• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.46 no.6
• /
• pp.71-77
• /
• 2014

Despite the ubiquity of electronic media, paper is still the most generally readable carrier of information. Because paper materials are deteriorated by chemical, biological and physical factors over time, there have been major concerns about the decay of large collections of books, publications, old maps, historical artifacts, and written records. Therefore, manufacture of permanent paper has been a highly debated issue in paper conservation research. Through the use of permanent paper, our new records, journals, library books, art works, and all culturally and historically important documents can be preserved. In this study, handsheets were made of mixture of hemp bast fiber produced by soda pulping and HwBKP varying the amount of hemp. Physical, mechanical and optical properties of each handsheet were examined. As the ratio of hemp bast fiber increased, mechanical properties were improved significantly, but opacity decreased. After aging, the optical properties of the handsheets mixed with the hemp bast fiber more decreased than those of the non-mixed handsheet. The more mixture ratio of hemp bast fiber increased, the more decreasing rate of optical properties increased. As a result, it was confirmed that hemp bast fiber is a very promising resource for the manufacturing of permanent paper.

• Atmosphere
• /
• v.20 no.2
• /
• pp.173-186
• /
• 2010

The impact of the precipitation has been focused on losses in social and economical sectors. However, as growing the concerns of the future water shortage caused by the climate change, the precipitation should be consider in various views for an effective planning in the water resource management. A precipitation case occurred from 20 to 21 April 2009 was recorded as a welcome rain because it reduced the severe drought continued in Korea from winter season of 2008. In this study, economic values of the event was calculated with positive aspects in various sectors. The estimation is based on four major parts such as a secure of water resources, the improvement of air quality, the decrease of forest fires, and the reduction of the drought impact. The water resources only considered inflow waters into dams and the reservoirs managed by Korean public institutions and their economic values accounts for 5.92 billion won. Decreases of four air pollutants($PM_{10}$, $NO_2$, CO, and $SO_2$) were considered as the positive effects of the rainfall and estimated 175.4 billion won. The preventive effect of the forest fire after the rainfall results in 0.48 billion won. Finally, the rainfall during the drought period is effective to reduce the social costs of 108.65 billion won. Although the economic values estimated in this study explain parts of the positive effects of the precipitation, it can help to develop a comprehensive and systematic valuation system for the whole process of the precipitation. For doing this, various rainfall types should be analyzed in social-economic terms including economics, environments and hydrology.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.04a
• /
• pp.47-47
• /
• 2018

본 연구는 청옥산 산림유전자원보호구역을 대상으로 총 49개의 고정방형구를 설치하여 식물사회학적 방법으로 산림군락분류와 임분특성을 분석하였다. 그 결과 총 9개의 식생단위로 분류되었으며 군락단위로는 신갈나무군락, 잣나무군락, 일본잎갈나무군락, 독일가문비나무군락으로 분류되었다. 신갈나무군락은 소나무군, 철쭉군, 고로쇠나무군, 미역줄나무군으로 세분되었으며, 고로쇠나무군은 박달나무소군과 고로쇠나무전형소군으로, 미역줄나무군은 애기감둥사초소군과 미역줄나무전형군으로 세분되었다. 9개의 식생단위의 층위별 중요치 분석결과를 보면 교목층에서 신갈나무가 32.2% 가장 높게 나타났으며 잣나무(10.1%), 소나무(10%), 일본잎갈나무(9.1%) 순으로 나타났고, 아교목층에서는 신갈나무 (18.9%), 당단풍나무(11.7%), 물푸레나무(8.9%), 잣나무(7.2%) 등이 높은 값으로 분석되었다. 관목층에서는 철쭉(12.2%)와 당단풍나무(8%)가 높게 분석되었으며 다른 수종들은 10% 미만의 값을 가졌다. 초본층에서는 조릿대(8.5%), 산숙국(6.6%)등이 높게 나타났다. 식생단위별 종다양성지수를 보면 식생단위 8인 일본잎갈나무군락이 1.76로 가장 높았으며, 박달나무소군 1.73, 소나무군 1.72, 철쭉군 1.71 순으로 분석되었다. 우점도는 모든 식생단위에서 0.2 이하로 다수의 종이 우점하는 것으로 나타났다.

• Journal of Ecology and Environment
• /
• v.41 no.9
• /
• pp.256-264
• /
• 2017

Background: The aim of this study was to clarify the relationship between the sexual reproduction and the resource allocation in a natural Polygonatum humile population grown in a temperate mixed forest gap. For this aim, the plant size, the node which flower was formed, the fruiting rate, and the dry weight of each organ were monitored from June 2014 to August 2015. Results: Firstly, in 3-13-leaf plants, plants with leaves ${\leq}8$ did not have flowers and in plants with over 9 leaves the flowering rate increased with the number of leaves. Among plants with the same number of leaves, the total leaf area and dry weight of flowering plants were larger than those of non-flowering plants. The minimum leaf area and dry weight of flowering plants were $100cm^2$ and 200 mg, respectively. Secondary, the flowers were formed at the 3rd~8th nodes, and the flowering rate was highest at the 5th node. Thirdly, cumulative values of leaf properties from the last leaf (the top leaf on a stem) to the same leaf rank were greater in a plant with a reproductive organ than in a plant without a reproductive organ. Fourthly, fruit set was 6.1% and faithful fruit was 2.6% of total flowers. Biomasses of new rhizomes produced per milligram dry weight of leaf were $0.397{\pm}190mg$ in plants that set fruit and $0.520{\pm}0.263mg$ in plants that did not, and the difference between the 2 plant groups was significant at the 0.1% level. Conclusions: P. humile showed that the 1st flower formed on the 3rd node from the shoot's base. And P. humile showed the minimum plant size needed in fruiting, and fruiting restricted the growth of new rhizomes. However, the fruiting rate was very low. Thus, it was thought that the low fruiting rate caused more energy to invest in the rhizomes, leading to a longer rhizome. A longer rhizome was thought to be more advantageous than a short one to avoid the shading.

• Journal of Korean Society of Forest Science
• /
• v.108 no.4
• /
• pp.639-644
• /
• 2019

The purpose of this study was to examine the moderating effect of green space satisfaction on the relationship between the perception of air pollution and life satisfaction. To achieve this, the current study employed data from the 2018 Social Survey, and a sample of 37,461 participants was analyzed using moderated multiple regression analysis. Results showed that while greater satisfaction with green spaces improved life satisfaction, a more negative perception of air pollution within the community reduced life satisfaction. It was also found that green space satisfaction moderated the relationship between the perception of air pollution and life satisfaction. In other words, greater satisfaction with green spaces buffered the effect of a negative perception of air pollution on life satisfaction. The results of this study suggest that a green environment should be considered an important resource for preventing reduced life satisfaction, and illustrate that there is a need for developing various strategies for the expansion and improvement of green spaces within communities.

• Weed & Turfgrass Science
• /
• v.5 no.1
• /
• pp.23-28
• /
• 2016

Zoysiagrass possessing the leaf yellowing with excessive tillers was first found in a golf course in Gyunggi province at last three to four years ago and since then have rapidly spread many golf courses in Korea. The symptom is very similar to that of yellow tuft or downy mildew, which is caused by Sclerophthora macrospora, on cool-season turfgrasses including Kentucky bluegrass and ryegrass. Microscopic study was firstly carried out to look over the presence of the pathogen in the infected leaf and stem tissues. Oospores and sporangia, reported as typical indicators of downy mildew, were obviously observed from the infected leaves. Using a set of primers based on the 18S ribosomal DNA from S. macrospora, the specific DNA fragment corresponding the gene was amplified. This study reveals that S. macrospora might be involved in spread of leaf yellowing of zoysiagrass with excessive tillers.

• Journal of Ecology and Environment
• /
• v.43 no.3
• /
• pp.320-331
• /
• 2019

Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

• Journal of Ecology and Environment
• /
• v.45 no.4
• /
• pp.255-263
• /
• 2021

Background: Ecosystem service mapping is an important tool for decision-making in landscape planning and natural resource management. Today, pollination service mapping is based on the Lonsdorf model (InVEST software) that determines the availability of nesting and floral resources for each land cover and estimates pollination according to the foraging range of the desired species. However, it is argued that the Lonsdorf model has significant limitations in estimating pollination in a landscape that can affect the results of this model. Results: This paper presents a free software, named PollMap, that does not have the limitations of the Lonsdorf model. PollMap estimates the pollination service according to a modified version of the Lonsdorf model and assumes that only cells within the flight range of bees are important in the pollination mapping. This software is produced for estimating and mapping crop pollination in agricultural landscapes. The main assumption of this software is that in the agricultural landscapes, which are dominated by forest and agriculture ecosystems, forest patches serve only as a nesting habitat for wild bees and the surrounding fields provide floral resources. Conclusion: The present study provided new software for mapping crop pollination in agricultural landscapes that does not have the limitations of the Lonsdorf model. We showed that the use of the Lonsdorf model for pollination mapping requires attention to the limitations of this model, and by removing these limitations, we will need new software to obtain a reliable mapping of pollination in agricultural landscapes.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.6
• /
• pp.843-852
• /
• 2022

Despite continuous safety management, the death rate of construction workers is not decreasing every year. Accordingly, various studies are in progress to prevent construction site accidents. In this paper, we developed an AI-based priority inspection target selection model that preferentially selects sites are expected to cause construction accidents among construction sites with construction costs of less than 5 billion won (KRW). In particular, Random Forest (90.48 % of accident prediction AUC-ROC) showed the best performance among applied AI algorithms (Classification analysis). The main factors causing construction accidents were construction costs, total number of construction days and the number of construction performance evaluations. In this study an ROI (return of investment) of about 917.7 % can be predicted over 8 years as a result of better efficiency of manual inspections human resource and a preemptive response to construction accidents.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.11
• /
• pp.123-130
• /
• 2022

Recently, studies on the detection and classification of Android malware based on API Call sequence have been actively carried out. However, API Call sequence based malware classification has serious limitations such as excessive time and resource consumption in terms of malware analysis and learning model construction due to the vast amount of data and high-dimensional characteristic of features. In this study, we analyzed various classification models such as LightGBM, Random Forest, and k-Nearest Neighbors after significantly reducing the dimension of features using PCA(Principal Component Analysis) for CICAndMal2020 dataset containing vast API Call information. The experimental result shows that PCA significantly reduces the dimension of features while maintaining the characteristics of the original data and achieves efficient malware classification performance. Both binary classification and multi-class classification achieve higher levels of accuracy than previous studies, even if the data characteristics were reduced to less than 1% of the total size.