• The Korean Journal of Ecology
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• v.28 no.5
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• pp.305-320
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• 2005

Recently 64 species in Korea have been ranked as rare and endangered taxa by the Ministry of Environment using two categories, I and II. The original threat categories produced by the Ministry of Environment were developed to provide a standard for specifying animals and plants in danger of extinction and has been influential sources of information used in species conservation in Korea. However, the criteria by Ministry of Environment were applied to the whole taxa only by regional boundaries, especially in South Korea, rather than international context, and it also lacked an explicit framework that was necessary to ensure repeatability among taxa because of the absence of quantitative criteria to measure the likelihood of extinction. The World Conservation Union (IUCN) has developed quantitative criteria for assessing the conservation status of species. The threatened species categories, the 2000 IUCN Red List, proposed by SSC (Species Survival Commission) of IUCN have become widely recognized internationally. Details of threatened Korean plants, identified by applying the IUCN threat categories and definitions, were listed and analyzed. The number of species identified as threatened was only 34 out of 64 taxa (48.4%), while the rest of taxa were rejected from the original lists. Many of the species (51.6%, 33 taxa) excluded from the original list proposed by Ministry of Environment do not qualify as Critically Endangered, Endangered or Vulnerable because these taxa were widely distributed either in Japan or in China/far eastern Russia and there is no evidence of substantial decline in these countries. An evaluation of taxa in Korea has been carried out only based on subjective views and qualitative data, rather than quantitative scientific data, such as rates of decline, distribution range size, population size, and risk of extinction. Therefore, the national lists undermine the credibility of threatened species lists and invite misuse, which have been raised by other cases, qualitative estimate of risk, political influence, uneven taxonomic or geographical coverage. The increasing emphasis on international responsibilities means that global scale is becoming more significant. The current listings by Environment of Ministry of Korea should be challenged, and the government should seek to facilitate the resolution of disagreements. Especially the list should be flexible enough to handle uncertainty and also incorporates detailed, quantitative data. It is suggested that the highest priorities for the Red List should be given to endemic species in Korea first. After setting up the list of endemic species to Korea, quantitative data on population size and structure, distributional range, rated of decline, and habitat fragmentation should be collected as one of long term projects for the Red list categories. Transparency and accountability are the most important key factors. Also, species assessors are named and data sources referenced are required for the future objective evaluations on Korean plant taxa.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.443-454
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• 2010

Phthalate compounds are widely used as plasticizers in polyvinyl chlororide (PVC) resins and other industrial consumer products, and some of them are known to be endocrine disruptors. In Korea, a number of studies have been carried out for the measurement of phthalates in consumer products and drinking water. However, no data are available for those compounds in the ambient air where the general public are routinely exposed. In this study, we evaluated sampling and analytical methods for the determination of phthalates in the ambient atmosphere. A wide range of phthalates compounds were included in the target analytes, which are dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP). Most of samples were collected using a high volume sampler with a PUF/XAD-2 column/quartz fiber filter and then analyzed by GC/MS. Some of samples were simultaneously collected on XAD-2 using a low-volume sampler, together with high-volume samples. The analytical method applied in this study showed good repeatability and linearity. Quantitative detection limits were estimated from 0.60 to 17.84 ng/$m^3$ in air, depending on individual compounds. The field measurements were carried out at 3 sites located in Sihwa- Banwall industrial areas and a suburban area from January 2007 to November 2007. From the field experiments, DEHP, DMP and DBP appeared to be the most abundant compounds in the ambient air. It was also found that DMP, DEP and DBP were mainly distributed in the vapor phase, while BBP, DEHP and DOP were predominantly associated with the particulate phase. The concentrations of DEHP and DMP in the industrial areas ranged from 45.7 to 1,012.7 ng/$m^3$ and from 7.7 to 375.1 ng/$m^3$, respectively. Overall, the high-volume sampling method was demonstrated to be superior to the low-volume method for the determination of phthalates in the ambient atmosphere.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.544-552
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• 2011

The purpose of this study was to develop an analytical method for determining 15 polycyclic aromatic hydrocarbons (PAHs) of EU priority using gas chromatography (GC)-tandem mass spectrometry (MS). The PAHs in ground coffee were analyzed after being extracted using methods such as saponification-liquid-liquid extraction, Soxhlet extraction, and solid-liquid extraction. The solid-liquid extraction method showed the greatest repeatability and most efficient reduction of the matrix effect. GC-tandem MS for the quantification of the 15 PAHs showed better resolution and lower limit of detections (LODs) than GC-MS-selected ion monitoring (SIM) and high performance liquid chromatography with fluorescence detector. LODs of this method for the ground coffee types were 0.002-0.1 ${\mu}g/kg$ and limit of quantifications (LOQs) were 0.006-0.2 ${\mu}g/kg$ The recoveries ranged from 52.6 to 93.3%. Forty-six commercial types of ground coffee were analyzed to determine their PAHs contamination levels. PAHs concentration ranged from ND to 5.988 ${\mu}g/kg$. This study was conducted with toxicity equivalence factors, the U.S. EPA recommendation to identify dietary risks for PAHs in different types of coffee. The estimated average daily dose of PAHs was $5.24{\times}10^{-8}$ mg/kg body weight/day.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.523-530
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• 2002

Repeatabilities and Correlations among Average Daily Gain, Backfat Thickness and Lean Percent in Swine The repeatability, correlation and rank correlation coefficients among average daily gain, backfat thickness and lean percent were estimated on the basis of records tested from August 1999 to February 2000 with 695 pigs of Duroc, Landrace and Yorkshire boars and gilts tested at 2nd Korea Swine Test Station located in Ha-dong, Kyeongnam Province. The effect of the sex, breed and month of measured were estimated by the least square method. The repeatabilities were estimated from the component of variance among repeated measurements of the trait for the same animal. The results obtained are summarized as follow ; 1. The means of the major economic traits studied were 142.1 days, 173.7 days and 182.5 days for age at 1st, 2nd and 3rd measure, 57.9%, 56.2% and 55.2% for lean percent at 1st, 2nd and 3rd measure, 1.33cm, 1.61cm and 1.63cm for backfat thickness at 1st, 2nd and 3rd measure, 946.6g, 879.2g and 879.4g for average daily gain at 1st, 2nd and 3rd measure, respectively. 2. The correlation coefficients between the backfat thicknesses measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.424, 0.700 and 1.424, respectively. The correlation coefficients between the lean percent measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.493, 0.619 and 0.471, respectively. The correlation coefficients between the average daily gain measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.716, 0.861 and 0.601, respectively. 3. The rank correlation coefficients between backfat thickness measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.438, 0.693 and 0.441, respectively. The rank correlation coefficients between lean percent measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.508, 0.593 and 0.478, respectively. The rank correlation coefficients between average daily gain measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.704, 0.834 and 0.571, respectively. 4. The estimated repeatabilities of the traits studied were 0.428 for the lean percent, 0.374 for the backfat thickness and 0.673 for the average daily gain, respectively.

• Analytical Science and Technology
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• v.31 no.2
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• pp.96-105
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• 2018

This study aimed to improve the method for detecting eight secondary aliphatic amines (SAAs), so as to measure their concentrations in fresh water and tap water samples. NaOH (8 mL, 10 M) and benzenesulfonyl chloride (2 mL) were added to a water sample (200 mL), and the mixture was stirred at $80^{\circ}C$ for 30 min. An additional NaOH solution (10 mL) was added and the stirring was continued for another 30 min. The pH of the cooled mixture was adjusted to 5.5-6.0 by adding HCl (35 %), and the SAAs were extracted using dichloromethane (50 mL). This extraction was repeated once. The extract was then washed with $NaHCO_3$ (15 mL, 0.05 M) and dried over $Na_2SO_4$ (4 g). The extract was finally concentrated to 0.1 mL, of which $1{\mu}L$ was analyzed for SAAs by GC-MS. The linearity of the spike calibration curves was high ($r^2=0.9969-0.9996$). The detection limits of the method ranged from 0.01 to $0.20{\mu}g/L$, and its repeatability and reproducibility (expressed as relative standard deviation) were both less than 10 % (6.6-9.4 %). Its accuracy (measured in percentage error) ranged between 2.4 % and 6.1 %. The established method was applied to the analysis of five surface water and 82 tap water samples. Dimethylamine was the only SAA detected in all the water samples, and its average concentration was $0.79{\mu}g/L$ (range: $0.20-2.54{\mu}g/L$). Therefore, this study improved the analytical method for SAAs in surface water and tap water, and the regional and seasonal concentration distributions were obtained.

• The Journal of the Acoustical Society of Korea
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• v.20 no.4
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• pp.35-41
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• 2001

This paper describes Linear Discriminant Analysis and common vector extraction for speech recognition. Voice signal contains psychological and physiological properties of the speaker as well as dialect differences, acoustical environment effects, and phase differences. For these reasons, the same word spelled out by different speakers can be very different heard. This property of speech signal make it very difficult to extract common properties in the same speech class (word or phoneme). Linear algebra method like BT (Karhunen-Loeve Transformation) is generally used for common properties extraction In the speech signals, but common vector extraction which is suggested by M. Bilginer et at. is used in this paper. The method of M. Bilginer et al. extracts the optimized common vector from the speech signals used for training. And it has 100％ recognition accuracy in the trained data which is used for common vector extraction. In spite of these characteristics, the method has some drawback-we cannot use numbers of speech signal for training and the discriminant information among common vectors is not defined. This paper suggests advanced method which can reduce error rate by maximizing the discriminant information among common vectors. And novel method to normalize the size of common vector also added. The result shows improved performance of algorithm and better recognition accuracy of 2％ than conventional method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.263-267
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• 2007

Parabens are used in nearly all types of cosmetics and toiletries because they are formulated well and have broad spectrum of activity, interness, low costs and excellent chemical stability in relation to pH. 2-phenoxyethanol and chlorphenesin are common preservatives which are usually used in combination with parabens in cosmetics. Toxicity of parabens is generally low but application of parabens to damaged or broken skin has resulted in sensitization. Moreover, the possibility of their estrogenic potential, anesthetic effects and reproductive toxicity has been reported. Consequently there are some regulations in use of parabens. And the maximum permitted concentrations of chlorphenesin and 2-phenoxyethanol in cosmetic products are authorized by the same reasons. So it is important to control and estimate the amount of parabens in products. In this article, we proposed a valid method for the simultaneous determination of 8 preservatives including parabens in a short time using ultra performance liquid $chromatography^{TM}\;(UPLC^{TM})$. Separation of eight components was achieved in less than 10 min and resolutions were reasonable (USP resolution ${\geqq}\;2$). And limit of detection and quantification were evaluated. The method was suitably validated for specificity, linearity, precision (repeatability, intermediate precision) and accuracy for assay (recovery) based on International conference on harmonisation (ICH) guideline. The method was applicable to analysis of preservatives in cosmetic products.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.11-17
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• 2013

Purpose: The use of SUV which should be normalized by lean body mass (LBM) is recommended for PET response criteria in solid tumors. LBM which was determined by whole body CT was used for SUV normalization (SUL) in this study. The purpose of the present study was to assess interobserver and intraobserver reproducibility of SUL measurements in reference organs. Materials and Methods: F-18 FDG PET/CT was conducted on 52 subjects and LBMs were directly determine by whole body CT for normalization of SUV. The 3 cm diameter spherical VOI, $1\times2$ cm cylindrical VOI, 2 cm diameter spherical VOI were placed in the liver, descending aorta and spleen, respectively. Experienced two observers measured SULmax and SULmean in each organ. Repeated measurements were conducted two weeks apart by observer 1 blind to previous results. Similarly, measurements were conducted on the same patients by observer 2. For assessing reproducibility(or repeatability), the paired t-test, Pearson's correlation coefficients (CC), and technical error of measurement (TEM) were calculated. Results: For interobserver reproducibility in liver SULmax and SULmean, no significant differences were found between observers(paired t-test, P=0.536, 0.293, respectively). CC and TEM for liver SULmean were 0.909 (P=0.000) and 0.067 SUL unit, respectively. Corresponding figures for liver SULmax were 0.882 (P=0.000) and 0.117 SUL unit, respectively. For intraobserver reproducibility in liver SULmax and SULmean, no significant differences were observed within observer1 (paired t-test, P=0.374, 0.268, respectively). CC and TEM for liver SULmean were 0.924 (P=0.000) and 0.061 SUL, respectively. Corresponding figures for liver SULmax were 0.908 (P=0.000) and 0.104 SUL, respectively. Similarly, no significant differences were found in SULmax and SULmean of the spleen and aorta between observers. Conclusion: The current study demonstrated that both SULmean and SULmax measurements in normal reference organs are highly reproducible. Reproducibility of SULmean in reference organs were slightly better than SULmax. Interobsever technical error of measurement was less than 0.10 SUL unit for liver SULmean, and 0.12 SUL unit for liver SULmax. Intraobsever technical error of measurement was less than 0.07 SUL unit for liver SULmean, and 0.11 SUL unit for liver SULmax.

• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.258-264
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• 2017

The stability and accuracy of ultra-performance liquid chromatography (UPLC) used for evaluating the contents of rutin and quercetin in tartary buckwheat (Fagopyrum tataricum Gaertn.) seeds extracted by seven different extraction methods were determined. The seven extraction methods were reflux extraction (RE), ultra-sonification extraction (UE), stirrer extraction (SE), RE after UE (UE+RE), RE after SE (SE+RE), UE after SE (SE+UE), and RE with UE after SE (SE+UE+RE). Among the seven extraction methods used, RE yielded comparatively higher contents of rutin (2,277 mg/ 100 g) and quercetin (158 mg/100 g) than those yielded by other six extraction methods. The intra-day repeatability and inter-day precision of RE was 0.4-3.2% considering relative standard deviation (RSD), while accuracy was 88.8-102.4%. Therefore, RE with UPLC would be a rapid, accurate, and stable method for analyzing rutin and quercetin contents in tartary buckwheat.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.411-417
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• 2017

This study was conducted to establish the analysis method for the contents of choline in infant formulas and follow-up formulas by ion chromatograph (IC). To optimize the method, we compared several conditions for extraction, purification and instrumental measurement using spiked samples and certified reference material (CRM; NIST SRM 1849a) as test materials. IC method for choline was established using Ion Pac CG column and 18 mM $H_2SO_4$ mobile phase. The parameters of validation were specificity, linearity, LOD, LOQ, recovery, accuracy, precision and repeatability. The specificity was confirmed by the retention time and the linearity, $R_2$ was over 0.999 in range of 0.5~10 mg/L. The detection limit and quantification limit were 0.14, 0.43 mg/L. The accuracy and precision of this method using CRM were 95%, 2.1% respectively. Optimized methods were applied in sample analysis to verify the reliability. All the tested products were acceptable contents of choline compared with component specification for nutrition labeling. The standard operating procedures were prepared for choline to provide experimental information and to strengthen the management of nutrient in infant formula and follow-up formula.