• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.1-13
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• 1980

The purpose of the present study is to find the light intensity which induces maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by using three species of commercial fishes: filefish, Stephanolepis cirrhifer (Temminck et Schlegel), conger eel, Astroconger myriaster (Brevoort) and crucian carp, Carassius oarassius (Linnaeus). An experimental tank $(360L\times50W\times55Hcm)$ was set up in a dark room. An illumination system was attached to one end of the tank to control horizontal, light intensity. Six artificial light sources were prepared by combination of two light bulbs (5W, 150W) and seven filters. During the experiment water depth was maintained 50 cm level in the tank. The tank was marked into six longitudinal sections each being 60 cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish .in each section was counted 40 times every 30 seconds, and the gathering rates were obtain from the average number of fish in each section. In filefish the light intensity inducing maximum gathering rate was 0.7 lx(0.5-1.1 lx), and there nab little difference between day and night. Gathering rate varied propotionally to the length of illumination time. In conger eel the light intensities inducing maximum gathering rate were 1.9 lx(1.2-2.9 lx) in daytime and 5.2 lx (3.2-7.7 lx) at night. Thus, there was a considerable difference between day and night, but the gathering rate remained almost unchanged regardless to the length of illumination time. In crucian carp gathering rate did not show a definite pattern hut fluctuated irregularly. The gathering rate, however, was slightly higher at 16.21 lx, and there was little difference between day and night.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.454-467
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• 2016

In order to understand the seasonal characteristics of seawater in Asan Bay, the quality of this water was observed over four seasons form December 2011 to February 2013, and correlations between seawater quality variations and freshwater input were analyzed by a statistical method. The results, based on factor analysis, indicate that the two most important factors in understanding variation are freshwater input (37.7 %) and seawater exchange (24.4 %). Asan-ho and Sapgyo-ho are two major freshwater sources that affect inner (eastern) Asan Bay. Discharged freshwater from the inner bay strongly affects the spatial and temporal distribution of seawater in the bay overall during the summer rainy season. On other hand, water re-suspended from the bottom of the bay overwhelmed the water quality during the dry winter season. In conclusion, seasonal freshwater discharge dominated the water quality of the bay, and, consequently, DIP limited the growth of phytoplankton in the bay.

• Geophysics and Geophysical Exploration
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• v.20 no.2
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• pp.61-71
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• 2017

Recently, ground-penetrating radar (GPR) surveys have been actively carried out for precise subsurface void investigation because of the rapid increase of subsidence in urban areas. However, since the interpretation of GPR data was conducted based on the interpreter's subjective decision after applying only the basic data processing, it can result in reliability problems. In this research, to solve these problems, we analyzed the difference between the events generated from subsurface voids and those of strong diffraction sources such as the buried pipeline by applying the edge detection technique, which is one of image processing technologies. For the analysis, we applied the image processing technology to the GRP field data containing events generated from the cavity or buried pipeline. As a result, the main events by the subsurface void or diffraction source were effectively separated using the edge detection technique. In addition, since subsurface voids associated with the subsidence has a relatively wide scale, it is recorded as a gentle slope event unlike the event caused by the strong diffraction source recorded with a sharp slope. Therefore, the directional analysis of amplitude variation in the image enabled us to effectively separate the events by the subsurface void from those by the diffraction source. Interpretation based on these kinds of objective analysis can improve the reliability. Moreover, if suggested techniques are verified to various GPR field data sets, these approaches can contribute to semiautomatic interpretation of large amount of GPR data.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.502-509
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• 2013

To estimate greenhouse gas (GHG) emission, we established inventory of conventional rice cultivation from farmers in Gunsan and Iksan, Jeonbuk province in 2011~2012. This study was to calculate carbon footprint and to analyse the major factor of GHGs. We carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we tried to suggest agricultural methods to reduce GHGs that farmers of this case study can apply. Carbon footprint of rice production unit of 1 kg was 2.21 kg $CO_2.-eq.kg^{-1}$. Although amount of $CO_2$ emissions is largest among GHGs, methane had the highest contribution of carbon footprint on rice production system after methane was converted to carbon dioxide equivalent ($CO_2$-eq.) multiplied by the global warming potential (GWP). Source of $CO_2$ in the cultivation of rice farming is incomplete combustion of fossil fuels used by agricultural machinery. Most of the $CH_4$ emitted during rice cultivation and major factor of $CH_4$ emission is flooded paddy field in anaerobic condition. Most of the $N_2O$ emitted from rice cultivation process and major sources of $N_2O$ emission is application of fertilizer such as compound fertilizer, urea, orgainc fertilizer, etc. As a result of sensitivity analysis due to the variation in energy consumption, diesel had the highest sensitivity among the energies inputs. If diesel consumption is reduced by 10%, it could be estimated that $CO_2$ potential reduction is about 2.5%. When application rate of compound fertilizer reduces by 10%, the potential reduction is calculated to be approximately 1% for $CO_2$ and approximately 1.8% for $N_2O$. When drainage duration is decreased until 10 days, methane emissions is reduced by approximately 4.5%. That is to say drainage days, tillage, and reducing diesel consumption were the main sources having the largest effect of GHG reduction due to changing amount of inputs. Accordingly, proposed methods to decrease GHG emissions were no-tillage, midsummer drainage, etc.

• Journal of radiological science and technology
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• v.36 no.4
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• pp.291-297
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• 2013

This study is aimed to evaluate the effect of $T_{1/2}$ upon count rates in the analysis of dynamic scan using NaI (Tl) scintillation camera, and suggest a new quality control method with this effects. We producted a point source with $^{99m}TcO_4^-$ of 18.5 to 185 MBq in the 2 mL syringes, and acquired 30 frames of dynamic images with 10 to 60 seconds each using Infinia gamma camera (GE, USA). In the second experiment, 90 frames of dynamic images were acquired from 74 MBq point source by 5 gamma cameras (Infinia 2, Forte 2, Argus 1). There were not significant differences in average count rates of the sources with 18.5 to 92.5 MBq in the analysis of 10 to 60 seconds/frame with 10 seconds interval in the first experiment (p>0.05). But there were significantly low average count rates with the sources over 111 MBq activity at 60 seconds/frame (p<0.01). According to the second analysis results of linear regression by count rates of 5 gamma cameras those were acquired during 90 minutes, counting efficiency of fourth gamma camera was most low as 0.0064%, and gradient and coefficient of variation was high as 0.0042 and 0.229 each. We could not find abnormal fluctuation in $x^2$ test with count rates (p>0.02), and we could find the homogeneity of variance in Levene's F-test among the gamma cameras (p>0.05). At the correlation analysis, there was only correlation between counting efficiency and gradient as significant negative correlation (r=-0.90, p<0.05). Lastly, according to the results of calculation of $T_{1/2}$ error from change of gradient with -0.25% to +0.25%, if $T_{1/2}$ is relatively long, or gradient is high, the error increase relationally. When estimate the value of 4th camera which has highest gradient from the above mentioned result, we could not see $T_{1/2}$ error within 60 minutes at that value. In conclusion, it is necessary for the scintillation gamma camera in medical field to manage hard for the quality of radiation measurement. Especially, we found a tendency that count rate changes over time at this study, and we proved that it can effect $T_{1/2}$. And also, there is need of appropriate phantoms and the method of quality management like this study, because there are not any advice or limitation degrees for domestic medical purpose scintillation camera.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.246-254
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• 1991

Genetic structure of a Pinus densiflora population consisting of two subpopulations on the north-and south-facing slopes of a mountain was studied by allozyme analysis. Allozyme variants in aspartate aminotransferase(AAT), glutmate dehydrogenase(GDH) and leucine aminopeptidase(LAP) systems are encoded, at least, by eight loci ; five for AAT, one for GDH and two for LAP. Average number of alleles examined over six loci was 3.33. Average heterozygosity and genetic diversity computed over six loci were, respectively, 0.19 and 2.76 for parental population, 0.17 and 2.22 for progeny population. Differences in allelic frequencies between maternal sources at many of the investigated loci were found and between subpopulations on the north- and south-facing slopes. Allele frequencies of maternal origin at some of the loci were significantly different from each other between the two subpopulations. Thus it appears that the matings within and between subpopulations were not random and the mountain ridge that divides the north-and south-facing slopes isolate the two suhpopulations reproductively to a great extent. Some of the genotypes both in parental and progeny(embryo) groups deviate significantly from the Hardy-Weinberg equilibrium state. It appears from the result that the pine population is originated from a few limited ancestral trees and thus consanguineous matings are prevalent in this pine population.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.1
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• pp.13-20
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• 2007

This study was performed to investigate the concentrations of PM($PM_{10}$, $PM_{2.5}$, $PM_{1}$) and it's affecting factors in the subway from line 1 to line 8 in Seoul metropolitan area, from Sep. 1 to 30, 2005. PM concentrations were measured at the entrances and centers in subway passenger cabins by a light scattering equipment. And the affecting factors to PM were estimated based on the number of passenger, door open and close and running area etc. The geometric means of $PM_{10}$, $PM_{2.5}$ and $PM_{1}$ concentration in Seoul subway passenger cabins were $214{\mu}g/m^3$, $86.6{\mu}g/m^3$ and $27.0{\mu}g/m^3$, respectively. These mean concentrations in subway carriage were higher when it ran on an underground track than on a ground track. And running time(7AM-9AM, 11AM-13PM, 6PM-8PM) significantly influenced to the concentrations of $PM_{10}$, $PM_{2.5}$ and $PM_{1}$. Daily profile of $PM_{10}$ and $PM_{2.5}$, $PM_{1}$ expressed as an 10 minutes average, showed similar variation pattern over day period. In correlation analysis, significant relations among $PM_{10}$, $PM_{2.5}$ and $PM_{1}$ were detected(p〈0.01). In particular, correlation coefficient between $PM_{10}$and $PM_{1}$ was highly significant(r=0.94). Further study is needed to identity the sources of PM in subway cabins and to compare pollutants concentration among subway lines.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.212-220
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• 2013

Recently, there has been tremendous increase in human-computer/machine interaction system, where the goal is to provide with an appropriate service to the user at the right time with minimal human inputs for human augmented cognition system. To develop an efficient human augmented cognition system based on human computer/machine interaction, it is important to interpret the user's implicit intention, which is vague, in addition to the explicit intention. According to cognitive visual-motor theory, human eye movements and pupillary responses are rich sources of information about human intention and behavior. In this paper, we propose a novel approach for the identification of human implicit visual search intention based on eye movement pattern and pupillary analysis such as pupil size, gradient of pupil size variation, fixation length/count for the area of interest. The proposed model identifies the human's implicit intention into three types such as navigational intent generation, informational intent generation, and informational intent disappearance. Navigational intent refers to the search to find something interesting in an input scene with no specific instructions, while informational intent refers to the search to find a particular target object at a specific location in the input scene. In the present study, based on the human eye movement pattern and pupillary analysis, we used a hierarchical support vector machine which can detect the transitions between the different implicit intents - navigational intent generation to informational intent generation and informational intent disappearance.

• Journal of Animal Science and Technology
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• v.62 no.1
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• pp.64-73
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• 2020

Producing animal products from farm to table emits massive amounts of greenhouse gases (GHGs). Modified meal plans, mainly including vegetables and grains, have been recommended to reduce GHG emissions. However, these meal plans have not been developed with regard to the micronutrient content, but rather with regard to the energy requirements of grains and vegetables, which could result in a nutritional imbalance. For this reason, we investigated a common Korean suggested meal plan (SMP) from the National Institute of Agricultural Sciences, in which nutritional conditions were considered, and evaluated its GHG emissions using the Life Cycle Assessment Inventory Database and nutritional values. The SMP, which included meat, was based on the Korean Nutrition Society for adult men age 19 to 29, and was changed to a vegan meal plan (VMP). Animal-based protein sources were substituted for meat alternatives, such as beans and tofu, for which carbon footprint data was available. To compare the nutritional differences, the 9^th Korean Food Composition Tables I and II were consulted. To calculate GHG emissions, the carbon footprint data of the food was converted to a CO₂ equivalent (CO₂e) using a procedure from the Foundation of Agriculture Technology Commercialization and Transfer. It was found that GHG emissions per calorie were 18% lower for the VMP when compared to the SMP. However, if GHG emissions per total amino acids were evaluated, the VMP GHG emissions per total amino acids were 0.12 g CO₂e/mg, while the corresponding value for the SMP was 0.06 g CO₂e/mg. The Korean daily meat intake reported by the Korea Agricultural Statistics Service was 37.1% lower than in the SMP, but when converted to a protein intake the figure was 17.0% lower. It was found that each SMP resulted in more GHG emissions than the VMP, but when considered as GHG emissions per total amino acids, the opposite pattern was apparent. There is a need to conduct more detailed studies of the variation in GHG emissions with different meal plans, using the daily meat intake per person.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.57-65
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• 2014

Spatial and temporal distributions of zooplankton were measured in an oligotrophic pumped storage-type hydroelectric reservoir which was composed of two reservoirs exchanging water daily, with water going up at night and going down during the day. Repetitive diel disturbance of the water column can be a unique feature of this reservoir system. Chl-${\alpha}$ concentration was highest in the early winter season. Phytoplankton density was lower in summer monsoon due to high flushing rate on rainy days. The zooplankton density was higher in the smaller upper reservoir possibly due to lower fish density in the upper reservoir. In the seasonal variation a time gap was observed between the phytoplankton bloom and the zooplankton bloom (particularly a rotifer, Keratella cochlearis). It is likely to that Keratella production is partially supported by heterotrophic food sources than phytoplankton. The dominance of a mixotrophic dinoflagellate (Peridinium bipes f. ocultatum) might have complicated the trophic relationship between phytoplankton and zooplankton. Our results provide some ecological information of zooplankton community in a highly disturbed alpine reservoir ecosystem relying on mostly allochthonous organic matter.