• Journal of the Korean GEO-environmental Society
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• v.14 no.7
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• pp.39-50
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• 2013

Crib wall is one of the segmental grid retaining walls using headers and stretchers to establish the framework of the wall. In this method, grids formed by the intersection of headers and stretchers are generally filled with the gravel to maintain the weight of the wall. Therefore, the construction can be carried out with higher speed and much economically when compared with the concrete retaining wall. Furthermore, it has high drain capacity, and environmentally friendly aspects also have been pointed out because the possibility of the planting at the front of the wall. However, in the wooden crib wall method, the relative movement between the individual headers and stretchers was generally recognized, and stress redistribution in the gravel filling was also observed when subjected to the external loading and self-weight of filling. In this study, it was analyzed fracture types and causes of wooden crib wall through detailed investigation and analysis of a large crib wall construction site. As a results, it occurred the damage in the members of 5.7% in a total of 2,315 locations and the damage of header occurred in the members of a header 80.2%. The 65.7% of the damaged header are concentrated in the lower part of crib wall. Therefore, it was analyzed the differences of fracture types and causes of wooden crib wall depending on the installation position and the kinds of members. It is considered basically the members of various forms of distortion and the grain affecting.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.636-642
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• 2006

To make a new fairy ring of Tricholoma matsutake in situ, the way of production and transplanting of ectomycorrhizal seedlings of T. matsutake using Pinus densiflora was investigated after transplanting from 2000 to 2005 as well as the method to improve their survival rate for the fungus. For the production of ectomycorrhizal pine seedlings, the seedlings planted at the edge of fairy ring of T. matsutake in November showed 97% of the survival rate, while those planted in April showed 80% of the rate. For the complete infection of the T. matsutake, it required more than two years after planting. The infection rate of mycelia for the ectomycorrhizal seedlings was 17.6% when the natural seedlings were used, whereas it was relatively low when the seedlings prepared from the nursery were used. The survival of T. matsutake mycelium reached up to 22% by the transplanting in April, while the mycelium transplanted in October and November showed less than 5% of the survival. The survival of T. matsutake on the transplanted seedlings was the highest in the seedlings having 50% of infection rate before transplanting. Excavation of the ectomycorrhizal seedling to examine the vitality of ectomycorrhizal roots of T. matsutake resulted in the perishing of them. Therefore, the method using a 'rice bag triers' to check living mycelium of T. matsutake without digging of transplanted seedlings was introduced in this study. In addition, it is recommended that the examination has to be conducted at least two years after transplanting.

• Land and Housing Review
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• v.8 no.3
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• pp.189-200
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• 2017

The work breakdown structure and the precedence relations by work activity are very important because they are the basic data for estimating the construction duration in the construction work. However, there is no standard to accurately estimate the construction duration since the size of the school facilities construction is smaller than the general construction work. Therefore, some schools are unable to open in March or September and the delay of the construction duration can cause damage to the students. To solve this problem, this study developed a work breakdown structure of school facilities construction work and analyzed the precedence relations by work activities. The work breakdown structure of the school facilities construction is composed of three steps. The operations corresponding to level 1 and level 2 are as follows. (1) 2 preparatory work categories; preparation period and temporary construction. (2) 17 architectural work categories; temporary construction, foundation & pile work, reinforced concrete work, steel roof work, brick work, plaster work, tile work, stone work, waterproof construction, wood work, interior construction, floor work, metal work, roof work, windows construction, glazing work and paint construction. (3) 7 mechanic and fire work categories; outside trunk line work, plumbing work, air-conditioning equipment work, machine room work, city gas plumbing work, sanitation facilities and inspection & test working. (4) 4 civil work categories; wastewater work, drainage work, pavement work and other work. (5) 1 landscaping work categories; planting work. The work breakdown structure was derived from interviews with experts based on the milestones and detailed statements of existing school facilities. The analysis of precedence relations by school facilities work activity utilized PDM(Precedence Diagramming Method)which does not need a dummy and the relations were applied using FS(Finish to Start), FF(Finish to Finish), SS(Start to Start), SF(Start to Finish). The analysis of this study shows that if one work activity is delayed, the entire construction duration may be delayed because the majority of the works are FS relations. Therefore, it is necessary to use the Lag at the appropriate time to estimate the standard construction duration of the school facility construction. Lag is a term used only in the PDM method and it is used to define the relationship between the predecessor and the successor in creating the network milestone. And it means the delay time applied to the two work activities. The results of this study can reasonably estimate the standard construction duration of school facilities and it will contribute to the quality of the school facilities construction.

• Journal of vocational education research
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• v.29 no.3
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• pp.107-132
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• 2010

The purpose of this study was to investigate the effects of learning achievement by comparing project approach group and the control group on the unit of growing flowers and vegetables in practical arts education. For this purpose, the experimental study on the unit of growing flowers and vegetables was achieved with 63 students(5th grade 2 classes) in S elementary school. The project approach model (Chung, Sung-bong) was applied to the experimental group, and the traditional model to the control group. To verify the effects of each class, nonequivalent control group post test-only design was applied 10 times. The SPSSWIN(ver 12. 0. 1) was used for analyzing the frequency and t-tests. The results of this study were as follows ; First, there was significant effect of learning achievement(cognitive domain) in the project approach groups. In addition, learning achievement of the experimental group has been showed significant difference about intellectual function and ability but not about knowledge. Second, there was significant effect of learning achievement(psychomotor domain) in the project approach groups. In other words, there has been showed significant difference in basic skill and integrated skill for growing flowers and vegetables but not in elemental skill for planting. Third, as the post test, there existed significant effect(affective domain) in the project approach groups. In other words, there was a meaningful difference in acceptance, value, belief, actualization but not in interest. Based on these results, It is believed that the project approach model in the unit of 'growing flowers and vegetables' is more effective than the traditional learning method in learning achievement of learners' cognitive, psychomotor and affective domain.

• Korean Journal of Heritage: History & Science
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• v.55 no.3
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• pp.22-44
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• 2022

Lacquer, in addition to high-end crafts such as lacquerware inlaid with mother-of-pearl, was an important strategic material used in a wide range of fields such as industry, architecture, and munitions during the Japanese colonial era. In particular, as the demand for lacquer used in munitions soared in the 1940s when the war started, a ticket system was introduced to restrict its distribution. Meanwhile, Japan experienced a chronic shortage of lacquer as a result of the rapidly increasing demand for it, and thus went on to import Chinese lacquer after the late 19th century. After the 1910s, the market share of Chinese lacquer reached 90%, and the local situation in China began to affect the supply and demand for lacquer in Japan. To counteract the issue, the Japanese government increased the production of lacquer in Joseon. As for the project to increase lacquer production in Joseon, objective indicators were prepared through a number of tests in the 1910s and 20s, which paved the way for the project to begin in earnest in the 1930s. Lacquer trees were planted and training classes on how to collect lacquer were held throughout the country. The Japanese government promoted the lacquer production industry as a promising side job for Koreans. The project, implemented in various parts of the country, reaped fruitful results, and it provided the basis for lacquer production in Korea that has continued to this day. At that time, the major regions in the southern part of the country where the project was concentrated were Wonju, Okcheon, and Hamyang, regions that are still known today as major production sites. The improved method of collecting lacquer taught to Koreans by the Japanese has now become the main method of collecting lacquer in Korea. This study attempts to identify the current status of the project to increase lacquer production through various records from the Japanese colonial era with a view to contributing to the study of modern lacquer craft history.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.6
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• pp.75-87
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• 2023

This study presents an experimental design for demonstrating the role of nature-based solutions to climate change in the landscape and garden sector. The study suggests spatial strategies for a carbon-neutral society and its role as a cultural industry. This paper describes the use of a low-maintenance garden as part of a strategy for carbon reduction with the goal of protecting the environment and forming a carbon-neutral society. To this end, this study involved the design and construction of a realistic model garden to provide scientific data on the functions, spatial elements, and carbon neutrality of carbon-reducing gardens. The target site is located in the Sejong National Arboretum. The test area in which the carbon-reducing function is measured is located in the centre of the site, and other spaces include dry gardens, community gardens, and flower gardens intended for exhibition and relaxation. The experimental area is divided into several smaller areas within which the carbon-reducing effect is analysed according to the amount of biochar installed, the planting density, and the plant species present. The application of facilities and construction methods to promote carbon reduction were based on the method known as '10 types of carbon gardening for the earth'. In the model garden, we employed rainwater utilization facilities and used low-carbon certified wood and local materials. The carbon reduction effect of each facility and construction method is compared and presented here. The results are expected to serve as an important basis for realizing a carbon-neutral society and can be used as a reference in various fields that require sustainable development, such as the garden industry.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.337-346
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• 2023

Although wildlife bridge are built as a way to reduce habitat fragmentation caused by road construction, there is still a lot of debate about their effectiveness. Monitoring methods such as footprint traps and camera traps are used evaluate the effectiveness of wildlife bridge, but there is a limit to evaluate of effectiveness. In this study, the degree of use the wildlfe bridge was surveyed by striped field mouse that is likely use the wildlife bridge and surrounding as a habitat with capture-mark-recapture method.(Apodemus agraius). The distance and route of movement were identified by connecting the capture points, and the environmental factors on the use of the wildlife bridge implemented a generalized linear model(GLM) with the capture number of captured as a dependent variable. Consequently of capture, no individuals crossing the wildlife bridge, striped field mouse use the wildlife bridge as a habitat.The environmental factors affecting the use of mice were vegetation cover(1~2m, 2~8m, over 8m), vegetation construction, maximum diameter at breast height were positively correlated and slope was nagatively correlated. In conclusion, it is expected that the effectiveness of the wildlife bridge will be further improved by planting shrubs and trees and preventing high slope and cut slope increasing the utilization of the rat, such as being used as a food source in the ecosystem.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.1
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• pp.1-9
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• 1999

To find pertinent soil type and maintenance method for artificial planting ground, the effects of soil compositions{sandy loam(S), vermiculite(V), sandy loam+vermiculite+sand(SVS), sandy loam+ carbonized rice husk+sand(SCS), sandy loam+humus sawdust+sand(SHS)}, and fertilizers (organic, chemical) on plant(kentuckyblue grass) growth were measured and compared from the field experiment. The results are summarized as follows 1. the highest germination rate is found from "vermiculite(V)" and the lowest from "sandy loam(S)" among tested 5 soil compositions. 2. "sandy loam+vermiculite+sand(SVS)" composition shows the highest plant height growth effect (5cm growth during tested 3 months) comparing to other 4 compositions. 3. "sandy loam+vermiculite+sand(SYS)" composition shows the highest ground covering rate after first two months, but it concede its order to "sandy loam+humus sawdust+sand(SHS)" composition after next one month growing. 4. the effects of fertilizers are follows 1) Among the blocks where no fertilizer was tried, the predominant height growth was obvious in "sandy loam+carbonized rice husk+sand(SCS)" and "sandy loam+humus sawdust+sand(SHS)" composition. 2) Among the blocks where chemical fertilizer was tried, relatively positive results were found from "vermiculite(V)" and "sandy loam+vermiculite+sand(SYS)" blocks on germination and growth rate. But on the ground coverage ratio, the effect of "sandy loam+carbonized rice husk+sand(SCS)" composite precede that of those 2 composites. 3) Among the blocks where organic fertilizer was tried, "sandy loam+humus sawdust+sand(SHS)" and "vermiculite(V)" blocks show relatively high ground coverage rate, growth rate than others. 4) When compositional differences were not considered, the block where organic fertilizer was tried shows most positive effects on all 3 measurements-germination ratio, height growth and ground covering.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.398-410
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• 1982

Summer crops grown in uplands are greatly diversified and show a large variation in difference with year and location in Korea. The principal factor for the variation is weather, in which precipitation and temperature play a leading role and such a weather factors as wind, sun lights also influence production of the summer crops. Since artificial control of weather conditions as a main stress factor for crop production is almost impossible, it must be minimized only by an improvement of cultivation techniques and crop improvement. Precipitation plays a role as one of the most important factor for production of the summer crops and it is considered in two aspects, drought and excess moisture. This country, which belongs to monsoon territory, necessarily encounter one of this stress almost every year, even though the level is different. Therefore, the facilities for both drought and excess moisture are required, but actually it is not easy to complete for them. On this account, crops tolerant to drought, excess moisture and pests should be considered for establishing summer crops. For the districts damaged habitually every season, adequate crops should be cultured and appropriate method of planting, drainage and weed control should be applied diversely. Injuries by temperature is mainly attributed to lower temperature particularly in late fall and early spring, although higher temperature often causes some damages depending upon the kind of crops. Sometimes, lower temperature in summer season playa critical role for yield reduction in the summer crops. However, certain crops are prevented to some extent from this kind of stress by improving varieties tolerant to cold, hot weather or early maturing varieties. As is often the case, control of planting time or harvesting is able to be a good management for escaping the stress. Lodging, plant diseases and pests are considered as a direct or indirect damage due to weather stress, but these are characters able to be overcome by means of crop improvement and also controlled by other suitable methods. In addition, polytical supports capable of improving constitution of agriculture into modern industry is urgently required by programming of data for the damages, establishment of damage forecasting and compensation system.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.129-136
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• 2012

This study was conducted to develop an efficient mass propagation method for the mature $Prunus$ $yedoensis$ Matsumura (43 to 58 years old). Cutting was conducted depending on cutting time, auxin treatments (IBA and NAA treatments mixed with talc powder), and cuttings position on shoots in a plastic house equipped with a fog system without heating. Rooted cuttings were transplanted to a nursery bed, and their growth characteristics were investigated in order to check whether the cuttings are successful or not for roadside tree planting. The average rooting rate was highly significant ($P$ < 0.0001) in all treatments: cutting on June 1st (61.4%) was more than two times greater in rooting rate than that on August 1st (23.6%); IBA 1,000 $mg{\cdot}L^{-1}$ (90.8%) and IBA 500 $mg{\cdot}L^{-1}$ (89.2%) showed much greater rooting rates than those of the other treatments; upper part of the cuttings treated with IBA 1,000 $mg{\cdot}L^{-1}$ showed the highest rooting rate, 96.7%. The interactions among treatments in the average rooting rate were also significant. There were significant differences ($P$ < 0.0001) among the auxin treatments in the survival rate of leafed cuttings transplanted to a nursery bed. The average survival rate was 46.5%, and IBA 1,000 $mg{\cdot}L^{-1}$ treatment was the highest in leafed cuttings 79.2%, but most of leafless cuttings were dead. There were significant differences ($P$ < 0.0001) among the cuttings, grafts, and in the seedlings height, diameter at root collar, the number of roots, branches, and leaves, etc., and the cuttings was the best. We can expect a possibility of mass propagation of improved $P.$ $yedoensis$ Matsumura and a high planting survival rate through the transplanting of cuttings to a nursery bed in which the cuttings should be the following conditions: cutting in June to July, use of the upper part of cuttings, IBA treatment, and rooting in August in a cutting-greenhouse equipped with a fog system.