• Title/Summary/Keyword: multi-cells

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Multi-module Equalizer Circuit for Series-Connected Li-ion Batteries

  • Shin, Jong-Won;Seo, Gab-Su;Kim, Jong-Hoon;Cho, Bo-Hyung
    • Proceedings of the KIPE Conference
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    • 2010.07a
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    • pp.420-421
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    • 2010
  • In this paper, a multi-module selective battery equalizer for series-connected Li-ion battery pack is proposed. Selective Equalizer (SE) scheme achieves smaller volume and lighter weight than individual cell equalizer (ICE) by minimizing the part count of bulky circuit element. However, SE scheme shows slow balancing speed when the voltage imbalance simultaneously occurs in more than one cell. The proposed multi-module overcomes the problem by employing multiple power converters. Prototype hardware is implemented and experimented with 14Ah battery cells to validate the performance of the proposed equalizer.

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Joint Energy Efficiency Optimization with Nonlinear Precoding in Multi-cell Broadcast Systems

  • Gui, Xin;Lee, Kyoung-Jae;Jung, Jaehoon;Lee, Inkyu
    • Journal of Communications and Networks
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    • v.18 no.6
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    • pp.873-883
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    • 2016
  • In this paper, we focus on maximizing weighted sum energy efficiency (EE) for a multi-cell multi-user channel. In order to solve this non-convex problem, we first decompose the original problem into a sequence of parallel subproblems which can optimized separately. For each subproblem, a base station employs dirty paper coding to maximize the EE for users within a cell while regulating interference induced to other cells. Since each subproblem can be transformed to a convex multiple-access channel problem, the proposed method provides a closed-form solution for power allocation. Then, based on the derived optimal covariance matrix for each subproblem, a local optimal solution is obtained to maximize the sum EE. Finally, simulation results show that our algorithm based on non-linear precoding achieves about 20 percent performance gains over the conventional linear precoding method.

Maximum-Power-Point Tracking Using Multiphase Interleaved Converters Based on Multi-Unit Synchronization

  • Jantharamin, Niphat;Thongbuaban, Ponlawat
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.1
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    • pp.88-92
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    • 2014
  • This paper presents an application of a multiphase interleaved converter in tracking maximum power points (MPPs) of a photovoltaic (PV) panel regardless of environmental variations. Maximum power from the panel was extracted by means of the well-known the perturb-and-observe (P&O) method. The switching control technique used an interleaving scheme based on multi-unit synchronization. The converter performed harmonic attenuation without affecting the tracking speed. This approach is straightforward, reliable and inexpensive, and could be applied to any higher number of switching cells without difficulty.

A Study on Effective ATM Multi-Path Routing Method (효율적인 ATM 다중 경로 라우팅 기법에 관한 연구)

  • Go, Jang-Hyeok;Lee, Dong-Ho
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.3
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    • pp.681-691
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    • 1999
  • It was already proved that ATM stability and flexibility of service application, but because of the various characteristics of traffics and the QoS on user demand caused by them, there are a lot of researches for traffic management method. However, there are a few of researches for ATM routing method acting on traffic management practically. In this paper, we focus on multi-path routing method transporting cells with multiple paths and compare this method with existing single path routing method and analyze multi-path routing method into three elements with simple formula and propose anew methods improving the performance of ATM routing and simulate these methods.

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A study on Multi-cell Combined Network (다중 셀 결합 망에 관한 연구)

  • 조석팔
    • The Journal of Information Technology
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    • v.2 no.1
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    • pp.1-13
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    • 1999
  • Multi-cell combined networks that provide coverage to the same areas by several cells of different sizes are useful to accommodate high traffic density while keeping high quality of service. This gives an overview of recent contributions on this subject, Two main issues are considered: spectrum sharing between different layers with a focus on F/TDMA systems and teletraffic performance of multi-cell combined networks given different handover policies

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Deformation of multi-storey flat slabs, a site investigation

  • Tovi, Shivan;Goodchild, Charles;B-Jahromi, Ali
    • Advances in concrete construction
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    • v.5 no.1
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    • pp.49-63
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    • 2017
  • Traditional reinforced concrete slabs and beams are widely used for building. The use of flat slab structures gives advantages over traditional reinforced concrete building in terms of design flexibility, easier formwork and use of space and shorter building time. Deflection of the slab plays a critical role on the design and service life of building components; however, there is no recent research to explore actual deformation of concrete slab despite various advancements within the design codes and construction technology. This experimental study adopts the Hydrostatic Levelling Cells method for monitoring the deformation of a multi-storey building with flat slabs. In addition, this research presents and discusses the experimental results for the vertical deformation.

Development of a multi-sensing technique for temperature and strain field of high-temperature using thermographic phosphors (온도감응형 인광물질을 이용한 온도장 및 열변형 동시 계측 기법 개발)

  • Im, Yujin;Yeom, Eunseop
    • Journal of the Korean Society of Visualization
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    • v.19 no.3
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    • pp.77-83
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    • 2021
  • Solid oxide fuel cell (SOFC) operates at high temperatures in range of 600-800℃. Since layers of SOFC are composed of different substances, different thermal expansion in SOFC can result in defects under high temperature conditions. For understanding relation between temperature field and the thermal deformation in SOFC, temperature and strain field were simultaneously estimated using thermographic phosphors by optical measurement. Temperature fields were obtained by the life-time method, and the temperature differences of one specimen was checked with thermocouple. The thermal deformation was estimated by digital image correlation (DIC) method with extracted phosphorescence images. To investigate the deformation accuracy of DIC measurement, thermographic phosphors were coated with and without grid pattern on aluminum surface. Simultaneous measurement of temperature fields and thermal deformation were carried out for YSZ. This study will be helpful to multi-sensing of temperature field and thermal deformation on SOFC cells.

The Fission Yeast Gene Encoding Monothiol Glutaredoxin 5 Is Regulated by Nitrosative and Osmotic Stresses

  • Kim, Hong-Gyum;Park, Eun-Hee;Lim, Chang-Jin
    • Molecules and Cells
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    • v.20 no.1
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    • pp.43-50
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    • 2005
  • Glutaredoxin (Grx) is a small, heat-stable redox protein acting as a multi-functional glutathione (GSH)-dependent disulfide oxidoreductase. We have cloned the monothiol Grx5 gene from the genomic DNA of the fission yeast Schizosaccharomyces pombe. It has 1,904 bp, with one intron, and encodes a putative protein of 146 amino acids with a molecular mass of 16.5 kDa. Recombinant Grx5 produced functional Grx in S. pombe cells. NO-generating sodium nitroprusside (SNP, 1.0 and 2.0 mM) and potassium chloride (KCl, 0.2 and 0.5 M) increased the synthesis of ${\beta}$-galactosidase from a Grx5-lacZ fusion gene, and transcription of Grx5 was also enhanced by SNP and KCl. Synthesis of ${\beta}$-galactosidase from the Grx5-lacZ fusion was lower in Pap1-negative TP108-3C cells than in wild type KP1 cells, and when Pap1 was overproduced in KP1 cells, the level of ${\beta}$-galactosidase increased. We also found that Pap1 is involved in the induction of Grx5 by SNP and KCl. S. pombe Grx5 may play a crucial role in responses to nitrosative and osmotic stresses.

A systematic mRNA control mechanism for germline stem cell homeostasis and cell fate specification

  • Lee, Myon-Hee;Mamillapalli, Srivalli Swathi;Keiper, Brett D.;Cha, Dong Seok
    • BMB Reports
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    • v.49 no.2
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    • pp.93-98
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    • 2016
  • Germline stem cells (GSCs) are the best understood adult stem cell types in the nematode Caenorhabditis elegans, and have provided an important model system for studying stem cells and their cell fate in vivo, in mammals. In this review, we propose a mechanism that controls GSCs and their cell fate through selective activation, repression and mobilization of the specific mRNAs. This mechanism is acutely controlled by known signal transduction pathways (e.g., Notch signaling and Ras-ERK MAPK signaling pathways) and P granule (analogous to mammalian germ granule)-associated mRNA regulators (FBF-1, FBF-2, GLD-1, GLD-2, GLD-3, RNP-8 and IFE-1). Importantly, all regulators are highly conserved in many multi-cellular animals. Therefore, GSCs from a simple animal may provide broad insight into vertebrate stem cells (e.g., hematopoietic stem cells) and their cell fate specification.

Reversal of Resistance towards Cisplatin by Curcumin in Cervical Cancer Cells

  • Roy, Madhumita;Mukherjee, Sutapa
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1403-1410
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    • 2014
  • Epigenetic regulators like histone deacetylases (1 and 2), and viral onco-proteins (E6/E7) are known to be overexpressed in cervical cancer cells. The present study was designed to investigate the effect of curcumin on HDACs (1 and 2) and HPV E6/E7 in the cervical cancer cell line SiHa and a drug resistant clone $SiHa^R$ (derived from SiHa). It was further intended to investigate whether curcumin could sensitize the cells towards cisplatin induced cell killing by modulation of multi drug resistant proteins like MRP1 and Pgp1. Curcumin inhibited HDACs, HPV expression and differentially increased acetylation and up-regulation of p53 in SiHa and $SiHa^R$, leading to cell cycle arrest at G1-S phase. Up-regulation of pRb, p21, p27 and corresponding inhibition of cyclin D1 and CDK4 were observed. Cisplatin resistance in $SiHa^R$ due to over-expression of MRP1 and Pgp1 was overcome by curcumin. Curcumin also sensitized both the cervical cancer cells towards cisplatin induced cell killing. Inhibition of HDACs and HPVs led to cell cycle arrest at G1/S phase by alteration of cell cycle regulatory proteins. Suppression of MRP1 and Pgp1 by curcumin resulted in sensitization of cervical cancer cells, lowering the chemotherapeutic dose of the drug cisplatin.