• Journal of Bio-Environment Control
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• v.26 no.1
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• pp.7-12
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• 2017

This experiment was conducted to analyze the effect of drainage reuse rate on the growth and fruiting of summer paprika in closed hydroponic cultivation. The experiment was carried out for 25 weeks from March to September 2015 with 0, 20, 30, 50% mixing ratio of waste nutrient solution using non - recycling hydroponic cultivation as a control. As a result, stem diameter of the test was different in the groups 1 and 2, but no difference showed as the group progressed more than 3 groups. L.A.I tended to decrease with increasing drainage mixing ratio. The number of nodes in the 50% reuse test group was 1.4 compared to the control group, but there was no significant difference. The number of harvested nodes was significantly different in the control group (11.1 nodes) and the 50% reuse test group (8.7 nodes), and the harvested nodes tended to decrease as the drainage was reused. The ratio of harvest was also the same as that of the harvesting node, and the control was the highest at 33.2% and the lowest at the 50% reuse test at 27.6%. Relative yields were reduced by 30%, 35% and 45% in the control group in the first group, and this tendency was also observed in the second and fourth groups. However, in the 3 and 5 groups, the production of 50% test group increased by 13% and 5%. The ratio of unmarketable fruit was increased 2%, 4%, 4%, and 7% in 0%, 20%, 30% and 50% reuse test, respectively. In conclusion, if the decrease in yield due to the decline in early growth is carefully managed, even if the imbalance of inorganic ions occurs after the mid-term growth, the growth of the crop will enter into a stable period and the re-use will not be worried about the growth and the yield decrease.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.10-10
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• 2017

Rice consumption has been continuously decreasing as the eating habits of Koreans have become westernized and diversified. The per capita annual rice consumption in Korea has dropped sharply from 136.4 kg in 1970 to 61.9 kg in 2016. The Korean government, therefore, has been trying to promote rice consumption by invigorating the processed food industry using rice flour. To facilitate the market for processed rice foods, it is essential to develop proper milling technology in terms of flour particle size and damaged starch content to produce high quality rice flour at competitive cost. Dry milling and wet milling are the two major processes used to produce rice flour. Although the dry milling process is relatively simple with a lower production cost, damaged starch content increases because of the high grain hardness of rice. In wet milling, the quality of rice flour is improved by reducing flour particle size as well as damaged starch content through soaking procedures. However, the production costs are high because of the additional expenses associated with the disposal of waste water, sterilization and drying of the wet flour. Recently developed technologies such as jet milling and cryogenic milling also require expensive investment and production. Therefore, developing new rice cultivars with dry milling adaptability as well as good processing properties is an important goal of rice breeding in Korea. 'Suweon 542' is a floury endosperm mutant line derived from sodium azide treatment on a high-yield, early maturing, and non-glutinous japonica rice cultivar, 'Namil'. Compared with the wild type, after dry milling process, the grain hardness of 'Suweon 542' was significantly lower because of its round and loosely packed starch granules. Also, the flour of 'Suweon 542' had significantly smaller particles and less damaged starch than 'Namil' and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar. Recently, through collaborations with nine universities and food companies, a total of 21 kinds of processed prototypes, using the dry milling flour of 'Suweon 542', were evaluated. In the production of major rice processing products, there was no significant quality difference between the flours prepared by wet milling and dry milling. Although the amount of water added to the dough was slightly increased, it was confirmed that the recipe applying the wet flour could be used without significant change. To efficiently transfer the floury endosperm characteristics of 'Suweon 542' to other commercial rice cultivars, it is essential to develop DNA marker tightly linked to the target gene. Association analysis using 70 genome-wide SSR markers and 94 F2 plants derived from 'Suweon 542'/'Milyang 23' showed that markers on chromosome 5 explained a large portion of the variation in floury grains percentage (FGP). Further analysis with an increased number of SSR markers revealed that the floury endosperm of 'Suweon 542' was directed by a major recessive locus, flo7(t), located in the 19.33-19.86 Mbp region of chromosome 5, with RM18639 explaining 92.2% of FGP variation in the F2 population. Through further physical mapping, a co-segregate and co-dominant DNA marker with the locus, flo7(t) was successfully developed, by which, thereby, breeding efficiency of rice cultivars having proper dry milling adaptability with high yield potential or useful functional materials would be improved. 'Suweon 542' maintained the early maturity of the wild type, Namil, which can be used in rice-wheat double cropping systems in Korea not only for improved arable land but also for sharing flour production facilities. In addition to the high susceptibility against major rice diseases, nevertheless, another possible drawback of 'Suweon 542' is the high rate of viviparous under prolonged rainfall during the harvesting season. To overcome susceptibility and vivipary of 'Suweon 542', the progeny lines, derived from the crosses 'Suweon 542' and 'Jopyeong', an early maturing rice cultivar with multiple resistance against rice blast, bacterial blight, and rice strip virus, and 'Heugjinju', a anthocyanin pigment containing black rice cultivar, were intensively evaluated. As the outputs, three dry milling suitable rice elite lines, 'Jeonju614', 'Jeonju615', and 'Jeonju616' were developed.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.90-96
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• 2000

The composition of leachates varies depending on the waste characteristics, landfill age and landfilling method. Generally, leachates contain high dissolved organic substance and ammonia nitrogen whereas phosphorus concentration was very low. Leachate A produced from young landfill is characterized by high BOD5/COD ratio (0.8) whereas leachate C produced from old landfill has lower BOD5/COD ratio (0.1). Maximum biochemical methane potential of leachate A, B (from medium landfill) and C were 271,106 and 4 ml CH4/g-COD, respectively. On the other hand, the maximum biodegradability of leachate A, B, and C were 75,30, and 1%, respectively. These results indicated that anaerobic treatment of leachate from young landfill was effective in removing organic pollutants. In case of leachate C, carbon might reside in the form of large molecular weight organic compounds such as lignins, humic acids and other polymerized compounds of soils, which are resistant to biodegradation. The lag-phase period increased with the increasing organic concentration in leachate. In case of leachate A of concentration greater than 25%, the lag-phase period increased sharply. This implied that the start-up period of anaerobic process using an unacclimated inoculum could be extended due to the higher concentration of leachate. This relatively long lag-phase is probably related to the fact that most of the inhibitory compounds have been diluted beyond their inhibitory concentrations of less than 50%. Furthermore, the ultimate methane yield and methane production rate decreased as leachate concentration increased. It was anticipated the potential inhibition was related with the steady-state inhibition as well as the initial shock load.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.307-312
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• 2005

Since alpine upland in Pyungchang-gun has been typically applied every two or three years with saprolite, agricultural by-products are inputted to raise soil properties. Therefore, the effect of saprolite application on water quality in runoff and leachate should be monitored. To investigate water quality in runoff and leachate with various treatments of agricultural by-product, lysimeter with dimension of $0.85m{\times}1.75m{\times}0.30m$ was installed in Kangwon National University. Control, mixed compost with cow, chicken and sawdust by-product (CCSC), chicken manure by-product compost (CC), food waste by-product compost (FWC), and beer sewage sludge by-product compost (BSSC) at the rate of $10Mg\;ha^{-1}$ were mixed with soil in 25 cm depth, and water qualities in runoff and leachate were monitored from Jun. 4, 2004 to Oct. 18, 2004. EC ($0.8-2.2dS\;m^{-1}$) and concentrations of total N ($25-75mg\;L^{-1}$) and total P ($0.12-0.43mg\;L^{-1}$) were highest in both runoff and leachate of CC treatment. EC values in CC and FWC treatments continuously increased during lysimeter experiment, while total N and total P concentrations continuously decreased. Average total N concentrations in runoff taken from CCSC, FWC and BSSC treatments were 41, 34 and $37mg\;L^{-1}$, and in leachate were 35, 28 and $34mg\;L^{-1}$, respectively. Average total P concentrations were not different with different treatments. EC values in leachate were higher than those in runoff, and total N concentrations in runoff were higher than those in leachate.

• Journal of Internet Computing and Services
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• v.16 no.2
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• pp.77-83
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• 2015

Frequent pattern mining, which is one of the major areas actively studied in data mining, is a method for extracting useful pattern information hidden from large data sets or databases. Moreover, frequent pattern mining approaches have been actively employed in a variety of application fields because the results obtained from them can allow us to analyze various, important characteristics within databases more easily and automatically. However, traditional frequent pattern mining methods, which simply extract all of the possible frequent patterns such that each of their support values is not smaller than a user-given minimum support threshold, have the following problems. First, traditional approaches have to generate a numerous number of patterns according to the features of a given database and the degree of threshold settings, and the number can also increase in geometrical progression. In addition, such works also cause waste of runtime and memory resources. Furthermore, the pattern results excessively generated from the methods also lead to troubles of pattern analysis for the mining results. In order to solve such issues of previous traditional frequent pattern mining approaches, the concept of representative pattern mining and its various related works have been proposed. In contrast to the traditional ones that find all the possible frequent patterns from databases, representative pattern mining approaches selectively extract a smaller number of patterns that represent general frequent patterns. In this paper, we describe details and characteristics of pattern condensing techniques that consider the maximality or closure property of generated frequent patterns, and conduct comparison and analysis for the techniques. Given a frequent pattern, satisfying the maximality for the pattern signifies that all of the possible super sets of the pattern must have smaller support values than a user-specific minimum support threshold; meanwhile, satisfying the closure property for the pattern means that there is no superset of which the support is equal to that of the pattern with respect to all the possible super sets. By mining maximal frequent patterns or closed frequent ones, we can achieve effective pattern compression and also perform mining operations with much smaller time and space resources. In addition, compressed patterns can be converted into the original frequent pattern forms again if necessary; especially, the closed frequent pattern notation has the ability to convert representative patterns into the original ones again without any information loss. That is, we can obtain a complete set of original frequent patterns from closed frequent ones. Although the maximal frequent pattern notation does not guarantee a complete recovery rate in the process of pattern conversion, it has an advantage that can extract a smaller number of representative patterns more quickly compared to the closed frequent pattern notation. In this paper, we show the performance results and characteristics of the aforementioned techniques in terms of pattern generation, runtime, and memory usage by conducting performance evaluation with respect to various real data sets collected from the real world. For more exact comparison, we also employ the algorithms implementing these techniques on the same platform and Implementation level.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.3
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• pp.203-212
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• 2005

Cellulose insulation is primarily manufactured from recycled newsprint and treated with fire retardants for the fire resistance. Thanks to the fire retardants, it is not combustible and flammable. In addition to that, Its thermal resistance is much better than that of fiberglass or rock wool. It is made from waste paper and easily decayed when it is demolished, and it has small embodied energy. So it is very environment-friendly building material. For broader use of cellulose insulation in buildings in Korea, it is necessary to test its physical performance to compare the results with the requirements on the Korean Building Code. To this end, apparent thermal conductivity (ka) measurements of Korean-made loose-fill cellulose insulations were recently completed using equipment that was built and operated in accordance with ASTM C 518 and the fire resistance was tested in accordance with ASTM C 1485. Korean loose-fill cellulose has thermal conductivity about 5% greater than the corresponding U.S. product at the same density. This is likely due to differences in the recycled material being used. Both spray-applied and loose-fill cellulose insulation lose about 1.5% of their thermal resistivity for $5.5^{\circ}C$ increase in temperature. The fire resistance of cellulose insulation is increased in linear proportion to the increase of the rate of fire retardant. Thanks to the high fire resistance, cellulose insulation can be used as a substitution of Styrofoam or Urethane foam which is combustible. The thermal conductivity of cellulose insulation was $0.037-0.043W/m{\cdot}K$ at the mean specimen temperature from $4-43^{\circ}C$. It corresponds to the thermal resistance of "Na Grade" according to the Korean Building Code. The effect of chemical content on thermal conductivity was negligible for all but the chemical-free specimen which had the highest value for the thermal conductivity over the temperature range tested. The thermal resistance of cellulose insulation is better than that of fiberglass or rock wool, and its fire resistance is higher than that of Styrofoam or Urethane foam. Therefore it can be substituted for those above considering its physical performance. Cellulose insulation is no more expensive than Styrofoam or rock wool, so it is recommended to use it more widely in Korea.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1213-1221
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• 2006

In this study, granular sludge used in an anaerobic process treating brewery waste was inoculated in a laboratory scale of reactor to induce anaerobic ammonium oxidation(ANAMMOX). The reactor was operated with synthetic wastewater, which prepared at 1:1 ratio of $NH_4^+-N$ over $NO_2^--N$. Changes in nitrogen concentration, COD, alkalinity and gas production were analyzed. There are 3 phases of spanning in experimental period according to influent nitrogen concentration. In the Phase 1, each of the concentration of $NH_4^+-N$ and $NO_2^--N$ were increased from 1.91 $gN/m^3{\cdot}d$ to 14.29 $gN/m^3{\cdot}d$. Ammonium nitrogen loading(same as nitrite nitrogen) was 23.81 $gN/m^3{\cdot}d$ in the Phase 2 and 19.05 $gN/m^3{\cdot}d$ in the Phase 3, respectively $NO_2^--N$ has been removed up to 99% during whole period while the removal efficiency of $NH_4^+-N$ was significantly varied. In Phase 2, $NH_4^+-N$ was removed up to 75%. Microorganisms varied temporally through three phases were characterized by 16s rDNA analysis methods. ANAMMOX bacteria were dominantly found in phase 2 when the removal rate of $NO_2^--N$and $NH_4^+-N$ was the highest up to 99% and 75%, respectively. Due to erroneous exposed to air, the removal efficiency of $NH_4^+-N$ was unexpectedly lowered, but ANAMMOX bacteria still existed.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.303-311
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• 2007

The consumption of artificially crushed sands exceeds more than 30 percent of the domestic sand supply in South Korea, and its rate is still increasing. For the manufacture of crushed sand granites and granitic gneisses are preferred, fine fractions (i.e. sludge, particles finer than 63 microns) are removed by use of flocculation agents, and its amount occupy about 15 wt%. The sludges consist of quartz, feldspars, micas, chlorite/vermiculite, kaolinites, smectites and occasionally calcite. Among the clay minerals micas are usually predominant, and $14{\AA}$ minerals, kaolinites and smectites are rather scarce. Jurassic granites usually contain more kaolinites and smectites than those of Cretaceous to Tertiary granites, probably due to longer geologic ages. On the other hand, sludge from Precambrian gneiss does not contain kaolinites and smectites. Chemical analyses for the granites and their sludges show rather clear differences in most of major chemical components. Except for $SiO_2,\;Na_2O\;and\;K_2O$, all other components represent rather clear increase. Decrease of $SiO_2$ content is attributed to the relative decrease of quartz in the sludges. And the $Na_2O decrease is caused by a relatively stronger weathering property of albite compared to Ca plagioclase. The $K_2O$ content shows rather small differences throughout the whole samples. The increases of $Al_2O_3$ and other major components resulted from weathering processes and most of colored components are also concentrated in the sludges. Particle size analyses reveal that the sludges are categorized as sandy loams in a sand-silt-clay triangular diagram. The sludge is now classified as industrial waste because of its impermeability, and this result was also confirmed by rather higher hydraulic conductivities. For the environmental problems, and accomplishing effective sand manufacture, more fresh rocks with little weathering products must be chosen.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.147-153
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• 2017

The purpose of this study was to isolate Escherichia coli from flies and to assess pathogenic genes and antibiotic resistance of the isolates. A total of 188 flies were captured in agricultural environment including fruits farms (n = 19), fermented soybean farms (n = 9), municipal waste (n = 46), livestock farms (n = 66), slaughterhouses (n = 38), and manure ground (n = 10). E. coli isolates of captured flies were tested for pathogenic gene and antibiotic resistance using PCR methods and VITEK2 systems. As a result, E. coli from 63% (119/188) of the captured flies has been detected, and the detection rate of E. coli was the highest (89%, 31/34) in flies captured at particular slaughterhouse. Of the 34 isolates, 94% (32/34) were pathogenic gene (ST gene) positive. Twenty-six percent (31/119) of the E. coli isolates were observed being resistant to one or more antibiotics. Markedly, one of E. coli isolates from Livestock farms was resistant to 7 antibiotics including ampicillin, ampicillin/sulbactam, cefazolin, cefotaxime, gentamicin, levofloxacin, and trimethoprim/sulfamethoxazole. In addition, it was ESBL positive. The results of the present study may suggest a risk of transmission of pathogenic and antimicrobial resistant bacteria from flies to livestock environment Therefore, it may need to prevent introducing flies into the agricultural production environment for safe food production.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.874-882
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• 2019

In this study, the gasification characteristics of four types of unused woody biomass and one waste wood in a lab-scale bubbling fluidized bed gasifier (Diameter: 0.11 m, Height: 0.42 m) were investigated. Effect of equivalence ratio (ER) of 0.15-0.3 and gas velocity of $2.5-5U_0/U_{mf}$ are determined at the constant temperature of $800^{\circ}C$ and fuel feeding rate of 1 kg/h. The silica sand particle having an average particle size of $287{\mu}m$ and olivine with an average particle size of $500{\mu}m$ were used as the bed material, respectively. The average product gas composition of samples is as follows; $H_2$ 3-4 vol.%, CO 15-16 vol.%, $CH_4$ 4 vol.% and $CO_2$ 18-19 vol.% with a lower heating value (LHV) of $1193-1301kcal/Nm^3$ and higher heating value (HHV) of $1262-1377kcal/Nm^3$. In addition, it was found that olivine reduced most of C2 components and increased $H_2$ content compared to silica sand, resulting in cracking reaction of tar. The non-condensable tar decreases by 72% ($1.24{\rightarrow}0.35g/Nm^3$) and the condensable tar decreases by 27% ($4.4{\rightarrow}3.2g/Nm^3$).