• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.161-166
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• 2012

This Study, as part of a study on the application plan of overseas noise prediction models suitable for making domestic noise maps, analyzed the correlation between the differences in predicted noise levels by individual noise prediction model and surveyed data on General roads and Expressways. Separation distances of 5m and 10m, respectively were set from the ends of the general roads and the expressways at the points of measurements and to check the distribution patterns of sound power levels, the levels were measured at the heights of 1.5m and 3m, respectively. The latest revised versions of the five models (CRTN, RLS90, NMPB, Nord2000, ASJ2008) suggested in The Method of making Noise Maps were used as prediction models, and predicted noise levels were calculated by using commercial software SoundPLAN (Ver 7.1).

• MALSORI
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• 제25_26호
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• pp.27-37
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• 1993

This paper deals with the nature and function of intensification in Korean in a wider scope of context which was not paid proper attention. Unobserved new areas of intensification are paid more attention like sound split of polysemy e.g. [s'eda], [kyongk'i] by n of intensification and north Korean application of intensification on [wonsu] and intensification of borrowed English. The recent phenomenon of 'gwua' intensification is experimented on two groups of people, young students and old people beyond 65 years old by means of sociolinguistic analysis. The result shows that its intensification is a form of student violent power and a mark of extreme solidarity among activist students. In conclusion, the nature of so called saisiot[t] e.g. intensification is voiceless tensed pause and its functions are the polarization of the original meaning of the word, sound split of polysemy and attachment of social values by intensification.

• Journal of the Korean Graphic Arts Communication Society
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• 제23권2호
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• pp.15-23
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• 2005

This analog communication system overcomes a limit of the digital communication that used an electric power line, and shows a strong characteristic by decrease of impedance along a load or surge-voltage and the same noise. this system is to detect an sound signal added to light through an photo-sensor and a filter circuit. And a signal detected in this way is transmitted to sound through a speaker of an earphone again.

• Proceedings of the KSME Conference
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2005-2010
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• 2004

Ultrasonic cleaning is performed by cavitation which is caused by the change of the sound pressure due to the vibration in a cleaning tank. In this study, experiments on electric power and sound pressure with various temperatures, dissolved oxygen and the level of the fluid was done in order to find out how the changes in a cleaning tank affect cavitation. As a result of a series of experiments, we found that transducer impedance changes periodically in response to the variances of fluid and have a direct influence on cleaning efficiency.

• International Journal of Railway
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• 제6권3호
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• pp.125-130
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• 2013

Most of the test methods used for determining the acoustic performance of the noise barriers in Korean standards address the sound-proof panels but refer to noise barriers as a whole system or their in-situ performances less. Many new types of trains with different operating speeds have been developed and produced, and civil appeals against railway noise are becoming quite extensive. Considering these latest changes of circumstances, it is necessary to investigate the current standards and specifications pertaining to railway noise barriers. In this paper, criteria for the measurements and evaluations of noise barriers and sound-proof panels are examined and experimental studies are introduced. In order to suggest more efficient methods for reasonable evaluations of the noise barriers, frequency spectrums of the noise source, the power of the actual railway vehicles, are investigated and introduced.

• The Journal of Fisheries Business Administration
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• 제36권1호
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• pp.27-49
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• 2005

This paper represents a critical review of current the relationship between aquaculture and the environment, focusing on the development of marine aquaculture for conservation of resources and environment in Korea. Aquaculture has grown rapidly during the past few decades in Korea. This expansion was possibly because of the growing demand for aquatic products and the failure of the capture fishery to keep pace with the demand. Nevertheless, the aquaculture industry must counter criticisms about adverse environmental effects and lack of sustainability. The productivity of Korean aquaculture is decreasing by environmental pollution, is suffering difficulty because competitive power of the aquaculture industry is weak, external effects of aquiculture is giving negative effects to coastal fishery. Therefore, aquaculture must improve as environmentally sound aquaculture for fisheries sustainability, and intensive aquaculture of high density must convert by low input sustainable aquaculture. Finally, the aquaculture system of Korea has to change to aquaculture for conservation of non - renewable resources and environment, it may contribute to development of Korean fisheries.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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• pp.157-160
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• 2003

발전소에서 운전중인 기계들의 안전운전과 예지 보전을 위하여 발전설비의 고장 감지 및 진단과 상태 모니터링은 중대한 역할을 담당하고 있다. 이 연구에서는 설비의 안전하고 신뢰적인 운전을 위한 기계의 작동상태를 사운드 정보로 획득하고 분석하는 시스템을 제안하였다. 사운드 정보의 사용은 적은 양의 채널의 사용으로 많은 기계 및 설비의 이상 유무의 판별을 가능케 하며, 이를 획득하기 위하여 3개의 마이크로폰, 다채널 A/D변환기, 다채널 I/O Sound Card(Soundtrack DSP24) 및 PC로 시스템을 구성하였다. 소프트웨어 개발언어로서 Microsoft Visual C＋＋ 및 MATLAB을 이용하였다. 화력 발전소에 운전중인 주요기계들의 사운드 정보를 취득하여 취득한 기계별 사운드 정보를 이용하여 주파수 특성을 파악하고, 이를 이용하여 기기의 운전 상태진단을 가능하게 한다.

• Korean Journal of Audiology
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• 제23권3호
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• pp.160-166
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• 2019

Lots of neuroimaging and animal studies have revealed that tinnitus and hyperacusis share the same patterns in the bottom up central auditory process. The aim was to identify the abnormal central patterns commonly observed in both tinnitus and hyperacusis in humans. We investigated two cases of normal hearing: a tinnitus patient and a hyperacusis patient. We compared the differences between the severe temporal hyper-activated state (STHS), with spikes, fast beta and gamma frequencies after noise exposure, and the mild temporal hyperactivated state (MTHS), in no sound exposed condition. The power of the gamma band in the two cases was increased in both auditory cortices compared to the other brain regions. Our results of human with normal hearing were the first to identify how tinnitus and hyperacusis caused by sound are abnormally active and how they maintain constant pathological states.

• Journal of Audiology & Otology
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• 제23권3호
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• pp.160-166
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• 2019

Lots of neuroimaging and animal studies have revealed that tinnitus and hyperacusis share the same patterns in the bottom up central auditory process. The aim was to identify the abnormal central patterns commonly observed in both tinnitus and hyperacusis in humans. We investigated two cases of normal hearing: a tinnitus patient and a hyperacusis patient. We compared the differences between the severe temporal hyper-activated state (STHS), with spikes, fast beta and gamma frequencies after noise exposure, and the mild temporal hyperactivated state (MTHS), in no sound exposed condition. The power of the gamma band in the two cases was increased in both auditory cortices compared to the other brain regions. Our results of human with normal hearing were the first to identify how tinnitus and hyperacusis caused by sound are abnormally active and how they maintain constant pathological states.

• Steel and Composite Structures
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• 제44권6호
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• pp.829-843
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• 2022

This manuscript work presents a comprehensive continuum model capable to investigate the effect of porosity on vibro-acoustic behaviour of functionally graded (FG) beams resting on an elastic foundation subjected to thermal and mechanical loadings. Effects of uniform temperature rise and edge compressive load on the sound radiation characteristics are studied in a comparative manner. The numerical analysis is carried out by combining finite element method with Rayleigh's integral. Detailed parametric studies are accomplished, and influences of power law index, porosity volume, porosity distribution and boundary conditions on the vibro-acoustic response characteristics are analyzed. It is found that the vibro-acoustic response under mechanical edge compression is entirely different compared to from that under the thermal load. Furthermore, nature of grading of porosity affects the sound radiation behaviour for both the loads. The proposed model can be used to obtain the suppression performance of vibration and noise FG porous beams under thermal and mechanical loads.