• 제목/요약/키워드: Science and engineering graduate

검색결과 5,174건 처리시간 0.042초

Performance Evaluations of Quasi Resonant DC Link Assisted Three Phase Soft Switching Inverter for AC Servo Motor Drive

  • Yoshitsugu J.;Ando M.;Rukonuzzaman M.;Hiraki E.;Nakaoka M.;Inoue K.
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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    • pp.232-235
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    • 2001
  • This paper presents a circuit of the quasi-resonant DC link to achieve soft-switching three phase inverter using intelligent IGBT power module. The soft-switching operation in this circuit is confirmed simulation and experimental results. Its conductive noise is measured for electrical AC motor drive as compared with that of the conventional hard switching inverter.

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Fundamental Understanding of Nanoporous Carbons for Energy Application Potentials

  • Kaneko, Katsumi;Arai, Miki;Yamamoto, Masahiro;Ohba, Tomonori;Miyamoto, Jun-Ichi;Kim, Dong-Young;Tao, Yousheng;Yang, Cheol-Min;Urita, Kouki;Fujimori, Toshihiko;Tanaka, Hideki;Ohkubo, Takahiro;Utsumi, Shigenori;Hattori, Yoshiyuki;Konishi, Takehisa;Fujikawa, Takashi;Kanoh, Hirofumi;Yudasaka, Masakao;Hata, Kenji;Yumura, Motoo;Iijima, Sumio;Muramatsu, Hiroyuki;Hayashi, Takuya;Kim, Yoong-Ahm;Endo, Morinobu
    • Carbon letters
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    • 제10권3호
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    • pp.177-180
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    • 2009
  • The importance of nanopore structures of carbons is shown in terms of interaction potential for various molecules including supercritical gases such as $H_2$ and $CH_4$. The key factors for adsorption of supercritical $H_2$ and $CH_4$ are shown for single wall carbon nanohorn, single wall carbon nanotube, and double wall carbon nanotube. The cluster formation of molecules is a key process for water adsorption on hydrophobic carbon nanopores. The X-ray absorption spectroscopic examination elucidates an explicit dehydration structure of ions confined in carbon nanopores.

Zero Voltage Soft Switching PWM High-Frequency Inverter with Active Inductor Snubber for Induction Heated Roller in New Type Copy Machine

  • Muraoka S.;Feng Y.L.;Kunimoto H.;Chandhaket S.;Okuno A.;Nakaoka M.
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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    • pp.75-79
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    • 2001
  • This paper presents a novel version of an active voltage clamped ZVS-PWM high frequency inverter using IGBTs for electromagnetic induction eddy current-based rolling drum heating in new generation copy and printing machines in consumer business use. The operating principle of this inverter circuit and unique features are described herein. Its constant frequency duty cycle (asymmetrical PWM) controlled voltage source quasi-resonant soft switching high frequency inverter employing IGBTs is proposed, which is capable of achieving stable and efficient zero voltage soft switching commutation over a widely specified power regulation range from full power to low power. The operating performances in a steady state of this inverter is discussed and evaluated on basis of simulation and experimental results as an induction heated roller in new generation copy machine.

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Development of Induction Heated Hot Water Producer using Soft Switching PWM High Frequency Inverter

  • Fujita Kentarou;Moisseev Serguei;Gaimage Laknath;Chandhaket Sarawouth;Muraoka Hidekazu;Nakaoka Mutsuo
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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    • pp.491-494
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    • 2003
  • This paper presents a new conceptual electromagnetic induction eddy current-based stainless steel plate spiral type heater for heat exchanger or Dual Packs Heater in hot water producer, boiler steamer and super heated steamer, which is more suitable and acceptable for new generation consumer power applications. In addition, all active clamped edge resonant PWM high frequency inverter using trench gate IGBTs power module can operate under a principle oi zero voltage soft communication with PWM is developed and demonstrated for a high efficient Induction heated hot water producer and boiler in the consumer power applications. This consumer induction heater power appliance using active clamp soft switching PWM high frequency inverter is evaluated and discussed on the basis of the simulation and experimental results.

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Innovative Electromagnetic Induction Eddy Current-based Far Infrared Rays Radiant Heater using Soft Switching PWM Inverter with Duty Cycle Control Scheme

  • Tanaka H.;Sadakata H.;Muraoka H.;Okuno A.;Hiraki E.;Nakaoka M.
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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    • pp.64-68
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    • 2001
  • This paper presents an innovative prototype of a new conceptual electromagnetic induction heated type far infrared rays radiant heating appliance using the voltage-fed edge-resonant ZVS-PWM high frequency inverter using IGBTs for food cooking and processing which operates under a constant frequency variable power regulation scheme. This power electronic appliance with soft switching high frequency inverter using IGBTs has attracted special interest from some advantageous viewpoints of safety, cleanliness, compactness and rapid temperature response, which is more suitable for consumer power electronics applications.

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Novel green Sr4ScAl3O10:Eu2+ phosphor prepared by the melt quenching technique

  • Toda, Kenji;Iwaki, Masato;Katsu, Minenori;Kamei, Shin-nosuke;Kim, Sun-Woog;Hasegawa, Takuya;Muto, Masaru;Yamanashi, Ryota;Sakamoto, Tatsuya;Ishigaki, Tadashi;Uematsu, Kazuyoshi;Sato, Mineo;Yoon, Dae-Ho
    • Journal of Ceramic Processing Research
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    • 제20권3호
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    • pp.276-279
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    • 2019
  • New green-emitting Sr4ScAl3O10:Eu2+ phosphor was prepared using a novel melt quenching synthesis method. The temperature of raw materials irradiated with the strong light of the Xe arc-lamp was rose up to about 2273 K, followed by a sharp drop in the temperature after turn off the lamp. This method is a useful tool for rapid screening of novel phosphor materials.

Immunogenic cell death in cancer immunotherapy

  • Minji Choi;Jisoo Shin;Chae-Eun Lee;Joo-Yoon Chung;Minji Kim;Xiuwen Yan;Wen-Hao Yang;Jong-Ho Cha
    • BMB Reports
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    • 제56권5호
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    • pp.275-286
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    • 2023
  • Cancer immunotherapy has been acknowledged as a new paradigm for cancer treatment, with notable therapeutic effects on certain cancer types. Despite their significant potential, clinical studies over the past decade have revealed that cancer immunotherapy has low response rates in the majority of solid tumors. One of the key causes for poor responses is known to be the relatively low immunogenicity of solid tumors. Because most solid tumors are immune desert 'cold tumors' with antitumor immunity blocked from the onset of innate immunity, combination therapies that combine validated T-based therapies with approaches that can increase tumor-immunogenicity are being considered as relevant therapeutic options. This review paper focuses on immunogenic cell death (ICD) as a way of enhancing immunogenicity in tumor tissues. We will thoroughly review how ICDs such as necroptosis, pyroptosis, and ferroptosis can improve anti-tumor immunity and outline clinical trials targeting ICD. Finally, we will discuss the potential of ICD inducers as an adjuvant for cancer immunotherapy.

Blockade of Retinol Metabolism Protects T Cell-Induced Hepatitis by Increasing Migration of Regulatory T Cells

  • Lee, Young-Sun;Yi, Hyon-Seung;Suh, Yang-Gun;Byun, Jin-Seok;Eun, Hyuk Soo;Kim, So Yeon;Seo, Wonhyo;Jeong, Jong-Min;Choi, Won-Mook;Kim, Myung-Ho;Kim, Ji Hoon;Park, Keun-Gyu;Jeong, Won-Il
    • Molecules and Cells
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    • 제38권11호
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    • pp.998-1006
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    • 2015
  • Retinols are metabolized into retinoic acids by alcohol dehydrogenase (ADH) and retinaldehyde dehydrogenase (Raldh). However, their roles have yet to be clarified in hepatitis despite enriched retinols in hepatic stellate cells (HSCs). Therefore, we investigated the effects of retinols on Concanavalin A (Con A)-mediated hepatitis. Con A was injected into wild type (WT), Raldh1 knockout ($Raldh1^{-/-}$), $CCL2^{-/-}$ and $CCR2^{-/-}$ mice. For migration study of regulatory T cells (Tregs), we used in vivo and ex vivo adoptive transfer systems. Blockade of retinol metabolism in mice given 4-methylpyrazole, an inhibitor of ADH, and ablated Raldh1 gene manifested increased migration of Tregs, eventually protected against Con A-mediated hepatitis by decreasing interferon-${\gamma}$ in T cells. Moreover, interferon-${\gamma}$ treatment increased the expression of ADH3 and Raldh1, but it suppressed that of CCL2 and IL-6 in HSCs. However, the expression of CCL2 and IL-6 was inversely increased upon the pharmacologic or genetic ablation of ADH3 and Raldh1 in HSCs. Indeed, IL-6 treatment increased CCR2 expression of Tregs. In migration assay, ablated CCR2 in Tregs showed reduced migration to HSCs. In adoptive transfer of Tregs in vivo and ex vivo, Raldh1-deficient mice showed more increased migration of Tregs than WT mice. Furthermore, inhibited retinol metabolism increased survival rate (75%) compared with that of the controls (25%) in Con A-induced hepatitis. These results suggest that blockade of retinol metabolism protects against acute liver injury by increased Treg migration, and it may represent a novel therapeutic strategy to control T cell-mediated acute hepatitis.

A Power Estimation Method for ASIPs Considering Data Types of Variables in Application Programs

  • Kim, Tsutomu ura;Shibahara, Shin-ichi;Yoshinori Takeuchi;Masaharu Imai;Akira Kitajima;Michiaki Muraoka
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.387-390
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    • 2000
  • This paper proposes an efficient and accurate power estimation method for Application Specific Instruction set Processors (ASIPs). Proposed method takes advantage of the data types of variables in application program to be executed on the ASIP. According to the experimental results, the efficiency of proposed method was more than 1000 times as high as that of conventional RTL based power estimation method, and the estimation error was within 10% compared to a conventional gate-level accurate power estimation method

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