• KDI Journal of Economic Policy
• /
• v.29 no.3
• /
• pp.75-109
• /
• 2007

This paper empirically investigates the effects of import tariff on within-plant productivity growth in Korean manufacturing, using the detailed plant-level longitudinal data of the Korea Census of Manufacturers for the period of 1993-2003. Our main findings are as follows: First, the productivity changes of Korean manufacturing for the period under analysis were mostly induced by within-plant productivity gains, rather than within-industry and/or between-industry resource reallocations. Second, after controlling for firm-specific heterogeneity, the estimation results indicate that lowering tariff-barriers has a positive impact on within-plant TFP growth. We interpret the results in a way that trade liberalization through the removal of tariff and non-tariff barriers heightens the competitive pressure, which in turn creates incentives to reduce production and managerial inefficiency and to invest more on innovative activities. Third, we also find that plant productivity growth from reducing tariff barriers is particularly conspicuous within a year after tariff changes, which implies that plants are quickly adjusting to heightened import competition. On the other hand, our results show that the trade effect on employment creation proceeds relatively slow.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.48-48
• /
• 2017

The objectives of this study were to determine the dominance frequency of plant species between spring and summer, to provide useful information toward the conservation to increasing production cattle feed in grazing area in Hiroshima, Japan. The frequency of dominant plant species can adapt in the spring and summer, that consist of Paspalum dilatatum (spring 69.32% and summer 78.98%), Paspalum notatum (spring 47.73% and summer 98.30%), Trifolium repens (spring 73.86% and summer 81.25%). The observed plant species also influenced some productivity, which consists of plant height (spring 16.64 cm and summer 21.55 cm), vegetation cover rates (spring 77.18% and summer 81.36%, chlorophyll content (spring 41.72 mg/g Fw and summer 36.28 mg/g Fw), diversity index (spring 0.94 and summer 0.80), evenness index (spring 0.93 and summer 0.67), and species numbers (spring 32.0 and summer 21.0). It is proposed that Paspalum dilatatum, Paspalum notatum, and Trifolium repens, can be used to increase productivity of plant species as cattle feeds.

• The Korean Journal of Ecology
• /
• v.24 no.6
• /
• pp.335-339
• /
• 2001

The dynamic model was developed to simulate the photosynthetic rate of Phragmites communis stands in coastal ecosystem. The model was composed of the compartments of both climatic and biological variables. The former were photosynthetic photon flux density(PPFD), daily maximum- and minimum-temperature. The latter were combinations of the specific physiological responses of plant organs with the biomass of each organs. The PPFD and air temperature were calculated and using those values, gas exchange rate of each plant organ was calculated at every hour. The carbon budget was constructed using the modelled predictions. Analysis of annual productivity and fluxes showed that yearly gross population productivity, yearly population respiration and yearly net population productivity were 33.4, 21.3 and 12.1 $CO_2ton{\cdot}ha^{-2}{\cdot}yr^{-1}$, respectively. The final result was tested over two stands, produced promising predictions with regards to the levels of production attained. The model can be used to determine production potential under given climatic conditions and could even be applied to plant canopies with analogous biological characteristics.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.4
• /
• pp.314-321
• /
• 2014

Nuclear power plant projects are being increased all over the world. The construction of nuclear power plants needs huge money and time, which makes conducting a detailed analysis of productivity through the whole process. Reinforced-concrete works productivity field data was collected for more than one year and analyzed from a nuclear-power-plant project in Korea. The productivities of formwork, rebar-work, and concrete pouring were $0.54m^2/man{\cdot}day$, $0.06ton/man{\cdot}day$, $1.98m^3/man{\cdot}day$, respectively. Moreover, it is revealed that 'Day of the Week' is a driver of the formwork activity and 'Overtime' is for all of the three. The results will be a great interest of industry personnel estimating time and cost of a new nuclear power plant.

• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.3
• /
• pp.213-217
• /
• 1995

Leucaena leucocephala (lam. de Wit) is a multipurpose leguminous tree/shrub, promoted extensively for reforestation and rural development programmes, as well as in ruminant production. After a year of establishment in the plots, the overall leaves and twigs yield was on average 0.92 kg/plant, containing an average 23.34, 10.61, 5.32 and 10.13 percent CP, CF, and ash, respectively. The proximate and mineral compositions are affected by factors such as stage of maturity, type of cultivar, seasons, cutting intervals, different plant parts. Though leucaena contains toxic mimosine and tannins, these are not always deleterious for ruminants and rumen microbes can often degrade toxic factors into a nontoxic utilizable product Mimosine content is generally higher in the seed than other plant parts. Leucaena supplementation in ruminant ration showed higher digestibility co-efficient of proximate component, which may results in higher productivity. Considering its productivity, composition and nutritive value. L. Leucocephala could be more widely used as a protein source for ruminants in tropical and sub-tropical countries.

• Journal of Plant Biology
• /
• v.18 no.3
• /
• pp.122-128
• /
• 1975

With the cultivated mulberry plant which feeds silkworm on its leaves in sericulture, the measuring methods of biomass of terrestrial organs were compared and the annual net productivity was estimated. The measurement of the standing crops by means of allometric method on basis of relation between the parameter D230H, square of the diameter of the branch on 30cm high above ground($D{\frac}{2}{30}$) multiplied by its height(H), and the amount of leaves(WL) or of branch (Ws) was more accurate than other methods on basis of correlation between a character of the branch such as H, D30 or D230 and WL or Ws. The estimate of value of the net productivity of terrestrial parts of mulberry was 9.06-12.54 ton/ha.year, which was similar to that obtained from secondary forests in cool temperate zone.

• Mycobiology
• /
• v.34 no.4
• /
• pp.191-195
• /
• 2006

This study was conducted to investigate the different effects of ectomycorrhizal fungal (ECMF) species on the growth of seedlings of Pinus densiflora, and the effects of ECMF diversity on plant productivity. A total of five species of ECMF were isolated from root tips of pine seedlings collected from Mt. Songni and used as inocula. Pots containing pine seedlings were inoculated with either a single ECMF species or a mixture of five ECMF species. All of the seedlings formed ECM on their roots except for the control plants. The pine seedlings' growth responses varied by the different ECMF species. Also, pine seedlings inoculated with a mixture of five ECMF species showed the highest growth response. The results of the study suggest that the colonization of diverse species of ECMF will increase plant productivity, and the selection of suitable ECMF species could be an important factor for plant growth.

• Plant Resources
• /
• v.6 no.3
• /
• pp.178-182
• /
• 2003

This study was conducted to investigate the relationship between yearly variations of climatic elements and yearly variations of productivity in perilla. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 10 years from 1991 to 2000. The meteorological data gathered at the Yeosu Weather Station for the same period were used to find out the relationships between climatic elements and productivity. Yearly variation of the amount of precipitation in September was large with coefficients of variation(c. v.) of 11.1%, but the coefficient of variance(c. v.) in July and August were relative small with 1.8, 2.1%, respectively. Number of cluster per hill and weight of 1,000 grains were greatly with c. v. of 76.1, 79.3%, respectively, but the coefficients of variance(c. v.) of plant height and seed yield were more less with 9.58, 10.60%, respectively. Correlation coefficients between precipitation of September and seed yield were positively significant correlation at the level of 5.1%, respectively, but the duration of sunshine in September and seed yield were negatively significant at the level of 5.1%, respectively. Correlation coefficients of these, the plant height, number of branches per plant, cluster length, number of cluster per hill, weight of 1,000 grains and seed yield were positively significant at the level of 5.1% respectively.

• Mycobiology
• /
• v.35 no.4
• /
• pp.186-190
• /
• 2007

This study was conducted to investigate the effects of foliar endophytic fungi and arbuscular mycorrhizal fungi (AMF) on plant community structure in experimental microcosms containing an assemblage of five species of plants (Oenothera odorata, Plantago asiatica, Trifolium repens, Isodon japonicas and Aster yomena). Leaves of Sasa borealis, Potentilia fragarioides, and Viola mandshurica were collected in Chungbuk, Korea. Endophytic fungi were isolated from the surface sterilized leaves and identified to species level using molecular and morphological techniques. Four isolates of the endophytic fungi were inoculated to the leaves of host plants in the microcosms. Also, three species of AMF spores were extracted from pure cultures and the mixture of the three species inoculated to the roots of the plants. After four months of growth in a green house, effects of both symbiotic fungi on plant species diversity, community composition and productivity were examined. The plant species diversity showed significant differences with inoculation of the symbiotic fungi. Results indicate that AMF significantly affect plant productivity and plant community structure.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.333-336
• /
• 2012

In modern Construction Industry, as accumulation of capital and improvement of technology skills, buildings are becoming higher and more enormous, also the portion of steel works has been increasing. In addition, it is necessary to predict the optimum level of construction cost in a reasonable way. The composition of construction is direct construction cost, indirect construction cost and so on. However, it is not enough to study about indirect construction cost rather than direct construction cost. In this study, the state of productivity and indirect construction cost are analyzed in the steel production. As a result, the productivity and ratio of indirect cost in steel plant by inserted per 1ton are suggested.