• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.70-76
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• 2012

The independent component analysis (ICA) technique is a source identification method that uses statistical independence to separate source signals from measured signals. It has been successfully applied to various fields such as medical care and communication. In this study, the ICA technique was adopted to analyze the vibration source contribution of plate structures. The theory of the ICA technique is introduced and the procedure of the vibration source contribution analysis based on the ICA technique is proposed. To investigate the applicability of the proposed method to plate structures, numerical examples are presented for a rectangular plate under harmonic force excitations. The results show that the proposed method could become an effective tool for the vibration source contribution analysis of a plate structure.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.4
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• pp.387-396
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• 2003

A field study was conducted during the summer time of 2002 to determine compositions of volatile organic compounds (VOCs) emitted from vehicles and to develop source emission profiles that is applied to CMB model to estimate the source contribution of certain area. Source emission profile is widely used for the estimation of source contribution by the chemical mass balance model and have to be developed applicable for the target area of estimation. This study was aimed to develop source emission profile and estimation of source contribution of VOCs after application of the chemical mass balance (CMB) receptor model. After considering the emission inventory and other research results for the VOCs in Seoul, Korea, the sources like vehicle emission (tunnel), gas station (gasoline, diesel), solvent usage (painting operation, dry cleaning, graphic art), and gas fuels were selected for the major VOCs sources. Furthermore, ambient air samples were simultaneously collected from 09:00 to 11:00 for four days at eight different official air quality monitoring sites as receptors in Seoul during summer of 2001. Source samples were collected by canisters, and then about seventy volatile organic compounds were analyzed by gas chromatography with flame ionization detector (GC/FID). Based on both the developed source profiles and the database of the receptors, CMB model was intensively applied to estimate mass contribution of VOCs sources. Examining the source profile from the vehicle, the portion of alkanes of VOCs was highest, and then the portion of aromatics such toluene, m/p-xylene were followed. In case of gas fuel. they have their own components; the content of butane, propane, ethane was higher than any other component according to the fuel usage. The average of the source apportionment on VOCs for 8 sites showed that the major sources were vehicle emission and gas fuels. The vehicle emission source was revealed as having the highest contribution with an average of 49.6%, and followed by solvent with 21.3%, gas fuel with 16.1%, gasoline with 13.1%.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.2
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• pp.155-163
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• 2020

Indoor airborne particles are consisted of outdoor- and indoor-generated particles, which can be characterized by their compositions, generation features and toxicity. The identification of source contribution of indoor and outdoor origin to indoor particles is important to understand PM_2.5 transport in a building as well as its impact on occupant health. The objective of this study is to investigate seasonal source contribution to indoor PM_2.5 concentration depending on airtightness of apartment units. To evaluate the source contribution, particle transport including penetration, generation, exfiltration in an apartment housing unit was simulated by using CONTAM with particle and airflow simulation parameters obtained from field measurements. The result showed that the outdoor source contribution to indoor air was relatively dominant in the leaky housing unit during spring (77.2%) and winter (73.9%), and the indoor source was dominant in the airtight housing unit during summer (60.3%) and fall (60.7%). These results indicate the seasonal health risk of indoor PM_2.5 can be varied according to airtightness of apartment units.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.508-519
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• 2015

The objective of this study was to quantitatively estimate $PM_{2.5}$ source contribution in Gyeongsan. Ambient $PM_{2.5}$ samples have been collected on zefluor, quartz and nylasorb filter by $PM_{2.5}$ samplers of cyclone method from September 2010 to December 2012. Collected samples were analyzed for determining 17 inorganic elements, 8 ions, and 8 carbon components after pretreatment. Based on these chemical information, the PMF model was applied to estimate the quantitative contribution of air pollution sources. The results of the PMF modeling showed that the sources were apportioned by biomass burning source (15.5%), secondary sulfate source (16.0%), industry source (10.4%), soil source (7.0%), gasoline source (9.1%), incinerator source (10.4%), diesel emission source (11.0%), and secondary nitrate source (20.6%), respectively. To analyze local source impacts from various wind directions, the CPF analysis were performed using source contribution results with the wind direction values measured at the site.

• Knowledge Management Research
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• v.16 no.1
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• pp.55-69
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• 2015

Employees' knowledge contribution is one of the critical activities that maximize internal capability of the firm and facilitate organizational innovation by sharing scattered internal knowledge. This study integrates antecedents of knowledge contribution based on the theory of planned behavior(TPB). Utilizing TPB as a theoretical framework, expected reciprocity, subjective norm, and self-efficacy's direct effects on knowledge contribution were assessed. Additionally, interaction effects among expected reciprocity, subjective norm, and self-efficacy were explored. As the results of analysis, all the antecedents significantly influenced knowledge contribution. Interestingly, when the knowledge source's self-efficacy was high, the influence of expected reciprocity on knowledge contribution was decreased. Similarly, when the knowledge source's subjective norm for knowledge contribution was high, expected reciprocity's effect was weakened. This implies that when facilitating knowledge contribution, interaction effects among antecedents of knowledge contribution, as well as their direct effects, should be considered.

• Journal of Environmental Science International
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• v.17 no.4
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• pp.359-364
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• 2008

PM10 samples were collected from July 2007 to Oct. 2007 at Gwaebopdong(inland area) and Dongsamdong(coastal area), in Busan. This paper investigates the contribution of emission sources to PM10 mass in Busan. Source apportionment results derived from the chemical mass balance(CMB) method. A source profiles applied in this study is organized to minimize the collinearity among sources type via statistical method. Source profiles applied in this study utilized a measured value of fine particle directly sampled from metropolitan area such as Seoul and Incheon, After a CMB modeling, sulfate and nitrate related sources among those contributing to PM10 in Busan showed high contribution by 36.53% in Gwaebopdong and 42.02% in Dongsamdong.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.4
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• pp.285-296
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• 1997

The suspended particulate matters had been collected on quartz fiber fiters by a cascade impactor having 9 size stages for 4 years (Sep. 1991 to Dec. 1995) in Kyung Hee University-Suwon Campus. Membrane filters were used to collected the particulate matters on each stage. The weight concentration on each stage was obtained by a microbalance and further chemical element levels were determined by an x-ray fluorescence system. Based on these chemical information, our study focused on applying the target transformation factor analysis (TTFA), a receptor model, to identify aerosol sources and to apportion quantitatively their mass contribution. There are total of 63 ambient data sets. Each data set consists of the 8 size-ranged subdata sets characterized by 16 elemental variables. By the results, four to five sources were extracted from each size range and some sources reappeared in other size ranges. Then total of 8 source profiles were statistically generated from all the ranges, such as oil burning source, soil source, field burning source, gasoline related source, coal burning source, marine source, glass related source, and unknown sources. Apportioning aerosol mass to each source was intensively examined by investigating emission inventories near the study area. The results showed that soil particle source was the most significant contributor. However, coal and oil burning sources were the major anthropogenic ones. The study finally proposed some air quality control strategies to achieve the clean air quality in Suwon area.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.5
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• pp.495-505
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• 2005

This study is to estimate source contribution by air pollutantion types (point, area, line) over Seoul metropolitan area. The Air Pollution Model (TAPM) and the highly resolved anthropogenic and biogenic gridded emissions ($1km{\times}1km$) were applied to simulate $SO_2,\;NO_2,\;O_3\;and\;PM_{10}$ concentrations by seasons and contribution was estimated by their source types (point, area, line). The results showed that the simulated concentrations of secondary pollutant agreed well with observed values with an index of agreement (IOA) over 0.4, whereas IOAs over 0.3 were observed for most primary pollutants. The contributions of each source types by seasons were similar. The point source contribution was the highest for $SO_2$ at medium level ranged from $55.1\%\;to\;61.5\%$. But the contribution from area source during for the spring and summer increased as the concentration level increased. The line source contribution was the highest for $NO_2$ at all levels ranged from $68.3\%\;to\;93.1\%$. The results indicate that $SO_2$ emissions should be mainly controlled from point source, as well as area source at higher level concentration. Also, $NO_2\;and\;PM_{10}$ to from line source should be controlled.

• Journal of Environmental Science International
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• v.3 no.4
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• pp.393-402
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• 1994

It is necessary to examine the source contributions and the relationship between a receptor and sources for the resonable controlling of air pollution level of suspended particulate matters. Therefore, in this study, profiles of sources contributing to the concentration of suspended particulate matters, were developed and CMB model was applied to obtain information of source contributions and feasibility of CMB model application. According to the propose of this study, twenty-seven chemical species such as the elements, anions, and total carbon of thirty-six PMl0 and TSP data sets sampled at the Pomch'on receptor site in Pusan for a 24-hr period from May to Aug. 1992, were analyzed and three (transportation, soil, marine) different source profiles were developed through the field measurement. Applying CMB model to transportation, soil, marine, the results of source contribution by CMB model showed that the case with TSP was more suitable for CMB model than that with PMl0. And the average contribution of transportation source to TSP and PMlo concentration at Pomch'on receptor was calculated as 90.66 ㎍/m3(64%) and 23.27 ㎍/m3(39%), resfiectively, which showed that the contribution by transportation was dominant. The validation of CMB model was performed by means of the results of contributions from marine source for the wind direction sectors.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.2
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• pp.59-72
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• 1994

For a panel contribution of the passenger vehicle compartment, a model was created for acoustic analysis of the passenger vehicle compartment and through the acoustic normal modal analysis, frequencies and mode shapes of the resonance modes were calculated. Also, the contribution analysis of each panel was executed using acoustic reciprocal theorem, and through this analysis, normalized responses at the particular point indicate the relative contribution of each panel for generating noise and vibration