• Journal of Korea Foresty Energy
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• v.19 no.1
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• pp.7-12
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• 2000

This study was carried out to investigate the effect of light intensity on the growth and biomass production of Pinus thunbergii seedlings. The experiment was performed under five different light intensities such as 100, 50, 30, 10, and 25 of the natural full sun light intensity for 2 year in the field condition. The seedling showed the highest height and root collar diameter growth under natural full sun light. The height growth of the seedling under 50% of light intensity showed 96.4% of the control seedling in the first year, and 88.9% in the second year, and the root collar diameter growth showed 94.1% in the first year 77.6% in the second year. Height and root collar diameter growth was markedly reduced below 30% of relative light intensity, and the reduction rate of root collar diameter growth was higher than that of height growth. All the tested seedlings died under 2% of relative light intensity in the second year. Biomass production was also reduced by decreasing of relative light intensity, the reduction rate of root biomass production in both first and second years was higher than that of leaf or shoot biomass production. The lowest reduction was observed at the shoot in the first year, and at the leaves in the second year The highest T/R ratio was recorded by 3.55 in the seedling under 50% of relative light intesity in the first year, and by 4.88 under 10% of relative light intensity in the second year.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1516-1519
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• 2001

The data consisted of 369 lactation records for calvings over a sixteen-year period (1972-1987) and included only cows that had normal milk records. The data were analysed using a linear model containing the fixed effects of parity, year of calving and season of calving. The least squares means${\pm}$S.E. were $1,273{\pm}58.4kg$ for milk yield, and for post-partum body weight (kg) at 2, 3 and 4 months after calving were $343.40{\pm}3.96$, $346.10{\pm}4.10$ and $352.54{\pm}4.26$, respectively. With the exception of season of calving, the effects of parity and year of calving were significant (p<0.01) on the performance of the animals. Thus, the mean-milk yields 1162, 1351 and 1350, were similar for pre-, peak- and post rainy seasons, respectively. On the other hand, as parity increased from 1 to 3, milk yield also increased, but thereafter, there was a gradual decline in milk yield. Similarly, post-partum body weight also increased with parity. However, no consistent pattern for year effect was observed which probably was a reflection of the variation in climatic conditions, or forage quality and/or availability. The phenotypic correlations between milk yield and post-partum body weights were negative and small (ranging from -0.01 to -0.08). However, high milk production in cows was associated with longer calving interval. The implications from the phenotypic correlations are suggestive of one or two possibilities. Firstly, selection for increased body weight may actually result in decreased milk yield. Also, a substantial genetic antagonism may exist between milk yield and fertility in the crossbred cows. Therefore, it is important that selection to improve milk production should take into consideration the reproductive performance of the cows.

• Korean Journal of Poultry Science
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• v.10 no.1
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• pp.1-22
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• 1983

The Purpose of this study is to examine both supply and demand side of broiler chicken in Korea. Especially the paper aims to investigate the broiler chicken production Dressing and marketing pattern which may affect the demand for it. It is generally understood that broiler chicken production becomes unstable because of frequent market price fluctuation mainly due to disequilibrium of quantities demanded ana supplied It is important to point out that marketing in the form dressed chicken has been enforced by the regulation in Seoul area since March 1st, 1983, though live birds have been customarily marketed for year. It is assumed that the subsituation of chicken meat for beef would save foreign exchanges, because increasingly large amount of beef is imported mainly thanked to a chronical shortage in local production. Main findings of this study may be summarized as follows: 1) Broiler chicker production has been rapidly increased recently, estimating 180-200 million head per year with the trend of contineous increase year after year. Price fluctuation during the year is found, especially summer and winter mainly due to seasonal demand change. It is known that mal-funconing of broiler chicken market may be one of the causes for a large Price fluctuation. Accordingly the increase of marketing efficiency may reduce the price fluctuation and also positively impact on creating demand for the chicken consumption. 2) It is also interesting to note that 90 percent of broilers are grown on the floor and almost 86 percent of total broilers composed of so called high-bros, weighing on an average more than 1.6kg per head Approximately 8 weeks are required for of around marketing birds at the feed efficiency of around 2.3-2.5 Average broiler farm raises between 1,000 and 2,000 head, showing a quite small scale of operation. Only a few sampled farmers follow an all-in and all-out method in broiler production.

• Journal of Ecology and Environment
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• v.41 no.1
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• pp.19-28
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• 2017

Background: In order to investigate organic carbon distribution, carbon budget, and cycling of the subalpine forest, we studied biomass, organic carbon distribution, litter production, forest floor litter, accumulated soil organic carbon, and soil respiration in Taxus cuspidata forest in Halla National Park from February 2012 to November 2013. Biomass was calculated by using allometric equation and the value was converted to $CO_2$ stocks. Results: The amount of plant organic carbon was $13.60ton\;C\;ha^{-1}year^{-1}$ in 2012 and $14.29ton\;C\;ha^{-1}year^{-1}$ in 2013. And average organic carbon introduced to forest floor through litter production was $0.71ton\;C\;ha^{-1}year^{-1}$. Organic carbon distributed in forest floor litter layer was $0.73ton\;C\;ha^{-1}year^{-1}$ on average and accumulated organic carbon in soil was $51.13ton\;C\;ha^{-1}year^{-1}$ on average. In 2012, Amount of released $CO_2$ from soil to atmosphere was 10.93 ton $CO_2ha^{-1}year^{-1}$. Conclusions: The net ecosystem production based on the difference between net primary production of organic carbon and soil respiration was $-1.74ton\;C\;ha^{-1}year^{-1}$ releasing more carbon than it absorbed.

• Korean Journal of Organic Agriculture
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• v.10 no.1
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• pp.49-63
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• 2002

In order to supply 85% of total organic feed in ruminants and 80% in non-ruminants for organic animal production, nitrogen fixation ability of legume should be used in domestic roughages production. 50% of Europe organic farmer use intercropping legume in as green manure. This article is dealing with amount of biologically fixed nitrogen used by legumes and methods for estimating the transfer of biologically fixed N in rotation and separating the N benefit into fixed N and non-fixed N components are reviewed. Available data indicate that transfer amount of N to non legumes was from 50∼9.6(kg/ha) in legume-cereal rotations and proportion of legume N varied with seasons, 90% in summer, 50% in autumn. The important point in cropping system for legumes have to be included for organic forage production 6 year rotation is based on pasture system of 3 year pasture + 2 year annual(com, sudangrass), again pasture. Rye, barly and Italian ryegrass+legumes(vetch, crimson and pea) can be one of option in spring, com, soybean, sudangrass and Japanese bamyard millet would be seeded after spring harvest in the field. Farmer can make good use of rice paddy field as forge production potential area after harvesting rice. Italian, burly and rye+vetch and crimsonclover may be grown in autumn or spring time at the rice field.

• Plant Resources
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• v.6 no.3
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• pp.211-214
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• 2003

This study was conducted to produce effectively more leaves of Angelica acutiloba through year-round production system by using various mulching materials and polyethylene(PE) tunnel. Soil temperature by covering treatment was higher in PE mulching and PE tunnel than in rice straw mulching, especially showing the highest temperature in PE tunnel from April through May. Water content of soil was higher in PE mulching than in non-mulching. Leaf production of Angelica acutiloba through year-round production showed the highest in PE tunnel and root production in PE mulching. These results suggest that leaf production of Angelica acutiloba can be maximized through PE tunnel cultivation system.

• Plant Resources
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• v.8 no.1
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• pp.27-31
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• 2005

This study was conducted to produce effectively more leaves of Angelica acutiloba through year-round production system by using various mulching materials. Soil temperature by covering treatment was the highest in P.E.(Polyethylene Film) mulching and followed by rice straw mulching, especially showing highest temperature in Tr. PE(Transparent Polyethylene Film) from April through May. Water content of soil was higher in P.E. mulching than in non-mulching. Leaf and stem production of Angelica acutiloba through year-round production showed the highest in PE mulching also root production of Angelica acutiloba showed the highest in P.E. mulching. These results suggest that leaf and stem production of Angelica acutiloba can be maximized through P.E. mulching cultivation system.

• Journal of Forest and Environmental Science
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• v.39 no.3
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• pp.128-139
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• 2023

Urban forests serve multiple purposes by providing green resting spaces and environmental benefits for city residents. In the old city center, where parks are scarce, the campus of Kangwon National University, Chuncheon, Gangwon-do, South Korea, serves as an urban forest for students, faculty, and citizens. This study aims to quantitatively analyze the environmental functions of green spaces on campus, raising awareness about their importance among campus members. The total carbon storage of campus trees was estimated at 1,653,218 kg, including 1,512,586 kg in forest areas, 131,061 kg in planting spaces around buildings, and 9,571 kg in street spaces. The annual carbon uptake of campus trees was estimated to be 39,391 kg/year, with 30,144 kg/year in forest areas, 8,017 kg/year in planting spaces around buildings, and 1,230 kg/year in horizontal spaces. In addition, annual oxygen production was estimated to be 105,044 kg/year, with 80,385 kg/year in forest areas, 21,378 kg/year in planting spaces around buildings, and 3,281 kg/year in street spaces. Furthermore, we estimated carbon emissions from the use of on-campus facilities to be 4,856,182 kg/year, while oxygen consumption by members was estimated at 53,975 kg/year. However, the campus trees supplied a sufficient amount of oxygen, which was twice the amount required by school members. The carbon uptake amount was approximately 1% of the amount of carbon emissions, resulting in a modest contribution to improving the environmental conditions of the site.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.409-416
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• 2003

Marine populations are maintained through the processes of spawning, growth, recruitment, natural death and fishing in a marine ecosystem. Based upon each of these processes, a quantitative population dynamic model was developed to estimate damages in fishery production due to accidents in a fishing ground. This model was applied for the abalone culture grounds in Korean waters. Three components of damages were identified in the ecosystem of the abalone culture grounds, namely, physical damages in the substratum of the fishing ground, biological damages in the structure and function of the ecosystem, and damages in fishery production. Considering these three components the processes and durations of damages in fishery production were determined. Because the abalone population is composed of multiple year classes, damages influence all the year classes in the population, when they occur The model developed in this study is: $$y=(n_{\lambda}+1){\times}Y_E\;-\;\sum\limits^{n_\lambda-n_c}_{l=0}\;y_{n_c/i}$$ where, y is the expected damages in fishery production during the period of restoration of the damaged abalony population, $Y_E$ is the annual equilibrium yield, $n_{\lambda}$ is the maximum age in the population, $t_s$ is the year of damage occurrence, $n_c$ is the age at recruitment, and $\sum\limits^{n_\lambda-n_c}_{l=0}\;y\;_{n_c/i}$ is total expected lifetime catch of year classes which were recruited during the restoration period.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.68-75
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• 2006

The total production of the smelted copper reaches 450,000 tons per year, and the production of copper-related goods grows year by year owing to the extension of facilities and the development of production techniques. On the other hand, the volume of slag discharges by-produced at the time of copper smelting process is also on trend of increase. The by-produced copper smelting slag amounts to 700,000 tons a year, which is one and half times of the total smelted copper production. Accordingly nobody disagrees that comprehensive researches on how to deal with and how to reuse the accumulated smelting copper slag have to be encouraged. Even though the possible uses of the copper smelting slag have being made on various levels at present as materials for iron powder cement, sand-blasting and fire-proofing rock wool, but a considerable volume of the slag is abandoned as unnecessary by burying or piling up in careless in the open ground.