• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.5
• /
• pp.791-797
• /
• 2008

The officer of the deck(OOD) may sometimes have to carry out lookout as well as handling of auto pilot without a quartermaster at sea. The purpose of this paper is to develop the ship's auto pilot control module using speech recognition in order to reduce the potential risk of one man bridge system. The feature parameters predicting the OOD's intention was extracted from the sample wheel orders written in SMCP(IMO Standard Marine Communication Phrases). We designed a pre-recognition procedure which could make some candidate words using DTW(Dynamic Time Warping) algorithm, a post-recognition procedure which made a final decision from the candidate words using the feature parameters. To evaluate the effectiveness of these procedures the experiment was conducted with 500 wheel orders.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.6
• /
• pp.1035-1042
• /
• 2017

In this paper, we implement a public address system using power line communication in order to operate, extend, and expand the complicated public address devices and cables easily. Power line communication based public address system implemented consists of a public address control board and public address speaker boards which are suitable to digital streaming modulation. It can be noticed that we met satisfied results from performance measurement such as maximum audio output, audio channel response time, audio output SNR, and audio output THD+N.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.10
• /
• pp.1422-1432
• /
• 1993

Nonlinear mapping function of the HCNN( Hidden Control Neural Network ) can change over time to model the temporal variability of a speech signal by combining the nonlinear prediction of conventional neural networks with the segmentation capability of HMM. We have two things in this paper. first, we showed that the performance of the HCNN is better than that of HMM. Second, the HCNN with its prediction error measure given by weighted distance is proposed to use suitable distance measure for the HCNN, and then we showed that the superiority of the proposed system for speaker-independent speech recognition tasks. Weighted distance considers the differences between the variances of each component of the feature vector extraced from the speech data. Speaker-independent Korean digit recognition experiment showed that the recognition rate of 95%was obtained for the HCNN with Euclidean distance. This result is 1.28% higher than HMM, and shows that the HCNN which models the dynamical system is superior to HMM which is based on the statistical restrictions. And we obtained 97.35% for the HCNN with weighted distance, which is 2.35% better than the HCNN with Euclidean distance. The reason why the HCNN with weighted distance shows better performance is as follows : it reduces the variations of the recognition error rate over different speakers by increasing the recognition rate for the speakers who have many misclassified utterances. So we can conclude that the HCNN with weighted distance is more suit-able for speaker-independent speech recognition tasks.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.15 no.2
• /
• pp.122-127
• /
• 2004

Background and Objectives : Many studies have described and analyzed singer's formant and it has been shown that the epilaryngeal tube in the human airway is responsible for vocal ring, or the singer's formant. A similar phenomenon produced by trained singers in their speech led some authors to examine the speaker's ring. This study was designed to analyze the speaking voice of the singers and speaker's ring. Baterials and Methods : Ten tenors, fifteen baritones, fifteen sopranos and ten mezzo sopranos attending the music college, department of vocal music were chosen for this study. Fifteen male and fifteen female untrained normal speakers were chosen for control group. Each subject was asked to produce a sample of a sustained spoken vowel /ah/ sound for at least five seconds and read sentence 'Kaeul'. The sound data was analyzed using the Fast Fourier Transform(FFT) - based power spectrum, Long term average(LTA) power spectrum using the FFT algorithm of the Computerized Speech Lab(CSL, Kay elemetrics, Model 4300B, USA). Statistical analysis was performed using the Mann-Whitney test of the Statistical Package for Social Sciences(SPSS). Results : For LTA Power spectrum of/ah/ sound, a significant increase was seen in the 2,500-3,500Hz region(p<0.01) in four trained singer group compared with untrained speaker group, and a significant increase in the 9,000-10,000Hz region(p<0.01) in soparano group. Similarly, in sentence 'Kaeul', there was a significant increase in energy in the tenor, baritone, mezzo soprano group compared with the untrained speaker group in the 2,500-3,500Hz region(p<0.01), and a significant increase in all frequency region(p<0.01) in the soprano group. Conclusions : The LTA power spectrum suggests that trained singers group show more energy concentration in the 'singer's formant' region in the speaking voice, and authors believe this region to be the 'speaker's ring'. Further research is needed on the effect of singing training on the resonance of the speaking voice.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2775-2781
• /
• 2011

Urban Transit Train Radio is Radio Communication system that is used official business as leading motive for train safety running among the train crew and the central control center and drive-caring-chamber on main line and branch line. This system is operated that organizes talking path on handset of terminal after the train crew receives audio and understands call voice on speaker of terminal at calling the train of the central control center. When the central control center calls the specific train uses all call radio form, the train crew doesn't recognize the call cause the train situation, noise and action as train control. So there is a delay response cause reset call at the central control center. This research discusses the management of subway radio system and describes the call the train system that recognize train call number of all-call used between the central control center and the train crew.

• Journal of Korea Society of Industrial Information Systems
• /
• v.10 no.4
• /
• pp.90-96
• /
• 2005

This paper develops a multi-casting system could be used in a school and hospital and government and municipal public offices. The developed multi-casting system uses various educational multimedia titles effectively and is capable of remote control by using a network(LAN). The developed system includes speaker control module that make individual or group broadcasting, AV contents control module for using a diverse educational multimedia title effectively and light control module. The system uses RS-485C communication module and the effective control system interface based on GUI.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.5
• /
• pp.703-708
• /
• 2011

In this paper, most of the church except for a large church has accommodated many audience to install a balcony floor in a small space. therefore, dead zone and dislocated sound image localization is made due to this under-balcony seats. This paper propose that the problems of dead zone and dislocated sound image localization could be solved using computer simulation in the view of practical side. The economical computer simulation tool, Mapp online that can be found easily was used to the specified church. Installation a sub speaker for dead zone and -10 dB power control of the sub speaker to main speaker power for dislocated sound image localization was proposed. Computer simulation result shows that the value of definition for area was improved from "Normal" to "Very Good" which means about 52% improvement.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.1
• /
• pp.12-20
• /
• 2002

To control the noise of an enclosed sound field, we built a state space model using the acoustic modal parameter description. Using the state space model, we can investigate the controllability and observability, and find an appropriate position of control speaker and microphone to control sound field of the enclosed space. We implemented LQR(linear quadratic regulator) controller and reduced order observer to reduce the first acoustic mode. Experiments showed satisfactory results of 4∼10 dB reduction of magnitude of the first acoustic mode, and support the feasibility of the proposed scheme to lightly damped acoustic field.

• Journal of KSNVE
• /
• v.10 no.6
• /
• pp.941-948
• /
• 2000

Active noise control is an approach to reduce the noise by utilizing a secondary noise source that destructively interferes with the unwanted noise. In general, active noise control systems rely on multiple sensors to measure the unwanted noise field and the effect of the cancellation. This paper develops an approach that utilizes a single sensor. The noise field is modeled as a stochastic process, and an adaptive algorithm is used to adaptively estimate the parameters of the process. Based on these parameter estimates, a canceling signal is generated. Oppenheim assumed that transfer function characteristics from the canceling source to the error sensor is only a propagation delay. This paper proposes a modified Oppenheim algorithm by considering transfer characteristics of speaker-path-sensor This transfer characteristics is adaptively cancelled by the proposed adaptive modeling technique. Feasibility of the proposed method is proved by computer simulations with artificially generated random noises and sine wave noise. The details of the proposed architecture. and theoretical simulation of the noise cancellation system for three dimension enclosure are presented in the Paper.

• Journal of KSNVE
• /
• v.7 no.2
• /
• pp.301-310
• /
• 1997

This paper presents active noise control method to form the near-field quiet zone for passengers in an automobile. The actuator model including interior acoustic plant, speaker and amplifier is experimentally identified in forms of auto-regressive and moving average by means of least mean square algorithm, The digital controller is composed of the regulator and Kalman filter to be designed based on LQG (linear quadratic gaussian). If the actuator model is prefiltered with digital filter to be properly designed for concentrating control performance index on the frequency band of primary noise source, LQG design approach can be effectively applied for the design of headset controller. Experimental results demonstrate that near-field quiet zone showing about 10dB noise reduction at microphone position can be formed using the headset located at passenger seat.