• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.3
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• pp.198-207
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• 2012

In this study, we investigated the effect of ocean fertilization by deep sea water, using an ecosystem model which contains not only phytoplankton but also zooplankton. The model is based on NEMURO which consists of eleven compartments - two species of phytoplankton, three species of zooplankton, $NO_3$, $NH_4$, $Si(OH)_4$, particulate organic nitrogen, dissolved organic nitrogen and particulate silicon. We introduced nitrogen cell quota in the both species of phytoplankton, and silicon cell quota in the large phytoplankton in addition to the eleven compartments of NEMURO. We made the experiment at Izu Oshima Island in order to investigate the effect of ocean fertilization. In this experiment, we could not find clear differences between the cases with and without deep sea water. We investigated the causes of the experiment results by the model simulations. One of the causes was high concentrations of nutrients in surface seawater used in the experiment. Another was that the increase of total concentration of inorganic nitrogen does not necessarily accelerate the photosynthetic rate because inorganic nitrogen uptake rate is related to the ratio of $NO_3$ to $NH_4$. Because the model can represent the results of the experiment, we investigated the effect of ocean fertilization by deep sea water using this model. We found that the effect of ocean fertilization hardly appeared when the interval of the addition of deep sea water was too short, or the amount of deep sea water was too much. It is supposed that if the addition of deep sea water is too frequent or too much, the dilution of plankton's concentrations will exceed the effect of promoting phytoplankton's photosynthesis.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.735-742
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• 2010

Objective of this research was to investigate the influence of liming fertilizers on changes in soil chemical properties and growth of pansy 'Melody Yellow' in plug production. To achieve this, dolomite (DO) with 0, 1.0, 3.5, 8.0 or $13.0g{\cdot}L^{-1}$ and calcium carbonate (CC) with 0, 2.0, 2.5, 3.0, 3.5, or $4.0g{\cdot}L^{-1}$ in application rate were incorporated into peatmoss + vermiculite (1:1, v/v) during the formulation. The treatments of $3.5g{\cdot}L^{-1}$ of DO and 2.5 or $3.0g{\cdot}L^{-1}$ of CC had acceptable range of soil solution pH such as 5.6-6.2. Faster rising of pH was observed in root media containing CC rather than those of DO, indicating higher solubility of CC. The soil Ca concentrations in all treatments of CC were 2 times as high as those of DO. The treatments of 3.5 or $8.0g{\cdot}L^{-1}$ of DO had the highest soil Mg concentrations, but all treatments of CC had lower soil Mg concentrations than control indicating that additional applications of Mg fertilizers are required. The elevated application rate of DO or CC resulted in the increase of fresh and dry weight; however, plant heights were not influenced by application of liming fertilizers. The results of tissue analysis showed that application of DO or CC influenced the Ca and Mg contents, but did not influence the contents of other nutrients such as N, P, Fe, Mn, Zn and Cu.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.117-125
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• 2017

The role of fly ash in concrete become impotent with finding the characteristics of fly ash in which it is used as cement replacement material. In this paper, corrosion test results obtained by two test methods such as the long-term exposure corrosion test and the accelerated corrosion test method, were compared to investigated the corrosion resistance between fly ash concrete and normal concrete. Corrosion initiation time was measured in two types of concrete, i.e., one mixed with fly ash(FA) and the other without admixture(OPC). The accelerated corrosion test was carried out by four case, i.e., two samples is a cyclic drying-wetting method combined without carbonation(case 1) and combined with carbonation(case 2), and the other two samples is a artificial seawater ponding test method combined without carbonation(case 3) and combined with carbonation(case 4). Whether corrosion occurs, it was measures using half-cell potential method. The ponding test combined without carbonation was most effective in accelerating corrosion time of steel bars. The results indicated that the corrosion of rebar embedded in concrete occurred according to the order of OPC, FA. The delay relative ratio of corrosion obtained by corrosion initiation time between FA and OPC is 1.04 to 1.27. Consequently, fly ash concrete as the age increases its corrosion resistance was improved compared with OPC concrete.

• Journal of Aquaculture
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• v.10 no.2
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• pp.153-161
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• 1997

This study was conducted to evaluate the possible utilization and the replacing range of leather meal (LM) or meat and bone meal (MBM) as a fish meal replacer for the dietary animal protein source of growing israeli carp, Cyprinus carpio. Five different diets were formulated on isonitrigenous and isocaloric basis of 38.5% curde protein and 15.3 KJ/g diet. Percentage of the graded levels of replacement of white fish meal (WFM) by LM/MBM on the basis of crude protein were at follows : diet 1, 100% WFM (control) ; diet 2, 75% WFM+25% LM ; diet 3, 50% LM ; diet 4, 75% WFM+25% MBM ; diet 5, 50 WFM+50% MBM and LM or MBM, and approximately 64.5% of plant protein. After one week of conditioning period, fish averaging 10g were divided into five groups and fed one of the experimental diets for 12 weeks. In the first and the second 4 weeks of feeding trials, there were no significant differences in weight gain between two groups of fish fed diet 1 (control) and 2 (P>0.05), while fish fed diet 3, 4 and 5 had a significantly lower body weight gain than fish fed diet 1 (P<0.05). In contrast to those two periods, all diet groups were not significantly different compared to diet 1 in body weight gain during the third 4 weeks of feeding trial (P<0.05). These results indicated that LM and MBM could be used as a fishmeal replacer up to 50% in growing israeli carp.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.503-507
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• 2015

To examine the interannual variation of seedfall and seed viability rates of Acer pictum subsp. mono (APSM), we investigated the annual seedfall and seed viability of APSM in the natural broadleaved forest in Mt. Jungwang, Gangwon-do, from 2009 to 2014. The amounts of annual seedfalls from 2009 to 2014 were revealed to be 5,700, 4,060, 60,900, 403,450 and 310 ea/ha respectively. 2013 is presumed to be the masting year since large amounts of seedfall were revealed, compared to that of the other years in the study period. Also, the amount of seeds was significantly different among seed viabilities. Most fallen seeds were damaged or decayed, accounting for 47.88% of the total, followed by empty seeds, undeveloped seeds and sound seeds in that order. The percentage of sound seeds ranged from 6.7 to 31.0%, which marks the lowest average with 16.74%. In the masting year, 2013, a significantly larger number of sound seeds fell at 125,070 ea/ha, on the forest floor than in the other years (320~17,840 ea/ha). Meanwhile, the ratio of damaged or decayed seeds was the lowest at 38%, although the number of those seeds was the largest, 153,310 ea/ha, for the same year. These results imply that the surplus seeds are supplied for natural regeneration in the masting year, supporting the seed predator satiation hypothesis. More long-term researches should be conducted on the seed production of broadleaved trees.

• Food Science and Preservation
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• v.9 no.2
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• pp.212-220
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• 2002

Spray drying was used a means for microencapsulation of Aster scaber and Aster glehni. The optimum conditions of spray drying were found to be 210$^{\circ}C$ for the inlet temperature and 5 $m\ell$/min for the feeding rate. The color difference decreased by 12∼25 % far the herb extracts depending on storage temperatures. With an increase in storage temperature, color of the control changed considerably compared to microencapsulated powders. This is due to the fact that wall materials minimized effect of oxygen on the herb extracts. Microencapsulated powders in the amounts of 50 ppm and 250 ppm added to hydrogenated soybean oils led to lower acid values and conjugated diene values during 6 day storage. Compared to the control, the herb extracts displayed 16∼48% increase in antioxidation effect, while the microencapsulated powders exhibited 46∼88% increase. Extracts also showed lower conjugated dienoic acid contents than those of the control. Although antioxidation effect of the microencapsulated powders did not prevail on the significant level in the early stage of storage of oils tested, it became predominant after one week of storage as wall materials were gradually degraded under the high temperature thereby releasing core material from the microcapsule.

• Journal of Korean Elementary Science Education
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• v.19 no.2
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• pp.1-13
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• 2000

The purposes of this study were to survey the elementary students' conceptions of electric circuits and of electric currents, and to explore the relationships between them. The questionaire were developed into matched forms which corresponds to each conceptions of electric circuits and electric currents. The elementary students were selected from 4th and 5th grade in a elementary school in a large local city, which of the total numbers of students were 163. The student who have well-developed conception in electric circuits are superior in conceptions of electric currents to other student who have not in each items of questionnaire required to draw a simple basic electric circuits for lightening the bulb, to select the basic elements of circuits, to identify the arrangement of batteries and bulbs. So we concluded that the scientific conceptions of electric circuits could contribute to the scientific conceptions of electric currents, as expected in elementary science textbooks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.393-408
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• 1996

The effect of various levels of ascidian tunic extracts and carophyll pink on the growth rate, pigmentation, lipid and total cholesterol accumulation, and fatty acid compositions were studied in kuruma prawn, Penaeus japonicus. The kuruma prawn was fed the purified diets with or without ascidian tunic extract and carophyll pink at the levels of 100, 200, and 400 ppm for 8 weeks. In the experiment diet with ascidian tunic extracts or carophyll pink, the values of daily growth rate were ranged between $1.065\;to\;1.292%$, compared with control group. The content of astaxanthin in kuruma prawn was not significantly affected by the feeding levels of tunic extracts. Feeding of the tunic extracts, on the other hand, increased the kuruma prawn lipid and total cholesterol content, and pigment deposition in concentration-dependent manners without influencing the free astaxanthin concentration of prawn flesh and heads between two feeding groups(200 and 400 ppm). And it was also demonstrated that the dietary astaxanthin was deposited in kuruma prawn body tissue mainly as astaxanthin esters. The results suggest that the best feeding strategy for pigmentation in kuruma prawns is the diets with ascidian tunic extracts at the level of 4g/kg feed (200 ppm) for 8 weeks.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.21-27
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• 2020

This paper studies the impact of domestic and foreign economic activity on mobility among regions. The shortage of human resources and demand continues in Eastern Europeans. Especially Ukrainians, have entered the Polish labor market to make up for the scarce areas. As a result, Poland's supply and demand in Ukraine is disproportionate. Minimum wage increases are putting continued pressure on employers. Therefore, the regression equation in the form of job-seeker's economic activity ratio, y= AX²+B,(x=settlers) can be used to grasp the relationship between curves. According to the domestic and foreign workers who migrated, economic activities was rather than increasing the local population, the settlers of nearby large cities is more proportional. Empirical analysis has shown that the human resource hub has increased migration to large cities and industrial. The hub 'A'nation has been created for mobility in 4th wave re-industry, and the same re-industrialization (N₂) in other cities has attracted nearby human resources, but not settle. After all, the hub relationship between N₁ and N₂ is a mobile relationship. Due to wage inequality or a positive wellbeing chasm, workers are not settled plant area but a nearby city, or commuting between borders is easy to go into the hub central city. However, this proved on emerging from the relatively temporary settlers in the AI era.

• Korean Journal of Social Welfare
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• v.61 no.2
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• pp.33-60
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• 2009

This study aimed at examining whether the national rental housing supplied by Korea National Housing Corporation (KNHC) is truly contributing to the upward mobility of housing in low-income households without their own house by comparatively analyzing whether those who moved out of the national rental housing made upward, horizontal or downward housing type mobility. The subjects of this study included 333 people who had moved out of three national rental housing complexes in Cheongju, Chungcheongbuk-do in 2007, which had opened to the first residents two years ago. A telephone survey involving the subjects was carried out. Collected data were analyzed through frequency analysis, cross tabulation analysis and multiple regression analysis, with using the type of residential mobility(downward mobility, horizontal mobility or upward mobility) according to "housing size" and "housing costs" as a dependent variable, and personal and family environment and economic environment as independent variables. According to the results of the analysis, 76.4% of the households made an upward mobility, 1.6% remained little changed, and 22% moved downward in terms of "housing costs," compared to before moving into the national rental housing and while living there. Furthermore, in terms of "housing size" 61.8% of the households moved upward, 16.5% remained little changed and 19.7% moved downward. The variables affecting the upward mobility of housing type included the number of income earners in a household, income earner's occupation and education level. Income earner's amount of income, age and family to support, on the other hand, turned out to have little effect on the upward mobility. Based on the results of the study, the following suggests were made for the supply of effective national rental housing. First, various features of each type of residential mobility should be reflected. Second, national rental housing residents' self-sufficiency should be enhanced to help them move upward in housing type.