• 제목/요약/키워드: New energy

검색결과 13,047건 처리시간 0.052초

Management Automation Technique for Maintaining Performance of Machine Learning-Based Power Grid Condition Prediction Model (기계학습 기반 전력망 상태예측 모델 성능 유지관리 자동화 기법)

  • Lee, Haesung;Lee, Byunsung;Moon, Sangun;Kim, Junhyuk;Lee, Heysun
    • KEPCO Journal on Electric Power and Energy
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    • 제6권4호
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    • pp.413-418
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    • 2020
  • It is necessary to manage the prediction accuracy of the machine learning model to prevent the decrease in the performance of the grid network condition prediction model due to overfitting of the initial training data and to continuously utilize the prediction model in the field by maintaining the prediction accuracy. In this paper, we propose an automation technique for maintaining the performance of the model, which increases the accuracy and reliability of the prediction model by considering the characteristics of the power grid state data that constantly changes due to various factors, and enables quality maintenance at a level applicable to the field. The proposed technique modeled a series of tasks for maintaining the performance of the power grid condition prediction model through the application of the workflow management technology in the form of a workflow, and then automated it to make the work more efficient. In addition, the reliability of the performance result is secured by evaluating the performance of the prediction model taking into account both the degree of change in the statistical characteristics of the data and the level of generalization of the prediction, which has not been attempted in the existing technology. Through this, the accuracy of the prediction model is maintained at a certain level, and further new development of predictive models with excellent performance is possible. As a result, the proposed technique not only solves the problem of performance degradation of the predictive model, but also improves the field utilization of the condition prediction model in a complex power grid system.

Configuration of Fuel Cell Power Generation System through Power Conversion Device Design (전력변환장치 설계를 통한 연료전지 발전시스템 구성)

  • Yoon, Yongho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • 제21권6호
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    • pp.129-134
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    • 2021
  • Recently, the demand for electricity is gradually increasing due to the rapid industrial development and the improvement of living standards. In the case of Korea, which is highly dependent on fossil fuels due to such a surge in electricity demand, reduction and freezing of greenhouse gas emissions due to international environmental regulations will immediately lead to a contraction in industrial activities. Accordingly, there are many difficulties in competition with advanced countries that want to link the environment with the country's industrial production activities, and the development of alternative energy as a countermeasure is of great interest around the world. Among these new power generation methods, small-scale power generation facilities with relatively small capacity include photovoltaic generation, wind power generation, and fuel cell generation. Among them, the fuel cell attracts the most attention in consideration of continuous operation, high power generation efficiency, and long-term durability, which are important factors for practical use. Therefore, in this paper, the fuel cell power generation system was researched and constructed by designing the power conversion circuit necessary to finally obtain the AC power used in our daily life by using the DC power generated from the fuel cell as an input.

Mitochondrial OXPHOS genes provides insights into genetics basis of hypoxia adaptation in anchialine cave shrimps

  • Guo, Huayun;Yang, Hao;Tao, Yitao;Tang, Dan;Wu, Qiong;Wang, Zhengfei;Tang, Boping
    • Genes and Genomics
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    • 제40권11호
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    • pp.1169-1180
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    • 2018
  • Cave shrimps from the genera Typhlatya, Stygiocaris and Typhlopatsa (TST complex) comprises twenty cave-adapted taxa, which mainly occur in the anchialine environment. Anchialine habitats may undergo drastic environmental fluctuations, including spatial and temporal changes in salinity, temperature, and dissolved oxygen content. Previous studies of crustaceans from anchialine caves suggest that they have possessed morphological, behavioral, and physiological adaptations to cope with the extreme conditions, similar to other cave-dwelling crustaceans. However, the genetic basis has not been thoroughly explored in crustaceans from anchialine habitats, which can experience hypoxic regimes. To test whether the TST shrimp-complex hypoxia adaptations matched adaptive evolution of mitochondrial OXPHOS genes. The 13 OXPHOS genes from mitochondrial genomes of 98 shrimps and 1 outgroup were examined. For each of these genes was investigated and compared to orthologous sequences using both gene (i.e. branch-site and Datamonkey) and protein (i.e. TreeSAAP) level approaches. Positive selection was detected in 11 of the 13 candidate genes, and the radical amino acid changes sites scattered throughout the entire TST complex phylogeny. Additionally, a series of parallel/convergent amino acid substitutions were identified in mitochondrial OXPHOS genes of TST complex shrimps, which reflect functional convergence or similar genetic mechanisms of cave adaptation. The extensive occurrence of positive selection is suggestive of their essential role in adaptation to hypoxic anchialine environment, and further implying that TST complex shrimps might have acquired a finely capacity for energy metabolism. These results provided some new insights into the genetic basis of anchialine hypoxia adaptation.

Development Strategy of Korean Economy Through Economic Cooperation with Central Asian Countries (한국의 지속적인 경제성장을 위한 중앙아시아 진출 확대 전략)

  • Chung, Haing Deuck;Lee, Sang Ho
    • International Area Studies Review
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    • 제13권2호
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    • pp.311-368
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    • 2009
  • In order to survive the on-going natural resource war, Korea needs various efforts such as enhancing self-exploitation ratio, increasing the supply of new-reuse energy, strengthening cooperation with resource rich countries. Central Asian countries are geometrically far away from Korea. However, Korea should try to develop political, economic and ethnic relationship with those countries into much higher dimension to secure various natural resources. Major countries including U.S., EU. Japan and China are approaching Central Asian countries with long term perspective. Improving country-image through enlargement of ODA is the first concern of those countries. Korea should try to follow their practices. Government should try to improve Korea's image in the first place and lead economic cooperation with very detailed supportive measures to induce Korean firms' investment into the Central Asian countries. In the due process, a lot of information about those countries' political climate, social situation, ethnical composition, major religions, educational system, current state and structure of economies and industries, etc should be made available to Korean firms.

Creative Curiosity: Study of Alice Character in Lewis Caroll's Adventures of Alice in Wonderland (창조적 호기심 루이스 캐럴의 『이상한 나라의 앨리스의 모험』 연구)

  • Cho, Sungran
    • Cross-Cultural Studies
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    • 제41권
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    • pp.299-320
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    • 2015
  • Lewis Carroll's Alice's Adventures in Wonderland expands scope of Children's Literature genre by introducing the discourse of pleasure as opposed to that of didactic discipline. Carroll's narrative is important, not only for children's literature, but also as a forerunner of post/modernism of James Joyce with its language play and linguistic invention. Its treatment of Alice's body change follows the motif of body transformation in myth and literature. Comparing "stasis" of Susan Sontag's character Alice (James) in her play Alice in Bed and "movement" of Carroll's Alice, this study explores the issues of woman's alienation and the dichotomy of mobility/immobility in reality and in their literary representations. Focusing on a female child's double alienation as woman and child, I argue Alice's Adventures in Wonderland is a counter-narrative of alternative bildungsroman. Alice gains her subjectivity through her adventure by power of language and story-telling. Through representation of the dream/adventure of two desiring sisters, Carroll's narrative exhibits subversion of social order and emergence of new order of "chaosmos" out of chaos. As a method of study, this study traces genealogy of "curiosity" in myth and literature as a motivating force that triggers adventure and argues "creative curiosity" is a dynamic energy propelling Alice's adventure.

A Study on the Connective Validity of Technology Maturity and Industry for Core Technologies based on 4th Industrial Revolution (4차 산업혁명 기반 핵심기술에 대한 기술성숙도와 산업과 연계 타당성 연구)

  • Cho, Han-Jin;Jeong, Kyuman
    • Journal of the Korea Convergence Society
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    • 제10권3호
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    • pp.49-57
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    • 2019
  • The core technology development of the Fourth Industrial Revolution is linked to the development of other core technologies, which will change the industrial structure in the future and create a new smart business model. In this paper, tried to analyze the technology maturity level and analyze the technology maturity. To do this, used technology trend information to investigate and integrate the market, policy, etc. Of core technology of the 4th Industrial Revolution to achieve a comprehensive maturity level. Because technology maturity measures are scored by technology developers, prejudices may be acted upon according to a person's tendency, which may be a subjective evaluation. It is also a measure of the maturity of individual technologies, and thus is not suitable for evaluating the overall system integration perspective. However, it is possible to evaluate the maturity before integrating the core element technologies constituting the whole system and to use it as a means to compare the effect of the whole system and its feasibility and play an important role in the planning of technology development.

Intrinsic Porous Polymer-derived 3D Porous Carbon Electrodes for Electrical Double Layer Capacitor Applications (전기이중층 커패시터용 내재적 미세 다공성 고분자 기반 3차원 다공성 탄소 전극)

  • Han, Jae Hee;Suh, Dong Hack;Kim, Tae-Ho
    • Applied Chemistry for Engineering
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    • 제29권6호
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    • pp.759-764
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    • 2018
  • 3D porous carbon electrodes (cNPIM), prepared by solution casting of a polymer of intrinsic microporosity (PIM-1) followed by nonsolvent-induced phase separation (NIPS) and carbonization are presented. In order to effectively control the pore size of 3D porous carbon structures, cNPIM was prepared by varying the THF ratio of mixed solvents. The SEM analysis revealed that cNPIMs have a unique 3D macroporous structure having a gradient pore structure, which is expected to grant a smooth and easy ion transfer capability as an electrode material. In addition, the cNPIMs presented a very large specific surface area ($2,101.1m^2/g$) with a narrow micropore size distribution (0.75 nm). Consequently, the cNPIM exhibits a high specific capacitance (304.8 F/g) and superior rate capability of 77% in an aqueous electrolyte. We believe that our approach can provide a variety of new 3D porous carbon materials for the application to an electrochemical energy storage.

Acanthamoeba in Southeast Asia - Overview and Challenges

  • Bunsuwansakul, Chooseel;Mahboob, Tooba;Hounkong, Kruawan;Laohaprapanon, Sawanya;Chitapornpan, Sukhuma;Jawjit, Siriuma;Yasiri, Atipat;Barusrux, Sahapat;Bunluepuech, Kingkan;Sawangjaroen, Nongyao;Salibay, Cristina C.;Kaewjai, Chalermpon;Pereira, Maria de Lourdes;Nissapatorn, Veeranoot
    • Parasites, Hosts and Diseases
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    • 제57권4호
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    • pp.341-357
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    • 2019
  • Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hotspring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.

Development and Evaluation of Artificial Lightweight Soil Using Bottom Ash (바텀애시를 활용한 인공경량토양의 개발 및 성능 평가)

  • Kim, Chul-Min;Kim, Min-Woo;Cho, Gun-Young;Choi, Na-Rae
    • Journal of the Korean Recycled Construction Resources Institute
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    • 제6권4호
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    • pp.252-258
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    • 2018
  • A larger energy consumption and concentration of population induced green house gas glowing and heat island effect in the urban space. Roof green system was a effect method to reduce green house gas and heat concentration in the city. Therefore, construction of this system was increasing. Most of lightweight soil used in roof green system was perlite, but this caused dust and skin disease. So it needed to develop another new lightweight soli for roof green system. Meanwhile, a thermoelectric power plant generated bottom ash as a by-product. According to previous research, bottom ash could be used for artificial lightweight soil with 60 wt% of mixing rate. But this study was proceed to develop a artificial lightweight soil using bottom ash with higher mixing rate by 65 wt% and different organic ingredients. First, physical and chemical properties of bottom ash was investigated. Then test according to landscaping design standard was proceeded for various artificial lightweight soil mix types using bottom ash, bark, compost and coco peat. As a result, the artificial lightweight soil with 65% of bottom ash, 30% of bark and 5% of compost was suitable for low and middle range of soil standard.

A Comparative Study on the Revised Bills of the Regulatory Freedom Special Districts Act (focused on the Revised Bills by Proposed Kim Kyung-soo, Jung Sung-ho, Choo Kyung-ho, Hong Il-pyo) (규제자유특구법 개정안의 비교 고찰 (김경수, 정성호, 추경호, 홍일표, 개정안을 중심으로))

  • Kang, Min-Su;Choi, Ho-Sung;Cho, Han-Jin
    • Journal of the Korea Convergence Society
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    • 제10권3호
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    • pp.203-209
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    • 2019
  • Special Act on Regulatory Freedom Zone and Regional Special Development Zonet" introduced a new type of 'Freedom Special Zone of Regulation' that is legally distinguished from the existing Special Districts for Regional and Regional Development to support the innovative and strategic growth of the areas, and even passed a number of legal grounds for providing innovative regulations for regional development projects or regional strategic industries within the Special Districts. Starting with the bill legislation proposed by The Parliament Members, Kim Kyung-soo on behalf of 33 suggestors, Choo Kyung-ho, Jung Sung-ho and Hong Il-pyo submitted the bill legislation on behalf of 10 to 12 proposers, respectively. As a major matter of issue, the purpose, designation, scope of application, promotion system, application of A Bill of Three kind on Regulatory Innovation, and Balanced National Development, many kind of regulation as like types of menu, special cases, punitive regulations, and so on have been argued until the end of the bill proposed from the beginning. In this study, the differences between the bill suggested by the Parliament members and bill approved already are to be compared and analyzed to confirm how the items on issue were reflected for the bill finally and to draw up measures for the correct operation of the special regulations.