officer in firms listed on the Nairobi Securities Exchange (NSE). Data was collected from a sample of 37 firms listed on the NSE over a period of 23 years, from 1990 to 2012. The analysis was conducted at three stages. The canonical correlation technique was employed to investigate the bi-directional relationship between capital structure and performance and to select competing indicators of performance and capital structure. Second, the general linear model (GLM) procedure was used to test the effect of performance and ownership structure and to test the effect of capital structure and ownership structure. Lastly, the generalised estimating equation (GEE) was used to assess effects of performance, capital structure and ownership structure on change in CEO. The results revealed that a bidirectional relationship exists between capital structure and debt capital. The indicators found to be useful in examining the relationship between performance and capital structure are asset turnover ratio and total debt to the total asset ratio. The findings support the efficiency hypothesis but not the franchise hypothesis. The results also indicated that firms with a low asset turnover are with a low asset turnover are 3.045 times likely to change CEO compared to firms with a high asset turnover. The results also indicated that firms with high leverage (debt) are he results also indicated that firms with high leverage (debt) are 3.430 times likely to change CEO compared to firms in low leverage, while the firms with medium leverage are are are are 6.491 times likely to change CEO. Therefore managers should not be passive when it comes to choosing between equity and debt capital played a disciplinary role on firms listed on the NSE. / Business Management / DCom (Business Management)

Les systèmes neuromusculaires et musculo-squelettique sont considérés comme un système de systèmes complexe. En effet, le mouvement du corps humain est contrôlé par le système nerveux central par l'activation des cellules musculaires squelettiques. L'activation du muscle produit deux phénomènes différents : mécanique et électrique. Ces deux activités possèdent des propriétés différentes, mais l'activité mécanique ne peut avoir lieu sans l'activité électrique et réciproquement. L'activité mécanique de la contraction du muscle squelettique est responsable du mouvement. Le mouvement étant primordial pour la vie humaine, il est crucial de comprendre son fonctionnement et sa génération qui pourront aider à détecter des déficiences dans les systèmes neuromusculaire et musculo-squelettique. Ce mouvement est décrit par les forces musculaires et les moments agissant sur une articulation particulière. En conséquence, les systèmes neuromusculaires et musculo-squelettique peuvent être évalués avec le diagnostic et le management des maladies neurologiques et orthopédiques à travers l'estimation de la force. Néanmoins, la force produite par un seul muscle ne peut être mesurée que par une technique très invasive. C'est pour cela, que l'estimation de cette force reste l'un des grands challenges de la biomécanique. De plus, comme dit précédemment, l'activation musculaire possède aussi une réponse électrique qui est corrélée à la réponse mécanique. Cette résultante électrique est appelée l'électromyogramme (EMG) et peut être mesurée d'une façon non invasive à l'aide d'électrodes de surface. L'EMG est la somme des trains de potentiel d'action d'unité motrice qui sont responsable de la contraction musculaire et de la génération du mouvement. Ce signal électrique peut être mesuré par des électrodes à la surface de la peau et est appelé I'EMG de surface {sEMG). Pour un muscle unique, en supposant que la relation entre l'amplitude du sEMG et la force est monotone, plusieurs études ont essayé d'estimer cette force en développant des modèles actionnés par ce signal. Toutefois, ces modèles contiennent plusieurs limites à cause des hypothèses irréalistes par rapport à l'activation neurale. Dans cette thèse, nous proposons un nouveau modèle de relation sEMG/force en intégrant ce qu'on appelle le sEMG haute définition (HD-sEMG), qui est une nouvelle technique d'enregistrement des signaux sEMG ayant démontré une meilleure estimation de la force en surmontant le problème de la position de l'électrode sur le muscle. Ce modèle de relation sEMG/force sera développé dans un contexte sans fatigue pour des contractions isométriques, isotoniques et anisotoniques du Biceps Brachii (BB) lors une flexion isométrique de l'articulation du coude à 90°. / The neuromuscular and musculoskeletal systems are complex System of Systems (SoS) that perfectly interact to provide motion. This interaction is illustrated by the muscular force, generated by muscle activation driven by the Central Nervous System (CNS) which pilots joint motion. The knowledge of the force level is highly important in biomechanical and clinical applications. However, the recording of the force produced by a unique muscle is impossible using noninvasive procedures. Therefore, it is necessary to develop a way to estimate it. The muscle activation also generates another electric phenomenon, measured at the skin using electrodes, namely the surface electromyogram (sEMG). ln the biomechanics literature, several models of the sEMG/force relationship are provided. They are principally used to command musculoskeletal models. However, these models suffer from several important limitations such lacks of physiological realism, personalization, and representability when using single sEMG channel input. ln this work, we propose to construct a model of the sEMG/force relationship for the Biceps Brachii (BB) based on the data analysis of a High Density sEMG (HD-sEMG) sensor network. For this purpose, we first have to prepare the data for the processing stage by denoising the sEMG signals and removing the parasite signals. Therefore, we propose a HD-sEMG denoising procedure based on Canonical Correlation Analysis (CCA) that removes two types of noise that degrade the sEMG signals and a source separation method that combines CCA and image segmentation in order to separate the electrical activities of the BB and the Brachialis (BR). Second, we have to extract the information from an 8 X 8 HD-sEMG electrode grid in order to form the input of the sEMG/force model Thusly, we investigated different parameters that describe muscle activation and can affect the relationship shape then we applied data fusion through an image segmentation algorithm. Finally, we proposed a new HDsEMG/force relationship, using simulated data from a realistic HD-sEMG generation model of the BB and a Twitch based model to estimate a specific force profile corresponding to a specific sEMG sensor network and muscle configuration. Then, we tested this new relationship in force estimation using both machine learning and analytical approaches. This study is motivated by the impossibility of obtaining the intrinsic force from one muscle in experimentation.

Researchers perform multivariate techniques MANOVA, discriminant analysis and factor analysis. The most common applications in social science are to identify and test the effects from the analysis. The use of this multivariate technique is uncommon in investigating the effects of power usage and Province in South Africa on the amounts of the five power modes. This dissertation discusses this issue, the methodology and practical problems of the three multivariate techniques. The author examines the applications of each technique in social public research and comparisons are made between the three multivariate techniques. This dissertation concludes with a discussion of both the concepts of the present multivariate techniques and the results found on the use of the three multivariate techniques in the energy household consumption. The author recommends focusing on the hypotheses of the study or typical questions surrounding of each technique to guide the researcher in choosing the appropriate analysis in the social research, as each technique has some strengths and limitations. / Statistics / M. Sc. (Statistics)