• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.240-252
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• 2016

The purposes of this paper examines the extant to which congruence in leader and follower rating of LMX quality is related to organizational commitment, and perceptions of organizational politics(POPs). A conceptual model is introduced that identifies four combinations of leader and follower LMX ratings of Cogliser et al.(2009): balanced/low LMX(low leader and follower LMX), balanced/high LMX(high leader and follower LMX), follower overestimation(low leader LMX/high follower LMX), follower underestimation(high leader LMX/low follower LMX). The summary of results based on a sample of 236 matched pairs of leaders and followers in KOREA is as follows: First, balanced/high LMX and follower overestimation were associated with relatively high levels of affective organizational commitment, and perceptions of organizational politics. However, follower underestimation and balanced/low LMX was related to low levels of follower outcomes. In particular, follower underestimation and balanced/low LMX were significantly different from balanced/high LMX and follower overestimation. Second, perceptions of organizational politics was negatively related to affective organizational commitment in the four LMX relationship types. Especially, the negative relationship between POPs and organizational commitment was stronger for people who are low as compared with high in LMX quality. Theoretical and practical implications of our findings as well as directions for future research are provided.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.201-210
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• 2007

Pollution by chemical substances such as POPs, EDCs and PBTs in the ecosystem has become more complex and varied, increasing the possibility of irreversible damage to human health or the ecosystem. It is necessary to have a exposure assessment in a multi-media environment for various chemical substances is required for efficient management. This study applied MUSEM(Multi-media Simplebox-systems Environmental Model), a multimedia environmental model that can simultaneously evaluate the possibility of exposure of hundreds of chemical substances in order to efficiently manage chemical substances that can have negative impact on human health or ecological environment through environmental contamination. MUSEM executed the modeling for Japan by setting all 47 prefectures of japan as the regional area for 62 chemical substances and the rest of the territory of japan, excluding regional area, as the continental area and made the estimation of concentration among environment media in each administrative area and made the sensitivity analysis on Tokyo area. The results of simulation for chemical distribution showed that most of the target chemicals located in water region. The result of sensitivity analysis for octanol-water partition rate showed that the concentration change of soil in urban/industrial area and sediment in freshwater was high. In the case of sensitivity analysis for degradation rate showed that the concentration change of freshwater, soil in urban/industrial area, and sediment in freshwater was high.

• Analytical Science and Technology
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• v.21 no.3
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• pp.183-190
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• 2008

PFOS (Perfluorooctane sulfonate) and PFOA (Perfluorooctanoic acid) are environmental hormones which belong to potential future persistent organic pollutants (POPs), and it is easy to exposure to human because they are used in a wide variety of consumer products. We studied exposure route and the relativity through determining and monitoring of PFOS and PFOA in Korean plasma of metropolis, small town, rural area and industrial area. And we monitored the concentration of PFOS and PFOA regarding the gender and age. The older age is, the higher concentration of PFOS is. The mean concentration of PFOS and PFOA in men (4.74 ng/mL, 2.20 ng/mL) was higher than that in women (3.53 ng/mL, 1.17 ng/mL). In the comparison of residential areas, the mean concentration of PFOS and PFOA was the lowest in metropolitan plasma (2.47 ng/mL, 0.79 ng/mL) whereas it was the highest in the industrial area (6.57 ng/mL, 2.19 ng/mL).

• Resources Recycling
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• v.32 no.6
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• pp.45-53
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• 2023

This study discussed the trend and future strategy of adsorption technology R&D to effectively recover ammonia emitted from the livestock fields. A proper ammonia adsorbent should incorporate acidic or hydrogen bonding functional groups on the surface, as well as a high specific surface area and a good surface structure appropriate for ammonia adsorption. Activated carbon and minerals such as zeolite have widely been used as ammonia adsorbents, but their adsorption effects are generally low, so any improvement through surface modification should be necessary. For example, incorporation of metal chloride included in a porous adsorbent can promote ammonia adsorption effectiveness. Recently, new types of adsorbents such as MOFs (Metal-Organic Frameworks) and POPs (Porous Organic Polymers) have been developed and utilized. They have shown very high ammonia adsorption capacity because of adjustable and high specific surface area and porosity. In addition, Prussian Blue exhibited high ammonia adsorption and desorption performance and selectivity. This looks relatively advantageous in relation to the recovery of ammonia from livestock waste discharge. In the future, further research should be made to evaluate ammonia adsorption/desorption efficiency and purity using various adsorbents under conditions suitable for livestock sites. Also, effective pre- and/or post-treatment processes should be integrated to maximize ammonia recovery.

• The Korean Journal of Community Living Science
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• v.25 no.4
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• pp.629-636
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• 2014

Polybrominated diphenyl ethers (PBDEs) as flame-retardant additives have been used in a wide array of products, including building materials, electronics, furnishings, motor vehicles, airplanes, plastics, polyurethane foams, and textiles. They are structurally similar to PCBs and other polyhalogenated compounds. PBDEs are found in a variety of foods, and 95% of all human exposure to POPs comes from food. The major food sources are fish/seafood and dairy products. A number of studies have reported high levels of PBDEs in animals, increasing the public's concern over PBDE levels in animals. This study evaluates the relationship between the level of PBDEs according to piglet diseases. Salmonella spp. and Streptococcus are bacterial diseases. Porcine respiratory reproductive syndrome (PRRS) is a viral disease. The concentration of PBDEs in the piglet liver from viral diseases was higher than that from bacterial diseases. BDE-47 and BDE-99 were detected in most samples. More PBDEs were detected in the piglet liver from PRRS of North American type than from that of European type.

• Journal of Environmental Science International
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• v.14 no.9
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• pp.827-835
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• 2005

A three-dimensional ecological model (EMT -3D) was applied to Nonylphenol in Tokyo Bay. EMT -3D was calibrated with data obtained in the study area. The simulated results of dissolved Nonylphenol were in good agreement with the observed values, with a correlation coefficient(R) of 0.7707 and a coefficient of determination (R2) of 0.5940. The results of sensitivity analysis showed that biodegradation rate and bioconcentration factor are most important factors for dissolved Nonylphenol and Nonylphenol in phytoplankton, respectively. In the case of Nonylphenol in particulate organic carbon, biodegradation rate and partition coefficient were important factors. Therefore, the parameters must be carefully considered in the modeling. The mass balance results showed that standing stocks of Nonylphenol in water, in particulate organic carbon and in phytoplankton are $8.60\times 10^5\;g,\;2.19\times 10^2\;g\;and\;3.78\times 10^0\;g$ respectively. With respect to the flux of dissolved Nonylphenol, biodegradation in the water column, effluent to the open sea and partition to particulate organic carbon were $6.02\times10^3\;g/day,\;6.02\times10^2\;g/day\;and\;1.02\times10^1\;g/day$, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.757-766
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• 2012

In this study, we have examined concentration distribution and patterns of PCBs in waters, sediments and soils in an agricultural area of South Korea to investigate the relationship between PCBs sources and concentration levels. The concentration of PCBs in water samples were ranged from lower values below detection limit to 8.25 ug/L and the concentration of PCBs in sediment samples were ranged from lower values below detection limit to 76.67 ug/Kg. The concentration of PCBs in soil samples were ranged from lower values below detection limit to 23.51 ug/Kg. These contamination levels were far below the guideline values suggested for environmental quality assessment. The homologue patterns in samples varied from sample to sample, but isomer patterns were very similar with each other. PCB-138 and PCB-153 were predominant congeners in the soil and sediment, which were similar to the results obtained from previous studies. With these results, the assessment of potential sources of PCBs contamination in the sediments of the Nakdong river basin was performed. The principal components were extracted by Principal Component Analysis(PCA). As the result of PCA, it could be expected that PCBs in samples of this study were more affected by PCB products than combustion processes and mostly affected by already-known sources. The PCBs in the soil and sediment samples were related with commercial PCB products.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.285-291
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• 2008

A global binding agreement was adopted with the leading of United Nations Environment Program (UNEP) on May 22, 2001 in Stockholm to regulate the production and distribution on persistent organic pollutants (POPs). The agreement took effectuation with the ratification of 59 countries from the approval of 151 countries on May 17, 2004. After the approval on October 4, 2001, South Korea performed systematical investigation on POP-related substances such as chlordane, dichloro diphenyl trichloroethane (DDT), hexachlorobenzenes (HCB), heptachlor, polychlorinated biphenyls (PCBs) to get ready for the ratification of the convention with country-specific exemption. The domestic distributions of those chemical substances have been officially prohibited since the late 1960s to the early 1980s. Although there were occasional reports for the detection of some of those chemical substances, those performed minute signification in their existence in the environment. A series of investigation with documentary examination and fact-finding survey showed the possibility for the ratification on the convention without country-specific exemption.

• Journal of the Korean earth science society
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• v.26 no.2
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• pp.129-136
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• 2005

Continued observation of ARGO floats for years(about 4 years) makes the conductivity sensor more vulnerable to fouling by marine life and associated drift in salinity measurements. In this paper, we address this issue by making use of floats deployed in different years. Floats deployed in the East Sea and the Indian Ocean are examined to find out float-to-float match-ups in such a way that an older float pops up simultaneously with a newer deployment (with tolerable space-time difference). A time difference of less than five days and space difference of less than 100km are considered for the match-up data sets. For analysis of the salinity drift under the stable water mass, observations of the floats from deepest water masses have been used. From the cross-check of ARGO floats in the East Sea and the Indian Ocean, it is found that there is a systematic drift in the older float compared to later deployments. All drift results, consistently show negative bias indicating the typical nature of drift from fouled sensors. However, the drift is much less than 0.01, the specified accuracy of ARGO program.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.136-138
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• 2008

PCBs는 잔류성유기오염물질(POPs) 중 하나로 변압기 절연유 등에 주로 사용되어 왔으나 환경 및 인체유해성이 밝혀짐에 따라 생산 및 사용이 금지된 물질로써 국내에서는 절연유 중 PCBs 분석이 전력산업과 변압기 절연유의 재활용 및 처리 분야에서 매우 중요한 문제로 대두되고 있다. 그러나 현행 폐기물공정시험방법은 분석절차가 까다롭고 고가의 분석비용이 소모되며 고도로 훈련된 분석인력이 필요하다. 이에 본 연구에서는 보다 저렴한 비용으로 신속하게 PCB를 분석할 수 있는 간이 분석법을 개발하고자 하였다. 현행 폐기물공정시험방법에 대한 기술적 검토를 수행하여 복잡한 전처리 절차를 축소하고 번거로운 정성 및 정량작업을 간소화한 결과, 분석비용은 약 1/2, 분석시간은 약 1/3로 줄일 수 있었다. 본 연구에서 개발한 간이 분석법을 현행 공정시험법과 적절히 병행하여 사용 할 경우 폐 변압기의 신속한 분석이 가능하여 분석비용 절감에 따른 큰 경제적 효과가 있을 것으로 예상된다.