• Journal of Korean Society of Environmental Engineers
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• v.33 no.1
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• pp.47-53
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• 2011

$SF_6$ (Sulfur hexafluoride) possesses high GWP (Global Warming Potential) as sepcified by the IPCC (Intergonvernmental Panel of Climate Change). Recently, the recovery-separtion of $SF_6$ research area, including permeation properties studies using various membrane's materials and the practical operation of recovery-separtion using membrane of waste $SF_6$ gas is in the initial state. The separation efficiency of a single $SF_6$ and waste $SF_6$ mixture was evaluated using a PSF (polysulfone), PC (tetra-bromo polycarbonate) and PI (polyimide) hollow fiber membranes. According to the results of single gases permeation properties, PI membrane has the highest permselectivity of $N_2$ gas in $N_2/SF_6$ gas. Under the condition of P=0.5 MPa, the highest concentration of recovered $SF_6$ is 95.6 vol % in the separation experiment of $SF_6/N_2$ mixture gas by PC membrane. Under the operation pressure of P=0.3 MPa at a fixed retentate flow rate fixed of 150 cc/min, the maximum recovery efficiency of $SF_6$ is up to 97.8% by PSF membrane. From the results above, it is thought that the separation and recovery technique of $SF_6$ gas using membrane will be used as the representative eco-technology in the $SF_6$ gas treatment in the future.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.505-514
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• 2009

Aqueous potassium salt of serine was proposed as an alternative $CO_2$ absorbent to monoethanolamine (MEA) and its $CO_2$ absorption characteristics were studied. The experiment has been conducted using screening test equipment with NDIR type gas analyzer and vapor-liquid equilibrium apparatus. $CO_2$ absorption/desorption rate and net amount of $CO_2$ absorbed in cyclic process are the criteria to assess the $CO_2$ absorption characteristics in this study. Effective $CO_2$ loading of potassium salt of serine and MEA are 0.425 and 0.230 respectively. Cyclic capacities are 0.354 and 0.298 for potassium salt of serine and MEA. The absorption rate of the potassium serinate decreased sharply at $CO_2$ loading is 0.1 and were maintained approximately at half of MEA. To enhance the absorption rate of aqueous potassium salt of serine, small quantities of rate promoters, namely piperazine and tetraethylenepentamine were blended, so that rich $CO_2$ loading were increased by 13.7% and 18.7% respectively. The rich $CO_2$ loading of potassium salt of serine was 29.2% and 35.0% higher than those of aqueous sodium and lithium salt of serine, respectively. The absorption rate of potassium salt of valine and isoleucine which have similar molecular structures to serine were lower than that of serine because of the presence of bulky side group. Precipitation phenomena during $CO_2$ absorption were discussed by the aid of literatures.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.430-439
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• 2021

Essential oils with excellent antibacterial activity were used to study the inhibitory effect against the six types of food poisoning biofilms formed on the surfaces of polyethylene (PE) and stainless steel (SS) that are widely used for food processing instruments and containers. The antibacterial activity of 20 kinds of essential oils was tested using the disk diffusion method. The result showed the degree of antibacterial activity in the following order: cinnamon> clove> lemongrass> peppermint> pine needle (highest to lowest). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of cinnamon and clove oil were in the range of 0.63-1.25 mg/mL and 1.25-2.50 mg/mL, respectively. The MIC and MBC of lemongrass oil were 1.25-2.50 mg/mL and 2.50-5.00 mg/mL, respectively, showing slightly less antibacterial activity. Although the preventive effect of three types of essential oils on the biofilm formation differed slightly depending on food poisoning bacteria, PE, and SS, it was found that the precoating of 0.5% cinnamon, clove, and lemongrass oil on the PE and SS affects the formation of biofilm. Increased essential oil concentration significantly inhibited the biofilm formation for all food poisoning bacteria (P<0.05), and biofilms of Listeria monocytogenes and Staphylococcus aureus were not formed when treated with 0.5% cinnamon and clove oil. The elimination effect of food poisoning bacteria biofilms formed on the surfaces of PE and SS differed depending on the type of food poisoning bacteria. Still, the biofilm elimination effect increased as the essential oil concentration increased, and the biofilm elimination rate of clove oil was generally high. Therefore, this study found that the cinnamon and clove essential oils (0.5%) are suitable natural materials that effectively prevent, inhibit, and remove the biofilms formed by the food poisoning bacteria on the surfaces of polyethylene and stainless steel.

• Journal of Food Hygiene and Safety
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• v.36 no.6
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• pp.528-536
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• 2021

The purpose of the study was to investigate the content of sinigrin, an index component, in Brassica juncea extract and to evaluate the differentiation of lipocytes, inhibition of production of reactive oxygen species (ROS) and reduction of protein production by lipogenic factors (PPARγ, C/EBPα, aP2) in the processing of Brassica juncea extract and sinigrin in 3T3-L1 preadipocytes which induces Bisphenol A (BPA), an endocrine disrupting environmental hormone. From the investigation, the content of sinigrin in Brassica juncea extract, measured by HPLC, is found to be 21.27±0.2 mg/g. The XTT assay result on BPA-derived 3T3-L1 adipocytes shows there is no cytotoxicity found from 180 µM of sinigrin and 300 ㎍/mL of Brassica juncea extract. Moreover, both intracellular lipid accumulation and ROS production during differentiation of lipocyte are significantly reduced in cells processed with Brassica juncea extract and sinigrin. Lastly, it was also found that the production of transcription factors of lipocyte differentiation, PPARγ, C/EBPα and aP2, were found to be suppressed by the application of Brassica juncea extract and sinigrin. Such results reveals that Brassica juncea is effective in not only suppressing lipid accumulation in the environmental hormone bisphenol A-derived lipocyte, but also in reducing the ROS. The sinigrin-containing Brassica juncea is highly expected to be used in natural functional supplements that prevents the lipid metabolism disorders caused by BPA. There are necessities for additional clinical research and follow-up studies on the in vivo model to verify the relevant mechanisms.

• Journal of Korean Medical Ki-Gong Academy
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• v.7 no.2
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• pp.40-94
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• 2004

Recently, meditation, Zen meditation and Qigong became popular in western. For that reason, Value of Korea traditional methods for health promotion have been evaluated but theoretical evidence about that is insufficient. ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經). So, I reviewed history of Korea Qigong according to period, in order to produce theoretical evidence of Korea medical Qigong and investigated ${\ulcorner}$Han${\lrcorner}$ thought (${\ulcorner}$한${\lrcorner}$ 思想) as theoretical evidence of Korea Qigong. I have obtained following results by comparing meaning of god, a view of human body and practice method of the ${\ll}$Samilshingo${\gg}$ (三一神誥) with ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經). Sinsundo(神仙道) of native to race became active during the period of the Three Kingdoms but more disappeared due to under the influence of Taoism. So only has been remained in existence since the period of the unity silla. There could accept positively the foreign ideas belonging to Confucianism, Buddhism and Taoism have been brought since the period of the Three Kingdoms because ${\ll}$Samilshingo${\gg}$ (三一神誥), one of three the scriptures as the origin of ${\ulcorner}$Han${\lrcorner}$ thought(${\ulcorner}$한${\lrcorner}$ 思想) included the original form of three religion belonging to Confucianism, Buddhism, Taoism. Three common results as theoretical evidence of Qigong were found out by comparing ${\ll}$Samilshingo${\gg}$ (三一神誥) with ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經). First, in meaning of god, there is not only different from the gods of heaven and the gods of human but also keep understanding with each other and there was common feature of logical structure that function of god was divided into three. Second, In a view of human body, there were in common with ${\ll}$Samilshingo${\gg}$ (三一神誥) as theory of only as energy(氣一元論), theory of bisection as truth false(眞妄二分論), theory of trisection as spirit(性) destiny(命) nature(精) and mind(心) energy(氣) body(身)(性 命 精, 心 氣 身의 三分論) and ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經) as theory of only as energy(氣一元論), theory of bisection as shape and god(形神二分論), theory of trisection as nature(精) energy(氣) god(神) or shape(形) energy(氣) god(神)(精 氣 神, 形 氣 神의 三分論) according to formal part. Also, spirit(性) destiny(命) nature(精) as truths of three(三眞) were understand as nature(精) energy(氣) god(神) as treasure of three(三寶) by part of reason and mind(心) energy(氣) body(身) as false of three(三妄) were understand as nature(精) energy(氣) god(神) as treasure of three(三寶) by part of function. Third, In practice method, pause of thinking(止感) modulation of breath(調息). prohibition of sensibility(禁觸) mentioned in ${\ll}$Samilshingo${\gg}$ (三一神誥) as practice method each were understand regulation of an etiological cause as an internal cause, an external cause and not internal and external cause in oriental medicine. Namely, pause of thinking(止感) was understand as regulation method of emotion, mind and nature. modulation of breath(調息) was not only as modulation of energy from the inner parts of the body but also that from the internal and external parts of the body, prohibition of sensibility(禁觸) was understand as regulation method of ear, eye, mouth, and nose and posture, life style. These results suggest that ${\ll}$Samilshingo${\gg}$ (三一神誥) is worth meaning of Korea medical Qigong because meaning of god, a view of human body, practice method of mentioned in ${\ll}$Samilshingo${\gg}$ (三一神誥) is common with that of ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經) as theoretical evidence of Qigong.

• Journal of Intelligence and Information Systems
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• v.24 no.4
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• pp.111-136
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• 2018

In this paper, we propose a methodology to extract answer information about queries from various types of unstructured documents collected from multi-sources existing on web in order to expand knowledge base. The proposed methodology is divided into the following steps. 1) Collect relevant documents from Wikipedia, Naver encyclopedia, and Naver news sources for "subject-predicate" separated queries and classify the proper documents. 2) Determine whether the sentence is suitable for extracting information and derive the confidence. 3) Based on the predicate feature, extract the information in the proper sentence and derive the overall confidence of the information extraction result. In order to evaluate the performance of the information extraction system, we selected 400 queries from the artificial intelligence speaker of SK-Telecom. Compared with the baseline model, it is confirmed that it shows higher performance index than the existing model. The contribution of this study is that we develop a sequence tagging model based on bi-directional LSTM-CRF using the predicate feature of the query, with this we developed a robust model that can maintain high recall performance even in various types of unstructured documents collected from multiple sources. The problem of information extraction for knowledge base extension should take into account heterogeneous characteristics of source-specific document types. The proposed methodology proved to extract information effectively from various types of unstructured documents compared to the baseline model. There is a limitation in previous research that the performance is poor when extracting information about the document type that is different from the training data. In addition, this study can prevent unnecessary information extraction attempts from the documents that do not include the answer information through the process for predicting the suitability of information extraction of documents and sentences before the information extraction step. It is meaningful that we provided a method that precision performance can be maintained even in actual web environment. The information extraction problem for the knowledge base expansion has the characteristic that it can not guarantee whether the document includes the correct answer because it is aimed at the unstructured document existing in the real web. When the question answering is performed on a real web, previous machine reading comprehension studies has a limitation that it shows a low level of precision because it frequently attempts to extract an answer even in a document in which there is no correct answer. The policy that predicts the suitability of document and sentence information extraction is meaningful in that it contributes to maintaining the performance of information extraction even in real web environment. The limitations of this study and future research directions are as follows. First, it is a problem related to data preprocessing. In this study, the unit of knowledge extraction is classified through the morphological analysis based on the open source Konlpy python package, and the information extraction result can be improperly performed because morphological analysis is not performed properly. To enhance the performance of information extraction results, it is necessary to develop an advanced morpheme analyzer. Second, it is a problem of entity ambiguity. The information extraction system of this study can not distinguish the same name that has different intention. If several people with the same name appear in the news, the system may not extract information about the intended query. In future research, it is necessary to take measures to identify the person with the same name. Third, it is a problem of evaluation query data. In this study, we selected 400 of user queries collected from SK Telecom 's interactive artificial intelligent speaker to evaluate the performance of the information extraction system. n this study, we developed evaluation data set using 800 documents (400 questions * 7 articles per question (1 Wikipedia, 3 Naver encyclopedia, 3 Naver news) by judging whether a correct answer is included or not. To ensure the external validity of the study, it is desirable to use more queries to determine the performance of the system. This is a costly activity that must be done manually. Future research needs to evaluate the system for more queries. It is also necessary to develop a Korean benchmark data set of information extraction system for queries from multi-source web documents to build an environment that can evaluate the results more objectively.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.828-836
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• 2014

The purpose of this study evaluates the water quality of artificial deep pool (ADP) during the late spring and summer. we monitored the water quality, as pH, dissolved oxygen (DO), temperature and conductivity at two stations (St. 1. open water, St. 2. in the ADP). The water quality in the ADP is very stable, and temperature and DO are lower than the open water (average value; temperature $1.4{\sim}3.2^{\circ}C$, DO 2.4~3.6 mg/L). In particular, daily variation of temperature in the open water showed above $4^{\circ}C$, but ADP remained stable. The water quality was analyzed using two-way analysis of variance (ANOVA). The results of the analysis showed difference about temperature, pH, DO, conductivity (two-way ANOVA, p<0.05). The ADP has created an aqua environment in thermal and DO gradients by depth. About 1.2 m, Temperature and DO were sharply decreased. The Rhodeus uyekii is dominant species in pond of this study. The ADP offers optimum water temperature ($16.5{\sim}18.5^{\circ}C$) to the Rhodeus uyekii about spawning. Consequently, the ADP offers stable habitat than open water for fish and aquatic organisms during the summer. It is also a good shelter for fish from a thermal stress.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.4
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• pp.283-288
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• 2013

To evaluate the ability of the submerged plant, Ceratophyllum demersum's (C. demersum) to remove nutrients and to inhibit growth of cyanobacteria, a total of 6 mesocosms were conducted in a batch reactor for 9 days. From the 84 hr of the experiment, C. demersum was stabilized and showed daily cycle trends according to changes in pH and DO levels. The concentration of nutrients, $NH_3{^+}$, $NO_3{^-}$ and $PO_4{^3}$ continuously decreased until 9 days of the experiment, with the rapid decrease in nutrient concentration for the first 24 hours. High correlation coefficient ($r^2{\geq}0.96$, p<0.001) between the amount of C. demersum's biomass per unit area and the nutrients removal level were derived, and greater C. demersum's biomass per unit area showed higher removal efficiency of nutrients. However, there were differences in the C. demersum's activity level between batch reactors with higher and similar density of the C. demersum, but nonetheless water purification effect appears to have a significant influence due to attached algae and microorganisms. The growth rate of harmful cyanobacteria, Microcystis aeruginosa (M. aeruginosa) with C. demersum's density of 2,500 g $fw/m^2$ (100% of cover degree) was 0.31 /day, compared to the growth rate of 0.47 /day for the control group (0% of cover degree). In terms of number of cells, the control group had 1.7 times higher number of cells than the experimental group, proving that C. demersum has the ability to inhibit the growth of harmful cyanobacteria.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.472-487
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• 2020

With the emergence of abnormal climate due to the rapid industrialization, the importance of water quality management and management costs are increasing every year. In Korea, for the management of total phosphorus and total nitrogen, the major materials causing the water quality pollution, coagulants are injected in sewage treatment plants to process organic compounds. However, if the coagulant is injected in an excessive amount to PAC (Poly Aluminium Chloride), a secondary pollution problem might occur. As such, a study on the applicability of natural material-based coagulant is being conducted in Korea. Thus, this study aimed to evaluate the applicability of a mixed coagulant developed by analyzing water quality pollutants T-P, T-N as well as their turbidity, in order to derive the optimum mixing ratio between PAC and torrefied wood flour for the primary settling pond effluent. Under the condition where the content of PAC (10%) and torrefied wood flour is 1%, T-P showed the maximum removal efficiency of 92%, and T-N showed approximately 22%. This indicates that removal of T-N which includes numerous positively charged organic compounds that are equivalent to mixed coagulant is not well accomplished. Turbidity showed the removal efficiency of approximately 91%. As such, 1% of torrefied wood flour was determined to be the optimum addition. As a result of analyzing the removal efficiency for organic compounds by reducing PAC concentration to 7%, T-P showed a high maximum removal efficiency of 91%, T-N showed 32%, and turbidity showed the maximum of 90%. In addition, a coagulation process is performed by using the mixed coagulant based on 1% content of torrefied wood flour produced in this study by performing a coagulation performance comparative experiment with PAC (10%). As a result, PAC concentration was reduced to 30-50%, a similar performance with other coagulants in market was secured, PAC injection amount was reduced that an economic effect can be achieved, and it is considered to perform a stable water treatment that reduces the secondary pollution problem.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.495-503
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• 2012

The water quality of Gul-po Stream, the subject of this study, has been deteriorating because of the inflow of domestic sewage and the industrial wastewater due to industrialization and the problems relating to the structure of river including slow flow rate and the covering of river. In particular, the domestic sewage from small-medium sized factories by the river and large-scale industrial complex by the upper and middle streams of the river, and the domestic sewage from increasing population due to the regional development are the main pollution sources. Thus, this study aims to survey the water quality and the sediment affecting Gul-po Stream; monitor the state of pollution in water body; assess the yield of sediment and investigate the water quality of river and the problems arising from sediment; and then suggest reasonable ways to improve the situation. The findings from surveying pollution load shows the discharge increases up to average 72.8 times from the upper stream to the downstream of Gul-po Stream, and pollution load increases up to: SS 111 times, BOD 150 times, COD 145 times, the nutrient T-N 222 times and T-P 312 times on an average basis. As for the pollution concentration range, ignition loss is 1.29~12.43%; COD is 4,015~37,547 kg/day; T-N and T-P 94.8~352.5 kg/day and 81.8~372.3 kg/day, respectively. As for the releasing rate of sediment, T-N is -14.46~$156.61mg/m^2/day$; T-P is -11.53~$26.10mg/m^2/day$, indicating the likelihood of internal contamination due to the elution of sediment. This study is expected to be used as basic data to manage Gul-po Stream basin.