• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.1
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• pp.69-77
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• 2021

The noise environment was evaluated using the ISO recommended NR evaluation curve and PSIL (Preferred Sound Interference Level) in order to investigate the onboard educational environment according to the noise in the Motor Vessel Saehaerim, a fishing training ship under making way. As a result, NRNs were measured at 37-61 dB in accommodation areas, 44-56 dB in work areas, 37-57 dB in educational and conference areas, 83-103 dB in engine areas and 65.3 dB and 51.2 dB in the work and education areas respectively based on PSIL. The NRNs, which evaluated the cabin of the experimental ship according to the purpose, exceeded all of the indoor standard noise recommended by the ISO, and the PSIL had a generally short conversational distance within 0.25-2.3 m and 0.75-1.3 m for teaching and work areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2516-2523
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• 2013

Noise occurred when medical treatment in dental clinic will affect the patients. This study was measured the noise level and frequency in case of medical examination and also has evaluated the degree of indoor noise using the NR-curve, NRN and a distance to conversation between worker and patients using the PSIL. It shows that noise level was 69.3~81.5dB(A) and frequency was very high (more than 4K(Hz)) and analysis by NR-curve showed that it was exceed the noise permit level and distance to conversation was less than 1meter by PSIL. To remedy a fear of noise in patients and provide a conversational satisfaction, it's considered that choosing the low noise-vib. equipment, using the masking effect and set the room to explain. So It is possible to improve their competitiveness.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1123-1128
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• 2009

Noise radiated from medical treatment at dental clinic will affect the patients. On such point of view, We investigated the noise characteristics in case of medical treatment (scaling, tooth eliminating) and non-medical examination (idling) and also evaluated the degree of indoor noise using the evaluation index such as PSIL, NRN and made up a questionnaire about the reactions to noise. As a result of noise evaluation, it shows that the range of noise level is 67.7~78.3 dB(A) and frequency is very high (above 4 k Hz) and respondents are affected by noise (unpleasantness, hesitation to visit dental clinic, shivering with noise, being astonishment). Analysis by PSIL showed that it was no problem to conversation between worker and patient. But it exceeded the noise permit level in working space by NR-curve. To relieve a fear of noise in patients, they are considered to offer the ear protection, choose the low noisevibration equipment and use the masking effect. They are of great advantage to dental clinics to i prove dental service and competitiveness.

• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.181-188
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• 2022

In this paper, we proposed of the results of the noise level and appropriate conversation distance by applying the noise characteristics generated during treatment at a dental clinic to the NR-curve and PSIL. As a result of analyzing the noise characteristics during treatment at a dental clinic, it was analyzed that the noise level exceeded 60dB(A), which is the health preservation limit value caused by noise, and the noise level increased as the frequency increased. the result of evaluation applying it to the NR curve, some treatment exceeded the workplace noise standard, and as a result of analyzing the level of conversational disturbance between the worker and the patient, it is desirable to have the conversation at a distance of less than 1M for accurate communication. In order to improve the quality of medical service in dental clinic and to reduce dental fear, it is judged that soundproofing protective equipment is provided to workers, and soundproofing measures are needed for noise sources (treatment devices used in treatment) and sound sources (patients and workers).

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.4
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• pp.374-385
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• 2012

The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as "Loudness" and "Annoyance", psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of "Loudness" and "Annoyance" for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as "Loudness" and "Annoyance", with respect to a human's sense of hearing, a back-propagation neural network is applied.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.7
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• pp.650-656
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• 2011

The noise inside a naval vessel is very important in considering the need for hearing protection, improving the working environment and maintaining good communications for crews living on board a naval vessel. The indoor noise of a ship usually is specified by the A-weighted sound pressure level, but other evaluating parameters are required to reflect human senses more effectively. This paper uses additional noise indices related to room acoustics, such as NR(noise rating), NC(noise criterion), RC(room criterion), PSIL(preferred speech interference level) and loudness level to evaluate the noise inside cabins on a naval vessel. Using these psychological noise indices, allowable limit of noise level in cabins is suggested through psycho-acoustic evaluation for the noise in cabins.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.705-711
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• 2008

In case of the domestic condition, as the initiating from Sumjin River Dam, total 14 units of multipurpose dams had been constructed in 1965 for the roles of flood control, waterpower generation, irrigation, water supply, industrial water supply. In the case of such multipurpose dam, it produces electric energy by converting the potential energy utilizing its head and quantity of the water into kinetic energy. However, in this process, since during the time when the turbine connected to the hydraulic turbine dynamo revolves and there occurs a loud noise, it brings the physical, mental bad influences to those people also a decline of an effective working efficiency. On such point of view, after selection of various 16 measurement points, this study has measured and analyzed the travelling characteristics of noise generated at the hydraulic turbine dynamo in Daechung Dam, and also has evaluated the degree of indoor noise using the evaluation index such as PSIL, NC. As the result of noise-evaluation, in case of Daechung Dam, since the noise damage grade appears very seriously at various spaces, it is considering that its soundproof measure would be necessitated keenly. Also, it is considered that such data could be utilized as the valuable material hereafter for establishment of an efficient noise-reduction countermeasure and a comfortable working environment for the hydraulic turbine dynamo plant.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.231-235
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• 2007

Stone Industry in our country is classified mainly in view of supply of raw materials ingredients, as follows: Stone-Quarrying Industry who develops the natural resources, Stone Processing Industry who processes the quarried raw ore into construction materials and stone-products, Stony Mountain-Aggregate Industry who supplies the elementary raw materials ingredients to construction section, respectively. Among them, while Stone Processing Industry sells its turnover around billion-Won level per annum per a company, most of other job sites are paltry, adopting less than 10 employees, and it is real state that their working environments are also very coarse. The Noise originated from processing-instrument which generates at such Stone Processing Industry is as so repeatedly reiterating Loud Noise that most of the spot workers are forcedly imposing such dangers as the severe unpleasant feeling and hearing impairments. On this viewpoint, this Research is now analyzing on the frequency characteristics with regard to the Noise that generated from various processing-instruments, and then based on this, in order to grasp the influence of the Loud Noise generating when process the stone materials, this study has ever evaluated it with PSIL and NR. It is considered that such data could be used as the valuable material for establishment of a comfortable working environment hereafter.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.10
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• pp.537-544
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• 2009

On account of the technological development, intelligent building is on increasing where the artificial regulation on indoor environment is possible, thence the concern about those facilities such as water-supply facility, water-heater and drainage facility has becomes higher. However, due to diversification and complicated system of the facility-equipments, the noise generating from such facility equipment is gradually becoming a problem, and since especially equipment noises arising at the machine room frequently infringe into the resident's pleasant living environment with the complex types of an air-borne sound and a structure-borne sound, it is becoming the civil complaint. On such viewpoint, this Study ever observed the characteristics of noise generating from various facility-equipments in the building, and intended to evaluate the facility-noises by use of the valuation index such as PSIL, N, NC, NR. As result of, the facilities noise which happens in the machine room makes normal conversation very difficult due to high sound pressure level. Based on such data, this study is willing to present it as an essential material for establishment an efficient measure against the facility-noises arising at machine room hereafter.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.11
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• pp.1113-1120
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• 2012

This paper deals with the analysis of interior noise and low frequency noise characteristic for the Busan citizens to use public transport, Busan Metro Line 3. The interior noise evaluation index, articulation index(AI) is evaluated the lower value about average 22 % in a whole range, this is difficult to have a conversation. Also, noise criteria(NC) curve is partially evaluated as NC-65 below 2000 Hz, space type is evaluated as factories. Another of interior noise evaluation index, preferred speech interference level(PSIL) is evaluated the upper value about average 66 dB(A) in a whole range, this is evaluated to be interrupted. In the case of low frequency noise(20~200 Hz), the measurement of low frequency noise is assessed largely beyond noise criteria of ISO 226. The low frequency noise should be reduced because low frequency noise affects on psychological stress and displeasure although low frequency noise is not recognized by auditory sense. The low frequency noise criteria and guideline will be enacted from now on in Korea.