• The Journal of the Acoustical Society of Korea
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• v.28 no.4
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• pp.343-355
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• 2009

In order to restore the identity of sound environment and expand the sound culture of a region, the purpose of this study are to excavate the resources of soundscape and find out the plans for the preservation and promotion of soundscape resources peculiar to the region. For this purpose, this research is conducted through an interview survey of residents and an observation survey using listening walk in Hongdo, one of the southwesten island of Korea. The results of survey confirm that there are so many sounds to hear around Hongdo island, those are, natural sounds such as the song of the birds, the roar of the waves, the whistling sounds, the shriek of the seagulls, and the pebbles sounds washed away by the waves, and artificial sounds such as the steam-whistle signals, the ship's broadcasts, the voice of tourists, the sounds of church bells, lighthouse sirens etc. The results suggest that it is necessary to consider several ways for restoration of an unique soundscape in Hongdo island, those are, improvement for efficient management of a ship's broadcasts in public areas, removal of a ferry in Hongdo swimming beach, management of Dangsanje (a religious service), preservation of a lighthouse siren and a foghorn, restoration and improvement of underground stream, management and control of public fish market, restoration of brooklet, management of cooperative system for a fish market, restoration of PoongO-Gut (a ritual for a large harvest) and a skate festival, management of a Hongdo sports meeting, sound quality modification of a boat whistle, restoration of orientalia such as a funeral bier, ecosystem preservation activity of the shore and ocean, and promotion of amenity for fascination and vitality in a rural community. Also, a sound map is drawn up for many tourists so as to realize the importance of sound environment and identity of soundscape and to gain their experience at first hand in Hongdo island.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1296-1303
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• 2014

This study was conducted to develop predictive models for the growth of Bacillus cereus on carrot treated with slightly acidic electrolyzed water (SAcEW) and ultrasonication (US) at different storage temperatures. In addition, the inactivation of B. cereus by US with SAcEW was investigated. US treatment with a frequency of 40 kHz and an acoustic energy density of 400 W/L at $40^{\circ}C$ for 3 min showed the maximum reduction of 2.87 log CFU/g B. cereus on carrot, while combined treatment of US (400 W/L, $40^{\circ}C$, 3 min) with SAcEW reached to 3.1 log CFU/g reduction. Growth data of B. cereus on carrot treated with SAcEW and US at different temperatures (4, 10, 15, 20, 25, 30, and $35^{\circ}C$) were collected and used to develop predictive models. The modified Gompertz model was found to be more suitable to describe the growth data. The specific growth rate (SGR) and lag time (LT) obtained from the modified Gompertz model were employed to establish the secondary models. The newly developed secondary models were validated using the root mean square error, bias factor, and accuracy factor. All results of these factors were in the acceptable range of values. After compared SGR and LT of B. cereus on carrot, the results showed that the growth of B. cereus on carrot treated with SAcEW and US was slower than that of single treatment. This result indicates that shelf life of carrot treated with SAcEW and US could be extended. The developed predictive models might also be used to assess the microbiological risk of B. cereus infection in carrot treated with SAcEW and US.

• 한국지구물리탐사학회:학술대회논문집
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• 2002.09a
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• pp.101-125
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• 2002

A lake seismic survey was carried out to investigate possible geohazards for construction of the underground LPG storage at Namyang Lake. The proposed survey site has a land-lake combined geography and furthermore water depth of the lake is shallow. Therefore, various seismic methods such as marine single channel high resolution seismic reflection survey, sonobuoy refraction survey, land refraction survey and land-lake combined refraction survey were applied. Total survey amounts are 34 line-km of high resolution lake seismic survey, 14 lines of sonobuoy refraction survey, 890 m of land refraction survey and 8 lines of land-lake combined refraction survey. During the reflection survey, there were severe water reverberations from the lake bottom obscured subsurface profiling. These strong multiple events appeared in most of the survey area except the northern and southern area near the embankment where seems to be accumulated mainly mud dominated depositions. The sonobuoy refraction profiles also showed the same Phenomena as those of reflection survey. Meanwhile the results of the land-lake combined refraction survey showed relatively better qualities. However, the land refraction survey did not so due to low velocity soil layer and electrical noise. Summarized results from the lake seismic survey are that acoustic basement with relatively flat pattern appeared 30m below water level and showed three types of bedrock such as fresh, moderately weathered and weathered type. According to the results of the combined refraction survey, a velocity distribution pattern of the lake bottom shows three types of seismic velocity zone such as >4.5 km/s, 4.5-4.0km/s and <4.0km/s. The major fault lineament in the area showed NW-SE trend which was different from the Landsat image interpretation. A drilling was confirmed estimated faults by seismic survey.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.190-197
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• 2001

Noise-induced hearing loss(NIHL) was the highest rate (43.5%~58.5% from 1996 to 1998) of positive findings through specific medical program in Korea. There were much more NIHL at workers of automobile manufacturing factories than other manufacturing factories. The specific aim of the present study was to determine the noise exposure of automobile press lines, according to their job titles, press line types(auto, semiauto), dosimeter parameters setting. There were a total 11 press lines sampled at a automobile manufacturing company. Among those press lines, 10 press lines were autolines with acoustic enclosure, one semiauto press line was no aucostic enclosure Noise exposure data were sampled for an work shift using noise dosimeter, which recorded both time-weighted average(TWA) and 1-min average. The mean OSHA TWA(Korea TWA with threshold 90) was $80.7dB(A){\pm}4.7dB(A)$ for leader, $82.8dB(A{\pm}4.5dB(A)$ for pallette man, $76.7dB(A){\pm}4.3dB(A)$ for press operators, $76.6dB(A){\pm}5.6dB(A)$ for crane operators, $77.1dB(A){\pm}2.8dB(A)$ for forklift drivers, whereas the mean NIOSH TWA was $88.9dB(A){\pm}1.7dB(A)$ for leader, $89.6dB(A){\pm}2.1dB(A)$ for pallette man, $86.7dB(A){\pm}1.8dB(A)$ for press operators, $88.5dB(A){\pm}2.0dB(A)$ for crane operators, $87.7dB(A){\pm}1.0dB(A)$ for forklift drivers. While L10 for NIOSH TWA samples was 84.8 dB(A) ~ 87.3 dB(A), L10 for OSHA TWA samples was 69.5 dB(A) ~ 77.4 dB(A). L10 means that the TWA for 90% of the samples exceeded L10. Among OSHA TWA(Korea TWA with threshold 90) samples for pallette man, 7.7 % exceeded 90 dB(A), the OSHA permissible exposure level, but OSHA TWA samples for the other job titles didn't. Among NIOSH TWA samples, the samples over 85 dB(A), the NIOSH recommended exposure limit, was 100% (leaders), 83.3 %(operators), 97.4%(palletteman), 100%(forklift drivers), 91.7 %(crane operator). The results of One-way random effects analysis of variance models shows that the difference between job titles was significant by OSHA TWA(p<0.05), but not significant by NIOSH TWA(p>0.05). NIOSH TWA samples were significantly higher than OSHA TWA samples(P<0.05). Regression analysis was used to obtain relationships between OSHA TWA samples and NIOSH TWA samples. In this case the coefficient of determination = 0.90, which shows the high degree association between two methods. Regression equation, NIOSH TWA = 0.552 * OSHA TWA + 42.13 dB(A), shows that if OSHA TWA is known, NIOSH TWA can be predicted by the equation. The mean TWA difference between threshold 80 dBA and 90 dBA was significant(p<0.01). While the TWA noise exposures were 7.7% above the Korea(OSHA) PEL, they were more than 83.3% over NIOSH REL. Automobile workers were exposed to noise level that could be potentially damaging to their hearing. It found that there is approximately 25% excess risk of hearing loss even if a worker is protected to the PEL in according to NIOSH study.

• Cross-Cultural Studies
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• v.44
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• pp.211-237
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• 2016

This paper seeks to explore the new relationship between music and poetry established in the beginning of the Modern Era. This was a period when reading silently was the dominant culture rather than reading aloud and orality was limited due to the emergence of literacy and print culture. A poet sensitive to the characteristics of the period, $Mallarm{\acute{e}}$ created his own concept of music and new creative principles of poetry from it. We analyze his "Divigation" and letters, in particular, the "Crisis of vers", "Music and Literature", "Mystery in the letters", and "About the book." Firstly, $Mallarm{\acute{e}}$ connects music with the mystery and the sacred: the mystery surrounds the music and the music is oriented with the sacred. The sanctity is that of the human race and has existed within humans since the beginning. Transposing the characteristics of this music to the poetry is his first creative principle of poetry. However, $Mallarm{\acute{e}}$ called music a totality of relationships that exist between objects without reducing the dimension to only the instruments or the sound. His definition is abstract, regarding music as a complete rhythm, the atmosphere and the air. Secondly, we have the question of how to realize music in a poem. As the music is surrounded by the mystery, $Mallarm{\acute{e}}$ can transpose the sacred to a poem in mysterious ways. This leads to his second principle of poetry: make a poem as a structure. In other words, 'musically', based on the disappearance of real objects and the initiative of the poet, he created a structure with only the words. We can create an acoustic structure but $Mallarm{\acute{e}}$ created a visible structure to overcome the incompleteness of the sound of a word in the diffusion of print culture. In this manner, the use of silence as much as sound and the use of visual as much as aural components were introduced in poetry as important motifs and the essentials of creation. This new relationship between poetry and music and the creative principles drawn from it appear to be the areas to which attention should be focused in the research of poetry.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.57-75
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• 2019

Soundscapes have the potential to help people experience the historical background and cultural traditions by the scenery of a local area and to be used as a cultural and tourism resource. This concept was first explained in detail by M. Schafer and has been developed as a new way of experiencing landscapes using various senses. This research studied the soundscape of Kyodong Island, the so-called "Island of Peace" and designed new cultural acoustic content for education and tourism. Kyodong Island is located right below the Northern Limit Line and the whole island is in the Civilian Controlled Area. The political and economic status of the island has been changed dynamically by the Korean War and the division of the country. These days, the island needs to realize the vision of the "Island of Peace" in a more creative way using local resources, including its "cold war landscape" and the natural scenery of the region. This research applied the concept of a soundscape to document the island, and to reproduce it in an artistic way. A workshop was conducted to learn concepts and techniques of soundscapes with a sound artist. Listening, recording, conducting interviews, and literature research was used to study the soundscape of the island. After that, this research reconstructed the soundscape of the island through a soundscape composition. The main theme of the composition story was the "Hope and Wish for the Harmony and Peace" to show the vision of the "Island of Peace". The initial sub-theme for the introduction part was "First Encounter with Kyodong Island" arranging the representative soundscape, which could be the first impression of the region. The second sub-theme was "War and Tension" using several soundscapes as a metaphor for the tragedy of the Korean War. The third sub-theme was "Everyday Life of Kyodong Island" which described the energy of the present day, after the wounds of the war have healed. The final sub-theme was "Harmony and Peace" using traditional music and keynote sounds of the region as a reminder of the peaceful past, before the war. The recording files were documented as two types of sound maps. One was a two-dimensional map to show the soundscapes from one point of view, and the other used the online application called "Sound Around You". The final artwork was displayed at an exhibition and uploaded on YouTube to be shared publicly. Through this project, we discovered the potential of soundscapes as a medium to preserve the history and local identity, as well as presenting a new vision. The artwork will be exhibited at historically and culturally meaningful places on the Island to utilize the underused places as local tourist attractions and educational resources.

• Journal of the Korean earth science society
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• v.45 no.2
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• pp.136-146
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• 2024

This paper introduces the seismic facies classification and mapping of igneous bodies found in the sedimentary sequences of the Yellow Sea shelf area of Korea. In the research area, six extrusive and three intrusive types of igneous bodies were found in the Late Cretaceous, Eocene, Early Miocene, and Quaternary sedimentary sequences of the northeastern, southwestern and southeastern sags of the Gunsan Basin. Extrusive igneous bodies include the following six facies: (1) monogenetic volcano (E.mono) showing cone-shape external geometry with height less than 200 m, which may have originated from a single monogenetic eruption; (2) complex volcano (E.comp) marked by clustered monogenetic cones with height less than 500 m; (3) stratovolcano (E.strato) referring to internally stratified lofty volcanic edifices with height greater than 1 km and diameter more than 15 km; (4) fissure volcanics (E.fissure) marked by high-amplitude and discontinuous reflectors in association with normal faults that cut the acoustic basement; (5) maar-diatreme (E.maar) referring to gentle-sloped low-profile volcanic edifices with less than 2 km-wide vent-shape zones inside; and (6) hydrothermal vents (E.vent) marked by upright pipe-shape or funnel-shape structures disturbing sedimentary sequence with diameter less than 2 km. Intrusive igneous bodies include the following three facies: (1) dike and sill (I.dike/sill) showing variable horizontal, step-wise, or saucer-shaped intrusive geometries; (2) stock (I.stock) marked by pillar- or horn-shaped bodies with a kilometer-wide intrusion diameter; and (3) batholith and laccoliths (I.batho/lac) which refer to gigantic intrusive bodies that broadly deformed the overlying sedimentary sequence.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.9-18
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• 2024

The importance of active sonar systems is emerging due to the quietness of underwater targets and the increase in ambient noise due to the increase in maritime traffic. However, the low signal-to-noise ratio of the echo signal due to multipath propagation of the signal, various clutter, ambient noise and reverberation makes it difficult to identify underwater targets using active sonar. Attempts have been made to apply data-based methods such as machine learning or deep learning to improve the performance of underwater target recognition systems, but it is difficult to collect enough data for training due to the nature of sonar datasets. Methods based on mathematical modeling have been mainly used to compensate for insufficient active sonar data. However, methodologies based on mathematical modeling have limitations in accurately simulating complex underwater phenomena. Therefore, in this paper, we propose a sonar signal synthesis method based on a deep neural network. In order to apply the neural network model to the field of sonar signal synthesis, the proposed method appropriately corrects the attention-based encoder and decoder to the sonar signal, which is the main module of the Tacotron model mainly used in the field of speech synthesis. It is possible to synthesize a signal more similar to the actual signal by training the proposed model using the dataset collected by arranging a simulated target in an actual marine environment. In order to verify the performance of the proposed method, Perceptual evaluation of audio quality test was conducted and within score difference -2.3 was shown compared to actual signal in a total of four different environments. These results prove that the active sonar signal generated by the proposed method approximates the actual signal.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.196-213
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• 2001

A split beam ultrasonic transducer operating at a frequency of 70 kHz to use in the fish sizing echo sounder was developed and the acoustic radiation characteristics were experimentally analyzed. The amplitude shading method utilizing the properties of the Chebyshev polynomials was used to obtain side lobe levels below -20 dB and to optimize the relationship between main beam width and side lobe level of the transducer, and the amplitude shading coefficient to each of the elements was achieved by changing the amplitude contribution of elements with 4 weighting transformers embodied in the planar array transducer assembly. The planar array split beam transducer assembly was composed of 36 piezoelectric ceramics (NEPEC N-21, Tokin) of rod type of 10 mm in diameter and 18.7 mm in length of 70 kHz arranged in the rectangular configuration, and the 4 electrical inputs were supplied to the beamformer. A series of impedance measurements were conducted to check the uniformity of the individual quadrants, and also in the configurations of reception and transmission, resonant frequency, and the transmitting and receiving characteristics were measured in the water tank and analyzed, respectively. The results obtained are summarized as follows : 1. Average resonant and antiresonant frequencies of electrical impedance for four quadrants of the split beam transducer in water were 69.8 kHz and 83.0 kHz, respectively. Average electrical impedance for each individual transducer quadrant was 49.2$\Omega$ at resonant frequency and 704.7$\Omega$ at antiresonant frequency. 2. The resonance peak in the transmitting voltage response (TVR) for four quadrants of the split beam transducer was observed all at 70.0 kHz and the value of TVR was all about 165.5 dB re 1 $\mu$Pa/V at 1 m at 70.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The resonance peak in the receiving sensitivity (SRT) for four combined quadrants (quad LU+LL, quad RU+RL, quad LU+RU, quad LL+RL) of the split beam transducer was observed all at 75.0 kHz and the value of SRT was all about -177.7 dB re 1 V/$\mu$Pa at 75.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The sum beam transmitting voltage response and receiving senstivity was 175.0 dB re 1$\mu$Pa/V at 1 m at 75.0 kHz with bandwidth of 10.0 kHz, respectively. 3. The sum beam of split beam transducer was approximately circular with a half beam angle of $9.0^\circ$ at -3 dB points all in both axis of the horizontal plane and the vertical plane. The first measured side lobe levels for the sum beam of split beam transducer were -19.7 dB at $22^\circ$ and -19.4 dB at $-26^\circ$ in the horizontal plane, respectively and -20.1 dB at $22^\circ$ and -22.0 dB at $-26^\circ$ in the vertical plane, respectively. 4. The developed split beam transducer was tested to estimate the angular position of the target in the beam through split beam phase measurements, and the beam pattern loss for target strength corrections was measured and analyzed.

• Journal of Preventive Medicine and Public Health
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• v.6 no.1
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• pp.51-63
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• 1973

This paper illustrate residual hearing and socio-medical background on the hearing impaired children, 207 comming to Deaf School. attached to Hankuk Social Work College, Taegu, Korea. The survey was performed through interview with their parents and testing by diagnostic audio-meter (TRIO, AS 105 type) at soundproof room from March 10, to November 28, 1973. The results obtained were as follows. 1) The attendance rate of the compulsory primary school was markedly lower tendency in female than male according to directly proportional to prevalence rate of deafness among them. If was showed the deeper gap in the more superior school (middle and high school). 2) Who entered at the suitable age to each school (six years old to primary school, 12 years to middle and 15 years to high) was 11.3%. And who were enrolled in school age to each school (6-11 years for primary. 12-14 years for middle and 15-17 years for high) was 45.9% (43.7% in male, 50.0% in female). 3) As causative disease, congenital case, were 23.6% included of 13.5% of heredity and 10.1% of troubles during pregnancy; the total acquired cases were 47.9%, it was classified as 11.6% of convulsion from any other diseases, 7.7% of measles, 7.7% of other febrile diseases, 3.4% of drug (the most of streptomycin) intoxication, 2.4% of meningitis, 1.5% of epidemic encephalitis and 31.3% of other diseases; and unknown cases were 28.5%. 4) 31.4% of who included congenital cases lost their hearing within six months old, 11.6% in 6-11 months. 9.7% in 1-2 years old and 14.0% in 2-3years old. Consequently we obtained that the most cases 90.0% were lost their hearing within 3 years after birth. 5) According to qualities of hearing leases the most of cases were perceptive, 197(97.5%), only two cases were conductive, and eight cases were mixed. 6) The status of residual hearing according to average grade of hearing loss. $B(=\frac{a+2b+c}{4}$ as table 13) were as follows. Two cases were normal (one was mute and another was severe speach disorder). Ten cases, moderate. Moderately severe cases were 40 (19.3%). Severe cases, 38(18.4%). Scale out, profound cases, 48 (23.3%). And impossible testing cases because that were infantile or had some mental disorder were 69 (33.3%). 7) The using rate of hearing aides was only 12.0%. Among them who had some more residual hearing and could showed hearing effect with hearing aide have used more many proportionary but who were difficult to expect that effect were rare.