Pitch Period Research Articles

Navigation Condition Effect on Ship Motion in some Sea State

According to analyzing the identity of ocean wave, theory of wave energy spectrum was applied to compute the curve of wave elevation vs. time in some sea state. Based on ship motion equations, ship motion was acquired by the simulation software of the of ship strip theory in some situation. How different navigation conditions effect on ship motion is researched in some sea state. The results show the change of degree of abaft the beam badly influenced the amplitude and periods of pitch, it also influenced periods of heave and amplitude of roll. The change of ship speed influenced the amplitude and periods of pitch, it also influenced periods of heave and roll.

단위 선택 기반의 음성 변환

ABSTRACT: A voice transformation (VT) method that can make the utterance of a source speaker mimic that of a target speaker is described. Speaker individuality transformation is achieved by altering three feature parameters, which include the LPC cepstrum, pitch period and gain. The main objective of this study involves construction of an optimal sequence of features selected from a target speaker’s database, to maximize both the correlation probabilities between the transformed and the source features and the likelihood of the transformed features with respect to the target model. A set of two-pass conversion rules is proposed, where the feature parameters are first selected from a database then the optimal sequence of the feature parameters is then constructed in the second pass. The conversion rules were developed using a statistical approach that employed a maximum likelihood criterion. In constructing an optimal sequence of the features, a hidden Markov model (HMM) was employed to find the most likely combination of the features with respect to the target speaker’s model. The effectiveness of the proposed transformation method was evaluated using objective tests and informal listening tests. We confirmed that the proposed method leads to perceptually more preferred results, compared with the conventional methods.

Research on Pitch Extraction Algorithm of Noisy Speech

Pitch detection in noisy environment plays an important role in speech analyzing and recognition. In the light of the properties of Hilbert-Huang transform and the EMD soft-threshold de-noising method, an effective pitch detection method for noisy speech signal is proposed in this paper. Firstly, the EMD soft-threshold de-noising method is applied to realize the background noise reduction, secondly, using the Hilbert-Huang transform to detect the pitch period of the de-noising speech signal. The analysis proposed in this paper show that, compared with the conventional methods of the pitch detection of the noisy speech, especially for the low signal to noise ratio (SNR), this approach has a higher accuracy.

Speech Enhancement Method under Low SNR

In this document, the pitch period is detected according to the sensitivity to weak sinusoidal signal and strong immunity ability to noise of Duffing oscillator, at the background of strong noise. And then enhancing pitch obtained by harmonic method. The test results show that the enhancing effect of this method is obvious under low SNR condition, and speech distortion is small.

Speech Enhancement Method under Low SNR

In this document, the pitch period is detected according to the sensitivity to weak sinusoidal signal and strong immunity ability to noise of Duffing oscillator, at the background of strong noise. And then enhancing pitch obtained by harmonic method. The test results show that the enhancing effect of this method is obvious under low SNR condition, and speech distortion is small.

Heart Rate Responses and Technical-Tactical Aspects of Official 5-A-Side Youth Soccer Matches Played on Clay and Artificial Turf

Using a randomized crossover design, this study aimed to compare the heart rate (HR) responses and match analysis parameters (i.e., type of action; the number of players involved in an action; the number of passes performed in a collective action; precision of the shots; lost balls; ball interceptions; dribblings; and tackles) of official 5-a-side youth male soccer matches played over 2 pitch surface (i.e., clay vs. artificial turf) conditions. Twenty-two young male soccer players (age 8.3 ± 0.4 years) engaged in 2 consecutive 15-minute periods in each experimental condition. During the match, 53% of HR responses exceeded 85% of the individual HR(peak). No difference emerged between both pitch surfaces and match periods for HR and match analysis indicators. The two 15-minute periods resulted in being appropriate for 8-year-old players, in resembling the intensity of play and the intermittent nature of adult soccer. The similar HR responses and technical-tactical patterns observed on the 2 surfaces indicate that youth match play is not affected by differences in pitch surface. To support the development of individual and team skills of young soccer players, coaches are advised to prioritize game knowledge based on divergent thinking and experience, rather than traditional teaching based on instructions.

High Quality Arabic Concatenative Speech Synthesis

This paper describes the implementation of TD-PSOLA tools to improve the quality of the Arabic Text-tospeech (TTS) system. This system based on Diphone concatenation with TD-PSOLA modifier synthesizer. This paper describes techniques to improve the precision of prosodic modifications in the Arabic speech synthesis using the TD-PSOLA (Time Domain Pitch Synchronous Overlap-Add) method. This approach is based on the decomposition of the signal into overlapping frames synchronized with the pitch period. The main objective is to preserve the consistency and accuracy of the pitch marks after prosodic modifications of the speech signal and diphone with vowel integrated database adjustment and optimisation.

Magnetic brain activity phase‐locked to the envelope, the syllable onsets, and the fundamental frequency of a perceived speech signal

During speech perception, acoustic correlates of syllable structure and pitch periodicity are directly reflected in electrophysiological brain activity. Magnetoencephalography (MEG) recordings were made while 10 participants listened to natural or formant-synthesized speech at moderately fast or ultrafast rate. Cross-correlation analysis was applied to show brain activity time-locked to the speech envelope, to an acoustic marker of syllable onsets, and to pitch periodicity. The envelope yielded a right-lateralized M100-like response, syllable onsets gave rise to M50/M100-like fields with an additional anterior M50 component, and pitch (ca. 100 Hz) elicited a neural resonance bound to a central auditory source at a latency of 30 ms. The strength of these MEG components showed differential effects of syllable rate and natural versus synthetic speech. Presumingly, such phase-locking mechanisms serve as neuronal triggers for the extraction of information-bearing elements.

Efficient apertureless scanning probes using patterned plasmonic surfaces

We present a novel concept to design apertureless plasmonic probes for near-field scanning optical microscopy (NSOM) with enhanced optical power throughput and near-field enhancement. Specifically, we combine unidirectional surface plasmon polariton (SPP) generation along the tip lateral walls with nanofocusing of SPPs through adiabatic propagation towards an apertureless tip. Three key design parameters are considered: the nanoslit width, the pitch period of nanogrooves for unidirectional plasmonic excitation and the pyramidal geometry of the NSOM probe for SPP focusing. Optimal design parameters are obtained with 2D analysis and two realistic probe geometries with patterned plasmonic surfaces are proposed using the optimized designs. The electromagnetic properties of the designed probes are characterized in the near-field and compared to those of a conventional single-aperture probe with same pyramidal shape. The optimized probes feature FWHM around 150nm, comparable with conventional NSOM designs, but over 3 orders of magnitude larger field enhancement, without degrading its spatial resolution. Our ideas effectively combine the resolution of apertureless probes with throughput levels much larger than those available even in aperture-based devices.

A DCT-Based Speech Enhancement System With Pitch Synchronous Analysis

Discrete cosine transform (DCT) has been proven to be a good approximation to the Karhunen-Loeve Transform (KLT) and has similar properties to the discrete Fourier transform (DFT). It also possesses a better energy compaction capability which is advantageous for speech enhancement. However, frame to frame variations of DCT coefficients even for a perfectly stationary signal can be observed. Therefore a DCT-based speech enhancement system with pitch synchronous analysis is proposed to overcome this problem. It reduces the drawbacks of fixed window shift and the amount of shift in the analysis window is now based on the pitch period, thus increasing the inter-frame similarities. Furthermore, a Wiener filter using the a priori signal-to-noise ratio (SNR) with an adaptive parameter is also derived and implemented as an advanced noise reduction filter. This proposed speech enhancement system is evaluated in terms of several objective measures and the experimental results demonstrate the good performance of the proposed system.

Harmonic modification and data adaptive filtering based approach to robust pitch estimation

A novel and robust pitch estimation method is presented in this paper. The basic idea is to reshape the speech signal using a combination of the dominant harmonic modification (DHM) and data adaptive time domain filtering techniques. The noisy speech signal is filtered within the ranges of fundamental frequencies to obtain the pre-filtered signal (PFS). The dominant harmonic (DH) of the PFS is determined and enhanced its amplitude. Normalized autocorrelation function (NACF) is applied to that modified signal. Then empirical mode decomposition (EMD) based data adaptive time domain filtering is applied to the NACF signal. Partial reconstruction is performed in EMD domain. The pitch period is determined from the partially reconstructed signal. The experimental results show that the proposed method performs better than the other recently developed methods for noisy and clean speech signals in terms of gross and fine pitch errors.

Magnetic brain activity directly reflects syllable onsets and pitch periodicity of a perceived speech signal.

Continuous speech evokes electrophysiological brain activity following the speech envelope (ENV), resembling the N100 responses to single acoustic events. Using magnetoencephalography (MEG), the present study tested further aspects of evoked activity, considering the positive part of the first derivative of the speech envelope (SYL), emphasizing syllable onsets, and a sinosoidal signal representing pitch periodicity (PIT), obtained by 50–180 Hz bandpass filtering of the rectified speech signal. MEG signals, recorded while the participants (n = 10) listened to 4‐s portions of natural or formant‐synthesized speech at a moderately fast or ultrafast speaking rate, were cross‐correlated with ENV, SYL, or PIT. Using dipole models, the cross‐correlated MEG signals were evaluated with respect to latency and amplitude of typical components. As expected, the ENV derivate showed an M100‐like response that was stronger over the right as compared to the left hemisphere. Regarding the SYL derivate, a more anterior component could be isolated, in addition to M50/M100‐like responses in the auditory system, presumably representing a late frontal component of the M50 deflection. The PIT derivate showed multiple peaks of alternating polarity bound to a central‐auditory source. The strength of these MEG components depended on rate and signal type.

Using spectral constancy to encode temporal pitch and improve cochlear-implant melody perception.

Despite good speech performance in quiet, melody perception remains a challenge to cochlear-implant (CI) users. Current CI pitch-encoding schemes significantly alter original signals, producing potentially detrimental effects on speech perception. The present study proposes to take advantage of spectral constancy to encode temporal pitch while minimizing signal distortion. Spectral constancy refers to unaltered timbre perception when the overall level of a signal is roved. For example, the vowel /a/ sounds the same independent of its overall level. The idea is to extract and encode pitch by increasing the gain of all channels proportionally and synchronously according to the pitch period. This scheme alters the temporal envelope of voiced sounds but preserves their spectral envelope in each time frame. It does not alter temporal envelope of unvoiced sounds, making it a good comprise between encoding pitch and preserving spectral and temporal envelopes. The new scheme has been implemented in a real-time speech processor and evaluated in nine nucleus CI users who identified ten melodies with minimal training and in a test protocol that randomized the stimulus presentation order. Compared with the standard continuous interleaved sampling strategy, the new scheme significantly improved CI melody perception by 10–20%.

Voiced/Unvoiced Classification and Pitch Period Detection Algorithm Based on Wavelet Transform

摘要: 该文提出了一种基于小波变换的鲁棒性基音周期检测方法。检测前在小波域上用Teager能量算子对语音信号进行清浊音判决，对浊音段采用空域相关函数提取基音周期。实验表明，与传统的小波变换算法和自相关法相比，该方法鲁棒性好，具有更高的准确性。 关键词: 基音检测; 小波变换; Teager能量算子; 空域相关函数

EXPERIMENTAL FORMULA FOR THE WAVE-INDUCED SHIP MOORING FORCE

The wave force dose not considered at the formula of mooring ship cable force in the Load Code for Harbor Engineering[JTJ215-98]. This brought the inconvenience to the calculation of designed cable force for mooring ship. By means of analysis for the laboratory model test result of mooring ship cable force under wave effect, Wave force formula of mooring ship under wave effect was gained. This formula well reflected the influence of ship size, ship load , ship rolling period, ship pitch period, wave period and wave height. The formula can be used in the calculation of standard value of mooring ship cable force under the wave effection, also it can be used to instruct the wave model test for mooring ship.
 
 
 References
 
 Zhang Ri-xiang. Liu Zhong-bo. Zhang Ning-chuan. 2003 .An Experimental Study on the Mooring Line Forces & Impact Forces of a Moored Ship Under the Combined Action of Wind,Wave and Current [J].,China offshore Platform, (01).15-18.
 
 Li Yan. Zheng Bao-you.Gao Feng. Meng Xiang-wei.2007.Model test study on the impact forces and mooring line forces of a moored ship under the combined action of wave and current [J].;The Ocean Engineering, (02).57-63.
 
 Ministry of transport of the People's Republic of China(1998).The Load Code for Harbor Engineering(JTJ215-98). [S].
 
 Jiang Qing. Ge Hong-zheng.Xie Peng.2007.Influence of Ship's Type and Tonnage on the Ship's Mooring Force [J]. Port & Waterway Engineering, (09).51-59.
 
 Wu Xiuhuan. 1999.Ship and maneuverability and seakeeping [M]. Ministry of transport of the People's Republic of China. p220.
 
 Zhang Wen-zhong. Etc.(2006): Model test of Mooring LNG ship at Jiangsu Provence, Tianjin Port Engineering Institute Ltd. of CCCC.

Apparatus And Method For Creating Pitch Wave Signals, Apparatus And Method For Compressing, Expanding, And Synthesizing Speech Signals Using These Pitch Wave Signals And Text-To-Speech Conversion Using Unit Pitch Wave Signals

A pitch wave signal creation method as a preliminary process for efficiently coding a speech wave signal having a fluctuated pitch period is provided. A speech signal compressing/expanding apparatus and a speech signal synthesizing apparatus using the method, and a signal processing associated therewith are further provided. The pitch wave creation method of the invention is essentially comprised of a method of detecting the instantaneous pitch period of each pitch wave element of the speech wave signal, and a process of converting a corresponding pitch wave element into a normalized pitch wave element having a predetermined fixed time length by expanding and compressing the pitch wave element on a time axis while retaining its wave pattern based on the each detected instantaneous pitch period. The speech signal having a pitch fluctuation can be compressed in high quality and high efficiency by coding or synthesizing the speech wave signal using the pitch wave signal creation method of the invention. Text-to-speech conversion using pitch wave signals.

Global Boundary-Centric Feature Extraction And Associated Discontinuity Metrics

Portions from time-domain speech segments are extracted. Feature vectors that represent the portions in a vector space are created. The feature vectors incorporate phase information of the portions. A distance between the feature vectors in the vector space is determined. In one aspect, the feature vectors are created by constructing a matrix W from the portions and decomposing the matrix W. In one aspect, decomposing the matrix W comprises extracting global boundary-centric features from the portions. In one aspect, the portions include at least one pitch period. In another aspect, the portions include centered pitch periods.

Initial Design of Tension Leg Platform for Offshore Wind Farm

As a floating foundation for wind turbine, dynamic response of offshore structure to external forces should be as small as possible because the motion of the structure imposes inertial force to a wind turbine system. Generally, a TLP (Tension Leg Platform) has favorable characteristics that its dynamic response in waves is negligibly small compared to other type of floating foundation. Our conceptual design of TLP for wind turbine was carried out in consideration of mooring force and easy maintenance. Numerical analyses were performed on dynamic response and tension deviation of leg in waves, natural frequency of vibration, and dynamic response to seismic load. As a result, it is found that natural periods of heave and pitch are rather short and amplitudes of motions are very small. It is also found that it keeps sufficient safety factor to extreme environmental conditions including earthquake, and is free from resonance with a wind turbine system.

音響分析ソフト「ＶＡ」の開発―軽度嗄声の音響分析―

The voice analyzer (VA) software program we developed for quantitatively analyzing voice quality uses zero-cross-picking to find individual basic pitch periods. Two such periods extracted from a voice waveform were analyzed to calculate the acoustic energy of harmonics separately from that of noise components. The program determines the ratio of harmonics to noise (Ra), F0, jitter, shimmer, APQ, and PPQ. Sustained vowel /a/ from 28 subjects without evident vocal problems such as hoarseness and 49 subjects with hoarseness were examined. Average female and male Ra among the nonhoarse were 31.9 dB and 34.4 dB, jitter 0.254% and 0.246%, and shimmer 0.168% and 0.116%. Among those with hoarseness, all parameter scored worse than in the nonhoarse in proportion to auditory impression.

An efficient approach using HOS-based parameters in the LPC residual domain to classify breathy and rough voices

Although a considerable number of studies have been focused on the analysis of pathological voices using conventional parameters such as jitter, shimmer, and signal-to-noise ratio (SNR), these parameters have been found to be sensitive to variations in pitch extraction algorithm and cannot analyze severely disordered voice signals which exhibit irregular or aperiodic waveforms. In this paper, higher-order statistics (HOSs) analysis, which is independent of pitch period, is derived from linear predictive coding (LPC) residuals to describe breathy and rough voices. Recordings of a sustained /a/ from 23 individuals with breathy voices and 30 individuals with rough voices were collected from the disordered voice database distributed by the Japanese Society of Logopedics and Phoniatrics. We extracted conventional parameters as well as the HOS-based parameters such as the normalized skewness and the normalized kurtosis. On the other hand, we calculated HOS-based parameters from the LPC residual domain. The results showed that the HOS-based parameters and the HOS-based parameters estimated from the LPC residual are different for rough and breathy voices. Conventional parameters were not distinctive for these voices. Classification and regression tree (CART) was used to combine multiple parameters and to classify breathy and rough voices. Using the HOS-based parameters, the CART achieved an accuracy of 85.0% with the optimal decision tree generated by means of the normalized skewness and kurtosis. When the HOS-based parameters using LPC residual were used, the optimal decision tree was 88.7% accurate and the variances of the normalized skewness and kurtosis were included.