• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.6
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• pp.431-436
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• 2002

The interior sound pressure level of the Korean high-speed train(KHST) is predicted by geometrical acoustic method. For the Purpose of assuring the prediction of Interior noise of KHST by the geometrical acoustic scheme, calculated sound level values of the Korean train express(KTX) by Identical geometrical method are compared with measured values of KTX prototype vehicle by experiment. Contribution of individual sound source of KHST vehicle Into the interior response positions is calculated and sound sources are classified in influential order. Hence, it is reasonable approach to reduce sound power of most contributing noise source first. Sensitivity of the interior response position's sound pressure level (SPL) with respect to train wall sections' transmission loss are carried on and acoustically sensitive spot is identified, for example window area for passenger cabin case. Those contribution and sensitivity analysis results are suggested to design quieter train efficiently.

• Archives of Plastic Surgery
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• v.32 no.6
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• pp.744-752
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• 2005

Many craniofacial and neurosurgical procedures rely on cranial bone as a bone graft. In the majority of instances, the bone heals and gives good results. But we found that if either the dura or the pericranium were missing adjacent to the cranial bone, bone absorption would be increased. We studied a single animal model, investigating the contribution of the dura and the pericranium in the process of cranial bone absorption. The animals were divided into four groups of each five animals depending on the differential blockade of the dura and/or the pericranium by silastic sheet. Bilateral $100-mm^2$, parietal bone flaps were harvested from mature rabbits. Animals were humanely killed after 12 weeks, and histomorphometric analysis was performed. The volume maintenance is as follows; Group I; 89.0%, Group II; 80.0%, Group III; 63.3%, Group IV; 52.4%. The weight maintenance; Group I; 87.1%, Group II; 79.4%, Group III; 61.6%, Group IV; 51.1%. The histological contribution of living bone; Group I; 92.9%, Group II; 85.6%, Group III; 71.1%, Group IV; 56.2%. Significantly increased bone absorption occurred in Group II, III, IV compared with Group I. Conclusions are: 1. Cranial bone absorption is effected by both the dura and the pericranium. 2. The dura is more important than the pericranium in preventing cranial bone absorption. 3. The dura to be the source of central cranial bone and the pericranium to be the source of peripheral cranial bone.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.10
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• pp.11-17
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• 2021

This study aims to know the contribution of external debt to Indonesia's economic growth. The data used a source from the Central Bank of Indonesia from 2011 to 2020. This empirical study uses a quantitative approach with Error Correction Model as the regression method. Government expenditure, government revenue, export, import, inflation, and exchange rate are control variables. The result of the descriptive statistic shows economic growth in Indonesia increased gradually from 2011 to 2020. The increase in economic growth occurred regardless of the contribution of external debt. It does, however, inform the public that Indonesia's economic system has seen successful investments. The result of the study is classified into long-term and short-term. External debt contributes to growth in the long term and has a significant impact. The study's findings will give Indonesia optimism that it can manage external debt as a source of domestic investment. This research may also persuade Indonesia to maintain its economic potency in the future. In the future, this research can be perfected, by adding a threshold level on the amount of Indonesia's external debt.

• Computers and Concrete
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• v.30 no.1
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• pp.43-74
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• 2022

Machine learning technique is recently opening new opportunities to identify the complex shear transfer mechanisms of reinforced concrete (RC) beam members. This study employed 1224 shear test specimens to train decision tree-based machine learning (ML) programs, by which strong correlations between shear capacity of RC beams and key input parameters were affirmed. In addition, shear contributions of concrete and shear reinforcement (the so-called V_c and V_s) were identified by establishing three independent ML models trained under different strategies with various combinations of datasets. Detailed parametric studies were then conducted by utilizing the well-trained ML models. It appeared that the presence of shear reinforcement can make the predicted shear contribution from concrete in RC beams larger than the pure shear contribution of concrete due to the intervention effect between shear reinforcement and concrete. On the other hand, the size effect also brought a significant impact on the shear contribution of concrete (V_c), whereas, the addition of shear reinforcements can effectively mitigate the size effect. It was also found that concrete tends to be the primary source of shear resistance when shear span-depth ratio a/d<1.0 while shear reinforcements become the primary source of shear resistance when a/d>2.0.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.650-651
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• 2008

In this thesis, source identification tool for NI-PXI equipment is developed with LabVEIW. For the purpose of examining propriety of developed tool, simulation is performed with several signals that have different frequency range. After checking the coherence functions for concerned frequency domain, an experiment is conducted on an evaporator that cause the principal noise of a refrigerator.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.520-529
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• 2015

The ambient $PM_{2.5}$ samples were collected by $PM_{2.5}$ sampler from September 2010 to December 2012 at Daegu University, Gyeongsan. A total of 260 samples were collected and 27 species were analyzed by inductively coupled plasma, ion chromatography, and thermal optical reflectance methods. Factor analysis identified four sources such as biomass burning source/secondary aerosol source, soil source, industry source, and incinerator source/mobile source. Also, backward trajectories were calculated using HYSPLIT 4 (Hybrid single-particle lagrangian integrated trajectory) model and PSCF (Potential source contribution function) model was applied to identify the possible source locations of carbonaceous species and water soluble ions species. PSCF results showed that the possible source locations of most chemical constituents measured in Gyeongsan were the industrial areas in the eastern coast of China, northeast regions of China, the Gobi Desert, and east sea of Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.2
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• pp.179-189
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• 2006

Ambient gas phase mercury concentrations including elemental mercury ($Hg^0$) were measured at the Potsdam, Stockton, and Sterling sites in NY from 2000 to 2003. Also, concentrations of ambient reactive gaseous mercury (RGM; $Hg^{2+}$) were measured at the Potsdam site during one year. The contribution of RGM($4.2{\pm}6.4pg/m^3$) was about $0.2{\sim}3%$ of the total gas phase mercury concentration measured (TGM: $1.84{\pm}1.24,\;1.83{\pm}0.32,\;3.02{\pm}2.14ng/m^3$ in Potsdam. Stockton, and Sterling, respectively) at the receptor sites. Potential Source Contribution Function (PSCF), a hybrid receptor modeling incorporating backward trajectories was performed to identify source areas of TGM. Using PSCF, southern New York, North Carolina, and eastern Massachusetts were identified as important source areas in the United States, while the copper smelters and waste incinerators located in eastern Quebec and Ontario were determined to be significant sources in Canada. The Atlantic Ocean was suggested to be a possible mercury source. PSCF incorporating back-dispersion and deposition was applied for RGM , as well as PSCF based on 2-days back-trajectories. Two different approaches yielded considerably different results, primarily due to the consideration of dispersion rather than deposition. Using back-trajectory based PSCF, eastern Ohio, southern New York, and southern Pennsylvania where large coal -fired power plants area located were identified as the large sources in US. Metallurgical industry located in eastern Quebec was resolved as well. From the result of back-dispersion and deposition based PSCF, Pennsylvania, mining facilities around Lake Superior, Toronto, Boston, MA, Quebec, and coal power plants in NY were identified to be the significant source areas for Potsdam site.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.E
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• pp.358-363
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• 1993

Total particulate mater (TPM), $NO_2$ and $NH_3$ were measured simultaneously in the smoking and non-smoking locations during an eleven month period from March 1986 to January 1987 at three sites in Chicago : Illinois Institute of Technology Cafeteria, Rush-Presbyterian St. Lukes Medical Center Cafeteria and a downtown office building. From this study, the mean concentrations of $NO_2$ and $NH_3$ were not significantly different between the smoking and non-smoking locations at any sampling site ; however, there was a statistical difference for TPM between the smoking and non-smoking locations. Activity factor was useful for describing the contribution from indoor source. The linear regression analysis was reasonable method for discriminating the individual contribution of source to determine the emission factor. The TPM emission factor determined from this technique was in good agreement with value from the literature.

• Journal of Information Technology Services
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• v.5 no.1
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• pp.149-164
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• 2006

The companies are trying to apply to software development approach by utilizing open-source components. The open-source components are new alternatives to solve limits of the previous software developments such as quality of software, time and cost of development. Accordingly, various analysis of open-source components were performed. However, the researches about the detailed procedures and methods to utilize open-source components in practical industry are immature. In this paper, we propose the procedures and cases for identifying, validating, selecting of suitable open-source components and for applying to change and modification. Proposed procedures and cases will be a great contribution to spread of utilizing the open-source.

• The Journal of the Acoustical Society of Korea
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• v.35 no.2
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• pp.118-124
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• 2016

In this paper, contribution analysis method using a partial coherence function is dealt with in the case of underwater radiation noise. When performing the contribution analysis using a partial coherence function, it is important to select the order of system input. But in the case of frequency correlated systems, it is very difficult to properly select the order of system input. In order to solve this problem, the contribution analysis is performed by subdividing the area of contribution using multiple coherence function. And the new contribution analysis method is presented by using the relationship between the contribution characteristic matrix and multiple coherence function. In order to validate the new method, calculation is performed about multi-input / single-output model which is composed of sine waves. The result of calculation shows that it is possible to derive the exact contribution values.