The Impact of the Morphological Characteristics of Leaves on Particulate Matter Removal Efficiency of Plants

Deokjoo Son,Kwang Jin Kim,Na Ra Jeong,Hyung Gewon Yun,Seung Won Han,Jeongho Kim,Gyung-Ran Do,Seon Hwa Lee,Charlotte C,Shagol 인간식물환경학회 2019 인간식물환경학회지 Vol.22 No.6

This study was conducted to find out differences in the removal efficiency of particulate matter (PM) depending on the type of plants and the morphological characteristics of leaves. A total of 12 plants were used, with three plants selected for each type of leaves (big leaf, small leaf, compound leaf, needle leaf). We measured the removed amount of PM10 and PM2.5, the structure of the abaxial leaf surface, and the weight of the wax layer of each plant. Plants with the high removal efficiency of PM included Pachira aquatica Aubl., Ardisia crenata, and Dieffenbachia Marianne , and plants with the low removal efficiency included Nandina domestica Thunb, Schefflera arboricola, and Quercus dentata. The abaxial leaf surface having a high removal efficiency of PM had many large wrinkles, and the abaxial leaf surface having a medium removal efficiency was flat and smooth. On the other hand, there were many fine hairs on the abaxial leaf surface with a low removal efficiency. According to the plant leaf type, the PM10 removal efficiency of plants with needle leaves was about three times higher than that of other plants. In particular, the wax layer of conifers weighed 6-24 times higher than those of other plants. The stomata of conifers were evenly distributed on the adaxial and abaxial leaf surfaces; however, the stomata of Sciadopitys verticillata appeared in the form of papillae unlike general stomata. Therefore, the removal efficiency of PM varied depending on the macro-, and micro-morphological characteristics of plant leaves such as the structure of the abaxial leaf surface, and the weight of the wax layer. Based on this research, selecting plants that are effective in reducing PM in consideration of the plant type and leaf characteristics will improve indoor air quality and decrease exposure of PM to human body.

Soil Microbial Communities Associated with Three Arctic Plants in Different Local Environments in Ny-Alesund, Svalbard

( Deokjoo Son ),( Eun Ju Lee ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.10

Understanding soil microbial community structure in the Arctic is essential for predicting the impact of climate change on interactions between organisms living in polar environments. The hypothesis of the present study was that soil microbial communities and soil chemical characteristics would vary depending on their associated plant species and local environments in Arctic mature soils. We analyzed soil bacterial communities and soil chemical characteristics from soil without vegetation (bare soil) and rhizosphere soil of three Arctic plants (Cassiope tetragona [L.] D. Don, Dryas octopetala L. and Silene acaulis [L.] Jacq.) in different local environments (coal-mined site and seashore-adjacent site). We did not observe any clear differences in microbial community structure in samples belonging to different plant rhizospheres; however, samples from different environmental sites had distinct microbial community structure. The samples from coal-mined site had a relatively higher abundance of Bacteroidetes and Firmicutes. On the other hand, Acidobacteria was more prevalent in seashore-adjacent samples. The relative abundance of Proteobacteria and Acidobacteria decreased toward higher soil pH, whereas that of Bacteroidetes and Firmicutes was positively correlated with soil pH. Our results suggest that soil bacterial community dissimilarity can be driven by spatial heterogeneity in deglaciated mature soil. Furthermore, these results indicate that soil microbial composition and relative abundance are more affected by soil pH, an abiotic factor, than plant species, a biotic factor.

Optimal two-part tariffs of inputs

Deokjoo Lee,Hyungsik Oh 대한산업공학회 1994 대한산업공학회 춘계학술대회논문집 Vol.1994 No.4

진화게임이론을 이용한 적응적 전력제어 알고리즘

김덕주(DeokJoo Kim),김승욱(Sungwook Kim) 한국정보과학회 2010 정보과학회논문지 : 정보통신 Vol.37 No.3

최근 데이터 서비스에 대한 수요가 폭발적으로 증가하는데 반해, 사용가능한 자원은 한정되어 있기 때문에 효율적인 자원 관리가 네트워크 성능을 증가시키기 위한 중요한 요소가 되고 있다. 특히 무선 네트워크에 있어서 제한된 자원의 효율적 활용을 통해 더 많은 수요를 수용함으로써 소비자의 만족도를 증대시킬 수 있다. 본 논문에서는 진화게임을 이용한 적응적 전력제어를 통한 효율적인 자원 할당 기법을 제안한다. 제안된 기법은 네트워크의 채널 상황에 따라 적응적 분산방식으로 전송전력 수준을 조정하여 현재 네트워크 상황에 유연하게 대응함으로서 효율적인 네트워크 관리를 수행한다. 컴퓨터 시뮬레이션을 통하여 기존에 제안된 전력제어 기법에 비해 본 논문에서 제안한 방법이 다양한 네트워크 환경 하에서 우수한 성능을 가지는 것을 확인하였다. During wireless network operations, adaptive power control is an effective way to enhance the network performance. In this paper, a new online power control scheme is proposed based on the evolutionary game theory. To converge a desirable network equilibrium, the proposed scheme adaptively adjusts a transmit power level in a distributed online manner. With a simulation study, we demonstrate that the proposed scheme improves network performance under widely diverse network environments.

Successional changes in plant composition over 15 years in a created wetland in South Korea

Son, Deokjoo,Lee, Hyohyemi,Cho, Kang-Hyun,Bang, Jeong Hwan,Kwon, Oh-Byung,Lee, Eun Ju The Ecological Society of Korea 2018 Journal of Ecology and Environment Vol.42 No.4

Backgrounds: The main purpose of this research was to assess changes in vegetation structure, wetland index, and diversity index for a 15-year-old created wetland in Jincheon, South Korea. The created wetland consists of four sub-wetlands: a kidney-shaped wetland, a ditch, an ecological pond, and a square wetland. Vegetation and water depth data were collected at each site in 1999 and 2013, and Shannon diversity and wetland indices were calculated. Results: The total number of plant species increased from 18 in 1999 to 50 in 2013, and the ecological pond in 1999 and the ditch in 2013 presented the highest diversity indices (2.5 and 3.2, respectively). Plant species were less diverse in 1999 than in 2013, presumably because these initial wetlands were managed periodically for water purification and installation of test beds. The proportion of wetland plants, including obligate wetland and facultative wetland species, decreased from 83 to 56%, whereas upland plants, including obligate upland and facultative upland species, increased from 17 to 44%. After ceasing water supply, water depth in all four sub-wetlands declined in 2013. Thus, upland plants established more readily at these sites, resulting in higher diversity and lower wetland indices than in 1999. Conclusions: The major floristic differences between 1999 and 2013 were an increase in the number of upland plants and a decrease in wetland species. Although wetland indices were lower in 2013, the created wetland performed important ecosystem functions by providing habitats for wetland and upland plants, and the overall species diversity was high.

무선네트워크에서 공평성을 고려한 전력제어 알고리즘

김덕주(DeokJoo Kim),김승욱(Sungwook Kim) 한국통신학회 2010 韓國通信學會論文誌 Vol.35 No.3

B-ISDN 응용서비스의 개발 및 분류

이덕주,오형식 한국경영과학회 1994 經營 科學 Vol.11 No.1

B-ISDN(Broadband Integrated Services Digital Network)which is defined as a service or system requiring transmission channels capable of supporting rates above 1.5 Mbps has emerged as a new future telecommunication infrastructure. B-ISDN can integrate a wide range of services and the success of B-ISDN is crucially dependent on the development of user-needing application services. The purpose of this study is the conceptual development of B-ISDN application services. We survey on the kind of B-ISDN service, classify application areas by user groups, and develop B-ISDN application services. Finally we categorize B-ISDN application services by their application areas and necessary services.

Multivariate Relationships between Snowmelt and Plant Distributions in the High Arctic Tundra

Park, Jeong Soo,Son, Deokjoo,Lee, Yoo Kyung,Yun, Jong Hak,Lee, Eun Ju Botanical Society of Korea 2018 Journal of plant biology Vol.61 No.1

We investigated multivariate relationships among snowmelt, soil physicochemical properties and the distribution patterns of Arctic tundra vegetation. Seven dominant species were placed in three groups (Veg-1, 2, 3) based on niche overlap (Pianka's Index) and ordination method, and a partial least squares path model was applied to estimate complex multivariate relationships of four latent variables on the abundance and richness of plant species. The abundance of Veg-1 (Luzula confusa and Salix polaris) was positively correlated with early snowmelt time, high soil nutrients and dense moss cover, but the abundance of Veg-2 (Saxifraga oppositifolia, Bistorta vivipara and Silene acaulis) was negatively correlated with these three variables. Plant richness was positively associated with early snowmelt and hydrological properties. Our results indicate that the duration of the snowpack can directly influence soil chemical properties and plant distribution. Furthermore, plant species richness was significantly affected by snow melt time in addition to soil moisture and moss cover. We predict that L. confusa and S. polaris may increase in abundance in response to early snowmelt and increased soil moisture-nutrient availability, which may be facilitated by climate change. Other forb species in dry and infertile soil may decrease in abundance in response to climate change, due to increasingly unfavourable environmental conditions and competition with mosses.

Mowing: A cause of invasion, but also a potential solution for management of the invasive, alien plant species <i>Erigeron annuus</i> (L.) Pers

Song, Uhram,Son, Deokjoo,Kang, Changku,Lee, Eun Ju,Lee, Kyoo,Park, Jeong Soo Elsevier 2018 Journal of environmental management Vol.223 No.-

<P><B>Abstract</B></P> <P> <I>Erigeron annuus</I> is one of the major invasive, alien plants in Korea, and therefore research to manage (control) this invasive plant is essential. In this research, studies were conducted to determine the mechanisms by which <I>E. annuus</I> became the dominant plant at a landfill site and to develop management strategies for this alien plant. Because the seeds and seedling stage did not have superior adaptations to disturbed soil, demonstrate allelopathy, outcompete other species, or show rapid growth, the disturbance from mowing was likely the primary reason for the dominance of <I>E. annuus</I>. The areas without mowing showed a significant decrease in the coverage of <I>E. annuus</I>, whereas the mowed (managed) areas showed a significant increase. Additionally, mowing once increased the weight of reproductive organs by 50% and suppressed the growth of native species. Thus, the primary factor in the invasion of the alien species <I>E. annuus</I> was mowing, and, to control such an invasion, areas should be protected from mowing. Additionally, with selective mowing that targeted only <I>E. annuus</I>, mowing three times produced only approximately 10% of the reproductive organ biomass compared with that of the control. Because the flower stalk of <I>E. annuus</I> was relatively tall compared with that of native species in early summer, selective mowing might also provide a solution to control invasions of <I>E. annuus</I>. Therefore, with improved ecological understanding of the site and species, mowing of the right target during the optimal season and at an appropriate frequency is an environmental friendly solution to the management of <I>E. annuus</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We examined responsible factor for the Erigeron annuus invasion in managed reclaimed areas. </LI> <LI> Mowing was a responsible factor for <I>Erigeron annuus</I> invasion. </LI> <LI> Changing mowing season and mowing frequency suppressed invasion. </LI> <LI> Appropriate mowing could be a potential solution for controlling <I>Erigeron annuus</I> invasion. </LI> </UL> </P>

TFP를 이용한 목적기초연구투자의 경제적 효과 분석

Ko, MinSoo,Lee, DeokJoo 대한산업공학회 2008 대한산업공학회 추계학술대회논문집 Vol.2008 No.11

최근 10년간 기초연구에 대한 관심이 범세계적으로 높아지고 있는 추세에 있으며, 이는 기초연구가 고급 기술인력 양성을 통한 원천지식 및 기술확보의 중요한 수단으로 인식되고 있음에 기인한다. 한국의 경우 전체 기초연구투자가 80년대 중반 이후 꾸준히 증가하여 왔으나 기업의 기초연구 투자가 정부의 기초연구투자에 비해 낮은 수준에 머물러 있는 실정이다. 이는 기초연구의 산출물에 대한 기업의 사적 전유가 힘들고 높은 불확실성을 내포하고 있기 때문이다. 이러한 이유로 인해, 기초연구에 대한 투자가 사회적으로 바람직한 수준보다 낮은 투자가 이루어질 가능성이 높으며,따라서 정부가 기초연구에 투자를 늘림으로써 자원배분의 비효율성을 보완하고 나아가 기초연구에서 발생한 지식파급효과 또는 전이효과를 통해 기업의 연구개발 활동을 자극할 필요성이 존재하게 된다. 이와 같은 필요성에 의해서 정부나 또는 민간부문에서 기초연구에 대한 투자를 결정하고자 할 때 사전적으로 기초연구 투자의 경제적 효과에 대한 적절한 분석이 요구된다. 또한, 올바른 의사결정을 유도하기 위해서는 기초연구의 특성이 적절히 반영된 경제적 효과 측정 모형을 이용한 분석이 이루어져야 한다. 본 연구의 목적은 기초연구과정의 대표적인 특성인 투자에서부터 성과 달성까지의 시간지연(time-lag) 영향을 고려하여 기초연구 투자의 경제적 효과를 실증적으로 분석해보고자 하는 것이다. 이를 위하여 목적기초연구투자의 성과요소를 정의하고, 각 요소를 대표하는 실증변수를 설정한 후 총 요소생산성(TFP)모형을 이용하여 목적기초연구투자의 성과가 일정한 시간지연 후에 각 산업에 미치는 경제적 효과가 어느 정도인지에 대한 실증분석을 실시하였다. 분석결과 목적기초 연구투자의 경제적 효과는 산업별로 차이가 있으나 투자 후 10년째에 가장 큰 경제적 효과를 나타내는 것으로 분석되었다.