• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.625-626
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• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.621-622
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• 2008

• The Journal of the Acoustical Society of Korea
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• v.12 no.1E
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• pp.65-70
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• 1993

이 연구는 예술의 전당 연극극장의 실내 음향설계 평가에 관한 것으로, 실제 건물이 완성되어가는 중간단계에서 설계도면 검토와 현장에서의 음향실험을 통하여 합리적인 설계방안을 제시하고 그 결과를 최종 시공 과정에 적용하고자 한 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1570-1575
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• 1991

The feasibility of using an adaptive resonance network (ART2) with unsupervised learning capability for too] wear detection in turning operations is investigated. Specifically, acoustic emission (AE) and cutting force signals were measured during machining, the multichannel AR coefficients of the two signals were calculated and then presented to the network to make a decision on tool wear. If the presented features are significantly different from previously learned patterns associated with a fresh tool, the network will recognize the difference and form a new category m worn tool. The experimental results show that tool wear can be effectively detected with or without minimum prior training using the self-organization property of the ART2 network.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2E
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• pp.46-53
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• 2005

Agency for Defense Development (ADD) developed the Submarine Acoustic Information Management System (SAIMS Version 1.0) capable of interfacing some submarine sensors in operation and predicting detection environments for sonars. The major design concepts are as follows: 1) A proper acoustic model is examined and optimized to cover wide spectra of frequency ranges for both active and passive sonars. 2) Interfacing the submarine sensors to an electric navigation chart, the system attempts to maximize the applicability of the information produced. 3) The state-of-the-art database in large area is built and managed on the system. 4) An algorithm, which is able to estimate a full sound speed profile from the limited oceanographic data, is developed and employed on the system. This paper briefly describes design concepts and algorithms embedded in the SAIMS. The applicability of the SAIMS was verified through three sea experiments in October 2003-February 2004.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.3
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• pp.264-274
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• 2014

Time synchronization becomes a critical issue in underwater acoustic networks (UANets) because nodes cooperate together or individually work by communicating each other in diverse underwater applications. Compared with the time synchronization approaches in terrestrial networks, several intrinsic limitations of UANets (e.g., the unavailability of GPS, long propagation delay, mobility due to currents, limited energy consumption, or low data rate) need to be considered in synchronizing the timing among underwater nodes. For the purpose of developing more efficient time synchronization protocols for UANets, we review the existing approaches, which estimate both the clock offset and the clock skew of underwater nodes. Finally, we outline the state-of-the art time synchronization protocols for UANets by comparing and summarizing them according to their synchronization characteristics.

• Speech Sciences
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• v.11 no.2
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• pp.165-177
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• 2004

Western singers voice have been studied in music science since the early 20th century. However, Korean traditional singers voice have not yet been studied scientifically. This study is to find the physiological and acoustic characteristics of Pansori singers voices. Western singers participated for comparative purposes. Ten western singers and ten Pansori singers participated in this study. The subjects spoke and sung seven simple vowels /a, e, i, o, u, c, w/. An analysis of Glottal image was done by Scope View and acoustic characteristics of speech and singing voice were analyzed by CSL. The results are as follows: (1) Glottal gestures of Pansori singers showed asymmetric vocal folds. (2) Singing vowel formants of Pansori singers showed breathiness based on Spectrogram. (3) Music formant of western singers appeared in around 3kHz area, however, Pansori singers formant appeared in low frequency area. Modulation of vibrato showed 6 frequency per sec in case of western singers. Pansori singers showed no deep modulation of vibrato on spectrogram.

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.1-10
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• 2000

This work shows that it is possible to obtain information about more than one parameter from acoustic field information. A variety of ultrasonic Lamb wave modes were utilized to reconstruct thickness and density of an isotropic plate. An image reconstruction of one parameter (thickness of a plate) was carried out for four cases, i.e., the lowest symmetrical and anti symmetrical modes, and the fastest symmetrical and anti symmetrical Lamb waves among multiple modes. For two parameter reconstructions (thickness and density), the image processing was performed using the lowest symmetrical and antisymmetrical modes simultaneously. In this work, a modified version of algebraic reconstruction technique (ART), which is a form of finite-series expansion method, was employed to reconstruct the ultrasonically computed tomographic images. Results from several sample geometries are presented.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.171-176
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• 2022

This paper examines the historical meaning and value of sound art curating as a key type of interdisciplinary and convergence art practice that has been unfolding since the mid-20th century. Accordingly, this paper summarizes the developmental process from the beginning of 'sound art' to the present, but examines the context of visual art in which the material 'sound' functioned in chronological order, and focuses on curating cases of major sound art exhibitions. The purpose of this study is to analyze the impact and contemporary significance of the provided aesthetic experience. To this end, the text is divided into three sections and developed. The first section recognizes that the late 19th century futurist and Dadaist sound poetry, followed by Marcel Duchamp's 1913 attempt to combine musical score with visual art, had a profound influence on the visual music of avant-garde composer John Cage. This explains why this background caused the emergence of exhibitions dealing with 'sound' as a new medium. The second section explains that in the 1970s, sound as an artistic medium played a role in reflecting the critical relationship with the exhibition space dominated by visuality. In the third section, we analyze the curatorial methodology that allows the audience to experience sound as if it were a visual object within the organization of the exhibition hall from the 1980s to the present. Through this process, this paper critically treats the historical practice of customizing the perceptual structure in the exhibition hall, and considers the meaningful methodology of sound art curating considering the role of sound full of vitality in the contemporary art scene.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.286-294
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• 2010

Korea Institute of Geoscience and Mineral Resources (KIGAM) has installed and operated seven seismoacoustic (infrasound) arrays as well as seismic stations in Korea. The seismo-acoustic array, which consists of co-located seismometers and micro-barometers, can observe both seismic and infrasonic signals from distant explosive phenomena. The infrasound is defined as low frequency (<20 Hz) acoustic waves in atmosphere. In particular, it can be detectable at long distance due to its low energy attenuation during propagation in atmosphere. KIGAM adopted the infrasound technology to discriminate surface explosions from earthquakes only because the surface explosion generally generates infrasound following seismic signal. In addition to surface explosions, these arrays have detected diverse geophysically natural and artificial phenomena, such as infrasound signal from the North Korean nuclear test. This review introduced the state-of-the-art studies and examples of infrasonic signals in and around the Korean Peninsula. In conclusion, infrasound technology would be clearly accepted itself as a new Earth monitoring technology by expanding its detectable regime to lithosphere-Earth surface-atmosphere. In future, an advanced technology, which allows to analyze seismic and infrasonic wave fields together, will enlarge the understanding of geophysical phenomena and be used as a robust analysis method for remote explosive phenomena in the broad infrasound regime.