• International Journal of Automotive Technology
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• v.7 no.1
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• pp.43-49
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• 2006

In this paper, an index for the evaluation of a vehicle intake booming noise and intake sound quality were developed through a correlation analysis and a multiple factor regression analysis of objective measurement and subjective evaluation data. At first, an intake orifice noise was measured at the wide-open throttle test condition. And then, an acoustic transfer function between intake orifice noise and interior noise at the steady state condition was estimated. Simultaneously, subjective evaluation was carried out with a 10-scale score by 8 intake noise and vibration expert evaluators. Next, the correlation analysis between the psychoacoustic parameters derived from the measured data and the subjective evaluation was performed. The most critical factor was determined and the corresponding index for intake booming noise and sound quality are obtained from the multiple factor regression method. And, the optimal design of intake system was studied using the booming noise and the sound quality evaluation index for expectation performance of intake system. Conclusively, the optimal designing parameters of intake system from noise level and sound quality whose point of view were extracted by adapting comparative weighting between the booming noise and sound quality evaluation index, which optimized the process. These work could be represented guideline to system engineers, designers and test engineers about optimization procedure of system performance by considering both of noise level and sound quality.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.785-790
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• 2014

The purpose of this study is to identify the significant sound quality metric and compose the sound quality index of motor driven roller blind which is part of vehicle sunroof. Before subjective evaluation, sound characteristics of roller blind was analyzed and set the target operating sound for subjective evaluation. Thus, transfer sound of roller blind which has the characteristics of sound modulation was used for subjective evaluation. Linear regression was carried out by chosen Zwicker's metrics which are pointed by comments of jurors. Loudness and sharpness related metrics are prime metrics in sound quality index we composed. Effect of roller blind assay when it is attached to real vehicle was identified to evaluate the validity of index.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.367-374
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• 2005

This paper proposes a sound quality index to evaluate the vehicle interior noise. The index was developed using a correlation analysis of an objective measurement and a subjective evaluation data. First, the objective set of measurements was obtained at two specified driving conditions. One is from a wide-open test condition and the other is from a constant-speed test condition. At the same time, subjective evaluation was carried out using a score of ten scale where 17 test engineers participated in the experiment. The correlation analysis between the psycho-acoustic parameters derived from the objective measurement and the subjective evaluation was performed. The most critical factors at both test conditions were determined, and the corresponding equations for the sound quality were obtained from the multiple factor regression method. Finally, a comparative work between previous index and present index was performed to validate the effectiveness of the proposed index.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.8 s.101
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• pp.939-944
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• 2005

In this paper, a sound quality index for the evaluation of the vehicle intake noise was developed through a correlation analysis of the objective measurement and the subjective evaluation. First, intake orifice noise was measured at the wide-open throttle sweep condition. And then, the acoustic transfer function between intake orifice noise and interior noise was measured. Simultaneously, subjective evaluation was carried out with a 10-scale score by 8 special engineers. The correlation analysis between the psychoacoustic parameters derived from the measurement and the subjective evaluation was performed. The most critical factor was determined and the corresponding sound quality index for intake noise was obtained from the multiple factor regression analysis method. Finally, the effectiveness of the proposed index was validated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1202-1213
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• 2009

Muffler sound quality of a vehicle has widely been evaluated using commercial softwares. However, the commercial softwares are providing only simple sound quality index. To get better sound quality evaluation method of the muffler, a new approach is suggested based on the subjective sound quality test. The suggested subjective sound quality evaluation method is refined with the fuzzy theory. The developed method is applied for the evaluation of various kinds of vehicle muffler sounds.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.2
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• pp.65-71
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• 2020

Worldwide plant market keeps maintaining steady growth rate and along with this trend, domestic plant market and its contractors also maintain such growing tendency. However, in spite of its external growth, win-win growth of domestic material industry that occupies the biggest share in plant industry cost portion is extremely marginal in reality. Domestic plant material suppliers are required to increase awareness of domestic material brand by securing quality and reliability of international standard through improvement of design quality superior to that of overseas material suppliers. Improvement of design quality of plant material becomes an essential element, not an option, for survival of domestic plant industry and its suppliers. Under this background, in this study, priority and importance by each evaluation index was analyzed by materializing plant design stage through survey of experts and defining evaluation index by each design stage and based on this analysis result, evaluation index of stage-gate based decision-making process that may improve design quality of plant material was suggested. It is considered that by utilizing evaluation index of stage-gate based decision-making process being suggested in this study, effective and efficient decision-making of project decision-makers would be enabled and it would be contributory to improve design quality of plant material.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.311-317
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• 2017

In this study, the water quality index was calculated using the water quality monitoring data in the Nakdong River water system and the water quality status was compared with the living standard. The water quality index was selected by the RWQI method CCME-WQI currently used by the Ministry of Environment. The water quality items were selected as 7 items for pH, DO, EC, water temperature, TOC, T-N and T-P. The evaluation period was selected from the last three years (2013~2015) and water quality monitoring data measured within the period were used. As a result of the evaluation, the results of the previous evaluation showed similar tendency to the index of living environment, but the monthly evaluation showed different BOD and T-P results. Therefore, it is concluded that it is more reliable that more complex evaluation than single water quality evaluation is needed for efficient river management.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.1
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• pp.7-12
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• 2019

Variety of companies which carry out R&D projects supported by government are proposing quantitative evaluation index business plans. However, Many companies have difficulties in aspects of selecting quantitative evaluation index and in some cases they have troubles to get results from selecting unsuitable evaluation index. First of all, both methods of gathering the data to be analyzed and the products which are tested by the accredited testing institutes classifying by industrial sectors are classified as the quantitative evaluation index selected by the company according to the eight quality characteristics of ISO/IEC 25023 Standard. Secondly, based on the results of the quantitative evaluation indexes classified into eight quality characteristics of the ISO/IEC 25023 standard, the tendency of the quality characteristics of the quantitative evaluation indexes selected mainly by the companies will be understandable. It is hopefully expected that this research will be helpful to select a quantitative evaluation index to evaluate the quality of software products.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.8-14
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• 2008

This paper studies a more exact flicker evaluation method by detecting power quality disturbances and excluding the effects of power quality disturbances. Up to the present, power quality disturbances affect flicker evaluation index because power quality problems do not have been considered. However, flick index should represent only flicker without power quality disturbances. Thus, in this paper, we present the improved flicker evaluation method which removing the effects of power quality disturbances such as voltage sag and transient caused by fault and inverter/breaker switching. We detect voltage sag and transient using wavelet transform and remove the effects of power quality disturbances from flicker index.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.7 s.100
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• pp.821-828
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• 2005

In our life, we have used many digital appliances. They help us to improve the quality of life but sometimes give us unsatisfactory result. Because they produce specific noise. Especially vacuum cleaner produce much noise that is very annoying. So we need to study what sound metrics affect human sensibility. In this paper, we develop sound quality index for vacuum cleaner using the sound quality metrics defined in psychoacoustics. First, we carry out the subjective evaluation of vacuum cleaner sound to verify what vacuum sound feels good to human. And then artificial neural network estimated the complexity and the nonlinear characteristics of the relations between subjective evaluation and sound metrics. Finally the ANN is trained repeatedly to have a good performance for sound qualify index of the vacuum cleaner. As a result, the sound quality index of vacuum cleaner has a correlation of $93.5\%$ between the subjective evaluation and ANN. So, there exist three factors that Is loudness, sharpness, roughness which affect the sound quality of vacuum cleaner.