• Hwankyungkyoyuk
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• v.15 no.2
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• pp.86-99
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• 2002

The purpose of this study is to make clear the management of Environmental Education in Elementary school in Korea. To accomplish this purpose, The research for the actual condition of management of Environmental Education according to school, grade, and class was progressed. The researcher was analyzed Hindrance Factors of Sound Environmental Education in School and presented some suggestion on the basis of above-mentioned findings. On one side, the method of research is a case study on qualitative based way. A case study was conducted with it's focus on public elementary school in Seoul. As for major research methods, observation by participating in school field and in-depth interview were respectively employed; subsidiary methods included literature study. The findings of this study are as belows: First, Environmental Education was not managed practically with specific way in school. Second, Environmental Education by direct and actual outdoor experience was unusual. Third, most of class school work about Environmental Education was focused on not only the type of prescription after the environmental problem but also, the treatment of articles in newspaper and TV. Forth, educational compulsion such as “you have to do that.” was mainly used as Environmental guidance for sound attitude in school without clear reasons. In the last analysis, hindrance factors of sound management for environmental education in elementary schools were ‘passive adjustment’, ‘discriminative reception’, ‘absence of information resource’. these factors came from atmosphere of negligence environmental education in schools. Therefore, all of teachers have to affirmative belief and attitude as personal dimension and all of elementary schools improve environmental education system.

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.292-297
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• 2010

Sound absorption capability and anatomical features of kagikazura (Uncaria rhynchophylla) and larch (lalix kaemferi) wood were estimated. Sound absorption coefficients had been measured by the two microphone transfer function method and anatomical features of kagikazura wood examined by SEM observation. The sound absorption coefficients of Uncaria rhynchophylla was higher than lalix kaemferi. Especially, in the frequency range of 1 to 4KHz, sound absorption coefficients of kagikazura was about 2~3 times higher than those of lalix kaemferi. Abundant and big vessel observed on the cross sectional surface of kagikazura wood and simple perforation plate observed on the longitudinal surface. It was surmised that the abundant big vessel element and simple perforation plate behaved as a sound absorbing pore.

• Journal of the Korean Wood Science and Technology
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• v.46 no.4
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• pp.362-367
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• 2018

This study estimates the sound absorption capability of rice straw particle mats by two methods: the transfer function method and the reverberation room method. In the reverberation method, the central frequency was set to the one-third octave band in the 100-5000 Hz range; in the transfer function method, the frequency range was 500-6400 Hz. Both methods yielded similar noise reduction coefficients of the rice straw mats. The noise reduction coefficient was approximately 0.8, indicating a high sound-absorption property of the mats. Therefore, rice straw matting is a suitable candidate material for sound-barrier walls against highway noise.

• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.463-469
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• 2010

To suggest the practical use of fast growing tree, we estimated the physical and sound absorption properties of Cherospondias axillaris which is one of the japanese fast growing species. The average annual ring width and air dry specific gravity were 8 mm and 0.55 respectively. The sound absorption coefficients of Cherospondias axillaris wood generally seemed to be a little higher than those of other construction materials such as 6 mm thick gypsum board and 18 mm thick fiberboard, and considered that it could be used as a constructing material owing to relatively good mechanical properties and sound absorption properties.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.2
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• pp.85-92
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• 2022

The amphibian breeding habitat is confirmed by mating call. In some cases, the researcher directly identifies the amphibian individual, but in order to designate the habitat, it is necessary to map the mating call region of the amphibian population. Until now, it has been a popular methodology for researchers to hear mating calls and outline their breeding habitats. To improve this subjective methodology, we developed a technique for mapping mating call regions using Unmanned Aerial Vehicle (UAV). The technology uses a UAV, fitted with a sound recorder to record ground mating calls as it flies over an amphibian habitat. The core technology is to synchronize the recorded sound pressure with the flight log of the UAV and predict the sound pressure in a two-dimensional plane with probability density. For a demonstration study of this technology, artificial mating call was generated by a potable speaker on the ground and recorded by a UAV. Then, the recorded sound data was processed with an algorithm developed by us to map mating calls. As a result of the study, the correlation coefficient between the artificial mating call on the ground and the mating call map measured by the UAV was R=0.77. This correlation coefficient proves that our UAV recording system is sufficiently capable of detecting amphibian mating call regions.

• Journal of Environmental Science International
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• v.32 no.1
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• pp.25-35
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• 2023

The purpose of this study was to determine the optimal sound absorption conditions by comparing the sound absorption characteristics of fresh and air-dried leaves of Quercus glauca, the main species of evergreen broadleaf trees (EBLT) in southern Korea. The sound absorption coefficients (SACs) obtained under 18 conditions were comparatively analyzed. The SAC of air-dried leaves improved significantly with increasing leaf layer thickness. The highest average SAC in the fresh leaf group was 0.617, which was observed under the condition of a leaf specimen size of 0.5 × 0.5 cm² and a leaf layer thickness of 1.75 cm. In a group of air-dried leaves, this was 0.615 under the condition of a leaf specimen size of 0.5 × 0.5 cm² and a leaf layer thickness of 2.50 cm. The maximum value of SAC for each wavelength was observed under the condition of a leaf layer thickness of 2.50 cm consisting of 0.5 × 0.5 cm² leaf specimens, ranging from 1,400 Hz to 1,500 Hz.

• Hwankyungkyoyuk
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• v.8 no.1
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• pp.98-106
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• 1995

A current environmental issue, 'Enviromentally Sound and Sustainable Development(ESSD)' is very important in that it is for our common future. Environmental education is essential as a long-term strategy to realize sustainable environments and society. So we developed a new program about ESSD. The purposes of development were as follows. First, introduce ESSD to students, second, make them know ESSD appropriate to our nation, third, make change from economy-centered thoughts to environmental economy-centered thoughts, ultimately make form behaviors related to ESSD. To verify the effects of new developed program, the direct learning was carried out by 212 students in total. Post test scores of experimental groups were significantly higher than those of control groups about four goals, respectively. Therefore this program is effective to achieve four goals of environmental education for ESSD.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.881-890
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• 2022

As individual and group users actively use drones, the risks (Intrusion, Information leakage, and Sircraft crashes and so on) in no-fly zones are also increasing. Therefore, it is necessary to build a system that can detect drones intruding into the no-fly zone. General acoustic drone detection researches do not derive location-independent performance by directly learning drone sound including environmental noise in a deep learning model to overcome environmental noise. In this paper, we propose a drone detection system that collects sounds including environmental noise, and detects drones by removing noise from target sound. After removing environmental noise from the collected sound, the proposed system predicts the drone sound using Mel spectrogram and CNN deep learning. As a result, It is confirmed that the drone detection performance, which was weak due to unstudied environmental noises, can be improved by more than 7%.

• Research in Plant Disease
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• v.20 no.1
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• pp.1-7
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• 2014

Plant growth is considered the sum of cell proliferation and subsequent elongation of the cells. The continuous proliferation and elongation of plant cells are vital to the production of new organs, which have a significant impact on overall plant growth. Accordingly, the relationship between environmental stimuli, such as temperature, light, wind, and sound waves to plant growth is of great interest in studies of plant development. Sound waves can have negative or positive effects on plant growth. In this review paper we have summarized the relationship between sound waves and plant growth response. Sound waves with specific frequencies and intensities can have positive effects on various plant biological indices including seed germination, root elongation, plant height, callus growth, cell cycling, signaling transduction systems, enzymatic and hormonal activities, and gene expression.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.1
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• pp.40-47
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• 2003

This study was conducted to determine the sound paths and transmitted sound level in house. An air-conditioner system was selected a typical sound source. The measured transmission loss data shows that the apertures have an significant effect on the transmitted noise and comparable with the existing theoretical data. Therefore the complex aperture was substitute to quantitative apertures approximately. An effective simulation method, ray tracing and mirror image source method, was employed in the prediction of transmitted sound level. The measured results were efficiently reflected on the simulated results. So it is important that measuring the acoustic parameter prior to the prediction of the transmitted sound level in the house.