• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.56-62
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• 2010

Quality characteristics such as alcohol, acid, and sugar contents of takju brewing mashes prepared using several yeasts were investigated during 12-days of fermentation. Among the yeasts examined, S. cerevisiae led to the highest level of ethanol (10.2-13.4%) and total minor alcohols (0.729-0.831 mg/mL). Regardless of the yeasts used, the acidity showed drastic changes (pH from 3.4-4.2 down to 2.4-2.7) during the first 2 days, and displayed negligible changes from day 4. The total acid contents rapidly increased to the first 4 days of fermentation and leveled off from 4 to the end of fermentation period. The common organic acid components were lactic, succinic and acetic acids. The total and reducing sugar contents varied depending on the yeasts used, with mashes prepared using S. coreanus and S. rouxii producing the maximum total sugar contents (5.43-5.5%) at the end of fermentation. The reducing sugar showed its maximum (7.53-14.89%) at day 2, after which it decreased to its minimum levels (3.04-4.52%). The common free sugar components were glucose and fructose, while S. ellipsoideus led to a higher free sugar level (0.35-5.29%).

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.274-281
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• 2015

BACKGROUND: A lasting release of low levels of persistence chemicals including pesticides and pharmaceuticals into river has a bad influence on aquatic ecosystems and humans. The present study monitored pesticide residues in the Yeongsan and Seomjin river basins and their tributaries as a fundamental study for water quality standard of pesticides.METHODS AND RESULTS: Nine pesticides(aldicarb, carbaryl, carbofuran, chlorpyrifos, 2,4-D, MCPA, methomyl, metolachlor, and molinate) were determined from water samples using SPE-Oasis HLB(pH 2) and LC/MS/MS. Validation of the method was conducted through matrix-matched internal calibration curve, method detection limit(MDL), limit of quantification(LOQ), accuracy, precision, and recovery. MDLs of all pesticides satisfied the GV/10 values. Linearity(r²) was 0.9965- 0.9999, and a percentage of accuracy, precision, and recovery was 89.4-113.6%, 3.1-14.0%, and 90.8-106.2%, respectively. All pesticides exclusive of aldicarb were determined in the river samples, and there was a connection between the positive monitoring results and agricultural use of the pesticides.CONCLUSION: Monitoring outcomes of the present study implied that pesticides were a possible non-point pollutant source in the Yeongsan and Seomjin river basins and tributaries. Therefore, it is required to produce and accumulate more monitoring results on pesticides in river waters to set water quality standards, finally to preserve aquatic ecosystems.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.241-244
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• 2006

This study was conducted by using the ICP-AES (Inductively Coupled Plasma - Atomic Emission Spectrometry) to investigate the seasonal changes of copper and manganese content in the raw bovine milk. From July 2003 to June 2004, the milk samples were collected from the two geographical locations, Chungcheong-do and Jeolla-do, in Korean peninsula. Copper (Cu) content was determined in the range of min. 10.10 to max. 21.00 ${\mu}g$/100 mL (13.79 ${\mu}g$/100 mL) in spring, 5.06 to 15.41 (10.17) in summer, 5.04 to 19.70 (10.70) in autumn and 6.96 to 17.90 (12.11) in winter. For manganese (Mn), 3.00 to 8.30 (4.87) in spring, 2.30 to 6.44 (3.75) in summer, 2.81 to 6.04 (3.82) in autumn and 2.25 to 9.02 (4.48) in winter. Those data have shown that levels of copper and manganese was relatively constant but higher in Spring than other seasons, suggesting that the levels were not affected by seasons and different locations in Korea.

• Journal of the Korean Home Economics Association
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• v.39 no.1
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• pp.91-102
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• 2001

The non-starch polysaccharides in the cell wall of rice, glutinous rice, and black rice, were analyzed. They were fractionated into fractions; water-soluble, hot writer-soluble, ammonium oxalate-soluble, sodium hydroxide-soluble, potassium hydroxide-soluble, and the alkali-insoluble, according to the solvent solubility. The dietary fiber contents were 5.4% in glutinous rice, 4.2% in rice and 7.5% in black rice. The sodium hydroxide soluble fibers were abundant in each kind of rice, especially 4.01% in black rice. The water soluble fibers were 80% of dietary fiber in glutinous rice, 66% in rice, 86% in black rice. It was supposed that the content of the water soluble fibers in rice was increased by pounding. Pectic substances in water soluble fibers, hot water soluble fibers, and ammonium oxalate soluble fibers fraction, were 2.4% in glutinous rice fraction,1.59% in rice, and 1.12% in black rice. Alkali soluble fibers were considered as hemicellulose. Black rice contained 5.80% of hemicellulose, which was more than twice as much as glutinous rice(2.58%) and rice(2.22%). Alkali insoluble fibers were considered as cellulose, which showed no considerable difference. Among samples content of uronic acid in glutinous rice, rice and black rice were 0.9%, 0.66%, 1.8% respectively. Uronic acid of black rice was twice more than other samples tested. The fraction of black rice that uronic acid was extracted at most was the fraction of sodium hydroxide. Mono saccharides of the fraction was the glucose, the arabinose, the xylose.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1093-1101
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• 2000

The object of this study was to develop new BNR process using fixed-biofilm which could be applied to retrofit the existing wastewater treatment plant or to introduce as tertiary treatment plant. To achieve complete denitrification from typical raw sewage in Korea, external carbon source must be supplied because $SCOD_{cr}/T-N(NH_4{^+}-N+NOx-N)$of raw sewage was lower than other countries. In this study, the ratio of $SCOD_{cr}/NH_4{^+}-N$ was 2.49 and the influent $NH_4{^+}$-N concentration during the experimental period was varied from 25 to 37 mg/L. To enhance nitrogen removal from the sewage, the two processes using fixed biofilm were adopted as R-Hanoxic/mid.settler/aerobic/anoxic/ aerobic) and R-2(aerobic/mid.settlerlanoxic/anoxic/aerobic), respectively. In the comparison of $NH_4{^+}$-N, T-N effluent quality and T-N removal efficiency in both processes without external carbon source, R-1 process was better than R-2 process for nitrogen removal from raw sewage. With respect to $SCOD_{cr}$/NOx-N ratio and total nitrogen removal in each anoxic reactor of two processes, R-1's was more effective than R-2's for distributing organic matters of raw sewage. In the both processes using fixed biofilm, the amount of required alkalinity to remove unit $NH_4{^+}$-N were 5.18 and 5.76($g{\cdot}CaCO_3/g{\cdot}NH_4{^+}-N_{removed}$), respectively and were lower than activated sludge BNR process(7.14).

• Journal of agriculture & life science
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• v.43 no.2
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• pp.23-30
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• 2009

The object of this study was to evaluate the effect of the gibberellin treatment on fruit enlargement and ripening promotion in 'Niitaka' pear(Pyms pynfolia). Fruit weight was similar between $GA_{4+7}$ treatments and the gibberellin-paste control, but fairly increased of fruit weight compared to non-treatment Most effective time for $GA_{4+7}$ treatment to increase diameter and length was on 35 and 40 days after full bloom, respectively. Shape index was similar in all treatments. Fruit enlargement at the period of early growth, $GA_{4+7}$ 2.4% treatment was remarkably effective than $GA_{3}+GA_{4+7}$ 2.7% treatment or non-treatment However at the period of maturity, $GA_{4+7}$ 2.4% treatment and $GA_{3}+GA_{4+7}$ 2.7% treatment showed little differences in fruit enlargement and coloring. In maturing promotion effect, young fruit treated with $GA_{3}+GA_{4+7}$ showed similar fruit coloring to ethephon treatment on 35 days after full bloom, and both of those treatments promoted fruit coloring than non- treatment about 6 days. $GA_{3}+GA_{4+7}$ treatments resulted higher solid content and decreased acidity than non-treatment However, there was no differences in fruit hardness comparing to non-treatment As a result, gibberellin was most effective in fruit enlargement, so as all $GA_{3}+GA_{4+7}$ treatments were more effective on fruit enlargement than ethephon treatment or non-treatment Specifically, when $GA_{3}+GA_{4+7}$ was treated 35days after full bloom of flower, the diameter, the length and the shape of fruit index were best, and fruit coloring was good as well.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.49-50
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• 1982

The objective of this paper is to review the changes in fertilizer use pattern and to discuss some aspects of the fertilizer development in Korea. Fertilizer consumption in Korea have steadily increased to triple the application rates of N, P and K during the 15 years from 1965 to 1980, and Korea became one of the countries which apply fertilizers at the highest rate. The ratio of N: $P_2O_5$: $K_2O$ in fertilizer consumption changed from 55.4 : 31.4 : 13.1 in 1965 to 54.0 : 23.8 : 22.2 in 1980. It can be said that Korean farmers practise a balanced fertilization at least in view of fertilizer consumption as compared to other developing countries. However, differences in soil properties, crops, and climate varying as region were not reflected on fertilization. In the technological development of fertilizer, the chemical form and composition of the fertilizer as well as the suitability to the specific crops must be taken into consideration for the efficient use of fertilizers. Although organic fertilizers and manure are accepted as minor element suppliers, it is necessary to add minor elements into chemical fertilizers on the industrial process. Industrial waste may be used for the agricultural production as a measure of pollution control providing careful study on the waste.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.123-138
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• 2017

Since the stock market is driven by the expectation of traders, studies have been conducted to predict stock price movements through analysis of various sources of text data. In order to predict stock price movements, research has been conducted not only on the relationship between text data and fluctuations in stock prices, but also on the trading stocks based on news articles and social media responses. Studies that predict the movements of stock prices have also applied classification algorithms with constructing term-document matrix in the same way as other text mining approaches. Because the document contains a lot of words, it is better to select words that contribute more for building a term-document matrix. Based on the frequency of words, words that show too little frequency or importance are removed. It also selects words according to their contribution by measuring the degree to which a word contributes to correctly classifying a document. The basic idea of constructing a term-document matrix was to collect all the documents to be analyzed and to select and use the words that have an influence on the classification. In this study, we analyze the documents for each individual item and select the words that are irrelevant for all categories as neutral words. We extract the words around the selected neutral word and use it to generate the term-document matrix. The neutral word itself starts with the idea that the stock movement is less related to the existence of the neutral words, and that the surrounding words of the neutral word are more likely to affect the stock price movements. And apply it to the algorithm that classifies the stock price fluctuations with the generated term-document matrix. In this study, we firstly removed stop words and selected neutral words for each stock. And we used a method to exclude words that are included in news articles for other stocks among the selected words. Through the online news portal, we collected four months of news articles on the top 10 market cap stocks. We split the news articles into 3 month news data as training data and apply the remaining one month news articles to the model to predict the stock price movements of the next day. We used SVM, Boosting and Random Forest for building models and predicting the movements of stock prices. The stock market opened for four months (2016/02/01 ~ 2016/05/31) for a total of 80 days, using the initial 60 days as a training set and the remaining 20 days as a test set. The proposed word - based algorithm in this study showed better classification performance than the word selection method based on sparsity. This study predicted stock price volatility by collecting and analyzing news articles of the top 10 stocks in market cap. We used the term - document matrix based classification model to estimate the stock price fluctuations and compared the performance of the existing sparse - based word extraction method and the suggested method of removing words from the term - document matrix. The suggested method differs from the word extraction method in that it uses not only the news articles for the corresponding stock but also other news items to determine the words to extract. In other words, it removed not only the words that appeared in all the increase and decrease but also the words that appeared common in the news for other stocks. When the prediction accuracy was compared, the suggested method showed higher accuracy. The limitation of this study is that the stock price prediction was set up to classify the rise and fall, and the experiment was conducted only for the top ten stocks. The 10 stocks used in the experiment do not represent the entire stock market. In addition, it is difficult to show the investment performance because stock price fluctuation and profit rate may be different. Therefore, it is necessary to study the research using more stocks and the yield prediction through trading simulation.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.2
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• pp.101-108
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• 2017

Purpose: The proton used in proton therapy has a characteristic of giving a small dose to the normal tissue in front of the tumor site while forming a Bragg peak at the cancer tissue site and giving up the maximum dose and disappearing immediately. It is very important to verify the proton arrival position. In this study, we used the off-line PET CT method to measure the distribution of positron emitted from nucleons such as 11C (half-life = 20 min), 150 (half-life = 2 min) and 13N The range and distal falloff point of the proton were verified by measurement. Materials and Methods: In the IEC 2001 Body Phantom, 37 mm, 28 mm, and 22 mm spheres were inserted. The phantom was filled with water to obtain a CT image for each sphere size. To verify the proton range and distal falloff points, As a treatment planning system, SOBP were set at 46 mm on 37 mm sphere, 37 mm on 28 mm, and 33 mm on 22 mm sphere for each sphere size. The proton was scanned in the same center with a single beam of Gantry 0 degree by the scanning method. The phantom was scanned using PET-CT equipment. In the PET-CT image acquisition method, 50 images were acquired per minute, four ROIs including the spheres in the phantom were set, and 10 images were reconstructed. The activity profile according to the depth was compared to the dose profile according to the sphere size established in the treatment plan Results: The PET-CT activity profile decreased rapidly at the distal falloff position in the 37 mm, 28 mm, and 22 mm spheres as well as the dose profile. However, in the SOBP section, which is a range for evaluating the range, the results in the proximal part of the activity profile are different from those of the dose profile, and the distal falloff position is compared with the proton therapy plan and PET-CT As a result, the maximum difference of 1.4 mm at the 50 % point of the Max dose, 1.1 mm at the 45 % point at the 28 mm sphere, and the difference at the 22 mm sphere at the maximum point of 1.2 mm were all less than 1.5 mm in the 37 mm sphere. Conclusion: To maximize the advantages of proton therapy, it is very important to verify the range of the proton beam. In this study, the proton range was confirmed by the SOBP and the distal falloff position of the proton beam using PET-CT. As a result, the difference of the distally falloff position between the activity distribution measured by PET-CT and the proton therapy plan was 1.4 mm, respectively. This may be used as a reference for the dose margin applied in the proton therapy plan.

• Sleep Medicine and Psychophysiology
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• v.24 no.2
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• pp.106-117
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• 2017

Objectives: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder that is characterized by repetitive collapse or partial collapse of the upper airway during sleep in spite of ongoing effort to breathe. It is believed that OSA is usually worsened in REM sleep, because muscle tone is suppressed during REM sleep. However, many cases showed a higher apnea-hypopnea index (AHI) during NREM sleep than during REM sleep. We aimed here to determine the characteristics of REM sleep-dependent OSA (REM-OSA) and NREM sleep-dependent OSA (NREM-OSA). Methods: Five hundred sixty polysomnographically confirmed adult OSA subjects were studied retrospectively. All patients were classified into 3 groups based on the ratio between REM-AHI and NREM-AHI. REM-OSA was defined as REM-AHI/NREM-AHI > 2, NREM-OSA as NREM-AHI/REM-AHI > 2, and the rest as sleep stage-independent OSA (IND-OSA). In addition to polysomnography, questionnaires related to subjective sleep quality, daytime sleepiness, and emotion were completed. Chi-square test, ANOVA, and ANCOVA were performed. Results: There was no age difference among subgroups. The REM-OSA group was comprised of large proportions of mild OSA and female OSA patients. These patients experienced poor sleep and more negative emotions than other two groups. The AHI and oxygen desaturation index (ODI) were lowest in REM-OSA. Sleep efficiency and N3 percentage of REM-OSA were higher than in NREM-OSA. The percentage of patients who slept in a supine position was higher in REM-OSA than other subgroups. IND-OSA showed higher BMI and larger neck circumference and abdominal circumference than REM-OSA. The patients with IND-OSA experienced more sleepiness than the other groups. AHI and ODI were highest in IND-OSA. NREM-OSA presented the shortest total sleep time and the lowest sleep efficiency. NREM-OSA showed shorter sleep latency and REM latency and higher percentage of N1 than those of REM-OSA and the highest proportion of those who slept in a lateral position than other subgroups. NREM-OSA revealed the highest composite score on the Horne and ${\ddot{O}}stberg$ questionnaire. With increased AHI severity, the numbers of apnea and hypopnea events during REM sleep decreased, and the numbers of apnea and hypopnea events during NREM sleep increased. The results of ANCOVA after controlling age, sex, BMI, NC, AC, and AHI showed the lowest sleep efficiency, the highest AHI in the supine position, and the highest percentage of waking after sleep onset in NREM-OSA. Conclusion: REM-OSA was associated with the mild form of OSA, female sex, and negative emotions. IND-OSA was associated with the severe form of OSA. NREM-OSA was most closely related to position and showed the lowest sleep efficiency. Sleep stage-dependent characteristics could provide better understanding of OSA.