• Journal of Computing Science and Engineering
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• v.9 no.4
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• pp.190-203
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• 2015

Free and open source software (FOSS) has created a large pool of source codes that can be easily copied to create new applications. However, a copy should preserve copyright notice and license of the original file unless the license explicitly permits such a change. Through software evolution, it is challenging to keep original licenses or choose proper licenses. As a result, there are many potential license violations. Despite the fact that violations can have high impact on protecting copyright, identification of violations is highly complex. It relies on manual inspections by experts. However, such inspection cannot be scaled up with open source software released daily worldwide. To make this process scalable, we propose the following two methods: use machine-based algorithms to narrow down the potential violations; and guide non-experts to manually inspect violations. Using the first method, we found 219 projects (76.6%) with potential violations. Using the second method, we show that the accuracy of crowds is comparable to that of experts. Our techniques might help developers identify potential violations, understand the causes, and resolve these violations.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.4
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• pp.347-354
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• 2009

Frequency analysis is one of the most useful way to analyze response signal for the purpose of grasping the dynamic characteristics of system through Fourier transformation. Although it is very effective way for frequency analysis, it is hard to analyze out a specific sound or vibration component which is correlated with others. In this thesis, source contribution analysis tool for NI-PXI equipment is developed with LabVIEW using coherences of MISO(multiple-input single-output) model. For the purpose of examining propriety of developed tool, simulation is performed with several correlated signals that have different frequency range. After checking the OCF(ordinary coherence function) and PCF(partial coherence function) of the each signal for concerned frequency domain, an experiment is conducted on an evaporator that cause the principal noise of a refrigerator. This developed tool will be expected to build up more convenient and serviceable measurement system.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.4
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• pp.43-55
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• 1986

In the studies of noise reduction, it is important to know the generation mechanism of noise in order to identify the noise source. The relation between the structural vibration and the radiated sound is very complex and so this paper deals with a simplified radiation model that was originally developed as a verification tool for the acoustic intensity measurement procedure. As the first step for the identification of the noise source, this study deals with the noise evaluation by measuring sound pressure. On the next step, the acoustic radiational pattern is determined by the acoustic intensity method and this paper established that the acoustic intensity method is effective on the detection of noise. In the study, furthermore, the method could be used to predict the change in the sound radiational characteristics with the attachment of absorber and could be used in determining the attachment position.

• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.87-101
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• 2023

The constituents of a watershed control a wide range of ecosystem processes, such as, carbon sequestration, nutrient retention, and biodiversity preservation. Maintenance of a healthy watershed is advantageous to humans in many direct and indirect ways. Dissolved organic matter fluorescence analysis is one of the most commonly utilized parameters for water quality measurement, pollution source tracking, and determination of the ecological state of a watershed. Throughout the recent decades, the advancement in data processing, instrumentation, and methods has resulted in many improvements in the area of watershed study with fluorescence analysis. The current trend of coupling advanced instrumentations and new comparative parameters, such as, microplastics of different types, antibiotics, and specific bacterial contaminants have been reported in watershed studies. However, conventional methodologies for obtaining fluorescence excitation emission matrices and for calculating the fluorescence and spectral indices are preferred to advanced methods, due to their easiness and simple data collection. This review aims to gain a general understanding of the use of dissolved organic matter fluorescence analysis for diagnosis and source identification of watershed pollutions, by focusing on how the studies have utilized fluorescence analysis to improve existing knowledge and techniques in recent years.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.353-354
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.206-207
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.124-125
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• 2004

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.222-223
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• 2009

• The Bulletin of The Korean Astronomical Society
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• v.34 no.1
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• pp.83.2-83.2
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.486-489
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• 2004

The NAH based on the inverse BEM is used to reconstruct the source field, which is advantageous in dealing with the irregular source. In the implementation of this technique, a large number of pressure measurements is required because an over-determined pressure data set is required. These conditions accordingly cause the increase of measurement time and associated effort along with the error due to mal-positioning. The purpose of this study is to reduce such inconveniences: Instead of increasing the number of field pressure data, the number of transfer paths between the source and the receiver is increased by placing rigid scattering body in-between the source and receiver. For validating the usefulness and effectiveness of the method, the numerical analyses of interior problem are demonstrated. As a result, it is thought that the proposed method enables the measurement at smaller number of sensor positions and the monitoring of surface vibration with less experimental effects than before.