Fast pushing like forms of knee extension were previously studied (van Ingen Schenau, 1994, Bobbert 1994). From these the role of mono and bi-articular muscles was established for this type of pushing like motion patterns. The way whipping like forms of knee extension are controlled is however less understood. This study investigated the impact of skill level in modulating fast forms of knee extension. The investigation was carried out by using a Taekwondo fast front kicking action, mean peak leg angular velocity 18.65 rads/s, as the subject task. A total of 40 healthy male and female participants volunteered to take part in this study. Of these, 20 were skilled martial arts athletes while the remaining 20 were unskilled. Expert and novice groups were randomly divided into treatment and control groups. A ten week intervention program aimed at increasing the skill level of participants of the expert and novice groups was conducted. The kinematic profile of the execution of a fast front kick performed under various settings of velocity, range of motion and degrees of freedom was obtained by a high speed camera. The myoelectrical activity of selected muscle units was simultaneously obtained while kicks were video recorded. Expert and novice participants were tested pre and post intervention program. Of the available kinematic variables such as segmental angular velocities, joint linear velocities and intersegmental timing and coordination, it was found that only: peak ankle linear and leg angular velocities, intersegmental timing, thigh to leg peak angular velocity ratio and a calculated performance index, have the potential to discriminate differences in skill level in this form of kicking. Pre and post intervention differences between groups were assessed from these variables. It was of interest to this study to identify the sources of these differences. To this end, an inverse dynamics analysis of the interaction between segments during the execution of a front kick was performed. It was found that the interaction between segments evolves with increases in skill level. Expert athletes utilize a i) precursor knee flexion moment to assist hip flexion moment during the initial stages of the kicking action and ii) a late hip flexion moment to assist further increases of kicking speed. These moments were absent in the execution of a front kick by novice athletes. These findings were also obtained form an optimization approach to the analysis of interactive moments during kicking. An important conclusion from these analyses is that the view of a front kick as a proximal to distal motion pattern is inadequate. Evidence from this study suggests that this action is best defined as a distal-proximal-distal motion pattern in an expert population. It then indicates that skill gains rely on the utilization of intrinsic muscle properties to assist the execution of tasks like a front kick.

Pronunciation instruction in the English as a Second Language (ESL) classroom often focuses exclusively on production and fails to address students’ perception problems. This report attempts to explain why L2 learners struggle to perceive and produce segments accurately in their L2 and what can be done to help L2 learners overcome these problems. Accordingly, the report explores how L1 experience and segmental differences between Vietnamese and English contribute to these English language learners’ perception and production problems. The report also considers instructional methods that can be used to help ESL learners overcome their perception and production challenges and recommends several approaches for addressing segments that are often difficult for Vietnamese learners. / text

Abstract This study is to elucidate the possibility of DNA fragment identification method in the forensic detection of marine microalgae (Chlorella sp. and Nannochloropsis oculata) from human (Homo sapiens) body by 3% agarose gel electrophoresis of amplification fragments via PCR-amplified ribosomal gene small subunit (SSU) rDNA molecules as primers, which are specific nucleotide segments on conserved regions (18S rDNA region (NS1-NS2 primers))on SSU rDNA and on variable regions (internal transcribed spacer (ITS) regions (primer 2/primer 5 for ITS1 region and primer 3/primer 4 for ITS2 region)). NS1-NS2-amplified PCR fragments are 550 bp for C. sp., 550 bp for N. oculata and 600 bp for human. ITS1-amplified PCR fragments are 1, 2 and 4 bands for C. sp. (350 bp), N. oculata (400 and 450 bp) and human (300, 450, 500 and 580 bp), respectively, while ITS2-amplified PCR fragments are 1, 2 and 1 bands for C. sp. (430 bp), N. oculata (430 and 600 bp) and human (400 bp), respectively. By using human-specific primers (AmpFlSTR® Profilerä PCR Amplification Kit), only human can be identified in the sample containing C. sp., N. oculata and human DNA, whereas C. sp. and N. oculata can not be detected, indicating the prevention of algal interference in human-specific primer-PCR procedures via AmpFlSTR® Profilerä PCR Amplification Kit. Detection limits of C. sp. and N. oculata DNA were 50 and 10 pg, respectively. The results of present investigation show that algae can be distinguished from human by NS1-NS2-amplified PCR fragments but not between C. sp. and N. oculata, while C. sp., N. oculata and human can be distinguished by ITS1- or ITS2-amplified PCR fragments. Evidently, the specificity of DNA segments in marine microalgal and human DNA provides the base for investigation of cause of death in drowning case in the marine environment.

No description available.

Typically wire antenna structures are modeled by approximating curved structures with straight wire segments. The straight wire approximation yields accurate results, but often requires a large number of segments to adequately approximate the antenna geometry. The large number of straight wire segments or unknowns requires a large amount of memory and time to solve for the currents on the antenna. By using curved segments which exactly describe the contour of the antenna geometry the number of unknowns can be reduced, thus allowing for bigger problems to be solved accurately. This thesis focuses on the analysis of a helix antenna. The Method of Moments is used to solve for the currents on the antenna, and both the triangle basis and pulse testing functions exactly follow the contour of the helix antenna. The thin wire approximation is used throughout the analysis. The helix is assumed to be oriented along the z-axis with an optional perfect electric conductor (PEC) ground plane in the x-y plane. For simplicity, a delta gap source model is used. Straight feed wires may also be added to the helix, and are modeled similarly to the helix by the Method of Moments with triangular basis and pulse testing functions. The primary validation of the curved wire approach is through a comparison with MININEC and NEC of the convergence properties of the input impedance of the antenna versus the number of unknowns. The convergence tests show that significantly fewer unknowns are needed to accurately predict the input impedance of the helix, particularly for the normal mode helix. This approach is also useful in the analysis of the axial mode helix where the current changes significantly around one turn. Because of the varying current distribution, the improvement of impedance convergence with curved segments is not as significant for the axial mode helix. However, radiation pattern convergence improvement is found. Multiple feed structures for the axial mode helix are also investigated. In general, the many straight wire segments, and thus unknowns, that are needed to accurately approximate the current around one turn can be greatly reduced by the using the curved segment method. / Master of Science

No description available.

The purpose of this research was to determine if differences exist between the young/old (55-74) and the old/old (75+) regarding external search behavior and the importance of information sources.

Οι ρηξιγενείς ζώνες περιλαμβάνουν συνήθως ασυνεχή, υποπαράλληλα, κλιμακωτά ρηξιγενή τμήματα τα οποία χωρίζονται από ζώνες μεταβίβασης (relay zones). Καθώς οι ρηξιγενείς ζώνες εξελίσσονται, τα τμήματα των ζωνών αυτών, μπορούν να αλληλεπιδρούν μηχανικά και να ενώνονται σταδιακά, σχηματίζοντας έτσι δομές μεγαλύτερης κλίμακας με την αύξηση της παραμόρφωσης. Ο τρόπος με τον οποίο τα τμήματα αλληλεπιδρούν κατά τη διάρκεια της εξέλιξης των ζωνών, έχει γίνει αντικείμενο αρκετών ερευνών. Ωστόσο ακόμα και σήμερα οι γνώσεις μας για τις διεργασίες της αλληλεπίδρασης και της σύνδεσης των τμημάτων είναι περιορισμένες. Στην παρούσα εργασία, για τη μελέτη της τμηματοποίησης και του τρόπου σύνδεσης κανονικών ρηγμάτων, επιλέχτηκαν 3 περιοχές της Κεντρικής Ελλάδας: οι ρηξιγενείς ζώνες του Αιγίου και της Ελίκης στον Κορινθιακό κόλπο, οι ρηξιγενείς ζώνες της Αταλάντης και της Αρκίτσας στον Ευβοϊκό κόλπο και τέλος οι σύνθετες ρηξιγενείς ζώνες του Καπαρελλίου και της Δάφνης στην περιοχή της Βοιωτίας. Οι δύο πρώτες έχουν ΔΒΔ διεύθυνση, ενώ η τελευταία έχει σχεδόν Α-Δ διεύθυνση και αντιπροσωπεύει τη ζώνη παραμόρφωσης μεταξύ των δύο κύριων ζωνών rift. Η επιλογή των περιοχών αυτών έγινε με βάση την σημαντική τεκτονική τους δραστηριότητα τα τελευταία 1.5 εκατομμύρια χρόνια και την σπουδαιότητα τους στη νεοτεκτονική εξέλιξη της Κεντρικής Ελλάδας. Στην παρούσα διατριβή υπολογίστηκαν παράμετροι που αντανακλούν έμμεσα την κατανομή της τάσης γύρω από τα ρήγματα, όπως είναι η κατακόρυφη μετατόπιση (D), το μήκος των ρηγμάτων (L), ο αριθμός των ρηξιγενών τμημάτων κάθε ζώνης (n), η επικάλυψη (OL), η κλιμάκωση (S), και το μήκος της ζώνης μεταβίβασης (Lr). Οι παράμετροι αυτοί αποτελούν δείκτες του βαθμού σύνδεσης μεταξύ των ρηξιγενών τμημάτων καθώς και του βαθμού ωριμότητας μιας ενεργού ζώνης. Έτσι, χρησιμοποιήθηκαν αρχικά Ψηφιακά Μοντέλα Αναγλύφου (DEM) από τα οποία κατασκευάστηκαν τοπογραφικά προφίλ σε κάθε ρηξιγενή ζώνη, με σκοπό τον υπολογισμό της κατακόρυφης μετατόπισης των ρηγμάτων τόσο στα επι μέρους τμήματα όσο και στις ζώνες μεταβίβασης καθώς και η κατανομή της μετατόπισης κατά μήκος οροφής-βάσης των ρηγμάτων. Επίσης προσδιορίστηκε η γεωμετρία των ζωνών μεταβίβασης μεταξύ των ρηξιγενών τμημάτων, με σκοπό να εξετασθούν οι τρόποι σύνδεσης των τμημάτων με υπολογισμό του μήκους των μη επικαλυπτόμενων ζωνών (underlapping zone), των ζωνών επικάλυψης (overlap zone) και των κλιμακώσεων (separation/spacing). Τα μήκη των τμημάτων των ρηξιγενών ζωνών προβλήθηκαν σε διαγράμματα αθροιστικής συχνότητας με σκοπό την περιγραφή των πληθυσμών των ρηγμάτων στις τρεις περιοχές μελέτης. Τα διαγράμματα δηλώνουν μια πολυκλασματική κατανομή, που αντιπροσωπεύει διαφορετικούς πληθυσμούς ρηγμάτων που αλληλεπιδρούν ή μια εκθετική κατανομή που δείχνει ένα πρώιμο στάδιο κορεσμού των ρηγμάτων. Στη συνέχεια, κατασκευάστηκαν διαγράμματα της μέγιστης κατακόρυφης μετατόπισης των τμημάτων με το μήκος (D-L), με σκοπό να προσδιοριστεί σε ποιο στάδιο σύνδεσης βρίσκονται οι συγκεκριμένες ζώνες και να προταθούν μοντέλα εξέλιξης αυτών. Τέλος εξετάστηκαν και συσχετίστηκαν τα γεωμετρικά χαρακτηριστικά των ζωνών μεταβίβασης (μήκος κλιμάκωσης, μήκος επικαλυπτόμενων ή μη τμημάτων), με σκοπό την εξαγωγή συμπερασμάτων για την ικανοποίηση ή μη κριτηρίων αλληλεπίδρασης των τμημάτων και της πιθανής σύνδεσης αυτών. Η κατανόηση του ρόλου της τμηματοποίησης και του τρόπου σύνδεσης των τμημάτων των ρηξιγενών ζωνών μπορεί να βοηθήσει σημαντικά στην εκτίμηση της σεισμικής επικινδυνότητας μιας περιοχής, στην κατανόηση των ιζηματογενών διαδικασιών μπροστά από τα ρήγματα καθώς και στον προσδιορισμό παγίδων ρευστής φάσης και της μετανάστευσή τους, μιας και οι ζώνες μεταβίβασης δύναται να αποτελούν περιοχές διαφυγής ή εμπόδια στη ροή των ρευστών. / Fault zones are commonly composed of discontinuous, sub-parallel, stepping fault segments, separated by relay zones. During the growth of a fault zone, its segments interact mechanically and link up into gradually larger segments that eventually may form large structures, due to strain accommodation. The way that segments interact during the growth of a fault zone, has been the subject of several studies. Yet, present understanding of interaction and linkage of segments, continues to be shrouded by considerable uncertainty. Three areas in central Greece were chosen, to investigate the role of segmentation and linkage of normal faults: the Aigio and Eliki fault zones in the Gulf of Corinth, the Atalanti and Arkitsa fault zones in the Northern Gulf of Evoia and the composite fault zones of Kaparelli and Dafnes in Beotia area. The Gulf of Corinth and the Northern Gulf of Evia are WNW-trending grabens, while Beotia area represents the deformed zone between the two main rift zones. These areas have been chosen due to their significant tectonic activity in the last 1.5Ma and their great importance in the neotectonic evolution of central Greece. In this study, several parameters reflecting the stress distribution around faults, have been measured, such as the vertical displacement (D), the number of segments (n), the overlap (OL), the spacing (S) and the length of relay zone (Lr). These parameters are indicators of the degree of linkage between fault segments and the degree of maturity of an active fault zone. Digital Elevation Models (DEM) have been used to construct elevation profiles in every fault zone, in order to measure the vertical throw of each segment, and in the relay zones as well as the distribution of displacement in footwall and hanging wall blocks. In addition, the geometry of the relay zones between fault segments is defined by calculating the length of underlapping zone, the length of overlapping zone and the length of spacing, in order to examine the segment linkage. The lengths of fault zones’ segments have been illustrated in plots of cumulative frequency, in order to describe the fault population in the three study areas. The plots indicate either multifractal distribution that represents fault population with different characteristics that interact or exponential distribution that shows an early stage of fault saturation. The relationship between maximum vertical displacement and length is illustrated in d-L plots, in order to determine the linkage stage of the particular fault zones and to propose evolutionary models. Finally the geometric characteristics of relay zones (spacing, length of underlapping or overlapping segments) were examined, in order to investigate whether or not the segments satisfy the interaction criteria and their possible linkage. Segmentation and fault segment linkage plays an important role in evaluating seismic hazard of an area, the architecture of sedimentary deposits, as well as in fluid flow in faulted reservoirs since relay zones can act as leakage zones or barriers from the hanging wall to the footwall blocks.

The wavelet transform is a modern signal processing tool. The wavelet transform earned itself a great success mainly for its unique properties, such as the capability of recognizing very fast changes in processed signal. The theoretical part of this work is introduction to wavelet theory, more specifically wavelet types, a wavelet transform and its application in systems dealing with signal denoising. A main problem connected to speech signals denoising was introduced. The problem is degradation of the speech signal when denoising unvoiced parts. It is because of the fact that unvoiced parts and noise itself have very similar characteristics. The solution would be to apply different attitude to voiced and unvoiced segments of the speech. The main goal of this diploma thesis was to create an application implementing the speech signal denoising using the wavelet transform. The special attention should have been paid to applying different attitude to voiced and unvoiced segments of the speech. The demanded application is programmed as a grafical user interface (GUI) in MATLAB environment. The algorithm implemented in this form allows users to test introduced procedures with a great comfort. This work presents achieved results and discusses them considering general requirements posed on an application of given type. The most important conlusion of this Diploma Thesis is the fact that some kind of trade-off between sufficient signal denoising and keeping the speech understandable has to be made.

We examine the structural complexities of a 28-km long part of the Clark fault of the San Jacinto fault zone in southern California in order to better document its lateral extent and the style of deformation of its southeast end. Changes in structural style are observed as the Clark fault’s damage zone widens from ~ 1-2 km in crystalline rocks of the Peninsular Ranges southeastward to ~ 18 km in the sedimentary rocks of the San Felipe-Borrego subbasin of the Salton Trough. The Clark fault extends into the San Felipe-Borrego subbasin as the Arroyo Salada segment for ~ 11-12 km to a newly defined northeast-trending structural boundary. This structural boundary, referred to herein as the Pumpkin Crossing block, is a ~ 3-km wide and ~ 8-km long fault zone dominated by northeast-striking sinistral-normal strike-slip faults. Southeast of the Pumpkin Crossing block the newly defined San Felipe Hills segment extends the Clark fault another ~12-13 km southeast to its intersection with the Extra fault zone. The Clark fault may have nearly 14.5-18 km of right separation represented in the surface deformation of the Arroyo Salada and San Felipe Hills segments, but the total amount of strain is masked by the wide diffuse fault zone with its complex deformation patterns and geometries. The lateral change observed in microseismicity patterns across the Arroyo Salada and San Felipe Hills segment boundary supports our structural interpretations about the existence, location, and structure of this boundary. Vertical patterns in the microseismicity suggest that the Clark fault zone narrows at depth, dips steeply northeast in the subsurface, and must interact with at least one weak decollement layer(s) beneath and/or with the sedimentary basin. Structural deformation within the late Miocene to Holocene silty- and clay-rich sedimentary basin of the Salton Trough includes features characteristic of strike-slip faults, such as stepovers, conjugate faults, folds, flower structures, and fault bends, as well as many unique structures that include pooch structures, ramp-flat geometries of strike-slip faults, complex en echelon fault zones with localized shear distributed across a high frequency network of faults, and heterogeneous kinematic indicators within individual fault zones.