• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.340-347
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• 2015

The Commission for Conservation of Antarctic Marine Living Resources (CCAMLR) is utilized to manage krill resources using acoustic data collection and a scientific observer program operating on the fishing boats. However, the acoustic data were contained seriously noise, example of background, spike, and intermittent noise, due to purpose of fish boats. In this study, the noise removal techniques were confirmed the potential of the acoustic data analysis. Acoustic system and frequency used in the survey were commercial echosounder (ES70, SIMRAD) and 200 kHz split beam transducer. Acoustic data were analyzed using Echoview software (Myriax), and general data analysis and new noise removal method was used. Although a variety of noise, most of the noises have been removed using the noise removal processing. We confirmed the possibility of analyzing the acoustic data obtained from fish boats. The results will be useful for analysis of the acoustic data acquired from krill fishing boats.

• Journal of the Korea Furniture Society
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• v.28 no.4
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• pp.355-361
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• 2017

Indoor noise environment is an important factor when it comes to occupants comfort, especially in cafe. Results of the survey, 33.9% of occupants were feel unpleasant and sensitive about noise environment. Noise in cafe fluctuate depending on the finishing of both wall and ceiling, volume of the room, and the number of occupants in the room. Therefore, the noise meter device was used for measurement of various under conditions. Also, the subjective assessment of occupant noise was conducted through questionnaires. When the interior finish was exposed concrete, the maximum value of the noise measurement was 66.6 dB and the minimum value was 63 dB, respectively. Also, the result of subjective assessment of unpleasant noise were 5.43 and 4.96 point of 10 point of noise and echo, respectively. Otherwise, the interior finish was gypsum board, the maximum value of the noise measurement was 73.8 dB and the minimum value was 60.4 dB, respectively. Also, the result of subjective assessment of unpleasant noise were 3.88 and 3.95 point of 10 point of noise and echo, respectively. The results of the study showed that the noises and echoes in the cafes were lower than when did not.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.2
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• pp.179-184
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• 2010

In this study, the satisfaction rating to the floor impact sound was investigated for the residents in the apartment Building where the business scheme had been approved after 2005. The results are compared with existing research. The questionnaire survey was conducted to the 597 residents in 14 apartments complex which were applied with standard floor structure and approval floor structure. Most of respondents(71.1 %) answered that the performance of floor impact sound insulation, in case of standard floor structure, was improved compared to the apartments where they used to live. Comparing with the questionnaire survey result of existing research, the answered ratio of 'less annoyed' and 'less loud' is somewhat increased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2361-2367
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• 2011

In this paper survey and analysis of recent trends in noise barriers and noise measurements and assessments were conducted for providing design basis of ANC barriers. Looking at the results, transparent barrier(glass) has received the most attention in domestic and foreign countries, because it has a harmony with the surrounding environment and easy installation in a small space. For optimal barrier design using computer simulation, reliability of simulation has been verified and classified into 5 groups, according to barrier's upper cross section. Evaluation results of barrier's performance and design using computer simulation are as follows : In the case of the "B-type" barrier, it has improved maximum 2.5dB(A) at each point(R1~R6) and have a good workability. Therefore, "B-type" Barriers applied to the next active noise barrier system will be possible.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1347-1354
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• 1994

This paper deals with the experimental research, including measurement and analysis and field survey, on the causes of occurring noise defective gear boxes in hoist production plant in order to reduce the fraction of their occurrence. In this reserch following investigations are performed : measurement and gear-boxes, examination of each machining process of production, measurement and analysis of dimensional accuracy of each part, comparative vibration test with exchanging inaccurate parts. From these investigations, it is found that the machining accuracy of pinion gear tooth thickness is the most sensitive factor of noise problem. By maintaining the tooth thickness error within 0.05 mm tolerance in the gear cutting process, the fraction of noise defective gear-boxes are greatly reduced to less than 2%, where the usual rate of it has been 20-50%.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.358.1-358
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• 2002

Recently a number of social surveys on community response to environmental noises have been conducted. Since standardized noise annoyance scales were needed to compare the results from various areas, ICBEN(International Commission on Biological of Noise) Team 6 planned a international joint study and constructed comparable standardized noise annoyance scales using the same method. In Korea the survey was conducted in four areas such as Seoul, Taejon, Honam and Yongnam. 100 subjects participated in each area approximately. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.102-107
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• 2001

Recently, with the increasing of construction works, large construction equipment are used to reduce the term of work and labor cost in construction field. Therefore, construction equipment noise has caused much annoyance for a number of dweller in nearby construction field and it has become a very serious problem in our living environment. Neverthless, in our country, adequite guidelines for the construction equipment noise are very deficiency because of the lack of basic data and insufficient research works. From this point of view, this study attempts to survey the characteristics and prediction of piling noise in oil pressure method. On the basis of measurement value, we analysed about prediction possibility of piling noise in oil pressure method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.96-101
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• 2001

Recently, with the increasing of construction works, large construction equipment are used to reduce the term of work and labor cost in construction field. Therefore, construction equipment noise has caused much annoyance for a number of dweller in nearby construction field and it has become a very serious problem in our living environment. Neverthless, in our country, adequite guidelines for the construction equipment noise are very deficiency because of the lack of basic data and insufficient research works. From this point of view, this study attempts to survey the vertical SPL distribution of piling noise by oil pressure method in construction field. This study also present a basic data found a effective plans for piling noise by oil pressure method.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.1
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• pp.23-28
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• 2002

In order to survey the radiation characteristics of pure line noise of unwanted noise from overhead high voltage AC transmission lines, a disk type gap noise generator was manufactured. Disk size which decides capacitance between the noise generator and earth was selected through preliminary indoor experiments and analysis by using surface charge method. The capacitance is one of principal parameters related to the injection of a proper noise current into lines. On the basis of the capacitance obtained from calculation, 5mm of space was given to the gap of the noise generator to be installed o test line and an aluminum disk of 60cm radius was made. The field experiments were performed with the noise generator hung on the Kochang 765 kV full scale test line. As the results, the useful data which can be used to analysis the radiation characteristics of noise from transmission lines were obtained. Those are the directivity of antenna toward the line, lateral profiles, frequency spectra, height pattern and so on.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.712-713
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• 2009