• Journal of Environmental Policy
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• v.9 no.2
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• pp.3-19
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• 2010

Anyang-cheon(stream) runs through southern metropolitan area of Seoul to Han-river in Korea. Due to fast growth of Seoul, the water quality and quantity problems in Anyang-cheon have occurred. To cope with the problems, the Integrated Watershed Management program for Anyang-cheon was adopted and a KRW 26.1 billion (USD 21.8 million) pilot project (construction of 4 facilities such as reservoir) is suggested for 4 sub-watersheds of Anyang-cheon, which cost will be shared by the 12 local governments (LG). Three cost division schemes are compared. By Scheme 1, if the cost is borne by the LG in a watershed where the facilities are constructed (no cost division scheme), the LG in I is to bear 0.58% of the total construction cost, LG in watershed II 29.54%, LG in IV 0%, LG in V 69.88%. In particular, LG in IV in this scheme bears no cost because no facility is constructed, even though watershed IV is the major beneficiary of the facility construction. Scheme 2 is to share the cost by length of streams in each sub-watershed and the suggested cost share for each sub-watershed is 13.76% by I, 7.34% by II, 45.87% by IV, and 33.03% by V. However, this cost division scheme is fair only under the false assumption that the bargaining powers of group of LGs are identical. To suggest a better and fair division rule, Shapley Value, a cooperative game solution, is used to suggest Scheme 3. In Scheme 3, Shapley Value measures the summation of average marginal contribution of each player in all possible coalitions as cost division scheme and is known to provide a fair division considering bargaining power. In the context of Anyang-cheon, LGs in upper stream have superior bargaining position. The result suggests the cost division is fair under Scheme 3, when the cost shares are 0.29% by I, 14.77% by II, 50% by IV, and 34.94% by V, respectively.

• Journal of Labour Economics
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• v.24 no.3
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• pp.13-38
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• 2001

The question about whether a shorter workweek may increase employment has been a serious issue and been furiously debated among collective bargainers. The advocators recommend publicly that a reduction in standard working hours will provide benefits to the unemployed through the provision of new jobs, and also can improve the quality of life workers. The opponents argue that a shorter workweek will increase labor costs and induce firms to reduce their production levels, and consequently cut back their demand for labor. Although the debate is still continuing, considerable has been made toward achieving the goal workweek reduction. The analytical framework of this paper is a Putty-clay-model, in which the short-and long-term impacts of changes in working time on the employment associated with the interrelations of wages, prices, hourly labour productivity, the firm's labor demand, business cycle and economic growth etc. must be analyzed.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.161-170
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• 2008

Recently irregular dark-colored patches were found on the Kentucky teeing ground in a golf course in Gyunggi providence. Interestingly, blue-green algae from the leaf tissue sample containing black spot-stained symptoms were largely observed through microscopic study. In general, algae present on the upper soil surface or in the upper layer of root zone form dark brown layers of scum or crust, which invoked harmful effects to turf growth such as poor drainage, inhibition of new root development. In this observation, unlike the algae were sometime found in senescing leaves on contacted soil in July and August, the blue-green algae were detected within black spot-stained Kentucky bluegrass leaf tissues including leaf blade, ligule, auriclea as well as leaf sheath. The blue-green algae were also detected on the leaf and stem tissue adjacent to the symptomatic leaf tissues. Two species of blue-green algae, Phomidium and Oscillatoria, were greatly observed. Oscillatoria species was more commonly notified in all samples. In addition, the two species were found on a putting green showing yellow spot disease at another golf course in Gyunggi providence. The data from chemical control assay revealed that chemicals such as propiconazole, iprodione, and azoxystrobin decreased blue-green algae population and leaf spots, which finally resulted in enhanced leaf quality. All taken together, we strongly suggested that the disease-like phenomenon by blue-green algae might be very closely mediated with infection/translocation process in relation with turfgrass. It indicates that blue-green algae in turf management may play an adverse role as a secondary barrier as well as a pathogenic agent. This report may be helpful for superintendents to recognize and understand the fact that algae control should be provided more cautiously and seriously than we did previously in upcoming golf course management.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.543-548
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• 2011

Haiami is a new Japonica rice variety developed from a cross between 'Jinmibyeo' TR treated with ethyl methane sulfonate (EMS) EMS and 5-methytryptophan, and 'Gyehwabyeo' in order to develop a new premium quality rice variety by a rice breeding team of National Institute of Crop Science, Rural Development Administration in 2008. This variety has about 138 days of growth duration from transplanting to harvesting in central plain area of Korea. The heading date of this vareity was on $15^{th}$, August. The 'Haiami' has good semi-elect plant type and resistant to lodging with strong culm. The number of panicles/hill of 'Haiami' is more than that of 'Hwaseongbyeo'. This variety shows slow leaf senescence and considerable tolerance to viviparous germination. It is susceptible to leaf blast, bacterial blight, and insect pests, but resistance to rice stripe virus. The milled rice of this variety exhibited translucent, clear non-glutinous endosperm and short grain shape. The essential amino acid properties of 'Haiami' have more than 31% that of 'Hwaseongbyeo' in polished rice. This variety has premium palatability of cooked rice. The yield performance of this rice cultivar was about 5.38 MT/ha in milled rice in local adaptability test for three years from 2006 to 2008. 'Haiami' is adaptable to central and southern plain areas of Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.138-145
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• 2021

Perilla contains more than 60% of fatty acids. Linolenic acid is effective in preventing heart disease, improving learning ability, treating allergies, and preventing cancer. This study was carried out to improve the cultivation method to aid the stable production of perilla by developing a suitable inter-cropping system with sesame in the central region as well as to report a suitable planting time. The test results are summarized as follows. As the planting time of perilla in the inter-cropping system with sesame was delayed, the number of clusters and capsules decreased. The perilla yields in this system showed significant differences compared to that with the previous crops (sesame varieties) and planting period. The yield of perilla was significantly lower in the characteristic-Type B variety than in the characteristic-Type A variety and decreased significantly as the planting time was delayed. With regards to the quality characteristics of perilla, such as crude protein, crude fat, etc., there were no differences between previous perilla crops and those inter-cropped with sesame. The perilla composition did not show any difference during the planting period; however, with delay in the planting time, crude protein content increased but crude fat content decreased. Yield of perilla was 38% higher in a two-row (40 x 40 cm) system, compared to a single-row cultivation (110 x 20 cm) of perilla inter-cropped with sesame. These results suggest that the suitable method for inter-cropping perilla with sesame in the central region is to sow the characteristic-Type A variety in early May, and cultivate the perilla in two lines (40 x 40 cm) in mid-June. This was judged to be the best cultivation method in the central region.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.4
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• pp.31-37
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• 2010

Livestock manures have a potential to be a valuable resource with an efficient treatment. In Korea, 42 million tons of livestock manure were generated in 2008, and 84 % of them were used for compost and liquid fertilizer production. Recently recycling of livestock manure for biogas production through anaerobic digestion is increasing, but its utilization in agriculture is still uncertified. In this study, there was applied co-digestate to the paddy for rice cultivation based on N supplement. Co-digestate was fertilizer fermented with pig slurry and food waste combined with the ratio of 70:30(v:v) in its volumetric basis. For assessing the safety of co-digestate, it was monitored the contents of co-digestate for seasonal variation, resulted in no potential harm to the soil and plant by heavy metals. The results showed that soil applied with co-digestate was increased in exchangeable potassium, copper and zinc mainly due to the high rate of pig slurry in co-digestate applied. Considering high salt content due to the combination with food waste, strict quality assurances are needed for safe application to arable land though it has valuable fertilizer nutrient. Leachate after treatment showed that the concentration of nitrate nitrogen washed out within two weeks. Considering the salt accumulation results in soil, it is highly recommended that the application rate of co-digestate should not exceed the crop fertilization rate based on N supplement. With these results, it was concluded that co-digestate could be used as an alternative fertilizer for chemical fertilizer. More study is needed for the long-term effects of co-digestate application on the soil and water environment.

• Journal of Mushroom
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• v.13 no.2
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• pp.119-124
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• 2015

This study was carried out to characterize the chemical components of Flammulina velutipes during storage by different packaging film application for developing export winter mushroom to south east asia area. Changes of weight and growth rate from Flammulina velutipes were the lowest in testing packaging film at $15^{\circ}C$ among the films. The pH changes of Flammulina velutipesg was the highest in imported packaging film at $25^{\circ}C$. The changes of colors was measured by Hunter's color value, L value and yellowness (+b) were slightly decreased during storage. But the L value and yellowness (+b) were not affected by packaging films. Six organic acids were detected such as oxalic acid, lactic acid, malic acid, citric acid, acetic acid and succinic acid. The content of total organic acids were increased by storage period.

• Journal of Korean Society of Forest Science
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• v.35 no.1
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• pp.1-8
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• 1977

Forest soil fertility was evaluated through the approach of numerical method. In this study, the soil chemical properties analyzed for 35 different soil series as table 2 were cited in numerical analysis. Minimum contents of essential nutrients in the surface soil for a satisfactory growth of tree in the plantation were evaluated by comparing with Wild's standard as table 1. Demanding level of fertilization were evaluated by using the formula 1 as table 5. Similar relation of soil chemical properties between soil series were calculated through formula 2, and then classified into 5 groups in soil chemical properties. 1. General chemical properties of surface soil in case of 35 soil series. About 40 percent of 35 different soil series are less than 2 percent in organic matter, 10 ppm in available phosphorus, 1.25m.e/l00g in exchangeable calcium and 0.5m.e/l00g in exchangeable magnesium. Generally, shortage of exchangeable potash are not found. CEC less than 10m.e/l00g are in two thirds and strong acid soil less than PH 5.5 are in about four fifths. 2. Soil series requested or not the fertilization are indirectly evaluated from the formula 1 using the relative figure of chemical components of CEC, OM and MgO. Through this analysis, 8 different soil series have very poor quality in soil chemical capacity so that demands highly the fertilization. On the other hand, other 13 different soil series group have not been thought to need the fertilization according to chemical guality. 3. By the results comparing the similarity of chemical properties of forest soil, it is thought to be suitable that the forest soil fertility are divided into 5 groups as follows: 1. Low CEC soil 1-1 Low organic matter soil less than 2 percent 1-2 Medium organic matter soil less than 4 percent 2. High CEC and organic matter soil 2-1 Low magnesium soil 2-2 High magnesium soil 3. High magnesium and calcium soil as lime stone.

• Journal of the Korean Society of International Agriculture
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• v.31 no.3
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• pp.249-254
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• 2019

'Japonica 6' is a japonica rice variety developed from a cross between 'MS11', the beginning variety adaptable to tropical region, and 'IR86743-28-1-4', an elite line of high yield and good plant type by a Korea(RDA)-IRRI cooperative breeding program at IRRI in 2017. The growth duration of 'Japonica 6' is 121 days from sowing to harvest. It is 10 days later than that of the check variety 'MS11'. The culm length of 'Japonica 6' is 70 cm, and 1,000-brown rice grain weight is 26.7 g. It has a shorter culm and a larger grain. size than that of MS11. 'Japonica 6' is moderately resistant to blast disease but susceptible to bacterial blight, tungro virus and plant hoppers. The milled rice recovery rate of 'Japonica 6' is improved than that of 'MS11'. The head rice rate of 'Japonica 6' is significantly higher than that of 'MS11'. Yield of 'Japonica 6' is averagely 3.59 MT/ha of milled rice in 5 areas of the Philippines. The 'Japonica 6' was registered in Philippines and would be adaptable to the diverse regions of tropical Asia (Registration No in Philippines. BPI-NSIC-2017-Rc 484SR).

• Horticultural Science & Technology
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• v.34 no.2
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• pp.282-293
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• 2016

Root-knot nematodes (Meloidogyne spp.) are major plant pathogens that cause reductions in yield and quality of several solanaceous crops, including pepper (Capsicum spp.). These losses can be averted through planting of resistant cultivars. Plants are defined as resistant when they suppress nematode reproduction. In this study, the resistance degrees of 102 commercial cultivars of chili pepper (Capsicum annuum) to a root-knot nematode, Meloidogyne incognita, were evaluated by comparing the number of egg masses on their roots to those of 'PR huimangchan', a highly susceptible cultivar that exhibited the most egg masses of the chili pepper cultivars evaluated. Among these cultivars, forty-four (43.1%) showed resistance to M. incognita and eighteen (17.6%) were moderately resistant. The other cultivars (39.3%) were determined to be susceptible. For further study, six chili pepper cultivars (i.e., Gangryeokjosenggeon, Shinsegae, Muhanjilju, PR Bulrocho, PR Huimangchan, and Jjang) with different levels of resistance to the nematode were selected. Changes in resistance of the six cultivars under several conditions, such as inoculum concentration, plant growth stage, and cultivation period after transplanting were investigated. We found that an efficient screening method for resistance of chili pepper to M. incognita is to transplant the chili pepper seedlings 7 days before inoculation, to inoculate 28-day-old plants with M. incognita by loading 5,000 eggs per plant into the pot of soil, to cultivate the plants in a greenhouse ($25{\pm}5^{\circ}C$) for 45-60 days, to measure the number of egg masses on roots of the seedlings, and then to determine the resistance response of the plants by comparing the number of egg masses on the roots with a reference-susceptible cultivar 'PR huimangchan'.