• KDI Journal of Economic Policy
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• v.12 no.2
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• pp.51-79
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• 1990

Research on technical efficiency, an important dimension of market performance, had received little attention until recently by most industrial organization empiricists, the reason being that traditional microeconomic theory simply assumed away any form of inefficiency in production. Recently, however, an increasing number of research efforts have been conducted to answer questions such as: To what extent do technical ineffciencies exist in the production activities of firms and plants? What are the factors accounting for the level of inefficiency found and those explaining the interindustry difference in technical inefficiency? Are there any significant international differences in the levels of technical efficiency and, if so, how can we reconcile these results with the observed pattern of international trade, etc? As the first in a series of studies on the technical efficiency of Korea's manufacturing industries, this paper attempts to answer some of these questions. Since the estimation of technical efficiency requires the use of plant-level data for each of the five-digit KSIC industries available from the Census of Manufactures, one may consture the findings of this paper as empirical evidence of technical efficiency in Korea's manufacturing industries at the most disaggregated level. We start by clarifying the relationship among the various concepts of efficiency-allocative effciency, factor-price efficiency, technical efficiency, Leibenstein's X-efficiency, and scale efficiency. It then becomes clear that unless certain ceteris paribus assumptions are satisfied, our estimates of technical inefficiency are in fact related to factor price inefficiency as well. The empirical model employed is, what is called, a stochastic frontier production function which divides the stochastic term into two different components-one with a symmetric distribution for pure white noise and the other for technical inefficiency with an asymmetric distribution. A translog production function is assumed for the functional relationship between inputs and output, and was estimated by the corrected ordinary least squares method. The second and third sample moments of the regression residuals are then used to yield estimates of four different types of measures for technical (in) efficiency. The entire range of manufacturing industries can be divided into two groups, depending on whether or not the distribution of estimated regression residuals allows a successful estimation of technical efficiency. The regression equation employing value added as the dependent variable gives a greater number of "successful" industries than the one using gross output. The correlation among estimates of the different measures of efficiency appears to be high, while the estimates of efficiency based on different regression equations seem almost uncorrelated. Thus, in the subsequent analysis of the determinants of interindustry variations in technical efficiency, the choice of the regression equation in the previous stage will affect the outcome significantly.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.2
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• pp.33-40
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• 2014

The purpose of this study is to examine vegetation of the outer walls of the Jeongyi Town Wall in Jeju and analyze the characteristics and problems identified, for suggesting preliminary data for selecting species of plants appropriate for the greening of the walls in the southern temperate climate region, including Jeju. The result of this study is as follows. The number of plants growing naturally around the walls of the town was identified to be 52 taxa. Based on the list of naturalized plants, there are 5 taxa; Sonchus oleraceus, Houttuynia cordata, Crassocephalum crepidioides, Erigeron annuus and Lamium purpureum. The number of species by district was from 3 to 14 taxa with 7.1 taxa on average. Analyzing by the constancy class, plants in class III included Sedum bulbiferum, Trichosanthes kirilowii, Hedera rhombea and Boehmeria nivea. Manipulation of the species composition table shows that the number of plant species growing naturally around the walls of Jeongyi Town Wall is a total of 52 taxa, including 11 taxa by differential species of community and 41 taxa by companion species. The types of plants very useful for the covering of the walls are evergreen climbing vine, such as Hedera rhombea, Ficus thunbergii and Euonymus fortunei and deciduous climbing vine, such as Parthenocissus tricuspidata, Trichosanthes kirilowii and Paederia scandens. In addition, Ficus stipulata is identified as a vegetation more appropriate for the southern-ward lattice-blocked walls. Woody plants, such as Akebia quinata, Celastrus flagellaris, Ampelopsis brevipedunculata for. citrulloides, Rubus hirsutus, Clematis apiifolia and herbaceous plants, such as Dioscorea tenuipes, D. quinqueloba, D. nipponica, Cayatia japonica and Paederia scandens var. angustifolia are highly useful materials for climbing plants for covering the walls of the southern province. Pteridophyte, such as Lemmaphyllum microphyllum, Pteris multifida, Cyrtomium falcatum and Lygodium japonicumare suggested as very useful for increasing unique regional characteristics of the southern province, including Jeju.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.1
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• pp.53-59
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• 2010

The spatial variability in the food chain structure of an estuarine environment(Nanakita estuarine, Japan) was investigated using stable carbon and nitrogen isotope. Potential organic matter sources(TP:Terrstrial Plant, MPOM:Marine particulate organic matter, BMA:Benthic microalgae, EPOM:Estuarine particulate organic matter), sedimentary organic matter and benthic invertebrates(Nuttallia olivacea and Nereidae) were sampled at four locations with different tidal flat types(e.g. sanddy, sanddy-muddy and muddy). The main objective of the present study was to determine food sources of Nuttallia olivacea and Nereidae along with small-scale spatial variability within the community of benthic invertebrates. TP(${\delta}^{13}C=-26.6{\pm}0.76$ and ${\delta}^{15}N=2.7{\pm}0.31$) and EPOM(${\delta}^{13}C=-25.5{\pm}0.13$ and ${\delta}^{15}N=5.2{\pm}0.46$) were isotopically distinct from BMA(${\delta}^{13}C=-16.3$ and ${\delta}^{15}N=6.2$) and MPOM(${\delta}^{13}C=-19.6{\pm}0.08$ and ${\delta}^{15}N=8.9{\pm}1.70$). ${\delta}^{13}C$ values of sedimentary organic matter showed a distinct gradient in the range of -27.4 to -22.8‰ with a declining trend from the upstream to the downstream stations. The stable carbon and nitrogen isotope values of benthic invertebrates in the study site was -22.8 to -18.4‰ for ${\delta}^{16}C$ and 8.1 to 11.9‰ or ${\delta}^{15}N$, respectively. Mixing model(Isosource) calculations based on stable isotope measurements showed that benthic invertebrates of Nuttallia olivacea and Nereidae were found to be dominated by MPOM and BMA in stations. Whereas, TP and EPOM showed little influence to benthic invertebrates. The current result suggests that the different contribution for benthic invertebrates should be affected by both seasonal variation and physical factor among stations.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.333-344
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• 1989

The objectives of this study were to investigate the growth of Gyrophora esculanta and to establish a method of tissue culture of the plant. The results obtained were as follows : 1. The Gyrophora esculanta was found growing mostly on the rock slopes of 722 m to 1915 min elevation on mountains in Korea. 2. Trees growing in the vicinity of the G. esculanta were mainly Quercus spp., Pinus thunbergii, Acer spp. and Lespedeza spp, Especially Quercus spp. was found growing in all of the study site. 3. The average Length of the rock slopes with G. esculanta growing on was 14 m and their aspects were mostly south. 4. The G. esculanta were found growing on rocks of Crystalline Schist, Quartz, Liparite, Granite, ete. Particularly they were mostly found on granites. The gradient of the rock slopes was in the range of 22-90 degrees. 5. The mean number of individuals of G. esculanta per one rock slope ranged from 14 at Mt. Bukhan to 70 at Mt. Jrri. Their mean diameter ranged from 1.8cm at Mt. Munsu to 4.6cm at Mt, Sokri. 6. The average percentage of G. esculanta with fruit body was 17.6%. The highest value was found at Mt. Cheonhwang (24.0%). 7. When the 100 segments of rhizoid of Gyrophora esculanta cultured in Detmer's medium supplemented with kinetine 5mg/l and 2, 4-D 3mg/l, n callus of microspore origins were induced from about 20% of the segments. As the induced n callus was transplanted on the six different types of rocks, it was observed that the juvenile G. esculanta grew best on granite and the development rate of G. esculanta on the granite was about 55%.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.429-437
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• 2019

This study was conducted to examine the effect of humidification and shading during cutting propagation on growth and development of strawberry (Fragaria x ananassa Duch.) 'Maehyang' plants at a propagation stage. The runner cuttings were stuck on Nov. 23, 2017 in propagation benches set in a Venlo-type glasshouse. Four shading treatments, no shading (control, C), 55% shading with white lawn (W55), 55% black shading net (B55), or 100% black plastic film (B100) with either an intermittent fog system (H) or without fog system. The shading and fog systems were removed 2 weeks after sticking of strawberry cuttings. A nutrient solution for strawberry, which was developed by Yamazaki, was supplied once a day with electrical conductivity (EC) $1.6dS{\cdot}m^{-1}$ and pH 5.8. Growth parameters such as plant height, longest root, crown diameter, leaf chlorophyll, leaf area and fresh and dry weight were measured at 7 days and 26 days after sticking. There was no significant difference in growth of above-aerial part of strawberry. The overall growth of the strawberry roots was better grew by providing fog than that not provide fog. The root fresh weight and root dry weight after 26 days after sticking of strawberry cutting was the best in the treatment that provided fog system without shading (CH). The longest root after 26 days after sticking of strawberry cutting was the best in the treatments that provided fog system with either 55% white lawn (W55H) and 55% black shading net (B55H). These results suggest that morphogenesis of these plants were affected by humidification and shading types. In a broader perspective, these results can be used to optimize studies of other crops grown from cuttings.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.68-80
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• 2019

This study is to provide basic data for the user-oriented design for a middle school meditation forest in the future by analyzing the physical environment characteristics of existing middle school meditation forests, the users' utilization behavior, and the degree of the importance satisfaction. For this purpose, 24 evaluation indices based on site characteristics, naturalness, functionality, and the effectiveness of meditation forest sites were selected for analysis of importance satisfaction. We surveyed and analyzed the students and teachers of two middle schools 'A' and 'B' in Gwangju Metropolitan City. The results of this study are as follows. First, the perception and utilization rates of the meditation forests by students was significantly lower than teachers at both schools. 'A' school has a better use and recognition rate than the 'B' school. Second, the purposes of using meditation forests were rest (49.6%), weekday lunchtime (63.6%), with friends (65.0%) or colleagues (60%), and short (less than 10 minutes) rests (68.6%). They preferred flowers (30.0%) and shading plants (28.9%), mainly using shelters (57.9%) and walking trails (37.1%). Third, as a result of the importance of satisfaction analysis, the average score of the 24 items importance (3.81), higher than the satisfaction (3.62). The 24 items positioned in 4 quadrants are as follows: Nine items are in the I quadrant for 'persistent maintenance'. Three items are in the II quadrant for 'priority correction'. Seven items are in the quadrant III for 'low priority in the management and operation'. Five items are in the quadrant IV for 'avoid over effort'. For the comparison of two middle schools' satisfaction, 'A' school satisfaction was higher than 'B' school for 16 items, which showed a statistically significant difference. It is believed that the users in 'A' school are more satisfied than 'B' school because it has more forests and trails, better accessibility, and a variety of plant types and planting areas in the A school meditation forest. The results of the overall satisfaction analysis showed a significant difference between 'A' school (68.0%) and 'B' school (47.2%) as 'A' school has better shelters and trails. The rankings of the most satisfying space are walking trails (1st place) and shelters (2nd place). The reason for the highest satisfaction was for rest (stress relief and emotional support) in both 'A' and 'B' schools.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.55-62
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• 2019

Rapeseed meal, which is a byproduct of rapeseed oil extraction, improves crop productivity by supplying nutrients to the soil. The present study aimed to manufacture fermented rapeseed meal compost using two effective microbial agents and evaluate their efficiency as fertilizer. To types of fermented rapeseed meal, manufactured using either a bio-carrier or microbial agent, showed no differences in pH, electrical conductivity (EC), and total nitrogen content. However, the contents of $NH_4-N$ and $NO_3-N$ as inorganic nitrogen were increased by 5.6 times and 1.5 times, respectively, after 5 d of fermentation. Rapeseed meal fermented for 5 d was applied to tomato a basal fertilizer and after eight weeks, the plant height increased in all fermented rapeseed treatments compared to that in the chemical fertilizer treatment, and also the quantum yield of photosystem II (PS II) showed the same trend. The total nitrogen content of tomato leaves treated with a microbial fermented rapeseed meal was twice as high as that of that treated with a chemical fertilizer. It was confirmed that the increase in the tomato height was an effect of the rapeseed meal containing inorganic nitrogen, which can easily be absorbed by plants. From these results, it is considered that fermented rapeseed meal manufactured with an effective microbial agent for 5 d showed the highest inorganic nutrient content and greatest growth enhancement in tomato.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.114-133
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• 2013

This study aims to identify the natural damage of the Samcheonsaji Temple Site in Bukhansan National Park and to suggest the plans to minimize damage for the remains. The types of natural damage are classified into direct vegetation damage, indirect topographical damage, and artificial damage. The most popular causes of damage to temple sites include the roots of trees as direct vegetation damage and the soil erosion by rain or stream as topographical damage. Direct vegetation damage includes burial remains damaged by the root of trees and vines, but it is often observed that some trees have contributed to protection against collapse. Indirect topographical changes have damaged the ruins by soil erosion caused by floods or typhoons. Vegetation changes due to topographical reasons have also caused damage. Artificial reasons of damage include forestry operations and compaction by hikers. Based on the analysis of the findings, the following could be suggested as plans to resolve these problems: 1. Natural damage occurs slowly due to negligence. Therefore, it could be reduced by forestry improvement, including forest density control through thinning, planting to prevent landslides, maintaining grasslands nearby. 2. Deciduous broadleaf trees can be planted to reduce soil erosion by rainfall. It is necessary to maintain the density of forests at around $0.02{\sim}0.18trees/m^2$. 3. It would be good to grow Quercus spp and Carpinus spp or weaken the community of Robinia pseudoacacia and Pueraria lobata which disturb the ecosystem. Samcheonsaji Temple Site is located in Mt. Bukhan National Park that is a publicly owned property. Therefore, it is constantly maintained for natural preservation and vegetation management could be considered for the preservation of historical remains.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.100-121
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• 2009

This study is subjected to those gardens of the Korean Folk Village 'Oeam-Ri' designed in 1920s. - transitional period of traditional gardens - and define socio-cultural change's influences and through documents on garden design, descendant's testimony and measured drawings, to understand that period's garden culture's characteristics according to garden design elements. This study applied following analysis methods and procedures to derive out characteristics of transitional garden culture. Analysis on socio-cultural characteristics in 1920s. Analysis on actual condition of transitional garden's design. In this point Outline of the Garden, Space formation, Garden designing elements are (1) water landscape, (2) plant, (3) structures, (4) paving, to derive out characteristics of the transitional garden. The results follow as below; First, during the transitional period 1920s, the economical development, fueled by opening nation's door to foreign countries and indication of collapse of statue systems together with idea of practical science and Enlightenment Thought, was element of changes in garden style. Second, Garden Designers of transitional gardens in 'Oeam-Ri' were limited to upper class of the society. They were wealthy enough to maintain their high social statue in rapidly changing society. As results, tendency of returning to nature developed gardens located in a site of scenic beauty and development of geographical features arranging techniques, and also showed copying foreign styles. Third, arrangement of garden and space composition, in most cases, composed of buildings and yards. Changes in water landscape features and garden spaces are centered to main-yard. Major changes of the garden spaces are water landscapes and plants that showing foreign influences. Fifth, scenic appearance techniques appears with dense garden space and emphasizing visual scenic view. Sixth, the characteristics of transitional garden design techniques are development of geographical feature arranging techniques, changes and mixture of the materials and garden types, emphasizing garden's decorative beauty, change of concept of yard within house into garden, changes from 'borrowing of landscapes' to 'selecting landscapes', changes of front garden from emptiness to fullness, changes of attitudes of enjoying gardens from 'staying calm in the garden' to 'moving or walking in the garden', changes to inner-oriented view, and changes from 'just watching and enjoying the nature' to 'enjoying specific objects'. This study is one of the efforts to restore the identity of Korean Traditional Garden by approaching and observing modern era which function as bridge between tradition and present day, and we observed transitional aspects of changes of traditional garden into modern garden. Hereafter, more studies will be needed to Modern Garden Design be recognized as part of Korean Garden Design History and these would be author's next assignment.