• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.130-141
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• 2021

By reviewing previous literature, we analyzed the food sources of 20 out of 29 endangered fish species from freshwater ecosystems in South Korea. A total of 19 studies reported that food sources of 20 endangered fish species included 20 phyla, 31 classes, 58 orders, 116 families, and 154 genera. Arthropod, insecta, diptera, and chironomidae were the most fed animal food sources according to different resolution of taxa index on phylum, class, order and family. Similarity, bacillariophyta, bacillariophyceae, naviculales, and cymbellaceae were the most fed abundant plant sources. A larger number of fish species were reliant on animal food sources than plant food sources. 18 of the endangered fish preyed on arthropods, whereas only 6 species consumed bacillariophyta. To characterize the feeding groups of the 20 fish species, a hierarchical clustering analysis and non-metric multidimensional scaling analysis were conducted. The fish species were divided into two groups: 1) insectivores and 2) planktivores. A network analysis, which associated the link between endangered fishes and food sources, also revealed the same two groups. The highest hub score of food sources was for macroinvertebrates, including diptera (0.47), ephemeroptera (0.42), and trichoptera (0.38), based on the network analysis. Niche breadth was used to calculate the diversity of the food sources. Phoxinus phoxinus (0.57) showed thehighest food source diversity among the fish species, whereas Iksookimia pacifica (0.01) showed the lowest. This study will be utilized for the conservation and restoration of the endangered fish species.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.311-323
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• 2020

We analyzed food sources of 45 fish species in 28 genera of 12 families based on literature data in freshwater ecosystems of South Korea. The food sources of 45 fish species included in a total of 26 phyla, 42 classes, 94 orders, 189 families and 294 genera. Among them, animal food sources were 16 phyla, 24 classes, 54 orders, 126 families and 212 genera, whereas plant food sources were relatively small with 10 phyla, 18 classes, 42 orders, 63 families and 82 genera. The animal food sources were classified into Arthropod, Insecta, Diptera and Chironomidae according to taxa. Meanwhile, Bacillariophyta, Bacillariophyceae, Cymbellales and Cymbellaceae were the most abundant among the plant sources. Self-Organized Map (SOM) and network analysis were conducted the food sources were classified into taxonomic groups and the feeding types of fish : 45 fish species were divided into five groups, characterizing 1) fishvores, 2) invertebratevores, planktivores including 3) zooplankton and 4) phytoplankton, and 5) omnivores. The network analysis presented link association between fishes and food sources. Macroinvertebrate including diptera and ephemeroptera were revealed as hub food sources based on network analysis. This literature study would expect that the application model with the food source of fish could be utilized for the evaluation of the food network or chain in freshwater ecosystems.

• Journal of Radiation Industry
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• v.17 no.3
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• pp.275-282
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• 2023

Workers in nuclear power plants are likely to be exposed to radiation from various geometrical sources. In order to evaluate the exposure level, the point-kernel method can be utilized. In order to perform a dose assessment based on this method, the radiation source should be divided into point sources, and the number of divisions should be set by the evaluator. However, for the general public, there may be difficulties in selecting the appropriate number of divisions and performing an evaluation. Therefore, the purpose of this study is to develop an algorithm for dose assessment for arbitrary shaped sources based on the point-kernel method. For this purpose, the point-kernel method was analyzed and the main factors for the dose assessment were selected. Subsequently, based on the analyzed methodology, a dose assessment algorithm for arbitrary shaped sources was developed. Lastly, the developed algorithm was verified using Microshield. The dose assessment procedure of the developed algorithm consisted of 1) boundary space setting step, 2) source grid division step, 3) the set of point sources generation step, and 4) dose assessment step. In the boundary space setting step, the boundaries of the space occupied by the sources are set. In the grid division step, the boundary space is divided into several grids. In the set of point sources generation step, the coordinates of the point sources are set by considering the proportion of sources occupying each grid. Finally, in the dose assessment step, the results of the dose assessments for each point source are summed up to derive the dose rate. In order to verify the developed algorithm, the exposure scenario was established based on the standard exposure scenario presented by the American National Standards Institute. The results of the evaluation with the developed algorithm and Microshield were compare. The results of the evaluation with the developed algorithm showed a range of 1.99×10^-1~9.74×10^-1 μSv hr^-1, depending on the distance and the error between the results of the developed algorithm and Microshield was about 0.48~6.93%. The error was attributed to the difference in the number of point sources and point source distribution between the developed algorithm and the Microshield. The results of this study can be utilized for external exposure radiation dose assessments based on the point-kernel method.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.8
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• pp.759-766
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• 2016

This paper is on a system design of recognizing sound sources and tracing locations from detecting a section of sound sources which is strong in surrounding environmental sounds about sound sources occurring in an abnormal situation by using signals within the section. In detection of the section with strong sound sources, weighted average delta energy of a short section is calculated from audio signals received. After inputting it into a low-pass filter, through comparison of values of the output result, a section strong in background sound is defined. In recognition of sound sources, from data of the detected section, using an HMM(: Hidden Markov Model) as a traditional recognition method, learning and recognition are realized from creating information to recognize sound sources. About signals of sound sources that surrounding background sounds are included, by using energy of existing signals, after detecting the section, compared with the recognition through the HMM, a recognition rate of 3.94% increase is shown. Also, based on the recognition result, location grasping by using TDOA(: Time Delay of Arrival) between signals in the section accords with 97.44% of angles of a real occurrence location.

• Journal of Families and Better Life
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• v.24 no.5 s.83
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• pp.251-270
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• 2006

This study examined how the households used and combined financing sources to pay for college education. It compared the probability of using each source (current incomes, saving, education loans and grants) by households' socio-economic characteristics and analyzed which factors influence the decision to use each source and the amounts from each source for financing college education. Data for this study were from a questionnaire completed by 4-year college students (n=623) and were analyzed by t-tests, ANOVA and Heckman's two-step estimation models. The findings of this study were as follows: First, the most frequent source for college education was parents' savings and the second one was parents' incomes. Also, the most frequent combination of sources was saving and current incomes and the second was combination of three sources, saving, incomes and education loans. Second, the probability of using incomes was higher for younger students than for older students. The number of siblings showed significant differences among income, savings and education loans. Those who had higher incomes were more likely to use current incomes, saving, but less likely to borrow for financing college education. Middle-class income groups were more likely to borrow for education. Third, household incomes and asset holdings had generally positive impacts on the probability of using incomes and savings for college education, while total debt burden decreased both the probability and amounts of income and saving sources. The college costs had significantly positive effects on both the probability and the amounts of all of financing sources. Total grants received significantly decreased the amounts from incomes, savings and borrowing sources.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.2
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• pp.119-131
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• 2001

A total of 328 ambient PM-10 samples was collected by a PM-10 high volume air sampler during the periods of February 1997 to February 1999 from Kyung Hee University at Suwon Campus. The samples were analyzed for their bulk chemical compositions(Cu, Fe, Pb, Zn, Al, $Na^{+}$, $NH_{4}^{+}$, $K^{+}$, $Ca^{2+]$, $Mg^{2+}$, $Cl^{-}$, $NO_{3}^{-}$, and $SO_{4}^{2-}$ by both an atomic absorption spectrophotometer and an ion chromatograph. The purpose of this study was t develop a receptor methodology for quantitative assessment of PM-10 sources. The data obtained from this study were ex-tensively examined using the target transformation factor analysis(TTFA) and the chemical mass balance (CMB). When TTFA was initially applied seasonal basis. five sources(such as automobile-related, sulfate-related, incine-ration, soil and combustion-related) were identified both during winter and fall. Since the total number and the type of sources were resolved by TTFA for the four seasons, CMB was employed to cross-check the results of TTEA. The total of six source categories identified by TTEA was intensively investigated on the basis of source profiles acquired from various source libraries established both in Korea and abroad. The results of this study showed the applicability of two popular receptor models as a new methdology for quantitative assessment PM-10 sources in Korea. Seasonally segmented data sets with the combined application of TTFA and CMB yielded a physically reasonable source apportionment result and provided a mean to increase the number of potential sources. Furthermore, this study suggested the possibility of the CMB application to ambi-ent data from Korea after identifying potential sources through traditional factor analysis.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1152-1157
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• 2005

The effect of carbon sources on nisin Z biosynthesis in Lactococcus lactis subsp. lactis A164 was studied in batch culture using M17 broth containing different carbon sources. Among the eleven carbon sources tested, glucose, sucrose, and lactose were suitable carbon sources for cell growth of L. lactis A164. In particular, cells grown on lactose produced at least 3-fold greater amount of nisin Z than those on other carbon sources. Galactose resulted in less amount of cell mass than did sucrose or glucose, but gave a higher level of nisin Z activity. Northern blot analysis revealed. that lactose increased the transcription of the nisZ pre-peptide gene. Although galactose was less efficient than lactose, it increased the transcription of nisZ along with a higher level of nisin Z than did sucrose and glucose. These results suggest that the increased nisin Z production is correlated with the induction of nisZ by lactose and galactose. Among all the carbon sources tested, no remarkable differences were observed in nisRK and nisFEG transcripts, indicating that the lactose- or galactose-mediated induction is unique to the nisZ promoter.

• Nutritional Sciences
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• v.7 no.2
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• pp.98-106
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• 2004

The dietary vitamin $B_6$ intake of 185 Korean children aged 7-12 years (y), who showed no health problems, in the Seoul area and its sources were estimated using a modified Korean vitamin $B_6$ database. The age and sex of each subject was classified according to the classifications in the Korean Recommended Dietary Allowance (RDA). Dietary vitamin $B_6$ intake and food sources were estimated using the three-day recall method with the help of a trained interviewer. Food portion sizes were estimated by using standard household measures and published average portion sizes. The average daily vitamin $B_6$ intake was 1.69$\pm$0.50 mg/d in children aged 7-9 y, 1.86$\pm$0.44 mg/d in male children aged 10-12 y and 1.77$\pm$0.62 mg/d in female children aged 10-12 y. Less than 5% of the subjects consumed less than the Korean RDA of vitamin $B_6$. The average ratio of vitamin $B_6$intake to daily protein intake was 0.028$\pm$0.006 mg/g in children aged 7-9 y, 0.028$\pm$0.004 mg/g in male children aged 10-12 y and 0.029$\pm$0.007 mg/g in female children aged 10-12 y. The intake of vitamin $B_6$ was significantly (p<.01) positively correlated to the intake of all other nutrients. Foods from animal and plant sources provided 37% and 73% respectively, of total vitamin $B_6$. Major dietary sources of vitamin $B_6$ in children in the Seoul area were rice, soybean sprouts, pork, beef, cereal, kimchi, milk, onions, and potatoes. As for major dietary sources of vitamin $B_6$, the top 20 foods provided nearly 73-75% of the total vitamin $B_6$ consumed by Korean children.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.47.1-47.1
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• 2016

We present a preliminary result of search for CO molecular outflows toward a sample of 68 candidate Very Low Luminosity Objects (VeLLOs; Lint ${\leq}0.1L_{\odot}$) to help to understand their physical properties. The sources have been identified using the data at IR to radio wavelengths by M. Kim et al. 2016 toward nearby star-forming regions in the Gould belt. These sources were observed in rotational transitions 2-1 and 3-2 of $^{12}CO$, $^{13}CO$, and $C^{18}O$ molecules with SRAO, CSO, JCMT, and ASTE telescopes. In the beginning of our survey we made a single pointing observation in $^{12}CO$ 2-1 or 3-2 lines for our sample, identifying 53 sources as potential outflow candidates from their line wing features. We made full or partial mapping observations for these candidates with the same lines, finding 33 sources with bipolar or one-sided outflow features. Out of these 33 sources, 6 VeLLOs are previously known sources to have their outflows and 27 VeLLOs are found to be new outflow sources identified from this study. We estimated outflow properties with corrections for excitation temperature, optical depth, and inclination. Their outflow forces range from $8.7{\times}10^{-10}$ to $6.0{\times}10^{-5}M_{\odot}\;km\;s^{-1}yr^{-1}$ with a median value of $3.6{\times}10^{-7}M_{\odot}\;km\;s^{-1}yr^{-1}$, indicating that most of the VeLLOs are less powerful than those for protostars. Their accretion luminosities vary from $9.7{\times}10^{-9}$ to $166L_{\odot}$ with a median value of $0.004L_{\odot}$, implying that most VeLLOs have larger ratios of the accretion luminosity to the internal luminosity but a significant number of VeLLOs have smaller ratios. This result suggests that many of the VeLLOs can be explained with episodic accretion but a significant number of VeLLOs cannot.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.263-268
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• 2008

This study was carried out to investigate the quality characteristics of various honeys originating from different sources, and to identify factors potentially useful for distinguishing the honey sources. The sugar composition, moisture content and total acidity of twenty six honey samples were analyzed. The moisture contents were lowest in honeys from Acacia and were not greatly different with regard to honey sources. Fructose content was highest, followed by glucose, sucrose and maltose in all kinds of honey. Sugar composition did not show any reliable criterion useful for identifying the sources of honey samples. The fructose/glucose ratio did not differ among samples, however the ratios in honeys from Acacia and Chestnut were higher than honey from poly floral sources. The total acidity of honeys ranged 10.30-12.45 meq/kg regard-less of the source, thus acidity is not a useful criterion for identifying the honey source.