• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• 제18권2호
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• pp.65-69
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• 2013

In situ measurement of a primary production in East Sea, a marginal sea with a fair accessibility, is nonetheless an arduous task because of dynamic variability. In this study, we estimated the mean value of background (gross) primary production over the warm region of the East Sea based on a biogeochemical hypothesis. We propose an immiscible-shoaling hypothesis for the estimation of primary production, which assumes that primary production in the warm region occurred only by the nutrient supply through the Korea Strait. Annual primary production thus estimated is $209\;gC\;m^{-2}\;y^{-1}$, which is comparable to the satellite-based estimates of net primary production in the region. However, since this hypothesis assumes that primary production is based on only the new nutrients supplied to the system, primary production would increase by 40% if we release the assumption, and assume f = 0.6. This suggests that nutrient influx through the Korea Strait alone is more than enough to support primary production previously reported. Primary production may increase as much as two times if we considered other external perturbations excluded intentionally to estimate the background level of primary production, such as coastal upwelling, submerged ground water discharge, aeolian input, ocean dumping, and mixing by typhoons as well as the contribution of cyanobacteria that has not been quantified in the region. This implies the primary production in the warm region of the East Sea would be comparable to that of the Peru upwelling region with f = 0.6.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제4권2호
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• pp.189-197
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• 1994

Analytic methods for Cr(VI) level in industrial hygienic field were suggested by the National Institute for Occupational Safety and Health(NIOSH method 7600, 7604). There were growing needs for measurement of Cr(III) and Cr(VI) levels simultaneously. Two analytical methods were suggested to determine Cr(III) and Cr(VI) levels simultaneously. The one is method by using reversed phase high peformance liquid chromatography(HPLC) and the other is by using ion exchange HPLC. The purpose of this work was to evaluate the usefulness of these two analytic methods. For the difference of ionic charges of Cr(III)-ethylendiamine tetraacetic acid(EDTA) chelate and $CrO_4{^-2}$, we could detect them simultaneously by ion exchange HPLC. Also, we attempted to determine the levels of Cr(III) and Cr(VI) chelated with sodium diethyldithiocarbamate(NaDDTC) by using reversed phase HPLC. The confirmation of Cr(III) and Cr(VI) were checked by fraction collector and nameless atomic absorption spectrometer. The optimal conditions for the formation of Cr(III)-EDTA chelate were two hours incubation period with pH 5. Cr(III)-EDTA and Cr(VI) in EDTA solution were successfully separated by anion exchange column using $Na_2CO_3/NaOH$ mixture as mobile phase. Peaks of Cr(III)-EDTA and Cr(VI) in EDTA were identified at 5 minutes and 7 minutes of retention time respectively by the ion exchange HPLC. The formation of Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates were twelve hours incubation period. Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates were separated by reversed phase column using methanol and water mixture as mobile phase. Peaks of Cr(VI)NaDDTC and Cr(III)-NaDDTC chelates were identified at 13 minutes and 26 minutes of retention time respectively by the reversed phase HPLC. Due to reduction of Cr(VI) to Cr(III), it seems to be not suitable for simultaneous determination of Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates by reversed phase HPLS. Simultaneos determination of Cr(III) and Cr(VI) by ion exchange HPLC was more accurate and simple method.

• Journal of Food Hygiene and Safety
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• 제14권3호
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• pp.293-304
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• 1999

The purpose of this study was to evaluate the microbiological quality, and to assure the hygienic safety of the food production in the university food service facility located in Seoul in accordance with the Hazard Analysis Critical Control Point(HACCP) concepts. In the hygienic state assessment of kitchen, it has revealed that it was very important to remove water from the kitchen floor and to establish standard method for disinfection of cooking utensils. And foodservice workers were required to have training program for the safe handling of food and utensils since they did treat food without hygienic gloves. The kitchen layout had to be improved because the near distance of table with heating unit and shelf might cause the growth of microorganisms when prepared food was kept on the shelf. In terms of the timetemperature measurement and microbiological quality assessment during each of the food production phases, most of sengchae (raw vegetable dish) and namul (cooked vegetable dish) were treated within danger zone for food safeness ($5~60^{\circ}C$). It has shown that the microbiological quality of raw materials was very much inferior at the time of receiving based on the TPC($10^{5}~10^{7}$), coliform($10^{3}~1O^{6}$), which was not acceptable level(TPC:$10^{6}$, coliform:$10^{3}$) suggested by Solberg. Microbiological growth has increased in the both of sengchae and namul considerably during most of food production phase. Therefore, it is extremely important to reduce holding and serving time and to avoid treating food within the danger zone for food safeness. In addition, the prevention of cross-contamination during mixing the ingredients with improper equipments and with insanitary treatments by workers was also important to keep the food safety in this speciqic university foodservice facility.

• Journal of Plant Biotechnology
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• 제43권1호
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• pp.21-29
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• 2016

Remote Sensing (RS) is a technique to obtain necessary information in a non-contact and non-destructive method by using various sensors on the surface, water or atmospheric phenomena. These techniques combine elements such as sensors, and platform and information communication technology (ICT) for mounting the sensor. ICT has contributed significantly to the success of smart agriculture through quantification and measurement of environmental factors and information such as weather, crop and soil management to distribution and consumption stage, as well as the production stage by the cloud computer. Remote sensing techniques, including non-destructive non-contact bioimaging (remote imaging) is required to measure the plant function. In addition, bioimaging study in plant science is performed at the gene, cellular and individual plant level. Recently, bioimaging technology is considered the latest phenomics that identifies the relationship between the genotype and environment for distinguishing phenotypes. In this review, trends in remote sensing in plants, plants diagnostics and response to environment and status of plants phonemics research were presented.

• The Korean Journal of Food And Nutrition
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• 제20권2호
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• pp.150-157
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• 2007

Hamcho(Salicorinia herbacea, glasswort), a halophyte, is an annual succulent shrub that grows on coastal wetlands and has been regarded as a functional food for good health. Natural dried red and green Hamcho were extracted with 25% ethanol and water at 70$^{\circ}C$. The antioxidant activities of these four extracts were examined by six different assays, including the measurement of total phenolics, radical scavenging effects on 1,1-diphenyl-2-picrylhydrazyl(DPPH), nitric oxide(NO) and nitrite(NO$_2$) scavenging effects, reducing power, and the inhibitory effect on tyrosinase activity. The total phenolic contents of the four extracts were high at 237 ${\sim}$ 255 mg of gallic acid equivalents per 1 g of dried sample tested. The green Hamcho extracts contained more phenolic compounds than the red Hamcho extracts. When they were compared to tocopherols, the antioxidant activities of the green and red Hamcho powders were significantly higher at the same concentration levels(5 mg and 3 mg, respectively) in a POV test. The inhibition effects of the four extracts at a level of 75 ${\mu}l$ were higher than 98% in the POV test. The red Hamcho 25% ethanol extract showed a high significant effect on DPPH radical scavenging(SC$_{50}$, 90.1 ${\mu}l$). The green Hamcho 25% ethanol extract, however, showed a high significant effect on NO radical scavenging(SC$_{50}$, 6.1 ${\mu}l$). The NO$_2$ radical scavenging effect was assayed at pH 1.2, 4.2 and 6.0, and all the Hamcho extracts scavenged the NO$_2$ radical much more effectively at pH 1.2. The NO$_2$ scavenging effect of the red Hamcho 25% ethanol extract(64%) was as high as that of 5 mM vitamin C at pH 1.2(p<0.05). In the reducing power test, the red Hamcho 25% ethanol extract revealed the highest ferric ion reducing activity among the Hamcho extracts, and its activity was as high as that of 0.33 mg/ml of vitamin C. The four Hamcho extracts showed high tyrosinase inhibition effects of more than 80%, and their activities were higher than 50${\mu}$g of kojic acid. The green and red Hamcho 25% ethanol extracts totally inhibited tyrosinase activity(100%). Therefore, the results suggest that red Hamcho extracts may serve as useful natural antioxidants along with green Hamcho extracts.

• Journal of fish pathology
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• 제28권1호
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• pp.37-42
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• 2015

In the present study, we performed a dipping of olive flounder (average length and weight: $20{\pm}2.0cm$, $70{\pm}5.0g$) for a period of three hours a day, over two days, in a melted complex of oxytetracycline (OTC) and neomycin (N), by dissolving 25-10 ppm or 50-20 ppm in water. Subsequently, the remaining antibiotic density in muscle tissue collected from olive flounder was investigated, 1, 5, 14 and 40 days after discontinuation of the medication. 5 fish were used from each group. The standard graph drawn from the results of diluting two standard solutions of OTC and N based on various density levels, showed a relatively straight line with an $R^2$ of 0.9999 and 0.9952, respectively. The recovery rate of OTC was shown to be 90-93% and N, 88-95%. Upon measurement of the remaining antibiotic density in the test group that had been exposed to 25-10 ppm of the complex of OTC and N, $0.97{\pm}0.084{\mu}g/ml$ of OTC and $0.118{\pm}0.079{\mu}g/ml$ N were detected on 1 day of the test. No antibiotic density was detected after day 5 of the test. Regarding the test group that were exposed to 50-20 ppm of the complex of OTC and N, $1.324{\pm}0.062{\mu}g/ml$ of OTC and $0.788{\pm}0.05{\mu}g/ml$ N were detected on day 1 of the test, and no antibiotic density was detected after day 5 of the test.

• The Korean Journal of Food And Nutrition
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• 제10권1호
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• pp.60-64
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• 1997

This study attempted to examine the effect on sensory characteristics and texture of Paeksolgi in various volume of adding sugar and steaming time. The most favorite tendency on the quality was over 15% adding sugar and 20 minute steaming time. Evaluation was conducted through objective evaluation firstly and sensory evaluation secondly. The volume of adding sugar was the significant factors which affected the textual characteristics of Paeksolgi. But steaming time and interaction had not affected. In sensory evaluation on the various steaming time Paeksolgi made by steaming time for 20min and over 15% adding sugar showed the most favorite tendency on the overall quality. This condition corresponded to the high level of hardness, adhesiveness, gumminess in comparison with Rheoner measurement. In summary the most favorite factor was 12 hours of soaking time, 10% adding water, 1% of adding salt, over 15% adding sugar, 20 minutes steaming time.

• Journal of the Korea institute for structural maintenance and inspection
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• 제12권6호
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• pp.97-108
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• 2008

The use of fly ash to replace a portion of cement has resulted significant savings in the cost of cement production. Fly ash blended cement concretes require a longer curing time and their early strength is low when compared to ordinary Portland cement(OPC) concrete. By adopting various activation techniques such as physical, thermal and chemical method, hydration of fly ash blended cement concrete was accelerated and thereby improved the corrosion-resistance of concrete. Concrete specimens prepared with 10-40% of activated fly ash replacement were evaluated for their open circuit potential measurements, weight loss measurements, impedance measurements, linear polarization measurements, water absorption test, rapid chloride ion penetration test and scanning electron microscopy (SEM) test and the results were compared with those for OPC concrete without fly ash. All the studies confirmed that up to a critical level of 20-30% replacement; activated fly ash cement improved the corrosion-resistance properties of concrete. It was also confirmed that the chemical activation of fly ash better results than the other methods of activation investigated in this study.

• Culinary science and hospitality research
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• 제22권5호
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• pp.117-133
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• 2016

This study was to investigate the quality characteristics of sourdough bread made with 4 kinds of kamut sour starter. Kamut sour starters were made according to dough yield of sour starter and yeast adding on sour starter. We exmanined pH level, fermentation rate, specific volume, CrumbScan, moisture content, color value, texture analyzer, shelf-life test and sensory evaluation for observing quality characteristics of sourdough bread. From the results of pH measurement, kamut sourdough breads had lower pH value in dough and crumb pH than CON. In the experiment of dough's fermentation rate, CON had the rapidest fermentation rate among the samples initially, but the experimental groups also expanded as much as CON grew in spite of its slow fermentation. Specific volume and CrumbScan results suggested that CON had the largest volume. In addition, CM and TM had smaller volume than Pool and Biga. The sample that had the highest moisture content was Pool because its sour starter had the most amount of water. In color value test, CON had lighter crumb and crust color than other specimens. As a result of the TPA and shelf-life tests, CON had the softest hardness after 24 hours. However, Pool had similar hardness with CON after 72 hours. The result of the acceptance test of sourdough breads indicated that people prefered Pool and Biga to TM and CM. Difference test showed similar results with prior experiments. As the final outcome, Poolish was chosen as the optimal formula for kamut sour starter.

• Journal of the Korean Association of Geographic Information Studies
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• 제15권1호
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• pp.87-98
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• 2012

A river boundary is defined as the intersection between a main stream of a river and the land. Mapping of the river boundary is important for the protection of the properties in river areas, the prevention of flooding and the monitoring of the topographic changes in river areas. However, the utilization of the ground surveying technologies is not efficient for the mapping of the river boundary due to the irregular surfaces of river zones and the dynamic changes of water level of a river stream. Recently, the spatial information data sets such as the airborne LiDAR and aerial images are widely used for coastal mapping due to the acquisition of the topographic information without human accessibility. Due to these advantages, this research proposes a semi-automatic method for mapping of the river boundary using the spatial information data set such as the airborne LiDAR and the aerial photographs. Multiple image processing technologies such as the image segmentation algorithm and the edge detection algorithm are applied for the generation of the 3D river boundary using the aerial photographs and airborne topographic LiDAR data. Check points determined by the experienced expert are used for the measurement of the horizontal and vertical accuracy of the generated 3D river boundary. Statistical results show that the generated river boundary has a high accuracy in horizontal and vertical direction.