• Title/Summary/Keyword: cell loss

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Solar Cell Design for Large Area Multi Busbar Module Power Loss Reduction (대면적 Multi busbar 모듈 전력 손실 저감을 위한 태양전지 설계)

  • Juhwi Kim;Jaehyeong Lee
    • Current Photovoltaic Research
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    • v.11 no.1
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    • pp.34-37
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    • 2023
  • Solar energy had become the main energy industry of renewable energy along with hydroelectric power generation. One of the technologies that contributed to the popularization of photovoltaic power and the decrease in the unit price of photovoltaic modules was the large-area solar cell. However, as the area increased, the light receiving area increased and the current value increased accordingly. Since power loss occurs when the current value was large, the number of busbar was increased to increase the current collection rate, and a technology to lower the current value through half-cutting was developed. The bus bar of the solar cell served as a passage through which the generated current was transmitted. This was because when the number of busbar decreases, the moving distance of electrons increased, so the amount of power generation decreases and when it increases, shadows occured. An important aspect of the electrode design was the optimal balance of these busbars and number of fingers. Therefore, in this study, the characteristics of the solar cell according to the number of front bus bars of the large-area solar cell were simulated using Griddler 2,5 pro. After selecting the number of busbar with the best characteristics, the difference was compared by varying the number of fingers and a better direction for the number of cutting was presented.

Analysis of Dynamic Characteristics of 20 kW Hydrogen Fuel Cell System Based on AMESet (AMESet 기반 20 kW급 수소 연료전지 시스템 동특성 모델 해석)

  • JONGBIN WOO;YOUNGHYEON KIM;SANGSEOK YU
    • Journal of Hydrogen and New Energy
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    • v.34 no.5
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    • pp.465-477
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    • 2023
  • In proton exchange membrane fuel cell (PEMFC), proper thermal management of the stack and moisture generation by electrochemical reactions significantly affect fuel cell performance. In this study, the PEMFC dynamic characteristic model was developed through Simcenter AMESim, a development program. In addition, the developed model aims to understand the thermal resin balance of the stack and performance characteristics for input loads. The developed model applies the thermal management model of the stack and the moisture content and permeability model to simulate voltage loss and stack thermal behavior precisely. This study extended the C based AMESet (adaptive modeling environment submodeling tool) to simulate electrochemical reactions inside the stack. Fuel cell model of AMESet was liberalized with AMESim and then integrated with the balance of plant (BOP) model and analyzed. And It is intended to be used in component design through BOP analysis. The resistance loss of the stack and thermal behavior characteristics were predicted, and the impact of stack performance and efficiency was evaluated.

Induction of Autophagy and Apoptosis by the Roots of Platycodon grandiflorum on NCI-H460 Human Non-small Lung Carcinoma Cells (길경(桔梗)에 의한 NCI-H460 인체 비소세포폐암 세포에서의 autophagy 및 apoptosis 유발 효과)

  • Hong, Su-Hyun;Han, Min-Ho;Park, Cheol;Park, Sang-Eun;Hong, Sang-Hoon;Choi, Yung-Hyun
    • The Journal of Internal Korean Medicine
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    • v.35 no.3
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    • pp.317-331
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    • 2014
  • Objectives: The root of Platycodon grandiflorum (PG) has been known to possess a range of pharmacological activities including anti-cancer, anti-inflammatory, and anti-oxidant effects. The present study was designed to investigate whether or not PG-induced cell death was connected with autophagy and apoptosis in NCI-H460 human lung cancer cells. Methods: Effects on the cell viability and apoptotic activity were quantified using MTT assays and flow cytometry analysis, respectively. Protein activation was measured by immunoblotting. Autophagy was measured by LC3 immunofluorescence and immunoblotting. ROS production and loss of mitochondria membrane potential (MMP) were checked with flow cytometry analysis. Results: Following exposure to PG, NCI-H460 cell proliferation decreased simultaneously inducing autophagic vacuoles and up-regulation of microtubule-associated protein 1 light chain 3 and beclin-1 protein expressions. Interestingly, pre-treated with autophagy inhibitors, 3-methyladenin or bafilomycin A1 further triggered reduction of cell viability. PG treatment also induced apoptosis that was related modulation of Bcl-2 family proteins, death receptors and activation of caspases. In addition, PG stimulation clearly enhanced loss of MMP and reactive oxygen species (ROS) generation. Conclusions: Our results suggest that PG elicited both autophagy and apoptosis by increasing loss of MMP and ROS production. PG induced-autophagy may play a cell protective role.

The DLB Method for Multimedia Synchronization in the ATM Networks (ATM 망에서 멀티미디어 동기화를 위한 DLB 기법)

  • 구경옥;이병수;조용환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.4
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    • pp.842-854
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    • 1997
  • In this paper, the improved Dual Leaky-Bucket(DLB) algorithm is proposed to reduce the synchronous cell loss rate. The conventional DLB algorithm does not support synchronous cells, but the proposed algorithm gives higher priority to synchronous cells. To reduce synchronous cell loss rate, the synchronous cell detector is used in the proposed algorithm. Synchronous cell detector detects synchronous cells, and passes them cells to the 2nd Leaky-Bucket. So it is similar to give higher priority to synchronous cells. In this paper, the proposed algorithm used audio/videl traffic modeled by On/Off and Two-state MMPP, and simulated by SLAM II package. As simulation results, the proposed algorithm gets lower synchronous cell loss rate than the conventional DLB algorithms. The improved DLB algorithm for multimedia synchronization can be extended to any other cells which require higher priority.

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In-plane Switching Liquid Crystal Cell with a Mixed Bent Electrode Structure for Fast Response Time

  • Ko, Tae-Woon;Kim, Jae-Chang;Lee, Joun-Ho;Choi, Hyun-Chul;Ji, Seung-Hoon;Choi, Jung-Min;Lee, Chul-Hun;Lee, Gi-Dong
    • Journal of Information Display
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    • v.9 no.3
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    • pp.12-15
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    • 2008
  • A bent electrode structure is proposed in the super in-plane switching (S-IPS) liquid crystal (LC), as it can reduce the response time without loss of transmittance in the bright state. The electrode angle in each position of the bent electrode was optimized to simultaneously achieve high transmittance and fast response time. The electro-optical characteristics of the proposed LC cell structure were experimentally compared with those of the conventional cell. It was observed that the response time became over 8% shorter without loss of transmittance when the proposed bent structure was applied.

Cascode Low Noise Amplifiers with Coplanar Waveguide Structure for Wireless LAN Application

  • Kim, Jong-Ho;Kim, Ki-Byoung;Lee, Jong-Chul;Kim, Jong-Heon;Lee, Byungje;Kim, Nam-Young
    • Journal of electromagnetic engineering and science
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    • v.3 no.1
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    • pp.12-16
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    • 2003
  • In this paper, low noise amplifiers with coplanar waveguide structure are presented for Wireless LAN data communication application. For comparison of microwave performance, LNAs of cascode type and balanced type using cascode cell with the same substrate and same bias conditions are designed and implemented. A cascode type of LNA shows the gain of 12.45 ㏈, input return loss of 11.63 ㏈, and noise figure of 1.52㏈. A balanced type of LNA using cascode cell shows the gain of 6.58 ㏈, input return loss of 16.6 ㏈, and noise figure of 1.18 ㏈.

A Study on Acoustical Characteristics in Microcellular Foaming Plastics (초미세 발포 플라스틱의 음향특성 연구)

  • Cha, Sung-Woon;Kim, Hak-Bin;Lee, Byoung-Hee;Kang, Yon-Jun
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.9
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    • pp.71-77
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    • 2008
  • Microcellular foaming plastics create a sensation at polymer industrial for lowering product costs and overcoming a lowering of mechanical intensity. Among many advantages, microcellular foaming plastics is well known to have a good acoustical properties. This research based on the experiment of sound absorption and transmission characteristics inquire into acoustical properties of microcellular foaming plastics. Difference of transmission loss of microcellular foaming plastics and solid materials was defined as cell effect. Also, cell effect is expressed by sound reflection and sound absorption. This study is expected to fundamental research to present economical, functional alternative plan for products using sound absorption and transmission materials.

Physical Property Models and Single Cells Analysis for Solid Oxide Fuel Cell (고체산화물 연료전지를 위한 물성치 모델 및 단전지 해석)

  • Park, Joon-Guen;Kim, Sun-Young;Bae, Joong-Myeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.379-381
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    • 2009
  • The simulation model for metal-supported Solid Oxide Fuel Cell(SOFC) is developed in this study. Open circuit voltage is calculated using Nernst equation and Gibbs free energy is required by thermodynamic. The exchange current densities are compared with experimental results since exchange current density is most effective factor for the activation loss. Liu's study is used for the exchange current density of cathode, BSCF, and Koide's result is applied for the exchange current density of anode, Ni/YSZ. For the ohmic loss, ionic conductivity of YSZ is described from Kilner's mode and the data are compared with Wanzenberg's experimental data. Diffusivity is an important factor for the mass transfer through the porous medium. Both binary diffusion and Knudsen diffusion are considered as the diffusion mechanism. For validation, simulation results at this work are compared with our experimental results.

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ASIC design of high speed CAM for connectionless server of ATM network (ATM망의 비연결형 서버를 위한 고속 CAM ASIC 설계)

  • 백덕수;김형균;이완범
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1403-1410
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    • 1997
  • Because streaming mode connection server suitable to wide area ATM networks performs transmission, reception and lookup with time restriction for the transmission time of a cell, it has demerits of large cell loss incase that burst traffic occurs. Therefore, in this paper to decrease cell loss we propose a high speed CAM (Content Addressable Memory) which is capable of processing data of streaming mode connections server at a high speed. the proposed CAM is applied to forwarding table VPC map which performs function to output connection numbers about input VPI(Virtual Path Identifier)/VCI(Virtual Channel Identifier). The designed high speed CAM consist of DBL(Dual Bit Line) CAM structure performed independently write operation and match operation and two-port SRAM structure. Also, its simulation verification and full-custom layout is performed by Hspice and Composs tools in 0.8 .$\mu$m design rule.

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Endogenous Stem Cells in the Ear (귀에 존재하는 내인성 성체줄기세포)

  • Park, Kyoung Ho
    • Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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    • v.56 no.12
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    • pp.749-753
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    • 2013
  • Basically stem cells have characteristics of multi-potency, differentiation into multiple tissue types, and self-renew through proliferation. Recent advances in stem cell biology can make identifying the stem-cell like cells in various mammalian tissues. Stem cells in various tissues can restore damaged tissue. Stem cells from the adult nervous system proliferate to form clonal floating colonies called spheres in vitro, and recent studies have demonstrated sphere formation by cells in the tympanic membrane, vestibular system, spiral ganglion, and partly in the organ of Corti. The presence of stem cells in the ear raises the possibilities for the regeneration of the tympanic membrane & inner ear hair cells & neurons. But the gradual loss of stem cells postnatally in the organ of Corti may correlate with the loss of regenerative capacity and limited hearing restoration. Future strategies using endogenous stem cells in the ear can be the another treatment modality for the patients with intractable inner ear diseases.