Lee Y.-I.,Dankook University |
Chung O.-S.,Chungnam Development Institute |
Seo M.,Dankook University
Korean Journal of Parasitology | Year: 2016
Adult specimens of Oswaldotrema nacinovici (Digenea: Philophthalmidae) have been first identified in Korea from 2 migratory birds (whimbrels, Numenius phaeopus) which were found dead at a western seashore area near Gunsan. The worms were recovered in the intestine of these birds. The worms were morphologically characterized by a large ventral sucker in comparison to the oral sucker, an external seminal vesicle extending beyond the posterior margin of the ventral sucker, and conspicuous uterine seminal receptacle. It was noteworthy that metacercariae-like bodies were contained within the inflated regions of 2 ceca. Other intestinal trematode species found in whimbrels included Spelotrema pygmeum, Gynaecotyla squatarolae, Maritrema obstipum, and Himasthla megacotyle. Zoonotic potential of these trematode species should be taken into considerations. © 2016, Korean Society for Parasitology and Tropical Medicine.
Kim J.-Y.,Korea Transportation Safety Authority |
Kim J.-T.,Korea National University of Transportation |
Kim W.,Chungnam Development Institute
Canadian Journal of Civil Engineering | Year: 2015
This paper addresses drivers’ psycho-physiological condition under the influence of various freeway section types and elapsed driving times. The authors analyzed the electroencephalogram (EEG) signals (a, b, and q) of 51 drivers on a freeway in Korea. The findings show that the driver’s workload increases in tunnels and on left-curved sections, and that his or her concentration and response ability decrease after 60 min of elapsed driving time. The b/a ratios of EEG signals were found to be most effective in detecting differences in psycho-physiological responses. The results can help to promote safety on freeways by encouraging drivers to take rests every hour. © 2015, National Research Council of Canada, All Rights Reserved.
Kim G.,Hannam University |
Jung W.,Chungnam Development Institute
KSCE Journal of Civil Engineering | Year: 2010
Sand is the simplest capping material proposed to date to contain phosphorus in sediment in situ. This research was carried out to understand the role of sand capping in the speciation and release of phosphorus from sediment. Clean sand was laid on sediment sampled at a eutrophicated lake in one dimensional columns with different capping thicknesses. It could be understood from the experiments that sand capping with a thickness of less than 50 mm reduced the phosphorus concentration by over 85% and was effective in reducing the amount of phosphorus released from the sediment. Thicker sand capping reduces the amount of phosphorus released from the sediment to a greater extent. Since sand capping retards the release of phosphorus from the sediment, a higher fraction of non-apatite P (NA-P) was able to be converted into the less soluble Apatite-P (AP). © 2010 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg.
Yoon J.-J.,Chungnam Development Institute |
Ocean Science Journal | Year: 2015
An integrated model system was developed to apply surge-wave coupled simulations to the southern coast of Korea during Typhoon Sanba in 2012. Numerical experiments were carried out to examine the effects of land-dissipated wind on storm surges and the influence of wave-surge coupled simulations on storm surges and surface waves. These numerical experiments used a finite volume ocean model, FVCOM, coupled with a wave model SWAVE. Due to the complex geometry of the coastal area investigated, a high-resolution terrain-following unstructured grid was employed. Atmospheric forcing was generated by a planetary boundary layer model, which was revised by incorporating the effect of the land’s roughness on the typhoon wind. A detailed comparison shows generally good agreement between the measured and simulated wind, surge, and waves. In particular, improved results have been found for the simulation of storm winds and surges when considering the effect of land-dissipated wind. In addition, clearly improved results for storm surges were obtained when adding the coupling effect between waves and surges. The results show a maximum contribution of ~40% by the waveinduced surge to the peak surge height along the coasts. The mean rate of error for peak surge heights decreased from 29.6% to 21.3% after considering the effects of wind dissipation, and decreased again to 17.9% when adding the effects of the waves. These results imply that the effect of wind dissipation caused by land roughness and waves should be taken into account when determining storm surge heights. The results also show the effects of wave-current coupling influences the generation of waves. However, the magnitude of this coupling effect on wave heights was found to be relatively insignificant. © 2015, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.
Chen B.,Harbin Institute of Technology |
Kim Y.,Chungnam Development Institute |
Westerhoff P.,Arizona State University
Water Research | Year: 2011
Dissolved organic nitrogen (DON) derived from wastewater effluent can participate in reactions that lead to formation of nitrogenous chlorination by-products, membrane fouling, eutrophication, and nitrification issues, so management of DON is important for both wastewater reuse applications and nutrient-sensitive watersheds that receive discharges from treated wastewater. This study documents DON occurrence in full-scale water/wastewater (W/WW) treatment plant effluents and assesses the removal of wastewater-derived DON by several processes (biodegradation, coagulation, softening, and powdered activated carbon [PAC] adsorption) used for advanced treatment in wastewater reuse applications. After varying levels of wastewater treatment, the dominant aqueous nitrogenous species shifts from ammonia to nitrate after aerobic processes and nitrate to DON in tertiary treatment effluents. The fraction of DON in total dissolved nitrogen (TDN) accounts for at most 52% in tertiary treated effluents (median = 13%) and 54% in surface waters impacted by upstream wastewater discharges (median = 31%). The 5-day biodegradability/bioavailability of DON (39%) was higher, on average, than that of dissolved organic carbon (DOC, 26%); however, upon chlorination, the DON removal (3%) decreased significantly. Alum coagulation (with ≥8 mg/L alum per mg/L DOC) and lime softening (with pH 11.3-11.5) removed <25% of DON and DOC without selectivity. PAC adsorption preferentially removed more DOC than DON by 10% on average. The results provided herein hence shed light on approaches for reducing organic nitrogen content in treated wastewater. © 2011 Elsevier Ltd.
Hahn J.-S.,Korea Environment Institute |
Kim H.-C.,Chungnam Development Institute |
Kim J.-K.,Korea Research Institute for Human Settlements |
Ulfarsson G.F.,University of Iceland
Journal of Transport Geography | Year: 2016
Korea is experiencing a rapid increase in the number and proportion of the older population aged 65 and older. This study investigated personal and household characteristics affecting trip making of older adults (65 years and older) using data from the 2010 Household Travel Survey in Seoul. It was tested if the effects of characteristics were the same for the 65+ and the under 65 groups, and if the effects for older adults were the same for the 65–74 and the 75+ groups. Trips were also classified into mandatory and discretionary trips and models estimated for the 65+ group for those two trip purposes. The investigation was done with a heteroskedastic ordered logit model to account for age differences in unobserved variance. The analysis showed that the effects of personal and household characteristics on trip making varied significantly between the under 65 and 65+ groups, and between those 65–74 and those 75+. This further confirms the risk of viewing all older adults as similar to each other or to younger individuals. The study found heteroskedasticity due to age for the youngest (under 41) and the oldest (75+) groups but not for those 41–64-years-old. Specific results showed that men 65 or older have a lower probability of making more trips than women, especially mandatory trips, suggesting transportation policy needs to consider the genders differently. Having a driver's license and an automobile was linked to more trips for those 65–74 and for mandatory trips but not for those 75+ and not for discretionary trips of those 65+. Higher income was linked to more trips for older adults, especially mandatory trips. The results show the development of transport policies needs to consider the variance among the aged, such as gender, income, driving licensure and automobile ownership. © 2016 Elsevier Ltd
Chung O.-S.,Chungnam Development Institute |
Lee H.-J.,Dankook University |
Kim Y.-M.,Dankook University |
Sohn W.-M.,National University of Health Sciences |
And 2 more authors.
Parasitology International | Year: 2011
Gynaecotyla squatarolae (Digenea: Microphallidae) is a minute intestinal trematode whose natural hosts are aves. We conducted a feces screening survey in a coastal village of Muan-gun, where the residents routinely consume brackish water crabs as a food. Through this survey, a 50-year-old female was found to shed gymnophallid and heterophyid eggs in her stool, and 845 adult flukes were collected from her purged stool. The adult worms were morphologically grouped into three species. A total of 841 worms were Gymnophalloides seoi. Three worms were identified as G. squatarolae, and the last one proven to be Haplorchis pumilio. This is the first worldwide report of G. squatarolae infection in humans, and the first H. pumilio infection in Korean people. © 2010 Elsevier Ireland Ltd.
Yoo H.-J.,Gyeonggi Science High School |
Chung O.-S.,Chungnam Development Institute |
Seo M.,Dankook University
Korean Journal of Parasitology | Year: 2012
Migratory birds have been suspected as playing a central role in transmission of various trematodes, but few surveys have been undertaken in the Republic of Korea. In the present study, we describe new fauna of microphallid flukes in Korea. Two species of microphallids were found in the intestines of 2 migratory bird species, namely the red necked stints (Calidris ruficollis) and the terek sandpiper (Xenus cinereus), in a coastal area of Gunsan-si, Jeollabuk-do. The microphallids recovered from the latter were 451 μm in length and 217 μm in width, and the eggs were very small, 13 μm by 8 μm. They had the characteristic extracecal vitellaria intruding into the median posttesticular area, belonging to Endocotyle incana. Another microphallids were discovered from both migratory birds, 417 μm in length and 249 μm in width. The cirrus was projecting into the genital atrium in form of male papilla, and bounded by a muscular flap, termed pseudogonotyl. They were identified as Spelotrema pseudogonotyla in consideration of the distinctive male papilla and pseudogonotyl. Besides these flukes, Maritrema obstipum and Gynaecotyla squatarolae also were recovered. This paper is in fact the first report on the presence of Spelotrema and Endocotyle in Korea. © 2012, Korean Society for Parasitology.
PubMed | Dankook University and Chungnam Development Institute
Type: Journal Article | Journal: The Korean journal of parasitology | Year: 2017
Hong S.H.,Chungnam Development Institute
Papers in Regional Science | Year: 2014
This study investigates the magnitude of localization economies by analysing the relocation pattern of Korean establishments in the manufacturing sector. Relocation of establishments is identified by their move across the border of wards, counties, or cities and distinguished between beyond and within their workers' commuting distance. It seems that relocation beyond commuting distance costs more than that within commuting distance since the former includes additional costs related with searching for, hiring, and training new workers. Key findings of this paper show that external benefits from agglomeration are large enough to be recognized by manufacturers through relocation beyond the border of their workers' commuting area. When the own industry's share of employment in all manufacturing industries becomes doubled through relocation, the probability for establishments to relocate over a long distance across the boundary of their workers' commuting area rises by 17 per cent. The results for sub-samples divided by the age of establishments show that older establishments are more likely to relocate over a long distance to an area with disproportionate presence of establishments in the same industry. These results seem to fit product life cycle theory by Duranton and Puga. As the production process of the product becomes standardized, the firms producing that product tend to relocate to the specialized area where they can reduce the production costs by increasing dependence on the existing intermediate input suppliers, who are more likely to appear in a more specialized area. © 2013 RSAI.