• Title/Summary/Keyword: Technical Challenges

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The Technical Trends of Power MOSFET (전력용 MOSFET의 기술동향)

  • Bae, Jin-Yong;Kim, Yong;Lee, Eun-Young;Lee, Kyu-Hoon;Lee, Dong-Hyun
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.125-130
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    • 2009
  • This paper reviews the characteristics technical trends in Power MOSFET technology that are leading to improvements in power loss for power electronic system. The power electronic technology requires the marriage of power device technology with MOS-gated device and bipolar analog circuits. The technology challenges involved in combining power handling capability with finger gate, trench array, super junction structure, and SiC transistor are described, together with examples of solutions for telecommunications, motor control, and switch mode power supplies.

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Bioethanol Production Using Lignocellulosic Biomass - review Part I. Pretreatments of biomass for generating ethanol

  • Sheikh, Mominul Islam;Kim, Chul-Hwan;Yesmin, Shabina;Lee, Ji-Yong;Kim, Gyeong-Chul;Ahn, Byeong-Il;Kim, Sung-Ho;Park, Hyeon-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.5
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    • pp.1-14
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    • 2010
  • Bio-ethanol is a promising alternative energy source for reducing both consumption of crude oil and environmental pollution from renewable resources like lignocellulosic biomass such as wood, forest residuals, agricultural leftovers and urban wastes. Based on current technologies, the cost of ethanol production from lignocellulosic materials is relatively high, and the main challenges are the low yield and high cost of the hydrolysis process. Development of more efficient pretreatment technology (physical, chemical, physico-chemical, and biological pretreatment), integration of several microbiological conversions into fewer reactors, and increasing ethanol production capacity may decrease specific investment for ethanol producing plants. The purpose of pretreatment of lignocellulosic material is to improve the accessible surface area of cellulose for hydrolytic enzymes and enhance the conversion of cellulose to glucose and finally high yield ethanol production which is economic and environmental friendly.

Development of Amphoteric Polyacrylamide Retention System for ONP Recycled Pulp

  • Son, Dong-Jin;Kim, Bong-Yong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.5
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    • pp.24-30
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    • 2010
  • Papermaking technology has drastically improved over the last 20 years to face new challenges. Because environmental regulations have become increasingly strict, papermaking systems have had to accommodate elevated recycled pulp content and an increased use of recycled process water. Process water in papermaking systems has become more dirtier and reduced polymer efficiency. Amphoteric PAM demonstrated a higher degree of stability in a high conductivity environment compared to cationic PAM. This was illustrated by the improved retention performance, particularly the ash retention. This amphoteric polymer can be used for board or newsprint production using recycled pulp, especially for the systems where polymer dissolving water is high in conductivity and degradation of cationic functional groups of cationic PAM can occur.

Technical trend of stretchable electrodes (차세대 스트레처블 전극의 기술 개발동향)

  • Lee, Sang-Mok;Lim, Ji-Eun;Kim, Han-Ki
    • Vacuum Magazine
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    • v.4 no.2
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    • pp.15-23
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    • 2017
  • This article reviews technical trend in research of stretchable electrodes for wearable devices, bio-integrated devices, and stretchable electronics. Stretchable electronics is new emerging class of electronics following flexible electronics. One of the most difficult challenges in the development of stretchable electronic is to realize high performance stretchable electrodes with a low resistivity and high strain failure and stretchability against severe strain of the substrate. For this reason, there are many reports on the promising stretchable electrodes including CNT, graphene, Ag nanowire, and composite materials. We outline the recent research for stretchable substrate and stretchable electrode materials to realize highly stretchable electrodes.

NATO's Factor in Ensuring the National Security of Modern Ukraine

  • Biloshytskyi, Volodymyr;Hanhal, Artur;Mokliak, Sergii;Pysmennyi, Oleksii;Smolianiuk, Volodymyr
    • International Journal of Computer Science & Network Security
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    • v.21 no.12spc
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    • pp.689-695
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    • 2021
  • The study is based on the elaborated normative and legal documentation regulating the national security of modern Ukraine and the normative and legal documents adopted by NATO in the responding policy to the challenges that arose after 2014. The main advantages of cooperation with NATO are ensuring military security, developing army standards, improving the country's investment climate, and reducing expenditures on the army. The disadvantages of cooperation with NATO in hostilities with Russia are not highlighted. Still, defined obstacles show that Ukraine is not ready to realize entry into NATO in the short term. Such factors include weak information support, corruption, and unclear diplomatic decisions.

Technical Aspects of Combined Heart-Lung Transplantation

  • Ju, Min Ho;Je, Hyung Gon
    • Journal of Chest Surgery
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    • v.55 no.4
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    • pp.319-324
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    • 2022
  • Although organ transplants have become quite common, combined heart-lung transplantation (CHLTx) is unfamiliar at most institutions. While the remarkable rate of development in treatment options, such as drugs and mechanical circulatory support, have reduced the need for CHLTx, it remains the sole treatment option for a subset of patients with end-stage cardiopulmonary failure. For many cardiothoracic surgeons, CHLTx is not technically new or difficult, but it does pose challenges due to its low frequency and relative complexity. Thus, this review aims to describe the CHLTx technique in technical detail using the existing literature.

Single-Cell Genomics for Investigating Pathogenesis of Inflammatory Diseases

  • Seyoung Jung;Jeong Seok Lee
    • Molecules and Cells
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    • v.46 no.2
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    • pp.120-129
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    • 2023
  • Recent technical advances have enabled unbiased transcriptomic and epigenetic analysis of each cell, known as "single-cell analysis". Single-cell analysis has a variety of technical approaches to investigate the state of each cell, including mRNA levels (transcriptome), the immune repertoire (immune repertoire analysis), cell surface proteins (surface proteome analysis), chromatin accessibility (epigenome), and accordance with genome variants (eQTLs; expression quantitative trait loci). As an effective tool for investigating robust immune responses in coronavirus disease 2019 (COVID-19), many researchers performed single-cell analysis to capture the diverse, unbiased immune cell activation and differentiation. Despite challenges elucidating the complicated immune microenvironments of chronic inflammatory diseases using existing experimental methods, it is now possible to capture the simultaneous immune features of different cell types across inflamed tissues using various single-cell tools. In this review, we introduce patient-based and experimental mouse model research utilizing single-cell analyses in the field of chronic inflammatory diseases, as well as multi-organ atlas targeting immune cells.

Quorum quenching for effective control of biofouling in membrane bioreactor: A comprehensive review of approaches, applications, and challenges

  • Kose-Mutlu, Borte;Ergon-Can, Tulay;Koyuncu, Ismail;Lee, Chung-Hak
    • Environmental Engineering Research
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    • v.24 no.4
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    • pp.543-558
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    • 2019
  • In comparison to alternative advanced wastewater treatment technologies, the main problem associated with membrane bioreactor (MBR) technology, which has become prominent in recent years, is biofouling. Within these systems, biofouling is typically the result of a biofilm layer resulting from bacterial gathering. One biological system that can be employed to interrupt the process of bacterial gathering is called 'Quorum Quenching (QQ)'. Existing QQ applications can be classified using three main types: 1) bacterial/whole-cell applications, 2) direct enzyme applications, and 3) natural sourced compounds. The most common and widely recognized applications for membrane fouling control during MBR operation are bacterial and direct enzyme applications. The purpose of this review was to identify and assess biofilm formation mechanism and results, the suggestion of the QQ concept and its potential to control biofilm formation, and the means by which these QQ applications can be applied within the MBR and present QQ MBR studies.

3D Filmmaking for User-Selective UHD Stereoscopic Media System: A Case Study on the Film The Old, the New and the Other

  • Cha, Minchol;Hamacher, Alaric;Simon, Sebastien
    • Journal of Multimedia Information System
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    • v.8 no.4
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    • pp.277-284
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    • 2021
  • Despite skepticism about commercial potential, the stereoscopic 3D cinema is still a form that any filmmaker can choose to employ for its aesthetics and its immersive potential. Based on a haptic illusion, the stereoscopic media content requires a new perspective different from the principle of 2D media content in terms of creation and acceptance. This paper examines the technical and aesthetic issues of stereoscopic 3D film production from the perspective of today's emerging realistic and immersive media through a case study. One of the key factors for successful content creation and research and development in stereoscopic 3D cinema is the combination of artistic principles together with technical mastering of the new image technology. The purpose of this paper is to outline the principal challenges and research topics in stereoscopic 3D cinema through a case study of stereoscopic 3D pilot film production for the 'User-Selective UHD Stereoscopic Media Service Platform' of the ETRI (Electronics and Telecommunications Research Institute). This paper intends to examine stereoscopic 3D filmmaking workflow and production methodologies, as well as technical elements and aesthetic issues.

Packaging Framework System Under International Trade Rules

  • Du, Xue-fei;Cho, Hyun-sook
    • Asia-Pacific Journal of Business
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    • v.13 no.3
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    • pp.119-134
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    • 2022
  • Purpose - The purpose of this study was to expound the packaging framework system(PFS) under international trade rules. Design/methodology/approach - This study analyzed packaging framework system and packaging regulations and technical standards in international regulations and major countries and classified these in some standards Findings - First, the study provides packaging provisions associated with packaging regulations and technical standards (PRTS). Then, the basis of PFS in international trade rules was proposed; it is believed that the PFS was composed of packaging legal system in WTO institutional framework (WTO-PLS), international organization packaging standard system (IO-PSS) and major countries or regions packaging regulatory system (MCR-PRS). Secondly, this paper expounded relations and legal characteristics of the three packaging systems. Finally, This study investigated PRTS coverage under technical barriers to trade (TBT) and Sanitary and Phytosanitary measures (SPS). Research implications or Originality - The regulations associated with PRTS have played a key role in challenges to merchandise trade in international trade. This study has significance in classifying packaging related reticulations into several criteria unlike previous studies. Therefore it is hope that this study can provide a supplementary document for the existing research of PRTS.