• Journal of Korea Water Resources Association
• /
• v.41 no.4
• /
• pp.413-422
• /
• 2008

It is essential to locally adjust the Hargreaves parameter for estimating reference evapotranspiration with short data as a substitute of Penman-Monteith equation. In this study, evaluation of daily-based reference evapotranspiration is computed with Hargreaves equation. in Gyeonggi bay area including Ganghwa, Incheon, Suwon, Seosan, and Cheonan station for the time period of 1997-2004. Hargreaves coefficient is adjusted to give the best fit with Penman-Monteith evapotranspiration, being regarded as a reference. Then, the preferred parameters are validated for the same stations for the time period of 2005-2006. The optimization-based correction in calibration for 1997-2004 shows improved performance of the Hargreaves equation, giving 0.68-0.77 to 0.92-0.98 in Nash-Sutcliffe coefficient of efficiency (NSC) and 14.63-23.30 to 5.23-11.75 in RMSE. The validation for 2005-2006 shows improved performance of the Hargreaves equation, giving 0.43-0.85 to 0.93-0.97 in NSC and 14.43-26.81 to 6.48-9.09 in RMSE.

• Parasites, Hosts and Diseases
• /
• v.45 no.3
• /
• pp.205-211
• /
• 2007

The infection status of mullets Mugil cephalus (n = 139) and gobies (n = 35) Acanthogobius fIavimanus with metacercariae of Heterophyes nocens and Pygidiopsis summa was examined in 11 western, southern, and eastern coastal areas of the Republic of Korea, using a digestion technique. Heterophyid metacercariae were highly prevalent in mullets from western and southern coastal areas; Shinan-gun (100% for H. nocens and 100% for P. summa), Muan-gun (93% and 100%), Buan-gun (42% and 75%), Seocheon-gun (73% and 53%), Ganghwa-gun (47% and 100%), Sacheon-shi (47% and 77%), and Gangjin-gun (50% and 70%, respectively). Only 1 (10%) of 10 mullets from an eastern coastal area, i.e., Donghae-shi, was positive for P. summa metacercariae. Metacercarial densities were the highest in the trunk of mullets for H. nocens and the gill for P. summa. Gobies from Muan-gun were positive for H. nocens (40%) and P. summa metacercariae (40%), and gobies from Seocheon-gun revealed H. nocens metacercariae (20%). The metacercarial density was remarkably higher in mullets than in gobies. The results revealed that H. nocens and P. summa metacercariae are prevalent in mullets and gobies from coastal areas of the Republic of Korea, and the prevalence and intensity of infection vary according to geographical locality.

• Journal of The Korean Association For Science Education
• /
• v.24 no.5
• /
• pp.987-995
• /
• 2004

The purpose of this study was to analyze characteristics of problem solving process with proportional or compensational reasoning of the elementary school students. For this study, 85th grade students were selected and tested with Science Reasoning Task, information processing ability test and proportional and compensational reasoning tasks. This study revealed that students in mid concrete stage could solve the proportionality task and easy compensation task. But, most of the students could not solve difficult compensation task. And as the students got higher score in information processing test, it took them less time to solve the problem. The types of strategy used in solving proportional and compensational problem were categorized as the factor of change, building-up and the cross-product. Most of the students failed in problem solving used incorrect schema knowledge, procedure knowledge and strategy knowledge. Many students tended to use proportionality strategy to solve the difficult compensation task. Result of this study suggested that various task included different structure and the same schema knowledge can be effective for the advancement of students' proportional and compensational reasoning ability.

• Korean Journal of Plant Resources
• /
• v.23 no.4
• /
• pp.293-302
• /
• 2010

Taxa of Artemisia collected in Korea were constructed by molecular phylogenetic analysis based on the internal transcribed spacer(ITS) regions of nrDNA. The length of the ITS sequences aligned using the clustal X program was 636~643 bp, and the lengths of the ITS1 and ITS2 regions were 251~255 bp and 217~222 bp, respectively. The total number of variable sites was 95 for the entire sequence, and a parsimony- informative site represented an efficacious site in ITS1 rather than in ITS2. The maximum parsimony tree as calculated by the MEGA 4 program was clustered into five clades. The taxa(A. capillaris, A. japonica var. japonica, A. japonica var. hallaisanensis, A. japonica subsp. littoricora) degenerated ovary of clade 1 was supported as the subgenus Dracunculus by Ling's classification system. The results show that A. nakaii and A. fukudo were quite similar genetically(Boostrap 99%) and that the scientific name of Korean A. dubia should be reconsidered. A. sp. distributed in Ganghwa province was grouped with A. argyi(Boostrap 89%). These results suggest that the molecular techniques used in this study could be useful for the phylogenetic analysis of Korean Artemisia herbs having variations in their morphological characteristics.

• Korean Journal of Heritage: History & Science
• /
• v.52 no.4
• /
• pp.264-271
• /
• 2019

Cheomseongdae in Gyeongju, known as an astronomical observatory, is a cultural monument with great historical, academic, and artistic value, as its unique shape is preserved well in its original form. The outer structure, ground stability, and seismic reliability of Cheomseongdae have been assessed by numerous researchers through various scientific methods, but research on the underground structure has been insufficient. This paper contains detailed models of the underground structure of Cheomseongdae interpreted in 2D and 3D images based on the data acquired through GPR surveys conducted of features in and around the base of Cheomseongdae. As a result, the existence of twelve small features arranged in a circle, although only about half of them remain, was confirmed at a depth of 0.4 - 0.6m. Furthermore, a structure three bays long (north-south direction) and four bays wide (east-west direction) was detected beneath Cheomseongdae at the depth of 0.7 - 1.0m. Other than 2 layers of foundations as is known, a square structure with the dimensions of 7m × 7m is situated at a depth of 0.6m, directly under Cheomseongdae, and what is reading that is expected to be the foundation structure of Cheomseongdae was detected and confirmed. This foundation structure is circular with a diameter in the east-west direction of 11m and in the north-south direction of 12m. The northern, western, and eastern edges of this foundation structure are about 1m away from the foundation of Cheomseongdae, whereas the the south side extends to about 5m wide.

• Journal of Applied Biological Chemistry
• /
• v.56 no.1
• /
• pp.23-27
• /
• 2013

The roots of Brassica rapa ssp. were extracted with 95% aqueous ethanol and the concentrated extracts were partitioned using ethyl acetate (EtOAc), n-butyl alcohol and $H_2O$, successively. From the EtOAc fraction, five flavonoids were isolated through repeated silica gel and octadecyl silica gel (ODS) column chromatography (c.c.). Based on NMR, mass spectrometry (MS) and IR spectroscopic data, the chemical structures of the compounds were determined to be licochalcone A (1), 4,4'-dihydroxy-3'-methoxychalcone (2), liquirtigenin (3), liquiritin (4), and isoliquiritin (5). This is the first report of these compounds isolated from the root of this plant.

• Korean Journal of Plant Resources
• /
• v.33 no.2
• /
• pp.130-137
• /
• 2020

We found Diplachne fusca subsp. uninervia (J. Presl) P.M. Peterson & N. Snow, an unrecorded alien plant, in Gimpo-si, Gyeonggi-do and Ganghwa-gun, Incheon Metropolitan City. Diplachne fusca subsp. uninervia is native to North America (the USA and Mexico), Central America (Belize, Costa Rica, Honduras, and Nicaragua), the Caribbean (the Bahamas, Cuba, Jamaica, and Puerto Rico), and South America (Venezuela, Brazil, Bolivia, Ecuador, Peru, Argentina, Chile, Paraguay, and Uruguay). It is reported as an invasive species worldwide. Diplachne fusca subsp. uninervia is closely related to D. fusca subsp. fascicularis (Lam.) P.M. Peterson & N. Snow (Gaet-deu-reong-sae in Korean), an invasive species in Korea, and both are infraspecific taxa of the species D. fusca. Diplachne fusca subsp. uninervia is distinguished from D. fusca subsp. fascicularis by the small size of its spikelets, glumes, and lemmas, with apex awnless. Its common name is "Jom-gaet-deu-reong-sae" based on the short spikelets. We found that D. fusca (≡Leptochloa fusca), previously known as "Gaet-deu-reong-sae", was misapplied. It is morphologically different from D. fusca subsp. fascicularis. Therefore, we changed the scientific name of Gaet-deu-reong-sae from D. fusca (≡L. fusca) to D. fusca subsp. fascicularis based on the type specimens, original descriptions, and recent studies.

• Food Science and Preservation
• /
• v.23 no.5
• /
• pp.704-710
• /
• 2016

This study was conducted to investigate the antibacterial activities and sensory properties of a sauce containing tea extract and garlic vineger against raw fish. The sauce was evaluated antibacterial activity against Vibrio parahaemolyticus and Vibrio vulnificus which is considered as one of the major food borne pathogens. As a result, the sauce inhibited the growth of V. parahaemolyticus and V. vulnificus distinctly. In addition, the sauce with soy sauce and Kochujang showed the restricted growth of Vibrio parahaemolyticus and Vibrio vulnificus in sliced raw flatfish. Sensory evaluations were measured by 7-point hedonic scale using sliced raw flatfish with the sauce mixed with Kochujang and soy sauce. The score of texture in the sauce with Kochujang was significantly higher than that of regular Chokochujang (p<0.05). Moreover, total preference including appearance, texture, aroma and taste were significantly higher in the sauce with soy sauce than those of regular soy sauce (p<0.05). Consequently, the soy sauce with tea extract and garlic vinegar may enhance the satisfaction of consumer and antimicrobial activity that against V. parahaemolyticus and V. vulnificus, resulting in potential reduction the outbreaks of food borne pathogens.

• Journal of Korea Water Resources Association
• /
• v.41 no.5
• /
• pp.545-558
• /
• 2008

This study estimated the error involved in the areal average rainfall derived from incomplete radar information due to radar partial coverage of a basin or sub-basin. This study considers the Han-River Basin as an application example for the rainfall observation using the Ganghwa rain radar. Among the total of 20 mid-sized sub-basins of the Han-River Basin evaluated in this study, only five sub-basins are fully covered by the radar and three are totally uncovered. Remaining 12 sub-basins are partially covered by the radar to result in incomplete radar information available. When only partial radar information is available, the sampling error decreases proportional to the size of the radar coverage, which also varies depending on the number of clusters. Conditioned that the total area coverage remains the same, the sampling error decreases as the number of clusters increases. This study estimated the sampling error of the areal average rainfall of partially-covered mid-sized sub-basins of the Han- River Basin, and the results show that the sampling error could be at least several % to maximum tens % depending on the relative coverage area.

• Journal of Marine Bioscience and Biotechnology
• /
• v.8 no.1
• /
• pp.18-23
• /
• 2016

It is important to design photobioreactor by cheap material for economical microalgal biomass production. In this study, two types of marine photobioreactors (MPBR), made by either polyvinyl chloride (MPBR-PVC) or high density poly ethylene (MPBR-HDPE), are used and performance of these were compared. Tetraselmis sp. KCTC 12236BP is a green marine alga that isolated from Ganghwa Island, Korea, and the strain was used for marine cultivations using MPBR-PVC and MPBR-HDPE. The cultivations were performed three times in the spring season of 2012 using MPBR-PVC and of 2013 using MPBR-HDPE in the coastal area of Young Heung Island. As the results, MPBR-PVC shows higher biomass productivities than MPBR-HDPE, due to its high light transmittance. In the cultivations using MPBR-PVC, the average sea water temperature was $11.5^{\circ}C$ during the first experiment and $16.5^{\circ}C$ during the second and third experiments. Average light intensities during three times for experiments were 407.5, 268.1 and $273.0{\mu}{\cdot}E{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The maximum fresh cell weight and average biomass productivity were $1.2g{\cdot}L^{-1}$ and $0.12g{\cdot}L^{-1}{\cdot}day^{-1}$. These results showed that Tetraselmis sp. KCTC12236BP were adapted well with the environmental conditions from ocean, and grow in the MPBR-PVC and MPBR-HDPE.