• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.123-128
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• 2008

The Dissolved Organic Carbon (DOC) existing in a water includes both hydrophobic and hydrophilic substances however, most of the discussion focuses on hydrophobic substances. The hydrophobic fraction was easily removed by absorption or coagulation more than hydrophilic fraction. Therefore, control of the hydrophilic fraction is very important in water treatment process. This study is to determine the variation of DOC, the removal efficiency of DOC, and Trihalomethane formation potential (THMFP) after each stage of water treatment process by fractionating Natural Organic Matters (NOM) into hydrophobic and hydrophilic substance. DOC from raw water was fractionated at acidic pH (pH<2) using XAD 8 resin column, into two fraction : hydrophobic substance (i.e. humic substance) adsorbed on XAD 8 and hydrophilic substance which represent the organics contained in the final effluent. THMFP was carried out according to the following set condition: Cl2/DOC=4 mg/mg, incubation at $25^{\circ}C$ in darkness, pH 7 adjust with HCl or NaOH as necessary, and 72hour-contact time. THMs analyzed in this study were chloroform, bromodichloromethane, dibromochloromethan, and bromoform. Sewage was almost evenly split between the hydrophobic (56%) and hydrophilic fraction (44%). But, Aldrich humic substance (AHS) was found to contain less hydrophilics (14%) than hydrophobics (86%). The formation of THMs may depend on the source which is characterized by the composition of organic matters such as AHS and sewage. The THMFP yield of sewage and AHS were assessed as follows. The value of the THMFP reaction yield, AHS $172.65{\mu}g/mg$, is much higher than that of sewage $41.68{\mu}g/mg$. This illustrates possible significant difference in THMFP according to the component type and the proportion of organic matter existing in water source. Apparently AHS react with chlorine to produce more THMFP than do the smaller molecules found in sewage. Water treatment process may reduce THMFP, nevertheless residual DOC (the more hydrophilic substance) has significant THMFP. Further reduction in organic halide precursors requires application of alternative treatment techniques.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.155-164
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• 2010

Emission from biomass combustion such as meat charbroiling is an important source of organic aerosol. Since source profiles are necessary input profiles for source apportionment of aerosol by a chemical mass balance model, meat cooking organic source profiles are developed by measuring organic marker compounds, including palmitic acid, stearic acid, oleic acid and cholesterol as well as PAH compounds. Emissions from meat and pork charbroiling are collected on quartz filters with a PM10-high volume sampler, extracted with organic solvents, derivatized with diazomethane/TMS and analyzed by GC/MS isotope dilution method. Organic and elemental carbon are also analyzed by an OCEC analyzer. Wt.% of cholesterol to the organic carbon(OC) content from beef and pork charbroiling is only 0.056 and 0.062, but wt. % of all saturated fatty acids to the OC content from beef and pork charbroiling is 2.727 and 2.022, and the wt% of all unsaturated fatty acids to the OC content is 0.278 and 0.438, respectively. Content of total PAH compounds to the OC content from beef charbroiling is higher than that from pork charbroiling, and those are 0.116 wt% and 0.044 wt%. Among PAH compounds benzo(a)pyrene as a single compound is account for 0.0071 wt% and 0.0023 wt% of OC content from beef and pork charbroiling. Ratios of marker compound to cholesterol are calculated, and those values are in good agreement with the values already reported at the food cooking emission, indicating that they can be used as organic source profiles for the apportionment of organic aerosol.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.21-29
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• 2018

The purpose of this study is to explore supporting strategies for teaching and learning based on students' effect recognition and continuous intention in college flipped learning. It was analyzed 426 data by multivariate analysis of variance (MANOVA) by examining student's effect recognition and continuous intention on 15 flipped learning classes of K-university in Chungnam. The characteristics of learners were male, senior students, students who knew flipped learning, students who did not have previous experience, and students who were learning video at anytime. As a teaching strategy, it was found that effect recognition and continuous intention were high in the supplementary deepening flipped learning class and natural science or engineering area. As a teaching and learning supporting strategies, First, the university should develop and operate flipped class learning strategy program for females and low-grade students. Second, it should support the development of good flipped learning design and operation model of instructor. Third, it should support the development of high quality online learning contents that students can learn from time to time. Fourth, it should support the strengthening of teaching competency to develop and operate flipped learning classes. This study can be used as basic data to support and spread the effective flipped learning classes of the university in the future.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.68-76
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• 2006

A thermal time-based two-step phenological model was used to project flowering dates of Japanese cherry in South Korea from 1941 to 2100. The model consists of two sequential periods: the rest period described by chilling requirement and the forcing period described by heating requirement. Daily maximum and minimum temperature are used to calculate daily chill units until a pre-determined chilling requirement for rest release is met. After the projected rest release date, daily heat units (growing degree days) are accumulated until a pre-determined heating requirement for flowering is achieved. Model calculations using daily temperature data at 18 synoptic stations during 1955-2004 were compared with the observed blooming dates and resulted in 3.9 days mean absolute error, 5.1 days root mean squared error, and a correlation coefficient of 0.86. Considering that the phonology observation has never been fully standardized in Korea, this result seems reasonable. Gridded data sets of daily maximum and minimum temperature with a 270 m grid spacing were prepared for the climatological years 1941-1970 and 1971-2000 from observations at 56 synoptic stations by using a spatial interpolation scheme for correcting urban heat island effect as well as elevation effect. A 25km-resolution temperature data set covering the Korean Peninsula, prepared by the Meteorological Research Institute of Korea Meteorological Administration under the condition of Inter-governmental Panel on Climate Change-Special Report on Emission Scenarios A2, was converted to 270 m gridded data for the climatological years 2011-2040, 2041-2070 and 2071-2100. The model was run by the gridded daily maximum and minimum temperature data sets, each representing a climatological normal year for 1941-1970, 1971-2000, 2011-2040, 2041-2070, and 2071-2100. According to the model calculation, the spatially averaged flowering date for the 1971-2000 normal is shorter than that for 1941-1970 by 5.2 days. Compared with the current normal (1971-2000), flowering of Japanese cherry is expected to be earlier by 9, 21, and 29 days in the future normal years 2011-2040, 2041-2070, and 2071-2100, respectively. Southern coastal areas might experience springs with incomplete or even no Japanese cherry flowering caused by insufficient chilling for breaking bud dormancy.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.6
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• pp.681-692
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• 2017

In recent years, large-scale construction projects such as road pavement construction and new city construction have been carried out nationwide with by the expansion of social overhead facilities and base on the economic development planning, resulting in a rapid increase in artificial slope damage. The existing vegetation-based re-installation method of the slope surface greening method reveals various problems such as lack of bonding force, drying, and lack of organic matter. In this study, research was carried out using vegetation-based material and environmentally friendly soil additives, were are used in combination with natural humus, Bark compost, coco peat, and vermiculite. Uniaxial compressive strength was measured according to the mixing ratio of soil additives and the strength was analyzed. Experiments were carried out on the characteristics of the soil material to gauge the slope protection properties by using the soil compaction test method wherein the soil and the soil additive materials are mixed in relation to the soil height, the number of compaction, the compaction method (layer) and the curing condition. As a result of the experiment, excellent strength performance was demonstrated in soil additives using gypsum cement, and it satisfied vegetation growth standards by using performance enhancer and pH regulator. It was confirmed that the strength increases with the mixing of soil and soil additive, and the stability of slope protection can be improved.

• Journal of Service Research and Studies
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• v.14 no.1
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• pp.1-12
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• 2024

As the service robot market grows among the food technology industry, the quality of robot service that affects consumer behavioral intentions in the restaurant industry has become important. Serving robots, which are common in restaurants, reduce employee work through order and delivery, but because they do not respond to service failures, they increase customer dissatisfaction as well as increase employee work. In order to improve the quality of service beyond the simple function of receiving and serving orders, functions of recovery effort, fairness, empathy, responsiveness, and certainty of the process after service failure, such as serving employees, are also required. Accordingly, we assumed the type of failure of restaurant serving service as two internal and external factors, and developed a serving robot with a vocational ethics module to respond with a professional ethical attitude when the restaurant serving service fails. At this time, the expression and action of the serving robot were developed by adding a failure mode reflecting failure recovery efforts and empathy to the normal service mode. And by recruiting college students, we tested whether the service robot's response to two types of service failures had a significant effect on evaluating the robot. Participants responded that they were more uncomfortable with service failures caused by other customers' mistakes than robot mistakes, and that the serving robot's professional ethical empathy and response were appropriate. In addition, unlike the robot's favorability, the evaluation of the safety of the robot had a significant difference depending on whether or not a professional ethical empathy module was installed. A professional ethical empathy response module for natural service failure recovery using generative artificial intelligence should be developed and mounted, and the domestic serving robot industry and market are expected to grow more rapidly if the Korean serving robot certification system is introduced.

• Journal of Mushroom
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• v.22 no.3
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• pp.92-101
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• 2024

Hair dyeing, hair perming, and daily hair dryer use can substantially damage hair. Consequently, the demand for products containing natural ingredients for the care of damaged hair is growing. Although polyphenols with antioxidant effects are often used for hair conditioning, few studies have focused on hair conditioning, and the potential of Sparassis latifolia mushroom extract for hair improvement has not been evaluated to date. In this study, the antioxidant activity of and polyphenol content in hot water, 70% and 100% ethanol (EtOH), n-hexane, ethyl acetate (EtOAc), and water extracts of S. latifolia were analyzed. A hair treatment containing S. latifolia extract was prepared, and its effect on damaged hair was evaluated. The highest antioxidant activity was observed in the hot water and EtOAc extracts. Moreover, polyphenol analysis using high-performance liquid chromatography and liquid chromatography-mass spectroscopy confirmed that the EtOAc fraction has relatively high contents of specific polyphenols beneficial for hair. Based on these results, a hair treatment containing S. latifolia extract was applied to damaged hair, and hair improvement was evaluated using hair thickness, tensile strength, and scanning electron microscopy. The hair treatment containing 70% EtOH extract effectively improved hair condition. We postulate that this improvement was caused by the high hydrophobic polyphenol content in the 70% EtOH extract.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.233-242
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• 2020

As studies and developments of nano-material increase, the release of the nano-sized material to water environment increase. Especially, silver nanoparticles have been found as dissolved and particulate state since nano-silver particle have been intensively used in industrial and our living environment due to the anti-bacterial effect of the nano-particles. The silver nano-particles and silver ion gives adverse effect on ecology and US-EPA set a secondary drinking water standards as 0.1 mg/L. Current study focused on the analysis of silver in groundwater, small scale water supply systems in Gyeongbook area. The results have been compared with the secondary drinking water standards and discussed at the point of characteristics of the local area and purpose of use of the water sample. Among the total of 298 samples, 2 samples exceed the secondary drinking water standards of EPA, 0.64% rate. Community drinking water and simplified water service showed relatively high detection rate and groundwater gave relatively higher concentration of silver indicating anthropogenic source and natural source could contribute simultaneously on groundwater.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.92-97
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• 2012

Antimicrobial peptides (AMPs) are important components of living organisms acting against Gram-negative and Gram-positive bacterial and fungal pathogens. Cathelicidin human peptides have a variety of biological activities that can be used in clinical applications. AMPs are not produced naturally in large quantities, and chemical synthesis is also economically impractical, especially for long peptides. Therefore, as an alternative, heterologous expression of AMPs by recombinant techniques has been studied as a means to reduce production costs. E. coli is an excellent host for the expression of AMPs, as well as other recombinant proteins, because of the low cost involved and its easy manipulation. However, overexpression of AMPs in E. coli has been shown to cause difficulties resulting from the toxicity of the subsequently produced AMPs. Therefore, fusion expression was theorized to be a solution to this problem. In this study, AMPs were expressed as fused proteins with the glutathione S-transferase (GST) binding protein to protect against the toxicity of AMPs when expressed in E. coli. The LL37, and hybrid gaegurin and LL37 (GGN4(1-16)-LL37(17-32), which we designated as GL32, peptides were expressed as GST-fusion proteins in E. coli and the fusion proteins were then purified by affinity columns. The purified peptides were obtained by removal of GST and were confirmed by western blot analysis. The purified antimicrobial peptides then demonstrated antimicrobial activities against Gram-negative and Gram-positive bacterial strains.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.5-9
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• 2008

Researchers have investigated many upper bound techniques applicable to error probabilities on the maximum likelihood (ML) decoding performance of turbo-like codes and low density parity check (LDPC) codes in recent years for a long codeword block size. This is because it is trivial for a short codeword block size. Previous research efforts, such as the simple bound technique [20] recently proposed, developed upper bounds for LDPC codes and turbo-like codes using ensemble codes or the uniformly interleaved assumption. This assumption bounds the performance averaged over all ensemble codes or all interleavers. Another previous research effort [21] obtained the upper bound of turbo-like code with a particular interleaver using a truncated union bound which requires information of the minimum Hamming distance and the number of codewords with the minimum Hamming distance. However, it gives the reliable bound only in the region of the error floor where the minimum Hamming distance is dominant, i.e., in the region of high signal-to-noise ratios. Therefore, currently an upper bound on ML decoding performance for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix cannot be calculated because of heavy complexity so that only average bounds for ensemble codes can be obtained using a uniform interleaver assumption. In this paper, we propose a new bound technique on ML decoding performance for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix using ML estimated weight distributions and we also show that the practical iterative decoding performance is approximately suboptimal in ML sense because the simulation performance of iterative decoding is worse than the proposed upper bound and no wonder, even worse than ML decoding performance. In order to show this point, we compare the simulation results with the proposed upper bound and previous bounds. The proposed bound technique is based on the simple bound with an approximate weight distribution including several exact smallest distance terms, not with the ensemble distribution or the uniform interleaver assumption. This technique also shows a tighter upper bound than any other previous bound techniques for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix.