• KIEAE Journal
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• v.9 no.1
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• pp.99-106
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• 2009

This study aims to survey the acoustical environment in the region around airport where there are various transportation noises such as aircraft noise, railway noise and traffic noise, and to analyze the subjective response on the noise to the people who live in house or work in office nearby airport. Measurement and subjective response evaluation were carried out at the same time and outdoor noise level was measured all day long to calculate one day results such as average Leq or one day WECPNL etc. The results showed that the military aircraft produces very high level comparing with commercial aircraft, for instance the sound level of commercial outdoor was lower than that of military aircraft indoor. Double and triple window were more effective for controlling the noise than single window, which showed the possibility of sound insulation treatment by installing windows having higher sound insulation performance. Finally the subjective response was resulted that the most annoying noise is from aircraft and counterplan they hope is 'airport moving out'. Leq 65 dB(A), the criteria value of sound insulation treatment, was corresponding to the subjective response of median annoyance '4' out of 7th scale.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.2
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• pp.175-183
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• 2014

In this paper, we present the design and implementation of real-time sound localization based on $0.13{\mu}m$ CMOS process. Time delay of arrival (TDOA) estimation was used to obtain the direction of the sound signal. The sound localization chip consists of four modules: data buffering, short-term energy calculation, cross correlation, and azimuth calculation. Our chip achieved real-time processing speed with full range ($360^{\circ}$) using three microphones. Additionally, we developed a dedicated sound localization circuit (DSLC) system for measuring the accuracy of the sound localization chip. The DSLC system revealed that our chip gave reasonably accurate results in an experiment that was carried out in a noisy and reverberant environment. In addition, the performance of our chip was compared with those of other chip designs.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.4
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• pp.335-346
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• 2009

As the economy has grown and the main industry in Korea has been changed from secondary industry to tertiary industry, the importance of indoor environment has been a matter of common concern, in which one of the main concerns is to improve the indoor acoustic conditions. However, even though this is required more than before, there are no measures to protect the human being from the noise of electric home appliances. This is owing to the absence of the data about sound power level of electric home appliances. So, we investigate the sound power level of them and analyze the acoustical characteristics of each one. First, we tried to investigate the sound power measurement method of each electric home appliance. After it we test the sound power level of them. From the survey, we can know that the vacuum cleaner is the most noisy electric home appliance, and the refrigerator is the least noisy one. This results will help us predict the indoor noise level using the basic data of sound power level.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5936-5954
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• 2018

Eight out of the top ten the largest technology companies in the world are involved in some way with the coming mobile VR revolution since Facebook acquired Oculus. This trend has allowed the technology related with mobile VR to achieve remarkable growth in both academic and industry. Therefore, the importance of reproducing the acoustic expression for users to experience more realistic is increasing because auditory cues can enhance the perception of the complicated surrounding environment without the visual system in VR. This paper presents a audio downmixing system for auralization based on hardware, a stage of sound rendering pipelines that can reproduce realiy-like sound but requires high computation costs. The proposed system is verified through an FPGA platform with the special focus on hardware architectural designs for low power and real-time. The results show that the proposed system on an FPGA can downmix maximum 5 sources in real-time rate (52 FPS), with 382 mW low power consumptions. Furthermore, the generated 3D sound with the proposed system was verified with satisfactory results of sound quality via the user evaluation.

• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.14-20
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• 2007

The properties of the wood pellets from damaged wood by forest fire and sound woods were investigated. Oven-dry densities of pellets made from sound wood and the damaged wood of Pinus densiflora were 0.93~0.94 and 0.86~0.88, respectively. Compressive strength of the pellets from the woods was ranged from 145 to $168kgf/cm^2$, and there was little difference between the sound wood and the damaged wood of P. densiflora. Ash content for the sound wood and the damaged wood of Pinus densiflora were 0.32~0.37% and 0.25~0.35%, respectively, and calorific values of each pellet were ranged from 18 to 19 MJ/kg. The result of elemental analysis in carbon. hydrogen and oxygen showed 45.8~48.8%, 6.2~6.5% and 46.5~48.0%, respectively. Consequently, there seem no significant difference in the properties between damaged and sound wood pellets.

• KIEAE Journal
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• v.8 no.1
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• pp.31-36
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• 2008

For the comfortable housing life, comfortable and pleasant urban environment should be created for the people living in house and in city. There are lots of environmental conditions in city affecting house and life. Also most of all the noise pollution have been become major factor that makes people's life uncomfortable. Recently soundscape researches have been performed to create comfortable urban environment and various studies on the evaluation of urban environmental sounds are now undergoing. This study aimed to analyse the subjective characteristics through the subjective evaluation to the sounds measured with physical parameters and eventually to find out alternative evaluation method for urban environmental sounds. Adjectives applied to previous studies were used for the subjective evaluation and sound sources recorded in specific places were presented with picture at the same time. As a result, new physical parameters such as Lmax, Unbiased Annoyance, G, N and EmT have a feasibility to evaluation of urban environment sounds in terms of acoustic comfort.

• The Journal of Fisheries Business Administration
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• v.36 no.1 s.67
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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 Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.670-673
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• 2005

For the comfortable housing life, an urban environment should give comfort and pleasantness to people living in house and in city. There are lots of environmental conditions in city affecting house and life and most of all the noise pollution have been become factor that makes people's life hard without need to say. Recently researches have been performed to create comfortable urban environment and a study on the evaluation of urban environmental sounds is now undergoing. This study aimed to analyse the subjective characteristics through the subjective evaluation to the sounds measured with physical parameters and eventually to find out evaluation method for urban environmental sounds. Vocabularies applied to previous studies were used for the subjective evaluation and sound sources recorded in specific places were presented with picture at the same time.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.154-161
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• 2014

Demands for Korean Traditional Residence Complexes as a more humane resident space have recently been increasing for the purposes of users' health and convenience, built with the purpose of reflecting various trends. This study is aimed at examining the physical characteristics of design in residence complexes by analyzing the physical characteristics of the sound environment as auditory elements of Hanok Complexes and the relationship between spatial and visual test values. The results were shown as follows: In subjective evaluation at Hanok, Natural sounds were recognized higher but artificial sounds were lower. According to the interrelationship analysis between subjective evaluation and physical measurement values, entrance (regular-StdDev), yard (regular-NbEm, friendly-G), waterside (regular-articulation index(rooms), StdDev, $L_{min}$, Rem), etc had been shown highly related.

• KIEAE Journal
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• v.3 no.3
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• pp.27-34
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• 2003

As a result of supply-oriented housing policy of Korea since the 1960s, the number of apartment housing units has increased up to six million as of the end of 2001 that is 55% of total housing units. Although the needs of placid living environment increases according to the enhancement of residents' living standard, most of construction firms as apartment suppliers plan and design apartment buildings to maximize the profit and give rise the residents' petitions and troubles about floor impact noise. In consequence, the floor impact noise becomes one of principal problems of living environment, and the government placed the obligation of installing the noise isolation materials between upper and lower floors in 2001 and controlling the floor impact noise lower than 60dB from the middle of 2004. In other to provide the fundamental research data to enhance the reduction performance of floor impact sound, in this paper, the factors that influence on the floor impact noise are derived from the survey of many research papers and the performance of various materials used as noise reduction objects are compared and surveyed with the factors in the experiments in field and laboratory.