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1
Oliver, Morris Bernard. "Audible pedestrian signals: a feasibility study." Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/44130.
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This report represents a concentrated effort that
determines the feasibility of audible pedestrian signals.
These signals are devices which give auditory cues to help
the visually impaired cross safely at difficult
intersections. Surveys were sent out to over 100
organizations, audible signal manufacturers, and cities who
have knowledge of the devices, and responses were analyzed.
The devices were found to be feasible but only at certain
complex and confusing intersections. Twelve criteria for
the installation of the devices were developed as were
twelve criteria for the operation of the devices. Buzzers,
constant tones, bird calls, and voice signals were examined
by obtaining information from traffic engineers who had
experience with each sound. It was determined that
intermittent tones were the most effective for human
localization. For the most widely used devices, cost data
were developed for the products, installation, and maintenance. A partial listing of the U.S. and foreign
cities which have the devices was compiled along with a
partial listing of audible signal manufacturers. The
problems the visually impaired face as well as their
suggested solutions are listed. Topics for further study
include the use of hand-held devices which activate sound
signals at intersections and the development of tone schemes
for 4-leg and multi-leg intersections which are not north south
and east-west. An additional topic for future study
is the development of tone schemes for traffic circles.Master of Science
2
LeDew, Christopher. "SAFETY EFFECTS OF TRAFFIC SIGNAL INSTALLATIONS ON STATE ROAD INTERSECTIONS IN NORTHEAST FLORIDA." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3446.
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The purpose of this thesis is to explore how the installations of traffic signals affect crash experience at intersections, to identify those factors which help predict crashes after a signal is installed, and to develop a crash prediction model. It is the intent of this thesis to supplement the Manual on Uniform Traffic Control Devices Signal Warrant procedure and aid the traffic engineer in the signal installation decision making process. Crash data, as well as operational and geometric factors were examined for 32 state road intersections in the northeast Florida area before and after signal installation. Signal warrant studies were used as sources for traffic volumes, geometric information and crash history, before signal installation. The Florida Department of Transportation's Crash Analysis Reporting System (CARS) was used to gather crash data for the time period after signal installation. On average, the 32 intersections experienced a 12% increase in the total number of crashes and a 26% reduction in crash rate after signals were installed. The change in the number of crashes was not significant, but the rate change was significant with 90% confidence. Angle crash frequency dropped by 60% and the angle crash rate dropped by 66%, both are significant. Left-turn crashes dropped by 8% and their rate by 16%, although neither was significant. Rear-end crashes increased by 86% and the rear-end crash rate decreased by 5%. Neither of these changes was statistically significant. When crash severity was examined, it was found that the number of injury crashes increased by 64.8% and the rate by only 0.02%. Neither change was significant. Both the number of fatal crashes and the rate decreased by 100% and were significant. Property Damage Only (PDO) crashes increased by 96%, after signalization, but this change was not significant. The PDO rate, however, decreased by 46.5% and is significant. Operational factors such as AADT, turning movement counts, and speed limits; and geometric factors such as medians, turn lanes and numbers of lanes were considered to determine their effect on crashes at signalized intersections. Smaller roads, with low AADT, fewer lanes, and a rural character were found to benefit from signalization more than busier urbanized roads, in terms of crash rate reduction. The AADT, roadway cross section, number of lanes, medians, speed limit and left turn volume were all found to be important factors influencing crash rates. This thesis recommends: 1) the use of crash prediction models to supplement the MUTCD Crash Warrant, 2) the addition of a left-turn warrant to the MUTCD signal warranting procedure, and 3) development of an intersection database containing crash data as well as operational and geometric information to aid in future research.M.S.C.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering
3
Corr, Patrick H. "A study in the processing of speech signals." Thesis, Queen's University Belfast, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356880.
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Hamad, G. E. M. M. "A study of undesired signals in microwave circuits." Thesis, University of Kent, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235354.
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Franz, Mark L. "Local agency traffic sign retroreflectivity case study and model of observed traffic sign light intensity." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10473.
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Thesis (M.S.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains viii, 85 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references (p. 79-82).
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Malachias, Nickolaos. "Doppler shift and spread study for ionospherically propagated signals." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA284610.
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Strange, John. "VOICE AUTHENTICATIONA STUDY OF POLYNOMIAL REPRESENTATION OF SPEECH SIGNALS." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4015.
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A subset of speech recognition is the use of speech recognition techniques for voice authentication. Voice authentication is an alternative security application to the other biometric security measures such as the use of fingerprints or iris scans. Voice authentication has advantages over the other biometric measures in that it can be utilized remotely, via a device like a telephone. However, voice authentication has disadvantages in that the authentication system typically requires a large memory and processing time than do fingerprint or iris scanning systems. Also, voice authentication research has yet to provide an authentication system as reliable as the other biometric measures. Most voice recognition systems use Hidden Markov Models (HMMs) as their basic probabilistic framework. Also, most voice recognition systems use a frame based approach to analyze the voice features. An example of research which has been shown to provide more accurate results is the use of a segment based model. The HMMs impose a requirement that each frame has conditional independence from the next. However, at a fixed frame rate, typically 10 ms., the adjacent feature vectors might span the same phonetic segment and often exhibit smooth dynamics and are highly correlated. The relationship between features of different phonetic segments is much weaker. Therefore, the segment based approach makes fewer conditional independence assumptions which are also violated to a lesser degree than for the frame based approach. Thus, the HMMs using segmental based approaches are more accurate. The speech polynomials (feature vectors) used in the segmental model have been shown to be Chebychev polynomials. Use of the properties of these polynomials has made it possible to reduce the computation time for speech recognition systems. Also, representing the spoken word waveform as a Chebychev polynomial allows for the recognition system to easily extract useful and repeatable features from the waveform allowing for a more accurate identification of the speaker. This thesis describes the segmental approach to speech recognition and addresses in detail the use of Chebychev polynomials in the representation of spoken words, specifically in the area of speaker recognition. .M.S.
Department of Mathematics
Arts and Sciences
Mathematics
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Zhan, Xin S. M. Massachusetts Institute of Technology. "A study of seismoelectric signals in measurement while drilling." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/35084.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2005.Includes bibliographical references (leaves 93-98).
An LWD acoustic wave can move the excess charge in the electric double layer along the borehole wall to generate a streaming electric field. This thesis is an experimental and theoretical investigation of the electric field induced by the multipole LWD acoustic wave. The main goal of this thesis is to understand the mechanism in the seismoelectric conversion under the LWD geometry and prove the absence of the tool mode in the LWD-acoustic-wave induced electric signals. In this experimental study, we measured the seismoelectric signals excited by an acoustic multipole source in the scaled logging-while-drilling model. We put the scaled tool in a sandstone borehole to perform LWD seismoelectric and acoustic measurements. Monopole and dipole acoustic and the induced electric signals were recorded separately under exactly the same settings. The recorded acoustic and seismoelectric signals were analyzed in both time and frequency domains using a semblance method. We found no tool mode components in the electric signals by examining both the waveforms and the time and frequency domain semblances.
(cont.) The underlying mechanism is the electric double layer (EDL) at the steel water interface is much weaker than the one at the formation water interface. Thus, in the LWD seismoelectric signal, there should be no component with an apparent velocity of tool mode. Since only formation acoustic modes have their corresponding components in the electric signal, we calculated the coherence of the two kinds of signals in the frequency domain. By applying the coherence curve to filter the acoustic signals, we can eliminate the tool modes and pick out the formation acoustic modes. In the theoretical study, we developed a Pride-theory-based model for the LWD-acoustic-wave induced electric field. The electric field strength is calculated at the electrode positions along the borehole wall, analogous to what was done in the experiment. The electric boundary conditions, which are the continuity of the electric field at the borehole wall and disappearance at the LWD tool surface, reveal the underlying mechanism in the LWD seismoelectric conversion which is also the basis of our lab experiment. The absence of the tool modes in the synthetic waveforms of the electric field coincides with what we have observed in the experimental study.
(cont.) Both the experiment and the theoretical results confirm that measuring the seismoelectric signal generated by an acoustic multipole source during the LWD process can be an effective way to eliminate the tool wave contamination on the LWD acoustic measurements. This thesis research shows that seismoelectric logging-while-drilling may be a potential new method in formation property evaluation.
by Xin Zhan.
S.M.
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Hotokezaka, Kenta. "Theoretical study of signals from binary neutron star mergers." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188486.
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Adolfsson, Tobias, and Axel Dellenby. "Pre-study of optical LED units for shunting signals." Thesis, KTH, Hälsoinformatik och logistik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296561.
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Alstom wanted to investigate the possibility of adapting its light emitting diode (LED) technology for shunting signals in train traffic. The LED technology uses 50V, but Alstom wants to adapt it for 12V. The LED technology is energy efficient but needs to be adapted for existing signal interlocking by drawing a higher current. This meant that the possibility of reactive power compensation was investigated to obtain lower thermal dissipation in dwarf signal. The essay presents a couple of possible solutions. One of the solutions is to raise the voltage by using a booster converter to use the existing 50V LED unit. Capacitors were reviewed to be used in reactive power compensation to increase current supply. One of the solutions then became a capacitor bank. Simulations indicated that a booster converter and a capacitor bank can be used to adapt the circuit. However, some modifications must be made.Alstom ville undersöka möjligheten att anpassa sin lysdiodsteknik för dvärgsignaler i tågtrafiken. Lysdiodstekniken använder 50V men Alstom vill anpassa den för 12V. Lysdiodtekniken är strömsnål och behöver anpassas för befintliga signalställverk genom att dra en högre ström. Detta innebar att möjligheten för reaktiv kompensering undersöktes för att få en låg värmeutvecklingen i dvärgsignalen. I uppsatsen presenteras ett par möjliga lösningar. En av lösningarna för spänningen är en step-up omvandlare för att nyttja 50Vs enheten. Det gjordes också en genomgång av kondensatorer för att nyttjas i reaktivkompensering för att öka strömförbrukningen. En av lösningarna blev då ett kondensatorbatteri. Det kunde konstateras med matematisk simulering att step-up omvandlare och ett kondensatorbatteri kan användas för att anpassa kretsen dock måste vissa modifieringar utföras.
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Ferreira, Susana Catarina da Costa. "Study of the epigenetic signals in the human genome." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16568.
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Mestrado em Biomedicina MolecularEpigenetics can be defined as changes in the genome that are inherited during cell division, however without direct modify the DNA sequence. These genomic changes are supported by three major epigenetic mechanisms: DNA methylation, histone modification and small RNAs. Different epigenetic marks function by regulating gene transcription, because when these processes are altered, this triggers various diseases such as cancer. Thus, one main objective was to study the epigenetics signals in the human genome, meaning, whether there is dependence observed between the context and the occurrence of epigenomic marking. For this purpose we used histone epigenomes available in the NIH Roadmap Epigenomics Mapping Consortium database that contains various types of cells and various types of tissues. The present study employed different statistical methodologies, namely, statistical tests, effect size measures, residue analysis and hierarchical classification. With this analysis, we compared genomic contexts of epigenetic marking among chromosomes and among epigenomes. Complementing the analysis with a control scenario, without marking and factoring the CG content. As a result of this study, it was possible to identify one dependency between the context and the occurrence of epigenetic marking and we were able to identify specific genomic contexts in histone modifications.
A epigenética pode ser definida pela ocorrência de modificações no genoma, que são herdadas durante a divisão celular, não havendo no entanto modificações directas na sequência do DNA. Estas modificações genómicas são apoiadas em três grandes mecanismos epigenéticos: metilação do DNA, modificação de histonas e pequenos RNAs. Estas diferentes marcas epigenéticas podem ter como função regular a transcrição genética, pois quando existe algum tipo de alteração nestes processos, pode desencadear-se em diversas patologias como o cancro. Assim, o objectivo principal deste trabalho é estudar os sinais epigenéticos no genoma humano, ou seja, observar se existe dependência entre o contexto e a ocorrência da marcação epigenómica. Para esse efeito foram utilizados os epigenomas das histonas disponíveis na base de dados do NIH Roadmap Epigenomics Mapping Consortium que contêm vários tipos de células e vários tipos de tecidos. No presente estudo são empregues diferentes metodologias estatísticas, nomeadamente testes estatísticos, medidas do tamanho do efeito, análise de resíduos e classificação hierárquica. Com esta análise, comparam-se contextos genómicos da marcação epigenética entre cromossomas e entre epigenomas. Complementando a análise com um cenário de controlo, sem marcação e factorizando pelo teor de CG. Foi possível identificar uma dependência entre o contexto e a ocorrência de marcação epigenética, sendo possível identificar contextos genómicos específicos para as modificações das histonas.
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Jahanzeb, Danish, Gunnar Jönsson, and Joakim Eriksson. "Signals from the financial crisis : A study based on the effects of dividends signaling during the financial crisis on the Swedish Stock Exchange." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-176756.
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Rung, Johan. "Signals and Noise in Complex Biological Systems." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7862.
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Markle, Blake L. "A comparative study of time-stretching algorithms for audio signals /." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=31119.
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Algorithms exist which will perform independent transformations on frequency or duration of a digital audio signal. These processes have different results different types of audio signals. A comparative study of granular and phase vocoder algorithms, implementation, and their respective effects on audio signals was made to determine which algorithm is best suited to a particular type of audio signal.
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Gopalan, Ganesh. "Improvement of traffic flow conditions using access management techniques : a netsim study /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1426063.
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Bian, Yi. "A study of the influence of Loran-C receiver signal processing and other factors on sensitivity to interfering signals." Thesis, Bangor University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317321.
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Akassou, Imane. "Novel approaches to study vibrational signaling of insects." Doctoral thesis, Università degli studi di Trento, 2121. http://hdl.handle.net/11572/319440.
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Vibrational communication is one of the oldest modes of communication that represents an important component of animal behavior, yet it is the least explored among the different modalities. The study of substrate-borne vibrations has contributed to the understanding of multiple intra and interspecific interactions in insects. However, despite the increasing research in the field of biotremology, the exchange of vibrational signals in complex communication networks and in ecological contexts represents an understudied dimension of research. Therefore, the aim of the present work is to expand the study of vibrational signaling behavior of insects into more ecological systems, simulating natural situations in which they live and therefore provide more reliable information about their behavior. Different methodologies were applied according to different research questions. The study consisted of continuous recordings with a laser vibrometer of insect communication throughout a specific behavior, in a multiple individuals’ scenario and in natural conditions. Laboratory trials were conducted to reproduce and study the parental care behavior in burying beetles in relation to their stridulations. Comparing the stridulating behavior of Nicrophorus vespilloides between pre- and post-hatching care revealed higher signaling activity in post-hatching and the occurrence of different patterns of signals, which implies that the signals are likely involved in attracting the larvae toward the carrion and/or in coordinating their provisioning. These results raise questions about the exact function of the stridulations in the biparental care behavior of Nicrophorus beetles. Moving to semi-field conditions, individuals of the same sex of the spittlebug Philaenus spumarius have been recorded throughout their adult stage season. We found a higher and delayed vibrational signaling activity of females compared to males and complex intrasexual interactions consisting of signal overlapping in the case of females and signal alternating, partial or complete overlapping in the case of males. Our study has permitted to describe interactions that could mediate cooperative or competitive intrasexual behaviors in this species. Further reasearch is therefore needed to determine the functions of the reported intrasexual interactions. Finally, field recording trials in an organic vineyard showed that low vibrational signaling activity of an insect community was significantly associated with conditions of high temperature and wind velocity. Furthermore, the field recording methodology enabled the temporal monitoring of the agricultural pest Halyomorpha halys and the grapevine leafhopper Scaphoideus titanus. These findings confirm the validity of our method in assessing vibrational signaling in the vineyard and open the possibility to the use of biotremology techniques to detect the presence of insect pests in an orchard as a tool of monitoring. In this way, further research is needed to optimize the methodology to implement it in comparing vibrational signaling in vineyards with different management systems and in different types of orchards. Despite the challenges to use vibrational sensitive equipment in such ecological systems where interferences from noise, studied insects and the environment were encountered, the use of biotremology techniques has been proven feasible. Vibrational signals are better manifested when insects are studied in their natural habitats, interesting results can be obtained, and further questions would be asked for the ultimate understanding of this modality of animal communication. Overall, this thesis provides novel approaches to record and study vibrational signals of insects, which can be used as a basis to perform further experiments in the field of biotremology.
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Chen, Yongye. "Study of luminescence signals from quartz and their applications in geothermometry." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b40203955.
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Chen, Yongye, and 陳永曄. "Study of luminescence signals from quartz and their applications in geothermometry." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40203955.
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Almeida, Raquel Malta Nunes de. "Study of axion-like particles signals at the Cherenkov Telescope Array." reponame:Repositório Institucional da UFABC, 2018.
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Orientador: Prof. Dr. Marcelo Augusto Leigui de OliveiraDissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, Santo André, 2018.
O objetivo deste trabalho é discutir a distorção do fluxo de raios gama de altas energias (250 GeV ¿ 25 TeV) devido a processos de atenuação desde a fonte até sua chegada na Via Lactea. Entre esses processos estão a produção de pares pela interação com a radiação cósmica de fundo, principalmente EBL, e a oscilação de fótons em bosons pseudoescalares leves, chamados de partículas tipo áxion (ALPs). Também é discutido como será o sinal do fluxo detectado pelo Cherenkov Telescope Array, explicitando suas especificações técnicas e principais melhorias em relação aos detectores atuais, o que nos levará a uma nova geração de telescópios de raios gama.
The purpose of this research is to discuss the distortion of VHE gamma-ray flux (250 GeV - 25 TeV) due to attenuation processes along its path from the source to our galaxy, namely: pair production as a result of the interaction with the background cosmic radiation, especially EBL, and gamma-ray mix with a light pseudoescalar fundamental boson called axion-like particle (ALP). It is also discussed how this signal should appear at Cherenkov Telescope Array, emphasizing its technical specifications and major improvements over current IACTs, which will lead us to a new generation of gamma-ray telescopes.
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Purivigraipong, S. "Study of spacecraft attitude determination from phase information of GPS signals." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843145/.
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In this research study, several new algorithms are developed to achieve spacecraft attitude determination from carrier phase information of GPS (Global Positioning System) signals. The first focus is on resolving integer ambiguity in carrier phase difference measurements. A newly developed algorithm based on Gram-Schmidt Orthonormalisation (GSO) is proposed for medium length baseline observations. Using this newly developed attitude algorithm from vector observations, an instantaneous estimated attitude solution is obtained, which we call 'coarse attitude', from only four phase measurements collected from only two baseline observations. Then a 'fine' attitude solution from all phase measurements is estimated, using a sophisticated Kalman filtering estimator, once integer ambiguity has been resolved. The second focus is on estimating the relative phase offset error (line bias) in carrier phase difference measurements. A newly developed block bias search is proposed which finds an initially plausible solution of line bias for each individual baseline. The line bias from all phase measurements collected from each individual baseline is then re-estimated using a developed recursive least squares (RLS) estimator. A newly developed parallel architecture GPS receiver is being flown on the UoSat-12 minisatellite, with the capability for simultaneous measurements from 24 channels for attitude sensing. The final goal of this research study was to apply the developed algorithms to real GPS data, and a number of data files of phase differences of GPS signals logged on UoSat-12 were tested. Independent ADCS (Attitude Determination and Control System) data was used for the reference attitude determination. The results show that an instantaneous attitude error less than 4 degrees is achieved during coarse attitude acquisition, relative to the reference ADCS system. When all measurements are processed during fine attitude tracking, the error in attitude estimation is reduced to one degree error (1 sigma RMS), without any error mitigation for multipath, relative to the reference ADCS system.
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Cao, Yong. "A design of experimental approach to study the road marking luminance contrast and variable message signs /." View online ; access limited to URI, 2004. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3145413.
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Cullinane, M. "The study of cerebral emboli using transcranial doppler ultrasound : clinical and technical studies." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369127.
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Liu, LiChan. "Single epoch analysis and bi-hemisphere study of magnetoencephalographic (MEG) signals using vector signal transformation V3 magnetic field tomography (MFT)." Thesis, Open University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261057.
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Moretti, Daniela. "Exposure of neuronal networks to GSM mobile phone signals." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00949371.
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The central nervous system is the most likely target of mobile telephony radiofrequency field (RF) exposure in terms of biological effects. Several EEG (electroencephalography) studies have reported variations in the alpha-band power spectrum during and/or after RF exposure, in resting EEG and during sleep. In this context, the observation of the spontaneous electrical activity of neuronal networks under RF exposure can be an efficient tool to detect the occurrence of low-level RF effects on the nervous system. In this thesis research work we developed a dedicated experimental setup in the GHz range for the simultaneous exposure of neuronal networks and monitoring of electrical activity. A transverse electromagnetic (TEM) cell was used to expose the neuronal networks to GSM-1800 signals at a SAR level of 3.2 W/kg. Recording of the neuronal electrical activity and detection of the extracellular spikes and bursts under exposure were performed using Micro Electrode Arrays (MEAs). This work provides the proof of feasibility and preliminary results of the integrated investigation regarding exposure setup, culture of the neuronal network, recording of the electrical activity and analysis of the signals obtained under RF exposure. In the main experiment (16 cultures), there was a 30% reversible decrease in mean firing rate (MFR) and bursting rate (BR) during the 3 min exposures to RF. Additional experiments are needed to further characterize this effect, especially in terms of temperature elevation at the microscopic level.
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Haavie, Jon. "Sexual Signals and Speciation : A Study of the Pied and Collared Flycatcher." Doctoral thesis, Uppsala University, Department of Evolutionary Biology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3916.
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Speciation is the process in which reproductive barriers evolve between populations. In this thesis I examine how sexual signals contribute to the maintenance, reinforcement or breakdown of reproductive barriers.
Male pied flycatchers (Ficedula hypoleuca) and collared flycatchers (F. albicollis) differ in song and plumage traits. However, where the two species coexist, several pied flycatchers sing a song resembling the collared flycatcher (mixed song). Mixed song is not caused by introgression from the collared flycatcher but is due to heterospecific copying. Mixed song provokes aggressive behaviour in collared flycatcher males and leads to heterospecific pairing and maladaptive hybridization.
The species differences in song were found to be larger in an old than a young hybrid zone. This was due to a reduction in the frequency of mixed song in the pied flycatcher and a divergence in the song of the collared flycatcher. Apparently, mixed song causes maladaptive hybridization, which over time leads to reinforcement of reproductive barriers by a song divergence.
Previous studies have shown that a character displacement in male plumage traits reinforces species barriers. Hence both plumage and song divergence reduce the incidence of hybridization. The evolution of male plumage traits has been so rapid, or selection has been so strong that rapidly evolving molecular markers are unable to trace it.
Hybrid females mate with a male of the same species as their father. Previous studies have shown that females use male plumage traits controlled by genes linked to the sex chromosomes (the Z) in species recognition. An association between preference and a sex-linked trait through the paternal line may render reinforcement of reproductive barriers more likely.
In conclusion, sexual signals are affected by species interactions that cause breakdown or reinforcement of reproductive barriers.
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劉思恩 and See-yan Lau. "A study of intracellular signals of K-opioids in non-neuronal cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31214290.
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Lau, See-yan. "A study of intracellular signals of K-opioids in non-neuronal cells /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19667139.
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Hwang, Isabel. "An initial study on external warning signals for Quiet Road Transport Vehicles." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Produktutveckling, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-31111.
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The increasing number of electric and hybrid vehicles in urban areas has shown to be beneficial in reducing both air and noise pollution. However, the lack of sound when driving at low speed has negatively affected the pedestrian safety since many rely on the vehicle sound for orientation. Regulatory bodies have therefore introduced minimum sound requirements for all silent vehicles, which has resulted in a key challenge for car manufacturers to develop external warning signature sounds. The objective of this project has been to study how these signals should sound in order to fit the image of electric and hybrid vehicles and minimize noise and annoyance. To complete the study, five sound concepts with different characteristics and rhythms were developed using the concept generation process. In order to gain subjective impressions of the sounds, three measurement methods were utilized. The first listening test was performed to eliminate the possibility that the sound samples would be perceived variously loud in the upcoming tests. The second listening test was performed to gain information on how suitable the signals are for electric and hybrid vehicles, and the third listening test was conducted to obtain information on how much annoyance the signals contributed with. A reference signal representing an internal combustion engine was included in the tests as well. The results of the measurement methods showed that the sound samples with long tone sequences were more preferred than those with short tone sequences, and that the artificial approach was more popular than the sound of an internal combustion engine vehicle. It was also established that additional tests need to be performed in order to confirm that these results are valid. It was suggested that field tests should be conducted and that new sound concepts should be developed based on the results of these tests.
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Yamazaki, Ken'ichi. "Study on methods for regional geomagnetic field modeling to detect tectonomagnetic signals." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/144196.
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Kyoto University (京都大学)0048
新制・課程博士
博士(理学)
甲第12113号
理博第3007号
新制||理||1448(附属図書館)
23949
UT51-2006-J108
京都大学大学院理学研究科地球惑星科学専攻
(主査)教授 大志万 直人, 教授 田中 良和, 教授 橋本 学
学位規則第4条第1項該当
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Tang, Hao. "Pre-signal study at an at-grade intersection with separate right-turn phase." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96484.
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Thesis (MScEng)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Capacity waste happens when right-turn vehicles have right-of-way during a separate right-turn phase and lanes (e.g., through lanes) of the same approach of the intersection cannot discharge vehicles during that green phase. Right-turn traffic consumes the capacity which otherwise could be provided to through traffic movements at an at-grade signalized intersection. Therefore, it is widely considered that it would lower intersection capacity and increase total delay (Lin, Machemehl, Lee & Herman, 1984). The pre-signal strategy proposed in this research is specifically designed to improve this problem. The following aspects of this strategy were studied in this research, - Capacity benefits of this strategy, - Relationships between the capacity and the length of sorting area (the area between the two signals), - Signal timing of both main signal and pre-signal, - Clearance time of the sorting area, - Main signal phasing options - Signal coordination between the main signal and the pre-signal, - Utilization of the sorting area, and - Pre-signal strategy performance in a simulated environment. The results of this study showed that right-turn movement benefits significantly from this pre-signal strategy. For example, right-turn capacity can be doubled if a presignal is installed on one through lane of an approach with one right-turn lane. It was also found, the maximum approach capacity benefit is not affected significantly by the length of the sorting area for a given green period. The optimal green time and the available pre-signal green time for right-turn movement were also derived in this research. Different main signal phasing options were studied and compared. Phasing options which fit the proposed pre-signal strategy were found. Recommended values for right-turn green time of both signals were given based on different lengths of sorting area. The case study, which compared the performance of some critical movements at the intersection with and without the proposed pre-signal system, confirms the results concluded in this study. A potential problem with this strategy when applied at a real intersection is that it may confuse drivers. Drivers need to be educated and will need time to get familiar with this signal control method.
AFRIKAANSE OPSOMMING: Beskermde regsdraaifases vir verkeer by gelykvlak seinbeheerde kruisings gebruik die kapasiteit wat benut kon word deur deurbewegings. Dit verlaag interseksie kapasiteit en totale oponthoud verhoog. Die voorseinstrategie wat in die navorsing studie voorgestel word is spesifiek ontwikkel om die probleem op te los of te verminder. Die volgende aspekte van die strategie is ondersoek in die navorsingsstudie: - Kapasiteitsvoordele van die strategie. - Die verhouding tussen die kapasiteit en die lengte van die sorteringsarea (die area tussen die twee seine). - Seintydstoedeling van beide die hoofseinfase en die voorseinfase. - Ontruimingstyd van die stoorarea. - Hoofseinfaseopsies. - Seinkoordenasie tussen die hoofsein en die voorsein. - Benutting van die sorterings area, en - Voorseinstrategieprestasie in ‘n gesimuleerde omgewing. Die resultate bewys dat die regsdraaibeweging grootliks bevoordeel word nadat die voorseinstrategie ingestel is. Byvoorbeeld, regsdraaikapasiteit kan verdubbel word as ‘n voorseinfase ingestel word op een van die deurlane tesame met ‘n enkele regsdraailaan. Daar is ook gevind dat die kapasiteit nie grootliks beinvloed word deur die lengte van die stoorgebied nie. Die optimale groentyd en die beskikbare voorsein groen tyd vir die regsdraaibeweging is ook afgelei in die navorsing. Verskillende hoofseinfaseopsies is bestudeer en vergelyk. Faseringsopsies vir die voorgestelde voorseinstrategie is gevind. Voorgestelde waardes vir regsdraaigroentyd van voorseine en hoofseine is bereken om kapasiteit te verbeter, gebasseer op verskillende lengtes van die stoorarea. Die gevallestudie wat die prestasie op ‘n aanloop met en sonder die voogestelde voorseinstrategie vergelyk, bewys resultate wat ooreenstem met die bevindinge in die studie. Die verwagte probleem met die voorseinstrategie, wanneer dit ingestel word by ‘n werklike interseksie, is verwarring van die bestuurders. Bestuurders sal opgevoed moet word en sal tyd nodig hê om gewoond te raak aan die voorseinmetode.
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Folkesson, Jakob. "Bidders’ reactions on valuation signals – anempirical study of commercial propertyauctions in the UK." Thesis, KTH, Fastigheter och byggande, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-131471.
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Auctions have always been an important transaction tool for objects that requires an individual pricing, such as properties, antiquities, art, cars, jewellery and so on. However, few commercial property markets are employing this market making function with the consequence of more illiquid market segments. Previous research has focused on whether or not providing information signals about the object is beneficial to the seller or not from a theoretical point of view. Therefore, this report aims at empirically assess how provided valuation information affects the sale-outcome of commercial real estates. This study examines the quality of the sellers’ and auctioneer’s announced valuation signal to the bidders by utilizing conventional econometric hedonic models, where the dependent variables are factors determining the success of the auction and based on a dataset including guide-prices and an investment grade for each object. The result is that the sale probability increases and price settles closer to the ex-ante valuation for objects with a low signalled risk (low guide price yield) and a high grade (A). There is a strong correlation between guide price yields and initial transaction yields, i.e. bidders’ risk/reward assessment follows that of which is signalled from the sell side. Furthermore, the transaction yields are more inelastic than the guide price yields, i.e. this happens at less than a 1:1 proportional rate increase. This indicates that guide prices not optimally reflect the bidders’ valuation. Furthermore, the bidders do take external factors into account when assessing whether or not to make a bid. In general bidders tend to prefer low yielding buildings with a high investment grade.
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Tang, Man. "A study of the nonlinear dynamics nature of ECG signals using Chaos theory." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B34624843.
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DAI, DE-ZHI, and 戴得智. "Study of Interlocking for Railway Signals." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/69yh5s.
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碩士國立高雄應用科技大學
電機工程系博碩士班
104
In response to the evolution of rail transport，railway equipment and systems must be upgraded to improve their functionality and the efficiency of rail transportation. Railway signaling systems maintain and ensure transportation safety，and interlocking is the core of railway signaling systems. In this study，an operational procedure for the computerization of an interlocking system was established on the basis of transitioning from relay interlocking to electronic interlocking in a station operated by the Taiwan Railways Administration (TRA). Subsequently， the effects of the transition on the TRA’s train operations were investigated along with the safety and convenience of the maintenance procedures. The findings of this study may serve as a reference for the research and development of an interlocking system according to the TRA’s experience in enhancing system efficiency and safety. Additionally，further understanding of Taiwan’s domestic railway signaling system may attract talents for research and development related to integrating advanced technologies from around the world into Taiwan’s rail transportation system.
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LI, MING-AN, and 李明安. "Study about quantification of echo-sounder signals." Thesis, 1987. http://ndltd.ncl.edu.tw/handle/21395109163011169930.
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Wang, Tai-Lung, and 王泰隆. "A Study on Pitch Detection of Speech Signals." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/90214505304595573097.
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碩士國立高雄第一科技大學
電腦與通訊工程所
90
The objective of this thesis is to study the pitch detection methods of speech signals. Pitch is a very important feature in voiced speech and it is widely used in speech processing applications such as speech coding, speaker recognition, phonetics, and voice disease diagnostics. Although there are many pitch detection methods have been proposed, the accuracy and robustness against noise are needed to further improve. Recently, the wavelet transform has been widely applied to the pitch detection of speech signals, so the wavelet-based pitch detection method is our research direction. First, we simulate the Chen and Wang''s wavelet-based pitch detection method. We find that for some voiced speech if we detect the pitch from the negative portion of signal will be accurate than from the positive portion of signal. Besides, we simulate the method proposed by Shelby et al. It is the improved version of the first wavelet-based method proposed by Kadambe. In the thesis, the method modified from the Chen and Wang''s method is called method I, while the method improved from the Shelby''s method is called method II. In order to evaluate the accuracy and robustness against noise for the pitch detection methods, we add white Gauss noise to our test data in different signal-to-noise ratio and compare the error rate of pitch detection with the original works. From the experimental results, the error rates of the method I and method II are lower than Chen and Wang''s and Shelby''s methods, respectively. It verifies that our modifications for the original methods are beneficial for the accurate pitch detection of speech signals.
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Wang, Chia-Jen, and 王佳仁. "A Study on Data Hiding in Audio Signals." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/38675520631660704391.
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碩士國立交通大學
資訊科學系
88
Data hiding, is a technique to embed data in a digital media to cover secret information. This paper will provide two data hiding methods which will embed secret information in a digital audio media. One will embed data in a audio file expressed in the time domain, it provides high embedding capacity. The other in the frequency domain, it can resist audio compression under adding the error control code in the secret information. These two methods utilize some characteristics of sound, for example, loud sound can mask out quiet sound. Experimental results also show the effectiveness of these two methods.
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Lee, Chien-Der, and 李建德. "Study on Purification of the Bridge Vibration Signals." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/dmkt52.
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碩士中原大學
土木工程研究所
93
ABSTRACT Today, civil engineers still mainly use Fast Fourier transform to analyze the behavior of structures, but this method is only suitable for the structure vibration phenomenon of the linear and the stationary, so it produces to be stationary signals and speech to non-linear system, its analysis result has already lost the physics meaning represented of the signals. Furthermore, in carrying on the course of live load test of the bridge, it is unable to avoid the perturbation produced of the environment and various kinds of miscellaneous signals all around, so there will be mode mixing phenomenon in the vibration signals. This main purpose of research is to expect to be able to get rid of the mode mixing phenomenon effectively, therefore, it is main research try to with the Empirical Mode Decomposition(EMD) and Intermittence Criterion in this research, by means of decomposing function of special complex signals, attempt to purify the vibration signals of the bridge, make the signals cleaner and clearer. Adopt the live load test data of Shin Bin No.2 Bridge，Shing Nen Bridge and Metro Bridge the in the course, in EMD decomposition process adopt CE(Component from Extrema) and CEI(Component from Extrema with Intermittency Testing) two signal decomposition modes and don’t make signal decomposition mode to probe and compare,and change to different Intermittency Criterion limiting conditions in CEI mode at the same time, probe into the revise mode(n1-Δ) of Intermittency Criterion limiting value in the suitability that vibration signals purifies of the bridge, finally, using Hilbert-Huang Transform(HHT) to compare with results of different decomposition modes. According to the results of this study, the revise mode of Intermittency Criterion limiting value really is necessity to store, and is learnt analysis results of the signals of Shin Bin No.2 Bridge and, Shing Nen Bridge the purification results of CEI-15 is the best; from the Metro Bridge signals analysis of results, we can find, the purification results of CEI-30 mode is the best.
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Chi-YiChiu and 邱繼毅. "A Study for Nonlinear Model of WirelessCommunication Signals." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/xat529.
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Sin, Cheng-Tai, and 辛程泰. "The Study of Pain Signals Analysis of Brainwaves." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/me2eha.
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碩士樹德科技大學
資訊工程系碩士班
106
Pain is one of the most important feelings for humans self-protection, but I believe no one will like this unpleasant feeling. Serious or constant pain can have a negative effect on the body and mind. In this study, single-channel and EEG with dry electrodes was used to obtain brainwave signals, and map the result by FFT (Fast Fourier Transform). And use SPSS (Statistical Package for Social Science) to analyze and study the variation when the brainwaves with or without pain stimulus. The study results found, the pain stimulus will have an elevated effect on lower frequency bands and have a decreasing effect on higher frequency bands.
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Aurup, Golam Mohammad Moshiuddin. "User Preference Extraction from Bio-Signals: An Experimental Study." Thesis, 2011. http://spectrum.library.concordia.ca/7078/1/Aurup_MASc_S2011.pdf.
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Abstract
User Preference Extraction from Bio-Signals: An Experimental Study
Golam Mohammad Moshiuddin Aurup
The purpose of this study is to extract user preferences about a product from emotional responses. Literature on psychology reveals that human preferences are related to their emotions. In addition, literature on emotion recognition reveals that emotion can be extracted from physiological signals like the heart rate, skin conductance, brain signal etc. In this study, these two streams were brought together and a new approach was proposed to extract preference of users through the analysis of emotional responses from physiological signals. Brain signal (electroencephalography or EEG) was chosen in this regard for its relevance in emotion recognition literature. For the experimental study, Thought Technology’s biofeedback system was used in order to capture and process the users’ EEG signals while users are exposed to various images where each image represents a possible feature of a product. Experiments were performed in two phases. In the first phase, proposed method, hardware setting, and the hypothesis relating user preference and EEG values were tested on an image library. In the second phase, images relating to a product (automobile in our case) design or features were used to get preferences between competing products.
In the first phase, International Affective Picture System (IAPS) library images were used to develop experiments. This library provides a large database for emotion affecting images and is widely accepted in the emotion detection literature. Three participants and three two-image sets were used in this study. The relationship between preference and extracted values were established through graph plot and trend line analysis and effects of repetition of experiments or images were identified. Results supported that analysis of EEG signals can distinguish pleasant and unpleasant feeling about images. A maximum of 80% accuracy was obtained in establishing relationship between preference and signal values. Left frontal side of the brain provided with the best results and was utilized in the rest of the study. Possibility to use different frequency bands of EEG signal was also studied in this phase.
In the second phase of experiments, 8 image-sets relating to automobile design and features were used for a group of 11 participants. 60% of the participants responded with 70% or more accuracy. It was found that the cognitive preference of a participant was stronger than the aesthetic preference whenever there was a conflict between the two. Accuracy rate showed by participants varied with the quality of the tests; i.e. with the factors like image resolution, clarity, composition, subject, and background of images; and with the capability of the participant to identify the images properly.
Literature on brain activity reports that, for some people, the left side of the brain is more active than the right one. The opposite is true for others. The hypothesis relating preference and extracted values was corrected in this regard. The corrected hypothesis was termed the reverse hypothesis. At the beginning of phase 2 experiments, 4 experiments were developed with IAPS images to identify if the participant followed the preliminary hypothesis or the reversed one. The results showed that most participants performed better in the experiments with product images than the experiments with standard IAPS images.
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CHEN, RONG-TING, and 陳榮廷. "A characteristic study of AE signals under corrosive environment." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/69124095785027936029.
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Li, Chen-Yi, and 李宸毅. "Study of the Characteristics of Electrical Signals in Plants." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/38402333963674161898.
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碩士國立宜蘭大學
生物機電工程學系碩士班
98
Electrical signals have emerged as a subject of recent interest in plant physiological research, and two major types of electrical signals, action potential and variation potential, have been identified in plants. Action potential （AP） is a fast electrical pulse that has well-defined properties. Variation potential （VP） is not well defined in many aspects such as waveform, amplitude, polarity, and conduction velocity, and its generation is subject to different mechanisms. Chemical and hydraulic mechanisms are two candidates in the literature and have been studied in wounded plants. In this study, two novel methods were designed to investigate the mechanism of variation potential, including a method for blocking electrical signal transmission and a method for measuring hydraulic variation. The former method used the proton pump （H+/K+ ATPase） inhibitor, NH4Cl, to block electrical signal transmission while the control inhibitor （water） cannot block the transmission. The hydraulic change was measured by the latter method for heat-wounding tomato plants. Results showed that heat wound evoked both hydraulic pulse and VP in tomato plants; the transmission of VP was blocked by the inhibitor （NH4Cl） while the hydraulic pulse was not, indicating that VP was not induced by hydraulic variation. In addition, the hydraulic pulse preceded VP following the heat wound. We conclude that the wound-induced VP is not generated due to hydraulic variation but chemical mechanism.
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Tsai, Yu-Hung, and 蔡于弘. "Preliminary Study of Wireless Recording System for Neuronal Signals." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/61941398184972998708.
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碩士國立臺灣大學
醫學工程學研究所
99
It is known that the result of electrophysiology experiment reveals more realistic and integrated information while animals under testing are awake treated and freely moving. For this reason, wireless recording is an inexorable trend. However, well-developed wireless techniques such as FM, Zigbee, Bluetooth, etc. impose different limitation on the recording of neuronal signals. This thesis is a pilot research of wireless recoding system based on the concept that high data rate is necessary for continuously multichannel recording of neuronal signals. There are a transmitter module and a receiver module in this system. Since the most critical issues of the front-end transmitter module are low power consumption and as small as possible, low power amplifiers, filters and a high data rate transmitter are implemented in this study. A receiver module is build specifically for the high data rate transmitter. It contains the analog demodulation circuit, digital demodulation and the acquisition of data via USB. To deal with the non-synchronization problem of carrier and timing between transmitter and receiver ends, digital demodulation is done by computer program. In addition, a software user interface is programmed with C++ language to control the receiver module. A single channel compound action potentials is used for examination of the developed system, and we transmits 100 kHz sampled data at 3 Mbps while consuming 12 mA in total. Compared to the wired measurement, reconstructed wave with wireless transmission are 98.86% similar. Notwithstanding, this preliminary study provides a basis for further multichannel recoding.
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Pan, Chun-Yi, and 潘駿逸. "A Study on PAPR Reduction Methods for OFDM Signals." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/23757194506394390265.
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碩士國立交通大學
電信工程研究所
103
In order to meet the extreme requirement of data rate, researchers around the world have developed a lot of rate-increasing methods. Recently, orthogonal frequency division multiplexing(OFDM) has been regarded as one of the core rate-increasing technologies. By dividing the entire bandwidth into narrowband subcarriers, OFDM can provide high spectral efficiency. Also, the multipath effect can be easily equalized. Summarizing the above advantages, OFDM has become a key air interface for most modern wireless communication system. However, OFDM system suffers from several difficulties. One of the major drawbacks is the high peak to average power ratio(PAPR) at the transmitter. As signals operate on the nonlinearity of a high power amplifier(HPA), it is distorted and causes in-band distortion and out-of-band radiation. In our research, we propose three different PAPR reduction methods. First, a SLM method with CDMA side information is proposed. The difference between the conventional SLM method and the proposed one is that it provides another channel to transmit the side information, i.e., the index of phase sequence. Second, in order to improve the BER performance of traditional clipping scheme, we exploit some spreading codes to transmit the lost information caused by clipping. Third, a novel idea, in which OFDM waveform is shaped by an FIR filter or an all pass filter, is proposed. The numerical results show that by using the proposed methods, the PAPR of OFDM can be reduced, and the performance of OFDM is improved.
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Lin, Sin-Huei, and 林心惠. "A Study on Public Broadcasting： Focusing on Satellite Signals." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/yubej2.
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碩士國立交通大學
科技法律研究所碩士在職專班
106
The term “direct” in the definition of public broadcasting right has its meaning indeed. In the case of “the behavior of using satellites to transmit program signal to cable system operators”, as each cable TV receives signal only from the signal receiving relay station, at this time, the “original broadcast” action has not been completed. The “original broadcast” will only be completed when the satellite transmits the program signal to the “viewers”. Hence, this view does have impact on the existing market structure in Taiwan. The actual impact is on how to collect fees from users. Nonetheless, if some supporting measures are used, the impact can be reduced. In regards to the signal transmission of public broadcasting, according to the current international conventions and practices operated in different countries, most of them include microwave (signal) to be protected by broadcasting act, or “deemed” to be protected by copyright law (the chapter of Electronic Rights Management Information and Technological Protection Measures). The work that is transmitted by microwave and protected by copyright law will be observed by copyright law as usual. For the work that is transmitted by satellite and is protected by copyright law, unauthorized use without consent at this time will infringe the public broadcasting right of the owners of the work.
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Wu, Yi-Han, and 吳奕翰. "Using the seismic signals to study the coseismic landslide." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5080042%22.&searchmode=basic.
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碩士國立中興大學
水土保持學系所
107
The seismic signals generated by the landslide could be completely recorded by seismic stations. However, the coseismic landslide induced seismic signals significantly influenced by the ground motion generated by the earthquake, then causing analysis of coseismic landslide signals, including real-time seismic monitoring and determination of source location, to be challenged. Based on the seismic technique, our study would like to develop a flexible approach not only to study the non-cosiesmic landslide but also to probe the coseismic landslide event. Based on an assumption of the relationship between the horizontal seismograms and the landslide sliding direction, the amplitude tracking method (ATM) developed in this study can determine the sliding direction of landslide by using the ratio of peak amplitude in horizontal component A series of testing was conducted to verify the capability of ATM using synthetic waveforms for two landslide cases. Two landslide cases are the Xiaolin landslide occurred during the Typhoon Morakot and the Tsaoling coseismic landslide triggered by the Chichi earthquake. Furthermore, the ATM was modified to be ATM plus (ATM+), which can better understanding the coseismic landslide. Additioanl procedures such as the selection of signal window and seismic station were added in ATM+. In practical, the location of the landslide is usually an unknown parameter after landslide occurrence. Thus, the sliding direction determined by ATM+ could be used to map the possible landslide location by comparing with the aspect and slope angle of the geologically sensitive areas. This study demonstrated that ATM+ is a fluxble scheme and can facilitate the research topic related to landslide source process and development of disaster prevention and mitigation, especially for the coseismic landslde.
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Hsieh, Hsin-Ju, and 謝欣汝. "A Study of Modulation Spectrum Enhancement for Speech Signals." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/05093072893829122525.
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博士國立暨南國際大學
電機工程學系
104
The environmental mismatches caused by background noise, acoustical variations among different speakers and channel distortion often seriously impair the performance of the state-of-the-art speech recognition systems. In this dissertation, we have proposed a family of novel noise robustness algorithms to remedy this problem, and the general line of this research is divided into three significant aspects. First, the temporal series of the complex-valued acoustic spectra are compensated via statistics normalization and factor analysis algorithms, including histogram equalization (HEQ) and nonnegative matrix factorization (NMF). Second, we apply HEQ to the modulation domain of the sub-band acoustic spectrum. The band-pass filters are exploited to divide the acoustic spectrogram into several sub-bands, and then temporal modulation spectra for each sub-band spectrogram are compensated via HEQ. By doing so, we can evaluate the relative importance of different sub-band spectrograms in speech recognition. Finally, we explore an HEQ-based feature normalization framework with sub-band division along the cepstral and/or temporal axes, which can not only normalize the overall histograms of feature vector components but also normalize their local contextual (or structural) statistics both spatially and temporally. All evaluation experiments are carried out on the Aurora-2 database and task, and are further validated on the Aurora-4 database and task. The experimental results suggest that our proposed methods can offer substantial improvements over the baseline system and achieve performance competitive to or better than some of the existing noise robustness methods, including the well-known advanced front-end (AFE) extraction scheme in speech recognition.
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Hung, Chung-Ling, and 洪崇嶺. "Study on analysis, recognition and rendering of remote signals." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/04079153512602786637.
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博士國防大學中正理工學院
國防科學研究所
95
The adaptive approaches processing distinct remote signals from high resolution space imagery, underwater tones and dynamic motion of guided missile, respectively, are proposed in this dissertation. Regarding the first part, it is illustrated that Intensity–Hue–Saturation (IHS) technique, among various image fusion methods, represents the capability of quickly merging the massive volumes of data, and can yield satisfactory “spatial” enhancement but may introduce “spectral” distortion in IKONOS imagery. The approach of a fast IHS fusion technique with spectral adjustment is presented to solve this problem, and then demonstrates better performance than the original IHS method by the experimental results, both in processing speed and image quality. The aim of the second part is at studying underwater stationary acoustic signals and designing a feasible recognition system. In this proposed system, after the signal spectrum extracted, the wideband background noise removed, and the spectrum features detected by a peak selection algorithm ,then a noise subspace projection classifier with approximate maximum signal-to-interference ratio is designed as its recognition. The robustness of the proposed system has been shown in the results of experiments from real ship classes. With respect to the third part, if it is added the analyzing transient signals in the underwater acoustic signals, Fourier transform and wavelet transform are not satisfied for the requirements of analyzing time-vary underwater acoustic signals, for their basis functions are fixed. Therefore empirical mode decomposition, a useful analysis scheme for non-linear and non-stationary nature signals, is designed to extract the features from underwater acoustic signals for recognition by appropriate decomposed ordes. Through the experiments from diverse ship classes, the results demonstrate the robustness of the proposed method. In terms of the last part, the processes, hardware-in-the-loop simulation and flight (navigation) test, are essential for varied guided weapon systems in weapon system development. The study of this part adopts six-degree-of-freedom visualized simulation (6DOFVS) which has integrated of 6DOF and two visualized simulation approaches called Real Time Rendering (RTR) and Play Back Rendering (PBR) respectively to display the movement signals of missiles by multimedia, as the visualized display simulating these processes, facilitating analysis, diagnosis and verification of missile functions. Those two approaches supported each other and demonstrate well performance in this study by the instances of anti-air and underwater guided weapon systems.
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Kuan-JeChen and 陳寬哲. "Feasibility Study of Physiological Signals via Digital Image Data." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/15107545601797146719.
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