• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.33-39
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• 1985

This study was performed to investigate the damage to the primary production of Pinus thunbergii forest from air pollution around the Yeochon Industrial Estate. The data were observed at 6 sites in the vicinity of the above area. The vitality of pine trees and the accumulation of the soluable sulfur and the fluorine were analyzed. Their value was generally increased near the source of air pollutants. The biomass density and annual net production were $1.01kg/m^3$, 5.90 t/ha/yr in the stand 4 respectively and $0.66kg/m^3$, 0.32t/hr/hr in the stand 3 respectively. The net assimilation rate was 0.4 - 1.6 kg/kg/yr and the efficiency of leaf to produce stem was 0.3 - 1.3 kg/kg/yr. The annual growth percentage of volume was 16.0% at the slightly damaged area and 4.0% at the severly damaged area. The maximum mean annual increment per tree was $0.0040m^3$ and $0.0008m^3$ in same order.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.168-175
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• 2021

The optimal determination of seeding rate is critical to minimizing uncertainties about the large variations observed in forage quality and productivity when alfalfa is cultivated under different geographical areas and growing conditions. The objective of this investigation was to provide information about the proper seeding rate according to harvest timing for alfalfa cultivation in the Northern regions of Korea. Alfalfa was sown in September 2018 at a seeding rate of 20, 30 or 40 kg/ha and harvested four times in 2019: May 3, July 2, September 11, and October 13. Regardless of seeding rate, alfalfa plant height was longest at the third harvest (113 cm) and the shortest in the last annual harvest (43.8 cm). However, seeding rate had no effect on alfalfa plant height at any harvest. Forage relative feed value was increased in the first cutting but decreased in the third cuttings as seeding rate increased. However, seeding rate had slight effect on alfalfa forage quality components at the second and fourth cuttings. Total annual DM and crude protein production (in 4 harvests) was greater at higher seeding rates. Plots seeded at a rate of 40 kg/ha produced on average 1,257 and 2,620 kg/ha more forage (DM basis) than those seeded at a rate of 30 or 20 kg/ha, respectively. Forage DM production at the first, second, third, and fourth harvests accounted for 36.1, 24.0, 27.1, and 12.8 % of total annual DM production, respectively. Overall, small differences were seen when alfalfa seeding rate was different but maximum forage DM production (in four harvests) was detected when seeding rate was 40 kg/ha. These data could be useful to the alfalfa growers by allowing them to make more accurate trade-offs between seed price and the expected magnitude of forage yield gains in order to select the best seeding rate.

• 한국해양학회지
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• v.30 no.5
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• pp.403-412
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• 1995

The present study was performed to determine th growth and production of Mactra veneriformis on the Songdo tidal flat off Inchon. west coast of Korea. Monthly samples were collected from Marc 1989 to September 1990. The size distributions of shell length showed unimodal patterns from March to August 1989. The binodal pattern after September 1989 indicated a recruitment of young clams during this period. The density fluctuated irregularly, but showed a decreasing pattern over time on the whole. The density of the year class 1989 increased markedly after February 1990. The growth in shell length showed three phases during a year, a fast growth phase in spring, a slow growth phase in summer and autumn, and a lag phase in winter. The annual increment in shell length reduced with age. The flesh dry weight showed a peak in late spring just before the spawning period, and another peak in autumn. The length of annuli and the back-calculated flesh dry weight were used to describe the annual growth. The growth in shell length fitted to the von Bertalanffy model and the flesh dry weight to the Gompertz model. The absolute growth rate of the shell length reduced gradually with age. The year class 1985 had the highest L, and the yeat class 1986 the lowest L. The annual growth in weight showed a typical sigmoid curve. The growth rate was maximum at the age of 2 to 3. Year classes of 1984 and 1985 had higher values of W and higher absolute growth rates than those of 1986 and 1987. Maximum absolute growth rates of 1986 and 1987 year classes were recorded at younger ages than 1984 and 1985 year classes. The annual relative growth rates of length and weight decreased exponentially with age. Biomass in flesh dry weight increased till spring and thereafter decreased progressively. Maximum biomass was 134.6g m/SUP -2/ in August 1990. The biomass of 1989 yeat class occupied highest proportion in total biomass. Annual production in flesh dry weight from March 1989 to March 1990 was 67.9 g m/SUP -2/ year/SUP -1/. Cumulative production of 1989 year class was highest among all year classes, and that of year class 1984 was lowest. The production is high in spring and autumn, and very low in summer and winter.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.214-230
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• 2022

This paper discusses the characteristics and background of the production of white porcelain with the "Byeol(別)" inscription. Such porcelain was produced by the government-run porcelain kiln, Gwanyo(官窯), in the 16th and 17th centuries (from the 1560s to the 1640s), during the Joseon dynasty. The white porcelain ware, inscribed with either the term Byeol or "jwa(左)" and "u(右)," constituted a dual production system of white porcelain by Gwanyo starting in the 1560s. However, to date, few studies have examined Byeol-inscribed white porcelain. This, therefore, makes it difficult to achieve a comprehensive understanding of the evolution of inscriptions on the white porcelain produced by Gwanyo in the 15th to 17th centuries. Besides a regular annual stock of porcelain(年例進上磁器), Gwanyo also produced and supplied additional porcelain ware, or Byeol-gi, at the behest of the royal family or the court of Joseon. Byeol-inscribed white porcelain is a form of Byeol-gi, produced through extra firing, or Byeolbeon(別燔). According to use, Byeol-gi can be categorized as an item for national use(國用) or an item for internal use(內用). However, if the porcelain only carries the "Byeol(別)" inscription, it is difficult to identify its characteristics. Furthermore, as part of the annual production of porcelain was for the supply of Byeol-gi, and then for other purposes, the white porcelain came to be inscribed with dots indicating a change in ownership. In the 16th century, the royal family increased its consumption of white porcelain based on Shinyu Gongan(辛酉貢案), the government's fiscal reform measures. To guarantee a stable supply of exceptional Byeol-gi in light of Gwanyo's decline in the 1560s, the royal family benefited from the inscription of "Byeol." The white porcelain produced by Gwanyo was divided into annual offerings-those with the inscriptions "jwa(左)" and "u(右)"-and Byeol-gi, those with the inscription of "Byeol." They were managed separately from the commencement of production. Byeol-inscribed white porcelain was produced until the 1640s. During the mid-and late 1640s, Byeolbeon was temporarily suspended. Starting in the 1650s, the white clay used to produce the annual stock of white porcelain was sourced from regions other than those providing the clay for Byeol-gi production. The former used clay from Wonju(原州土) and Seosan(瑞山土), while the latter used clay from Gyeongju(慶州土) and Seoncheon(宣川土). According to the literature, the clay from Gyeongju and Seoncheon was much cleaner than that from Wonju and Seosan. Byeolbeon thus underwent a transformation, whereby production was separately managed, right from the stage of white clay mining. Ultimately, the need for the separate management of Byeol-gi through inscriptions diminished, resulting in the disappearance of Byeol-inscribed white porcelain.

• The Journal of Fisheries Business Administration
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• v.47 no.4
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• pp.65-75
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• 2016

The purpose of this study was to analyze the production and marketing control effects of aqua-cultured flounder required for stable income growth of aqua-cultured household. We analyzed the supply and demand structure of cultured flounder using the partial equilibrium model approach. And we estimated the optimal yield of cultured flounder and analyzed the effect of marketing control through constructed model. The main results of this study are summarized as follows. First, the fitness and predictive power of the estimated model showed that the RMSPE and MAPE values were less than 5% and Theil's inequality coefficient was very close to 0 rather than 1. It was evaluated that the prediction ability of the aqua-cultured flounder supply and demand model by dynamic simulation was excellent. Second, dynamic simulation based on policy simulation was conducted to analyze the price increase effect of production and shipment control of cultured flounder. As a result, if the annual production volume is reduced by 1%, 5%, and 10% among 32,852~37,520 tons, it is analyzed that the price increase effect is from 1.2% to 12.5%. Finally, this study suggests that the production and marketing control can increase the price of aqua-cultured flounder in the market. In this paper, we propose a policy implementation of the total supply system instead of conclusions.

• 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.

• Journal of the Korean Solar Energy Society
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• v.32 no.6
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• pp.68-75
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• 2012

Small hydropower is one of the many types of new and renewable energy, which is planning to develop, as the country is abundant in endowed resources. In order to fully utilize small hydropower resources, there is a need for greater precision in quantifying small hydropower resources and establish an environment in which energy sources can be discovered using the small hydropower resource management system. This study has given greater precision to calculate annual electricity generation and capacity of small hydropower plants of Nakdong river system by inquiring into average annual rainfall, basin area and runoff coefficient, which is anticipated to promote small hydropower resources utilization. Small hydropower resource management system was also established by additionally providing base information on quantified small hydropower resources and analysis function and small hydropower generator status, rivers, basin, rainfall gauging station, water level gauging station etc.. Small hydropower resource management system can be used gather basic information for positive applications of small hydropower energy nationwide.

• Korean Management Science Review
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• v.34 no.1
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• pp.15-25
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• 2017

We evaluated industry growth and employment effects of every possible pairs of 22 manufacturing sectors and 16 regions (i.e, 352 region-sectors). We used annual data of manufacturing sectors from 2008 to 2014 for the evaluation. The evaluation comprises of two steps; We first find several region-sectors that outperform others with respect to the effects of industry growth and employment, which are measured by location quotient analysis, shift share method, employment to GDP ratio and employment elasticity. In addition, cross-efficiency analysis follows to classify region-sector pairs into two sub-categories : efficient region-sectors that deserve to hold the current level of investments and inefficient region-sectors where we should consider efficiency improvements. To examine the efficiency, R&D investment, employment size, and capital investment were used as input factors and production volume, added value, changes in employment size, changes in annual salary per capita were used as output factors. For region-sector pairs that have outstanding growth and employment effects but are inefficient, we employed a CCR DEA model and analyzed how much to adjust the values of input and output factors to improve the efficiency scores. The analysis results showed that inefficiency is mainly due to several factors such as R&D investment, changes in employment size and changes in annual salary per capita.

• The Korean Journal of Ecology
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• v.12 no.4
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• pp.245-256
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• 1989

Nitrogen cycling was in vestigated in Piuns koraiensis plantations with different ages, 1, 2, 3, 6, 9 and 11 years, which were reforested after clear-cutting. Annual N input by bulk precipitation was 10kg., and output by runoff decreased as the plantation aged, especially in-N. The standing N content of the whole vegetation increased approximately 5 times through 11 years. Understory surpassed P. koraiensis plants in the distribution of standing N content for the initial 9 years, but reversed thereafter. Annual N uptake of P. koraiensis plants increased greatly through 11 years, but that of understory increased somewhat until 9 years and decreased thereafter. The maximum N uptake of the whole vegetation was made in the 9-yr-old plantation. In the 1-yr-old one, 59% of the maximum was already absorbed by understory which mainly consisted to herbs. The recycling coefficient, ratio of annual return to rptake, of the whole vegetation decreased as the plantation aged and the value of understory was greater than that of P koraiensis plants. On the contrary, the N use efficiency, ratio of the net primary production to N uptake, of the whole vegetation increased as the plantation aged and the value of understory was less than that of P. koraiensis plants. Consequently, it is emphasized that understory played an important role in such plantation reforesred after clear-cutting for the initial 9 years.

• The Korean Journal of Ecology
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• v.8 no.3
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• pp.133-140
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• 1985

Aboveground net productions of four stands in the coastal salt marsh of Incheon were estimated with three different methods: first method was to measure peak live standing crop; second to measure both live and dead standing crops; thrid to measure live and dead standing crops and dead disappearance as well. Net productions estimated by the first method were lowest with a difference of 28~50% from those by the third method. Whereas estimates by the second method approximated considerably to those by the third method with a difference of 4~15%. The third method figured out the highest values and seemed to be most appropriate in estimating net production of herbaceous community. Form these results it is known that live standing crop, dead standing crop and dead disappearance respectively accounted for about 60, 30, 10% of net production estimated by the third method. Annual net productions estimated by the third method for Suaeda japonica-Salicornia herbacea, Artemisia scoparia-Limonium tetragonum, Calamagrostis epigeios, and Sonchus brachyotus-Setaria viridis stand were 650, 1, 080, 1, 409 and 1, 126 g.$m^{-2}.yr^{-1}$, respectively.