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Fabrication of Strain Sensor Based on Graphene/Polyurethane Nanoweb and Respiration Measurement (그래핀/폴리우레탄 나노웹 기반의 스트레인센서 제작 및 호흡측정)

  • Lee, Hyocheol;Cho, Hyeon-seon;Lee, Eugene;Jang, Eunji;Cho, Gilsoo
    • Science of Emotion and Sensibility
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    • v.22 no.1
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    • pp.15-22
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    • 2019
  • The purpose of this study is to develop a strain sensor based on a nanoweb by applying electrical conductivity to a polyurethane nanoweb through the use of Graphene. For this purpose, 1% Graphene ink was pour-coated on a polyurethane nanoweb and post-treated with PDMS (Polydimethylsiloxane) to complete a wearable strain sensor. The surface characteristics of the specimens were evaluated using a field emission scanning electron microscope (FE-SEM) to check whether the conductive material was well coated on the surface of the specimen. Electrical properties of the specimens were measured by using a multimeter to measure the linear resistance of the specimen and comparing how the line resistance changes when 5% and 10% of the specimens are tensioned, respectively. In order to evaluate the performance of the specimen, the gauge factor was obtained. The evaluation of the clothing was performed by attaching the completed strain sensor to the dummy and measuring the respiration signal according to the tension using MP150 (Biopac system Inc., USA) and Acqknowledge (ver. 4.2, Biopac system Inc., U.S.A.). As a result of the evaluation of the surface characteristics, it was confirmed that all the conductive nanoweb specimen were uniformly coated with the Graphen ink. As a result of measuring the resistance value according to the tensile strength, the specimen G, which was treated with just graphene had the lowest resistance value, the specimen G-H had the highest resistance value, and the change of the line resistance value of the specimen G and the specimen G-H is increased to 5% It is found that it increases steadily. Unlike the resistance value results, specimen G showed a higher gauge rate than specimen G-H. As a result of evaluation of the actual clothes, the strain sensor made using the specimen G-H measured the stable peak value and obtained a signal of good quality. Therefore, we confirmed that the polyurethane nanoweb treated with Graphene ink plays a role as a breathing sensor.

Distributional Characteristics and Evaluation of the Population Sustainability, Factors Related to Vulnerability for a Polygonatum stenophyllum Maxim. (층층둥굴레(Polygonatum stenophyllum Maxim.)의 분포특성과 개체군의 위협요인 및 지속가능성 평가)

  • Kim, Young-Chul;Chae, Hyun-Hee;Ahn, Won-Gyeong;Lee, Kyu-Song;Nam, Gi-Heum;Kwak, Myoung-Hai
    • Korean Journal of Environment and Ecology
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    • v.33 no.3
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    • pp.303-320
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    • 2019
  • Plants interact with various biotic and abiotic environmental factors. It requires much information to understand the traits of a plant species. A shortage of information would restrict the assessment, especially in the evaluation of what kind of factors influence a plant species to face extinction. Polygonatum stenophyllum Maxim. is one of the northern plants of which Korea is the southern distribution edge. The Korean Ministry of Environment had designated it to be the endangered species until December 2015. Although it is comparatively widespread, and a large population has recently been reported, it is assessed to be vulnerable due to the low population genetic diversity. This study evaluated the current distribution of Polygonatum stenophyllum Maxim. We investigated the vegetational environment, population structures, phenology, soil environment, and self-incompatibility based on the results. Lastly, we evaluated the current threats observed in the habitats. The habitats tended to be located in the areas where the masses at the edge of the stream accumulated except for those that were located on slopes of some mountainous areas. Most of them showed a stable population structure and had re-established or recruited seedlings. Polygonatum stenophyllum Maxim. had the difference in time when the shoots appeared above the ground depending on the depth of the rhizome located in the underground. In particular, the seedlings and juveniles had their rhizome located shallow in the soil. Visits by pollinator insects and success in pollination were crucial factors for bearing of fruits by Polygonatum stenophyllum Maxim. The threats observed in the habitat of Polygonatum stenophyllum Maxim. included the expansion of cultivated land, construction of new buildings, and construction of river banks and roads. Despite such observed risk factors, it is not likely that there would be rapid population reduction or extinction because of its widespread distribution with the total population of more than 2.7 million individuals and the new populations established by the re-colonization.

The Nitrogen Behavior in the Continuous Inflow SBR according to Variations of Internal Recycling Rate (반송률 변화에 따른 연속 유입식 SBR 공정의 질소 거동)

  • Kim, Su-Yeon;Choi, Yong-Bum;Jo, You-Na;Han, Dong-Joon;Kwon, Jae-Hyouk
    • Clean Technology
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    • v.25 no.3
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    • pp.231-237
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    • 2019
  • The BOD removal efficiency according to HRT of the continuous inflow SBR process was decreased from 92.1 ~ 96.0% at HRT 9 ~ 15 h to 86.9 ~ 90.7% at HRT 6 h, but a stable removal efficiency was shown up to HRT 6 h. The T-N removal rate was decreased to 80.1 ~ 87.9% at HRT 12 ~ 15 h, to 71.9 ~ 87.0% at HRT 9 h, and to 60.1 ~ 65.7% at HRT 6 h. As a result of the test of removing organic matter and nitrogen, the optimum HRT of the continuous inflow SBR reactor is determined as 9 h. The TCODcr removal efficiency was 88.4 ~ 96.0% and the TBOD removal efficiency was 92.1 ~ 98.1% as a result of examination of organic matter removal efficiency according to a change in the recycling rate (1 ~ 5Q) at HRT 9 h, suggesting that the a change in the recycling rate has a minimal effect on the removal of organic matter. The T-N removal efficiency was 70.3 ~ 80.4% at 1 ~ 2Q, 77.2 ~ 85.6% at 3Q and 61.5 ~ 80.8% at 4 ~ 5Q according to a change in the recycling rate. The TP removal efficiency was reduced to 75.0 ~ 84.6% at 1 ~ 4Q and to 63.3 ~ 72.4% at 5Q. This is presumably because the release and ingestion of phosphorus (P) by microorganisms is not performed smoothly at 5Q or more. Therefore, the optimum recycling rate for removing organic matter and nutrients was found to be 3Q.

A Study on the Sustainable Ewha Mural Village in a Viewpoint of Urban Regeneration (도시재생 관점에서 지속가능한 이화동 벽화마을에 관한 연구)

  • Kim, bo-mi;Son, Yong-Hoon;Lee, Dong-Kun;Lee, Hyun-Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.3
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    • pp.1-11
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    • 2019
  • The purpose of this study is to propose a sustainable village-unit urban regeneration plan for the Ewha Mural Village, where mural artists recovered concrete fences to be followed by some residents damaging the mural paintings. Through a review of the existing literature and a preliminary survey, we derived the urban regeneration factors (environmental sustainability, economic sustainability, and social sustainability) applicable at the village level. After an empirical survey on the residents, we tried to identify various problems of the Ewha Mural Village. Residents selected the factors of accessibility, parking management, diversity of industries, creation of new jobs, community participation of residents for the mural village's activation, and stable living spaces. In the case of Ewha Mural Village, physical environment factors for the residents at the time of construction were not considered and the village was mainly planned using budget-based murals. Since then, the inequality of economic benefits intensified the conflicts among the residents. In addition, public benefits, such as establishing new industries and employing outsiders, were not provided, and these facts appear to have led to an unsustainable murals village, in which the murals that are the protagonists of the village revitalization are being destroyed. Therefore, the urban regeneration of Ewha Mural Village should be designed considering a region where some residential areas can be transformed into tourist areas. In addition, it is essential to employ a win-win method to improve the living environment, such as road maintenance, not only partial economic benefits, such as increased land-value, and to increase resident's value as a common asset within the village itself.

A Comparative Study on the Transition of Purlin Coupling Method of Korean and Chinese Ancient Wooden Constructions (한중 목조건축 도리 결합방식 변천(變遷)에 관한 비교연구)

  • Cha, Ju-hwan
    • Korean Journal of Heritage: History & Science
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    • v.47 no.4
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    • pp.22-47
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    • 2014
  • This study was to understand the basic principles of the East Asian wooden structure system research and analysis. The Korea and China ancient architecture internal structure research that the combination of girders and crossbeams position. The ancient wooden structures of eastern Asian countries, Korea and China are not much different from each other in the principles of the wooden architecture structure, combining pillars, purlins and crossbeams. However, it seems that age-division, local-division, national-division differs in detail techniques. China ancient wooden structures combination of purlin and crossbeam, and So-seul Timber(Chinese name: Chashou叉手, Tuojiao 托脚) seems to show differences according to the age of the fulcrum position, detailed approach is also different according to various historical dynasty. Before in the 15th century, Purlin and Crossbeam are coupled to each other, but since the 15th century, seems to have developed a technique combined with each other Girder and Crossbeam and to prevent buckling of the Crossbeam cross-sectional area increased dramatically. For Tuojiao in China Tang-Wudai dynasty(A.D. 618~979), can see that saw the top position Girder and Tuojiao no direct coupling, can be seen as maintaining the safety of the material than the material of the inner wooden structures prevent buckling of the purlin. Korea ancient wooden structures of Goryeo dynasty(A.D. 918~1391), So-seul Timber(Chinese name Tuojiao) why do not to use the fashion? To use Purlin Lower backing material techniques to prevent buckling is a popular trend to stable can be thought of as a preferred way to maintain. I think that with universality beyond the local-division, national-division and the two countries since the 15th century of Korea and China ancient wooden structures detailed mechanism for the purlin buckling. In middle-late Chosen dynasty, The effect of Deotgeolyi- techniques and fleeting beams reduce the purlin buckling that reduces the load transmitted from purlin and crossbeam of how to reduce the load on the roof portion of the architecture fleeting beams used, which of craftsmanship of the Chosen Dynasty building can be referred to as another technique for preventing buckling purlin. This Korea and China ancient architecture purlin beam structure and material So-seul Timber study. Seems to be able to provide a basic research study to restore and designed the old wooden architectures.

Comparison of Characteristics of Electrodeposited Lithium Electrodes Under Various Electroplating Conditions (다양한 전착조건에서 제작된 리튬 전극의 특성 연구)

  • Lim, Rana;Lee, Minhee;Kim, Jeom-Soo
    • Journal of the Korean Electrochemical Society
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    • v.22 no.3
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    • pp.128-137
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    • 2019
  • A lithium is the lightest metal on the earth. It has some attractive characteristics as a negative electrode material such as a low reduction potential (-3.04 V vs. SHE) and a high theoretical capacity ($3,860mAh\;g^{-1}$). Therefore, it has been studied as a next generation anode material for high energy lithium batteries. The thin lithium electrode is required to maximize the efficiency and energy density of the battery, but the physical roll-press method has a limitation in manufacturing thin lithium. In this study, thin lithium electrode was fabricated by electrodeposition under various conditions such as compositions of electrolytes and the current density. Deposited lithium showed strong relationship between process condition and its characteristics. The concentration of electrolyte affects to the shape of deposited lithium particle. As the concentration increases, the shape of particle changes from a sharp edged long one to a rounded lump. The former shape is favorable for suppressing dendrite formation and the elec-trode shows good stripping efficiency of 92.68% (3M LiFSI in DME, $0.4mA\;cm^{-2}$). The shape of deposited particle also affected by the applied current density. When the amount of current applied gets larger the shape changes to the sharp edged long one like the case of the low concentration electrolyte. The combination of salts and solvents, 1.5M LiFSI + 1.5M LiTFSI in DME : DOL [1 : 1 vol%] (Du-Co), was applied to the electrolyte for the lithium deposition. The lithium electrode obtained from this electrolyte composition shows the best stripping efficiency (97.26%) and the stable reversibility. This is presumed to be due to the stability of the surface film induced by the Li-F component and the DOL effect of providing film flexibility.

Conservation Scientific Diagnosis and Evaluation of Bird Track Sites from the Haman Formation at Yongsanri in Haman, Korea (함안 용산리 함안층 새발자국 화석산지의 보존과학적 진단 및 평가)

  • Lee, Gyu Hye;Park, Jun Hyoung;Lee, Chan Hee
    • Korean Journal of Heritage: History & Science
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    • v.52 no.3
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    • pp.74-93
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    • 2019
  • The Bird Track Site in the Haman Formation in Yongsanri (Natural Monument No. 222) was reported on the named Koreanaornis hamanensis and Jindongornipes kimi sauropod footprint Brontopodus and ichnospecies Ochlichnus formed by Nematoda. This site has outstanding academic value because it is where the second-highest number of bird tracks have been reported in the world. However, only 25% of the site remains after being designated a natural monument in 1969. This is due to artificial damage caused by worldwide fame and quarrying for flat stone used in Korean floor heating systems. The Haman Formation, including this fossil site, has lithofacies showing reddish-grey siltstone and black shale, alternately. The boundary of the two rocks is progressive, and sedimentary structures like ripple marks and sun cracks can clearly be found. This site was divided into seven formations according to sedimentary sequences and structures. The results of a nondestructive deterioration evaluation showed that chemical and biological damage rates were very low for all formations. Also, physical damage displayed low rates with 0.49% on exfoliation, 0.04% on blistering, 0.28% on break-out; however, the joint crack index was high, 6.20. Additionally, efflorescence was observed on outcrops at the backside and the northwestern side. Physical properties measured by an indirect ultrasonic analysis were found to be moderately weathered (MW). Above all, the southeastern side was much fresher, though some areas around the column of protection facility appeared more weathered. Furthermore, five kinds of discontinuity surface can be found at this site, with the bedding plane showing the higher share. There is the possibility of toppling failure occurring at this site but stable on plane and wedge failure by means of stereographic projection. We concluded that the overall level of deterioration and stability were relatively fine. However, continuous monitoring and conservation treatment and management should be performed as situations such as the physicochemical weathering of the fossil layer, and the efflorescence of the mortar adjoining the protection facility's column appear to be challenging to control.

The Effects of Experimental Warming on Seed Germination and Growth of Two Oak Species (Quercus mongolica and Q. serrata) (온난화 처리가 신갈나무(Quercus mongolica)와 졸참나무(Q. serrate)의 종자발아와 생장에 미치는 영향)

  • Park, Sung-ae;Kim, Taekyu;Shim, Kyuyoung;Kong, Hak-Yang;Yang, Byeong-Gug;Suh, Sanguk;Lee, Chang Seok
    • Korean Journal of Ecology and Environment
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    • v.52 no.3
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    • pp.210-220
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    • 2019
  • Population growth and the increase of energy consumption due to civilization caused global warming. Temperature on the Earth rose about $0.7^{\circ}C$ for the last 100 years, the rate is accelerated since 2000. Temperature is a factor, which determines physiological action, growth and development, survival, etc. of the plant together with light intensity and precipitation. Therefore, it is expected that global warming would affect broadly geographic distribution of the plant as well as structure and function ecosystem. In order to understand the effect of global warming on the ecosystem, a study about the effect of temperature rise on germination and growth in the plant is required necessarily. This study was carried out to investigate the effects of experimental warming on the germination and growth of two oak species(Quercus mongolica and Q. serrata) in temperature gradient chamber(TGC). This study was conducted in control, medium warming treatment($+1.7^{\circ}C$; Tm), and high warming treatment ($+3.2^{\circ}C$; Th) conditions. The final germination percentage, mean germination time and germination rate of two oak species increased by the warming treatment, and the increase in Q. serrata was higher than that in Q. mongolica. Root collar diameter, seedling height, leaf dry weight, stem dry weight, root dry weight, and total biomass were the highest in Tm treatment. Butthey were not significantly different in the Th treatment. In the Th treatment, Q. serrata had significantly higher H/D ratio, S/R ratio, and low root mass ratio (RMR) compared with control plot. Q. mongolica had lower RMR and higher S/R ratio in the Tm and Th treatments compared with control plot. Therefore, growth of Q. mongolica are expected to be more vulnerable to warming than that of Q. serrata. The main findings of this study, species-specific responses to experimental warming, could be applied to predict ecosystem changes from global warming. From the result of this study, we could deduce that temperature rise would increase germination of Q. serrata and Q. mongolica and consequently contribute to increase establishment rate in the early growth stage of the plants. But we have to consider diverse variables to understand properly the effects that global warming influences germination in natural condition. Treatment of global warming in the medium level increased the growth and the biomass of both Q. serrata and Q. mongolica. But the result of treatment in the high level showed different aspects. In particular, Q. mongolica, which grows in cooler zones of higher elevation on mountains or northward in latitude, responded more sensitively. Synthesized the results mentioned above, continuous global warming would function in stable establishment of both plants unfavorably. Compared the responses of both sample plants on temperature rise, Q. serrata increased germination rate more than Q. mongolica and Q. mongolica responded more sensitively than Q. serrata in biomass allocation with the increase of temperature. It was estimated that these results would due to a difference of microclimate originated from the spatial distribution of both plants.

A Case Study on Improvement of Records Management Reference Table by Reorganizing BRM : The case of Reorganization of Seoul's BRM and Records Management Reference Table (BRM 정비를 통한 기록관리기준표 개선사례 서울시 BRM 및 기록관리기준표 정비사례를 중심으로)

  • Lee, Se-Jin;Kim, Hwa-Kyoung
    • The Korean Journal of Archival Studies
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    • no.50
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    • pp.273-309
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    • 2016
  • Unlike other government agencies, the city of Seoul experienced a three-year gap between the establishment of a function classification system and the introduction of a business management system. As a result, the city has been unable to manage the current status of the function classification system, and this impeded the establishment of standards for records management. In September 2012, the Seoul Metropolitan Government integrated the department in charge of the standard sheet for record management with the department of function classification system into a new department: "Information Disclosure Policy Division." This new department is mainly responsible for record management and information disclosure, and taking this as an opportunity, the city government has pushed ahead with the maintenance project on BRM and Standards for Record Management (hereby "BRM maintenance project") over the past two years, from 2013 to 2014. The study was thus conducted to introduce the case for the improvement of standards for record management through the BRM maintenance project by mainly exploring the case of Seoul. During the BRM maintenance project, Seoul established a unique methodology to minimize the gap between the operation of a business management system and the burden of the person in charge of the BRM maintenance project. Furthermore, after the introduction of the business management system, the city government developed its own processes and applied the maintenance result to the system in close cooperation with the related departments, despite the lack of precedence on the maintenance of the classification system. In addition, training for the BRM managers of the department has taken place twice -before and after the maintenance-for the successful performance of the BRM maintenance project and the stable operation of the project in the future. During the period of maintenance, newsletters were distributed to all employees in an effort to induce their active participation and increase the importance of records management. To keep the performance of the maintenance project and to systematically manage BRM in the future, the city government has mapped out several plans for improvement: to apply the "BRM classification system of each purpose" to the service of the "Seoul Open Data Plaza"; to reinforce the function for task management in the business management system; and to develop the function of a records management system for the unit tasks. As such, the researchers hope that this study would serve as a helpful reference so that the organizations-which had planned to introduce BRM or to perform the maintenance project on classification system-experience fewer trials and errors.

Incidence of Viral Diseases on Solanaceae Crops in Gangwon Province (강원지역 가지과 작물 바이러스 발생현황)

  • Won, Heon-Seop;Park, Dong-Kwon;Kwon, Soon-Bae;Jo, Sun-Ok;Kang, Sung-Hee;Lee, Jae-Hong;Hwang, Se-Jeong;Jeong, Tae-Sung;Kim, Mi-Kyeong;Choi, Hong-Soo;Hong, Dae-Ki
    • Research in Plant Disease
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    • v.25 no.1
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    • pp.22-28
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    • 2019
  • This study researched the current occurrence status of viral diseases of solanaceous crops in the main production areas of Gangwon region, for four years from 2014 to 2018. From 2014 to 2018, in eight cities and counties including Chuncheon, CMV, BBWV2, PMMoV, TSWV, and PVY occurred in chilli peppers. In case of tomato, the research was performed in 2017 and 2018 while TSWV and TYLCV were verified in Chuncheon, Hoengseong, and Cheorwon. Especially, TYLCV occurred in Chuncheon region for the first time in 2017, which was verified in 2018. Lastly, the current occurrence status of viral diseases of bell peppers was researched in seven cities and counties like Gangneung, Hoengseong, and Cheorwon from 2015 to 2018. In the results, CMV, BBWV2, PMMoV, PepMoV, and TSWV were verified in bell peppers of Gangwon region. During the research period, there were no crops suspected or infected by BWYV, so that it is judged that there is no villiferous or infected aphid by this virus in Gangwon-do. Such results of this study could be used as the basic data for the stable production of crops through the early prevention of plant diseases occurring in the solanaceous crops of Gangwon region.