• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.477-478
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• 2010

It was in the mid-1980s when the shipboard noise analysis was introduced to the Korean shipbuilding industry. Since then through the continued efforts of the industries in the last decades, native computational codes dedicated to the shipboard noise prediction have been developed based on empirical formula and/or sophisticated theories such as SEA and PFM. This paper addresses some problems in dealing with predicting shipboard noise and the way how to overcome the uncertainties in the prediction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.75-80
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• 2002

The shipboard working environment of coastal ship s very inferior to the ground working environment and it causes the avoidance of shipboard working and the aging of crew. Especially the noise in ships causes an occupational disease such as hardness of hearing. Hence to reduce the shipboard working fatigue is necessary by the security of the comfortable shipboard working environment and residence environment. in the sea. And we propose the shipboard working environment by using the measurement results of the shipboard noise and vibration in the sea. And we propose the reduction measures of shipboard working fatigue based on the evaluation results of the shipboard working environment.

• Journal of Navigation and Port Research
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• v.27 no.1
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• pp.15-30
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• 2003

The shipboard working environment of coastal patrol ship is very inferior to the ground working environment and it cause the avoidance of shipboard working and the aging of crew. Especially the noise in ship cause on occupational shipboard working hardness of hearing. Hence to reduce the shipboard working fatigue is necessary by the security of the comfortable shipboard working environment and residence environment. in this paper, firstly we evaluate the shipboard working by suing the measurement results of the evaluation results of the shipboard working environment.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.7-14
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• 2006

In recent years, shipboard noise control is attracting increasing attention to human environmental conditions and crew's opportunity for rest and recreation with work on board. In order to minimize the noise levels, careful attention have to be paid by the experts from initial design stage to the delivery. This paper describes the outlines of shipboard noise control including general characteristics of shipboard noise, measurement, evaluation, prediction, and control measures considering the noise transmission mechanism from source to receiver space.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.849-854
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• 2000

Statistical energy analysis is suitable for shipboard noise prediction in many respects. It could effectively model the large and complicated ship structures for noise analysis. This paper introduces the procedure of SEA for shipboard noise analysis gained from author's experiences in the past few years. Also, prediction accuracies of shipboard noise analysis using statistical energy analysis are discussed. It is found that the prediction results could be much improved when using the actual measured data of source levels and material properties such as loss factors, absorption coefficients and etc.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.7
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• pp.509-516
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• 2014

This paper proposes estimation model of uncertainty in vibration measurement of shipboard equipment and analyzes the result of uncertainty estimation. Vibration of shipboard equipments affects underwater radiated noise that is important performance related to stealth of the naval vessel. Acceptance testing for shipboard equipment is required to guarantee the stealth performance of naval vessel. In measuring, detailed uncertainty estimation is essential to improve measuring reliability. Acceptance testing result of structure-borne noise and vibration is used to analyze uncertainty in vibration measurement of shipboard equipment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.355-358
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• 2008

This study deals with a substantial problems with SEA modeling methods in shipboard noise predictions. As a first problems with respect to modeling, fineness of model that represents a real structure is numerically investigated by comparison among 3 models, Fine, Coarse and Simplified models. Comparison reveals that Fine model shows the lowest noise level among them since this model involve more energy transfer paths than the other models. Influence of in-plane wave is also examined by numerical comparison. It is clear that inclusion of in-plane wave affects the high frequency and the cabin far from a source.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.519-524
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• 2011

The aim of this study is to develop an automated program for noise prediction in shipboard compartments, for this purpose of calculating noise levels accurately and quickly. The program calculates sound power level at HVAC components based on the empirical method suggested by NEBB and utilizing the manufacturer's test data. The program developed uses the GUI functions to help in efficient modeling and calculation. To verify the reliability of developed program, the predicted data was compared with the measured data in shipboard compartments. As a result, the average difference between predicted and measured data is ${\pm}3dB$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1990.10a
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• pp.53-58
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• 1990

The use of spreadsheet packages for solving noise control problems has been cited by several authors, eg Saha[1] and Thornton[2]. The effectiveness of using spreadsheet packages compared with the traditional computer programs written in high level languages was demonstrated when applied to relatively simple problems, such as the selection of hearing protectors or the prediction of noise equation which includes logarithmic additions at most represents the physics of the problem. The simplicity of the governing equation together with the requirement to handle a vast amount of data are considered to be the major reasons for noise control engineers to use spreadsheet packages. Although shipboard noise prediction seems to be very complicated, the calculation procedure itself is, in essence, identical especially true for prediction methods based on empirical formulae[3,4], ie the procedure that consists of the three basic elements, ie source, path and receiver. This paper discusses the application of spreadsheet package LOTUS 1-2-3 to shipboard noise prediction problems. A utility program of the package is written using macro functions and is shown to be especially useful for noise control engineers who are unfamiliar with spreadsheet packages. In addition, a new type of empirical formula, to estimate structureborne noise transmission loss, is proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.411-415
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• 2007

The reduction of airborne and structure-borne noise of a shipboard pump for a navel ship is very important because the noise levels of the pump must not exceed criteria such as MIL-STD. In this paper, several practical examples of reducing the noise levels are presented. The examples show that the inadequate rotor-balancing and shaft-alignment results in the increase of the structure-borne noise on all lower mounts. It is also found that the unequal loading on mounts can cause the dramatically increasing the noise levels on certain local positions. Since the piping system arrangement such as valve location, flexible joint, and elbow location affects on the noise measurement, care must be taken to minimize the unnecessary noise from the piping system.