• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.553-568
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• 2018

Chromophoric Dissolved Organic Matter (CDOM) plays a dominant role in absorbing UV-VIS light and is also important in the biogeochemical carbon cycle due to the production of carbon dioxide from photo-oxidation at the sea surface in marine environments. Since absorption by CDOM was recently found to be responsible for increasing the energy absorbed in the mixed layer by 40 % over pure seawater, the importance of CDOM absorption in seawater for increasing sea surface temperature has come to be well recognized. We measured aCDOM and the absorption characteristics of CDOM during spring 2012 and 2014 in the southwestern East Sea. Distribution of CDOM in spring 2012 and 2014 was compared and S value was used to find the source of CDOM in the study area. As a result, the average $a_{CDOM}$ was $0.237m^{-1}$ ($0.009{\sim}0.988m^{-1}$) and the average S value was $16{\mu}m^{-1}$,which shows coastal properties. Also a positive correlation between Chl a and CDOM was observed ($r^2=0.34$), with an especially strong correlation near coastal stations. aCDOM in 2014 was about 40 % higher than aCDOM in 2012 during spring in the study area. This difference in aCDOM concentration resulted not only from annual variation but also from stratification and photobleaching in late spring 2012. This observation implies the possibility of flux of carbon dioxide into the atmosphere as a result of photo-oxidation in the East Sea.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.303-309
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• 2005

Olive flounder (Paralichthys olivaceus) is the major mariculture fish in Korea. The annual aquaculture production of olive flounder in Korea during the period of 2003 was 300,000 ton (2002 Statistics, Ministry of Maritime Affairs & Fisheries, Korea Government). Anesthetics is very necessary in aquaculture to minimize stress and damage during harvesting, grading, transportation, spawning induction and handling to fish. In the present study, isoeugenol as new anesthetic in marine fish, especially olive flounder, was examined to know the efficacy and proper concentration. As a result, olive flounder adult was exhibited sedation at 5 ppm at 10 and $15^{\circ}C$, and 7.5 ppm at $20^{\circ}C$, respectively. Anesthesia was required at least 10, 7.5 and 10 ppm at $10^{\circ}C$, $15^{\circ}C$ and at $20^{\circ}C$, respectively. In case of fry, the effect of sedation was observed from 2.5 ppm at $10^{\circ}C$ and 5 ppm at 15 and $20^{\circ}C$, respectively. Anesthesia was observed from 2.5 ppm at $10^{\circ}C$, 5 ppm at 15 and $20^{\circ}C$, respectively. In acute toxicity test, it was impossible to explore $LD_{50}$ with the concentration of isoeugenol adult at $15^{\circ}C$ used, but over immersion volume of 15 ppm at $15^{\circ}C$ was observed mortality in fry. Based on the present study, isoeugenol was identified as a safe and active anesthetic to olive flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.82-87
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• 1983

The aging and growth of Spisula sachalinensis from Ingu over the period from December 1981 through November 1982 were studied. The rings on the shell were used as the character for age determination. The ring where the translucent zone shifts to the opaque one was regarded as an annulus. The time of its formation was estimated by monthly variations of marginal growth rate in the shell. It was formed once a year over the period from August through September. The shell length at the formation of the annulus was estimated by taking the mean shell length corresponding to each of the annual ring. From analysis of mean shell length at the formation of the annulus, von Bertalanffy's growth equation was estimated as follows; $l_t=126.38(1-e^{-0.262(t-0.656)})\;W_t=485.85(1-e^{-0.262(t-0.656)})^3$ Back-calculated shell lengths estimated from this equation was quite consistent with actual shell lengths.

• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.592-599
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• 2016

In the 21st yearly session of the Conference of the Parties (COP 21) of the 2015 United Nations Climate Change Conference, held in Paris, France, in December 2015, the "Paris Agreement" was negotiated; this is a new global agreement on the reduction of climate change, which encourages every country to participate in countermeasures for global climate change. Along with such movements, the electric railway sector has also been actively engaged in low carbon technology. This paper studied the building of a 1.5MW photovoltaic power generation system using the rooftop of the Gwangmyeong Station Building, which is the largest roof among the high-speed railway station buildings in Korea; this station has passenger traffic that reached about 7 million in 2014. For this study, we configured an optimized photovoltaic (PV) power generation system and then estimated the expected annual energy production by using PV system software; we also calculated the expected revenue that could be obtained by linking this source to the power distribution system. The obtained data were used to analyze the contribution of low-carbon energy that could be obtained by introducing a PV power generation system on the roof of an electric railway station building.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.295-302
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• 2014

Mottled skates, Beringraja pulchra, mainly found in the Yellow Sea were caught by otter trawl at 30 stations from 2002 to 2013 to identify the distribution patterns and ecology of the fish in the eastern Yellow Sea. A total of 442 individuals of mottled skate were caught at the 112 hauls of the total 892 hauls. The fish was widely distributed in the entire survey area in spring and autumn, and mainly caught in the northern offshore in summer and in the southern part in winter. The under-yearlings of the mottled skate were mainly caught in the offshore in spring and autumn. The mottled skates were found at the temperature ranges of $3.8{\sim}14.5^{\circ}C$, and the salinity of 31.2~34.2. The catch data of the fish suggested that water temperature be a critical factor for the distribution with the optimal ranges of $5{\sim}14^{\circ}C$. Salinity and water depth were not critical as much as the water temperature for the distribution of the mottled skates in the Yellow Sea. Also, the annual fluctuations of the fish catch were reviewed using the catch data from korea fisheries cooperative and national statistics from 1991 to 2009.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.477-482
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• 2007

Forest biomass became a topic because we have growing interest in global environmental issues and environment-friendly energy resources. This study was carried out to estimate the forest biomass and develop a program for biomass information management in Korea. The total forest biomass (million ton) were 521 for gross forest, 403 for productive forest and 201 for commercial forest in 2005. Also, the annual biomass production in forest was 20 million ton which was equivalent to 94,290 Gkcal of heating value and about 9 billion won of paraffin oil. The biomass growing rate (every 10year) increased from 4.95% in 1985 to 5.30% in 1995 but turn down 4.46% in 2005. The factors that the forest stock could be converted to the forest biomass have developed according to forest type. Therefore, it is impossible to estimate the exact biomass by tree species. In this reason, the demands of the development of the factors by tree species was raised. In addition, it is on time to develop an equation for estimation of biomass by species using dbh and height as independent factors.

• Resources Recycling
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• v.12 no.1
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• pp.48-54
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• 2003

Odor-removing polyethylene film utilizing waste shell powder (annual production: 250,000 ton) was prepared. Odor removal was designed to work by cation or cationic surfactant adsorbed onto the shell surface by ion-exchange: cationic surfactants (DTAB (n-dodecyltrimethylammonium bromide), CTAB (n-cetyltrimethylammonium bromide) and DHAB (n-dihexade-cyldimethylammonium bromide), and cations $Ce^{3+}$ , $Mg^{2+}$ and $Al^{3+}$) were used. Surface-modified waste shell powder was com-pounded with LDPE to produce 20 wt% shell masterbatch (MB), and the MB was again blended with LDPE to get shell-containing LDPE films with 3,5, 10 wt% of shell (width: 40 cm, thickness: 40 $\mu\textrm{m}$). Mechanical properties of the various shell-LDPE films maintained more than 80 % of that of pure LDPE film. Both shell film modified with cationic surfactant and one without shell surface-modification showed excellent odor-removing ability.

• Elastomers and Composites
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• v.47 no.2
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• pp.129-140
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• 2012

The objective of this study was to estimate the practical recycling rate of plastic products, so that the study was conducted to build material flow diagram for PVC profile. For this objective, product generation, waste generation and recycling status were investigated. Using collected and analyzed status data, analysis of material flow by product and building material flow diagram were conducted. As result of estimating the recycling rate by product, The sum of domestic demand was 525,448 ton and waste generation was 105,853ton in PVC flooring and profile. The sum of generation of recycling product and raw material was investigated to be 76,004ton(14.46%), which is higher compared to recycling obligation(8.5%) in 2009. To build the material flow diagram in the years(5~20years) ahead, prediction of future demand was based on the assumption that there will be no difference in annual generation of current and future. As the recycling rate of flooring and profile increases, it is estimated to reach 20% in 2013 according to the material flow diagram.

• Journal of Digital Convergence
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• v.10 no.7
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• pp.267-272
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• 2012

Overcoming harsh light environment, as well as increased growth of crops even in high-quality production can play an important role when using the LED light system of photosynthetic products will be able to effectively reduce consumption. In this study, low efficiency of farm greenhouses, growing annual reduction in income due to rising operating costs and increase crop growth by inducing the proper planting environment Factory-type raise farmers' income and at the same time will contribute to the increase of Light device using LED Supplemental through photosynthesis, promote and improve product quality, plant growth regulators are considered possible for them to develop more efficient LED devices and LED Optical processing devices of Light leaf lettuce grown using normal fluorescent or incandescent bulbs grown in the results than the growth can see that the speed improvements. Usually shipped from seedling to harvest leaf lettuce from 25 to 30, whereas optical processing device be required red light (wavelength: 645nm) using a leaf of lettuce grown enough to be harvested after seven days increased the rate of growth. In addition, red light (wavelength: 645nm) and blue light (wavelength: 470nm) emitting at the same time, room, and grown for 5 days to harvest the growth rate was fast enough.

• Journal of Forest and Environmental Science
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• v.23 no.2
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• pp.109-118
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• 2007

This study was conducted to provide the fundamental data of the policy plan for the security of forestry labour and the revitalization of forestry mechanization by analysing the status of forestry labor and the training plan. In forestry, the total number of employer and the labour cost have slightly increased annually, but the number of employer for timber harvesting has decreased. Therefore, the organization of expert forestry mechanization unit and the training of operator will be necessary. The number and person of forest management unit, the working days of the year and income have increased in Korea. However, the working days per month of forest management unit were only 15 days, which are only 180 days per year. In the results of the calculated number and person of forest management unit for the Korean forest tending volumes, about 349 forest management units are required. In case of adjusting 12 persons per 1 unit, 4,185 persons are required. In calculated results of the optimum forestry mechanization unit and member's number by the adjusting of tower yarder harvesting system for annual timber harvesting production volume, it was known to necessary the 250 forestry mechanization unit and the 1,250 members which are calculated at 5 persons per 1 group.