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A Study on the Reinforcement Effect Analysis of Aging Reservoir using Grout Material recycled Power Plant Byproduct (발전부산물을 재활용한 그라우트재의 노후 저수지 보강효과 분석에 관한 연구)

  • Seo, Se-Gwan;An, Jong-Hwan;Cho, Dae-sung
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.2
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    • pp.23-33
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    • 2021
  • In Korea, many reservoirs have been built for the purpose of solving the food shortage problem and supplying agricultural water. However, the current 75.6% of the reservoirs are in serious aged as more than 50 years have passed since the year of construction. In the case of such an aging reservoir, the stability due to scour and erosion inside the reservoir is very reduced, and if concentrated rainfall due to recent abnormal weather occurs, the aging reservoir may collapse, leading to a lot of damage to property and human life. Accordingly, each agency that manages aging reservoirs uses Ordinary Portland Cement (OPC) as an injection material and applies the grouting method. However, in the case of OPC, it may deteriorate over time and water leakage may occur again. And there are environmental problems such as consumption of natural resources and generation of greenhouse gases. So, there is a need to develop new materials and methods that can replace the OPC. In this study, an laboratory test and analysis were performed on the grout material developed to induce a curing reaction similar to that of OPC by recycling power plant byproduct. In addition, test in the field such as electric resistivity survey, Standard Penetration Test (SPT), and field permeability test were performed to analyzed to reinforcement effect and determine the possibility of using instead of OPC. As a results of the test, in the case of recycled power plant byproduct, the compressive strength was 2.9 to 3.2 times and the deformation modulus was 2.3 to 3.3 times higher, indicating that it is excellent in strength and can be used instead of OPC. And it was analyzed that the N value of the reservoir was increased by 1~2, and the coefficient of permeability (k) decreased to the level of 8.9~42.5%. showing sufficient reinforcing effect in terms of order.

Effects of 12 weeks of home-based exercise program in patients with ankylosing spondylitis (강직성 척추염 환자에 대한 12주간의 가정기반 운동 프로그램의 효과)

  • Cho, Kyoung-Hwan;Jeon, Yunah
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.3
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    • pp.771-785
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    • 2021
  • This study was performed to provide detailed and comprehensive information on inflammation-related blood indicators, joint range of motion, pain scale, and psychological indicators by patient characteristics by performing a 12-week home-based exercise program for ankylosing spondylitis patients. For the purpose of this study, 10 patients with ankylosing spondylitis were selected by age (30s vs. 40s vs. 50s), gender (male vs. female), and duration (less than 5 years vs. 5 years or more). The home-based exercise program was a combination of aerobic exercise and Pilates-based resistance exercise, and was performed 4 times a week for 12 weeks at an intensity of 50-70% of maximal heart rate (MHR). As a result, after 12 weeks of home-based exercise intervention, the blood C-reactive protein (CRP) concentration of patients with ankylosing spondylitis decreased (-35.6%, p=.002), and the blood inflammation level was improved, and each joint (hip, lumbar, cervical) improved mobility (p<.05). In addition, the bath ankylosing spondylitis disease activity index (BASDAI) was decreased by -67% (p=.001) and the visual analogue scale (VAS) was decreased by -64.8% (p=.001), stiffness and pain has been alleviated. In particular, as the degree of depression decreased by -65.5% (p=.001) and the degree of anxiety by -55.2% (p=.003), 12 weeks of home-based exercise improved not only physical changes but also psychological factors. On the other hand, there was no difference in exercise effect according to age, gender, and disease duration in ankylosing spondylitis patients (p>.05). These results suggest that the 12-week home-based exercise applied in this study can be an effective exercise program that can be universally used for ankylosing spondylitis patients regardless of patient characteristics.

A fundamental study on the automation of tunnel blasting design using a machine learning model (머신러닝을 이용한 터널발파설계 자동화를 위한 기초연구)

  • Kim, Yangkyun;Lee, Je-Kyum;Lee, Sean Seungwon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.5
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    • pp.431-449
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    • 2022
  • As many tunnels generally have been constructed, various experiences and techniques have been accumulated for tunnel design as well as tunnel construction. Hence, there are not a few cases that, for some usual tunnel design works, it is sufficient to perform the design by only modifying or supplementing previous similar design cases unless a tunnel has a unique structure or in geological conditions. In particular, for a tunnel blast design, it is reasonable to refer to previous similar design cases because the blast design in the stage of design is a preliminary design, considering that it is general to perform additional blast design through test blasts prior to the start of tunnel excavation. Meanwhile, entering the industry 4.0 era, artificial intelligence (AI) of which availability is surging across whole industry sector is broadly utilized to tunnel and blasting. For a drill and blast tunnel, AI is mainly applied for the estimation of blast vibration and rock mass classification, etc. however, there are few cases where it is applied to blast pattern design. Thus, this study attempts to automate tunnel blast design by means of machine learning, a branch of artificial intelligence. For this, the data related to a blast design was collected from 25 tunnel design reports for learning as well as 2 additional reports for the test, and from which 4 design parameters, i.e., rock mass class, road type and cross sectional area of upper section as well as bench section as input data as well as16 design elements, i.e., blast cut type, specific charge, the number of drill holes, and spacing and burden for each blast hole group, etc. as output. Based on this design data, three machine learning models, i.e., XGBoost, ANN, SVM, were tested and XGBoost was chosen as the best model and the results show a generally similar trend to an actual design when assumed design parameters were input. It is not enough yet to perform the whole blast design using the results from this study, however, it is planned that additional studies will be carried out to make it possible to put it to practical use after collecting more sufficient blast design data and supplementing detailed machine learning processes.

Characterization of Antidiabetic Compounds from Extract of Torreya nucifera (비자나무 추출물의 항당뇨 활성물질의 특성 연구)

  • Kim, Ji Won;Kim, Dong-Seob;Lee, Hwasin;Park, Bobae;Yu, Sun-Nyoung;Hwang, You-Lim;Kim, Sang Hun;Ahn, Soon-Cheol
    • Journal of Life Science
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    • v.32 no.1
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    • pp.1-10
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    • 2022
  • Natural products have gained increasing attention due to their advantage of long-term safety and low toxicity for a very long time. Torreya nucifera is widespread in southern Korea and Jeju Island and its seeds are commonly used as edible food. Oriental ingredients have often been reported for their insecticidal, antioxidant and antibacterial properties, but there have not yet been any studies on their antidiabetic effect. In this study, we investigated several biological activities of T. nucifera pericarp (TNP) and seeds (TNS) extracts and proceeded to characterize the antidiabetic compounds of TNS. The initial results suggested that TNS extract at 15 and 10 ㎍/ml concentration has inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, that is 14.5 and 4.35 times higher than TNP, respectively. Thus, the stronger antidiabetic TNS was selected for the subsequent experiments to characterize its active compounds. Ultrafiltration was used to determine the apparent molecular weight of the active compounds, showing 300 kDa or more. Finally the mixture was then partially purified using Diaion HP-20 column chromatography by eluting with 50~100% methanol. Therefore we concluded that the active compounds of TNS have potential as therapeutic agents in functional food or supplemental treatment to improve diabetic diseases.

Application of Environmental Friendly Bio-adsorbent based on a Plant Root for Copper Recovery Compared to the Synthetic Resin (구리 회수를 위한 식물뿌리 기반 친환경 바이오 흡착제의 적용 - 합성수지와의 비교)

  • Bawkar, Shilpa K.;Jha, Manis K.;Choubey, Pankaj K.;Parween, Rukshana;Panda, Rekha;Singh, Pramod K.;Lee, Jae-chun
    • Resources Recycling
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    • v.31 no.4
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    • pp.56-65
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    • 2022
  • Copper is one of the non-ferrous metals used in the electrical/electronic manufacturing industries due to its superior properties particularly the high conductivity and less resistivity. The effluent generated from the surface finishing process of these industries contains higher copper content which gets discharged in to water bodies directly or indirectly. This causes severe environmental pollution and also results in loss of an important valuable metal. To overcome this issue, continuous R & D activities are going on across the globe in adsorption area with the purpose of finding an efficient, low cost and ecofriendly adsorbent. In view of the above, present investigation was made to compare the performance of a plant root (Datura root powder) as a bio-adsorbent to that of the synthetic one (Tulsion T-42) for copper adsorption from such effluent. Experiments were carried out in batch studies to optimize parameters such as adsorbent dose, contact time, pH, feed concentration, etc. Results of the batch experiments indicate that 0.2 g of Datura root powder and 0.1 g of Tulsion T-42 showed 95% copper adsorption from an initial feed/solution of 100 ppm Cu at pH 4 in contact time of 15 and 30 min, respectively. Adsorption data for both the adsorbents were fitted well to the Freundlich isotherm. Experimental results were also validated with the kinetic model, which showed that the adsorption of copper followed pseudo-second order rate expression for the both adsorbents. Overall result demonstrates that the bio-adsorbent tested has a potential applicability for metal recovery from the waste solutions/effluents of metal finishing units. In view of the requirements of commercial viability and minimal environmental damage there from, Datura root powder being an effective material for metal uptake, may prove to be a feasible adsorbent for copper recovery after the necessary scale-up studies.

The Diaspora Narrative and Aesthetics in Handol's Tarae (한돌 타래의 디아스포라 서사와 미학)

  • Shin, Sa-Bin
    • Journal of Popular Narrative
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    • v.26 no.3
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    • pp.189-219
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    • 2020
  • This study is an analysis of Handol Heung-Gun Lee's Tarae, which is a coinage combining the Korean words for "playing an instrument" and "song", in terms of narrative and aesthetics. The components for analysis are the phenomena and nature of binary oppositions between nature and human beings, between alienation and interest, between division and unification, and between diaspora and people of the national community. Tarae in the period from the late 1970s to the early 1990s described the experience of pain and loss from non-resistance and disobedience in protest against social problems that emerged during the era of miliary dictatorship, such as industrialization, urbanization, reckless development, Westernization, university-oriented education, the gap between rich and poor, human alienation, and the conflicts arising from the division of the nation. After Handol overcame the lack of creative motivation with self-reflection and effort, Tarae took the form of a diaspora epic meta-narratives integrating the "sound of nature and his true nature" and "the awareness of diaspora and the spirit of the Korean people". The epics of the homeland, the national soil and the people, which began with "Teo", became more intense in terms of a sense of diaspora as they shifted their focus from an origin to a path with "Hanmoejulghi" as the turning point. Handol seeks inspiration in the source of narrative rather than in music. His Tarae focuses on "adding rhythm for lyrics". For this reason, the semiotic features of Tarae have a limitation in that its extrinsic phonology is simple even if its intrinsic meaning (i.e., emotion of sadness) is profound and subtle. In order to elicit sympathy from the audience and impress them, it is necessary to strike a balance between the implicit (semantic) part and the explicit (phonological) part. To share the emotion of sadness with more people, it is necessary to strengthen phonological elements. Sympathy for sadness and deep impression on the audience are more often induced by the mood of similar sentiments than by the stories of the same experience. The aesthetics of sadness in Tarae began with the narratives of past experience which were expressed in the contexts of loss, loneliness, and poverty that Handol had experienced since childhood. However, the aesthetics of sadness, deepened over the period of a long hiatus in Handol's career as a composer, formed the narratives of ultimate salvation, embodying even the diaspora experience of others (e.g., displaced people, overseas adoptees, ethnic Koreans in Russia, victims of Japanese military sexual slavery, etc.). This gave Tarae the potential to go beyond the limits of the ethnic group of Korea. Tarae, as a "dispersed sound", can benefit from the appeal of deep sadness at the point of contact with other forms of world music. It may form a global diaspora discourse because Tarae is oriented towards interculturalism rather than anti-multiculturalism. The future challenge and goal of Handol's Tarae would be to continue to find areas of sympathy and broaden the horizon of awareness as diaspora music.

Chinese Socialism and Nationalism (중국식 사회주의와 민족주의)

  • Cho, Bonglae
    • The Journal of Korean Philosophical History
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    • no.27
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    • pp.223-254
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    • 2009
  • This thesis is aimed at researching the formation of democracy in socialist China. Due to a sense of cultural superiority on the basis of their developed civilization, they already formed a strong cultural nationalism, which has come to firm up into "Sinocentrism" through long periods of time. However, there arose a sense of crisis due to the Western invasion after the Opium War and the intellectuals in China happened to seek the solution to rescuing their mother land from ruin; in the midst of this process, the theory of social evolution of the West was introduced and accepted. The acceptance of this theory of social evolution gradually transformed in confrontation with a logical limit that China defeated in international competition could not but be plundered by imperialism after all, but it contributed to Chinese intellectuals' forming the concept of the modern state nationalism of the West deviating from cultural Sinocentrism. After the Russian Revolution, a large number of Chinese progressive intellectuals developed their socialist movement with the recognition that Marxism was a practicable alternative to rescue China from its crisis. The Chinese Communist Party was under guidance of the Comintern from the early process of its formation, in which they emphasized the fact the national liberation struggle in colonialized countries was an indispensable element in the world communist movement under the condition of the control of the world by imperialist capital at that time and subsequently, Marxism characterized by resistant nationalism in China gained its cause. Afterwards, the People's Republic of China was established by the Chinese Communists which came to get widespread support from the Chinese through anti-imperialism &feudalism in the process of the Sino-Japanese War, and thus China equipped with a full-blown socialism system set sails. However, with the relations with the Soviet Union getting worse under the international conditions of a cold war, the development of the Chinese socialism couldn't but resort to the concentrated power of its people, which was linked to the boost of continuous patriotism of the Chinese Communists. Particularly, due to the newly-emerging contradictions after reform & opening [gig kifng], China underwent disruption; thus, as an ideology to integrate such disruptive elements, Sinocentrism based on China's cultural pride re-appeared. Recently, a very strong form of Sinocentrism has come to the fore as their superiority of traditional cultures is emphasized in China whose international position as an economic power has been raised.

Square and Court -Social Imagination of Korean Cinema in Blacklist Era (광장과 법정 -블랙리스트 시대 한국영화의 사회적 상상력)

  • Song, Hyo-Joung
    • Journal of Popular Narrative
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    • v.25 no.4
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    • pp.159-190
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    • 2019
  • This paper aims to examine to the political unconsciousness of social movies that have caused social repercussions in the 2010s, and to study the social imagination of Korean films at that time. Korean Movies such as (2013), <1987>(2017) and (2017) reflect the ethos of civil society based on common sense and justice. The epic structure was the same as that of ordinary citizens, who move toward a public space (court, square) after awakening their political correctness. More than anything else, the fact that such films were based on "a historical fact" could have been a strategy to avoid censorship in the era of the blacklist. In these social films, courts and squares have become places for democracy. The conservative government of the time was tired of anti-government resistance and the politics of the square. Thus, films from directors and producers blacklisted were difficult to produce. That's why the court in the movie during this period could become a symbolic proxy for the "legitimate" reenactment of the politics of the square, which was subject to censorship and avoidance by the regime of the time. Meanwhile, the square has gradually become the main venue for political films that advocate "historic true stories." The square of the 1980s, which appeared in the movies, will be connected to the Gwanghwamun candlelight square that audiences experienced in 2017. Furthermore, it was able to reach the concept of an abstract square as an "open space for democracy." At the foundation of these works is a psychological framework that equates the trauma of the failed democratic movement of the 1980s to the trauma of the failed progressive movement of the 2010s. Through this study, we were able to see that social political films in the 2010s were quite successful, emphasizing "political correctness" and constitutional common sense. But they also had limitations as "de-political popular films" that failed to show imagination beyond the censorship of the blacklist era.

Analysis of the Effect of the Etching Process and Ion Injection Process in the Unit Process for the Development of High Voltage Power Semiconductor Devices (고전압 전력반도체 소자 개발을 위한 단위공정에서 식각공정과 이온주입공정의 영향 분석)

  • Gyu Cheol Choi;KyungBeom Kim;Bonghwan Kim;Jong Min Kim;SangMok Chang
    • Clean Technology
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    • v.29 no.4
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    • pp.255-261
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    • 2023
  • Power semiconductors are semiconductors used for power conversion, transformation, distribution, and control. Recently, the global demand for high-voltage power semiconductors is increasing across various industrial fields, and optimization research on high-voltage IGBT components is urgently needed in these industries. For high-voltage IGBT development, setting the resistance value of the wafer and optimizing key unit processes are major variables in the electrical characteristics of the finished chip. Furthermore, the securing process and optimization of the technology to support high breakdown voltage is also important. Etching is a process of transferring the pattern of the mask circuit in the photolithography process to the wafer and removing unnecessary parts at the bottom of the photoresist film. Ion implantation is a process of injecting impurities along with thermal diffusion technology into the wafer substrate during the semiconductor manufacturing process. This process helps achieve a certain conductivity. In this study, dry etching and wet etching were controlled during field ring etching, which is an important process for forming a ring structure that supports the 3.3 kV breakdown voltage of IGBT, in order to analyze four conditions and form a stable body junction depth to secure the breakdown voltage. The field ring ion implantation process was optimized based on the TEG design by dividing it into four conditions. The wet etching 1-step method was advantageous in terms of process and work efficiency, and the ring pattern ion implantation conditions showed a doping concentration of 9.0E13 and an energy of 120 keV. The p-ion implantation conditions were optimized at a doping concentration of 6.5E13 and an energy of 80 keV, and the p+ ion implantation conditions were optimized at a doping concentration of 3.0E15 and an energy of 160 keV.

Effect of Sulfur Dioxide Gas and Abscisic Acid Pretreatment on Physiological Susceptibility and Growth Damages of Coniferous Seedlings (아황산(亞黃酸)가스 및 ABA 전처리(前處理)가 침엽수(針葉樹) 유묘(幼苗)의 생장피해(生長被害)와 생리적(生理的) 감수성(感受性)에 미치는 영향(影響))

  • Lee, Im Kyun;Kim, Young Chai
    • Journal of Korean Society of Forest Science
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    • v.83 no.3
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    • pp.331-343
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    • 1994
  • This study was conducted to find out the effect of $SO_2$ gas on growth of tree species and the effect of pretreatment of ABA to Pinus koraiensis. Abies holophylla and Taeus cuspidata on the susceptibility for $SO_2$ gas damage. The survey was carried out on the water contents of leaf and shoot, and the acidities of bark and leaf, and the chlorophyll and water soluble sulfur contents, and the changes of transpiration rates on selected seedlings exposed to $SO_2$ gas at seven levels : 0ppm, 0.5ppm, 1ppm, 2ppm, 4ppm, 26.4ppm ABA, 56.8ppm ABA. The results obtained from this research are as follows : 1. The water contents of leaf and shoot of the three tree species decreased with increasing concentrations of $SO_2$ gas and the relative susceptibility of Abies holophylla was larger than those of Taxus cuspidata and Pinus koraiensis because moisture diminution rates were higher in leaves and shoots of Abies holophylla than those of other species. 2. The acidities of bark and leaf of the three tree species increased with increasing concentrations of $SO_2$ gas. The relative susceptibility of Pinus koraiensis in bark acidity was larger than those of Abies holopfaylla and Toxus cuspidata. Abies holophylla was more susceptive than Pinus koraiensis and Taxus cuspidata. 3. Water soluble sulfur contents of the three tree species increased with increasing concentration of $SO_2$ gas. The relative susceptibility of Taxus cuspidata in water soluble sulfur contents was lager than those of Pinus koraiensis and Abies holophylla. 4. Leaf chlorophyll contents of the three tree species decreased with increasing concentrations of $SO_2$ gas. The order of the relative susceptibility in leaf chlorophyll contents was Taxus cuspidata, Abies holophylla and Pinus koraiensis. 5. Correlation coefficients among the measurement were highly significant for $SO_2$ treatment in all three tree species. 6. The transpiration rates of Abies holophylla and Taxus cuspidata did not change until up to 220 minutes after initiation of $SO_2$ gas fumigation, and changed a little during the time between 220 minutes and 270 minutes. On the other hand, Pinus koraiensis continued to change in transpiration rates little by little from the start of $SO_2$ gas treatment up to 270 minutes, meaning that Pinus koraiensis is less sensitive to ABA. 7. When 2ppm of $SO_2$ was treated. ABA pretreatment effect was detected on the six measurement parameters. ABA affected the resistance of plants by inducing stomata closure. 8. The order of relative susceptibility of the three tree species to $SO_2$ gas fumigation was Abies holophylla, Taxus cuspidata and Pinus koraiensis. Pinus koraiensis was more resistant to $SO_2$ gas than Abies holophylla and Taxus cuspidata.

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