• Title/Summary/Keyword: A cell

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Triple junction 태양전지의 a-SiGe middle cell에 관한 연구 (Study of hydrogenated a-SiGe cell for middle cell of Triple junction solar cell)

  • 박태진;백승조;김범준
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.83.1-83.1
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    • 2010
  • Hydrogenated a-SiGe middle cell for triple junction solar cell was investigated with various process parameters. a-SiGe I-layer was deposited at substrate temperature $245^{\circ}C$ and hydrogen content(R) was up to 26.7. Low optical bandgap(1.45eV) of a-SiGe cell was applied for middle cell although a-SiGe single cell efficiency with low Ge content was higher. And this cell was applied to the middle cell of a glass superstrate type a-Si/a-SiGe/uc-Si triple junction solar cell. The triple junction solar cell was resulted in the initial efficiency of about 9%, area $0.25cm^2$, under global AM 1.5 illumination.

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A semi-automatic cell type annotation method for single-cell RNA sequencing dataset

  • Kim, Wan;Yoon, Sung Min;Kim, Sangsoo
    • Genomics & Informatics
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    • 제18권3호
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    • pp.26.1-26.6
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    • 2020
  • Single-cell RNA sequencing (scRNA-seq) has been widely applied to provide insights into the cell-by-cell expression difference in a given bulk sample. Accordingly, numerous analysis methods have been developed. As it involves simultaneous analyses of many cell and genes, efficiency of the methods is crucial. The conventional cell type annotation method is laborious and subjective. Here we propose a semi-automatic method that calculates a normalized score for each cell type based on user-supplied cell type-specific marker gene list. The method was applied to a publicly available scRNA-seq data of mouse cardiac non-myocyte cell pool. Annotating the 35 t-stochastic neighbor embedding clusters into 12 cell types was straightforward, and its accuracy was evaluated by constructing co-expression network for each cell type. Gene Ontology analysis was congruent with the annotated cell type and the corollary regulatory network analysis showed upstream transcription factors that have well supported literature evidences. The source code is available as an R script upon request.

Analysis of a Symmetric Active Cell Balancer with a Multi-winding Transformer

  • Jeon, Seonwoo;Kim, Myungchin;Bae, Sungwoo
    • Journal of Electrical Engineering and Technology
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    • 제12권5호
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    • pp.1812-1820
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    • 2017
  • This paper analyzes a symmetric active cell balancer for a battery management system. The considered cell balancer uses a forward converter in which the circuit structure is symmetric. This cell-balancing method uses fewer switches and is simpler than the previously proposed active cell-balancing circuits. Active power switches of this cell-balancing circuit operate simultaneously with the same pulse width modulation signals. Therefore, this cell-balancing circuit requires less time to be balanced than a previous bidirectional-forward-converter-based cell balancer. This paper analyzes the operational principles and modes of this cell balancer with computer-based circuit simulation results as well as experimental results in which each unbalanced cell is equalized with this cell balancer. The maximum power transfer efficiency of the investigated cell balancer was 87.5% from the experimental results. In addition to the experimental and analytical results, this paper presents the performance of this symmetric active cell-balancing method.

Matlab을 이용한 망막신경절세포 감수야 구성 (Reconstruction of Receptive Field of Retinal Ganglion Cell Using Matlab)

  • 예장희;진계환;구용숙
    • 한국의학물리학회지:의학물리
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    • 제17권4호
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    • pp.260-267
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    • 2006
  • 개개의 망막신경절세포는 자신이 담당하고 있는 망막의 특정부위에 빛자극이 가해지면 그 빛자극의 특징을 활동전위의 형태로 인코딩하게 된다. 이때 개개의 망막신경절세포가 담당하고 있는 망막의 특정부위를 감수야(receptive field)라 부른다. 그러므로 망막신경절세포의 전기적 특성을 파악하기 위해서는 감수야의 위치를 규정하는 작업이 반드시 필요하다. 그 이유는 감수야의 배열 상태를 알게 되면 신경절세포가 어떻게 시각자극을 인코딩하는지 그 메커니즘에 관한 통찰이 가능하기 때문이다. 본 논문에서는 무작위 바둑판 자극을 MEA의 개개 채널에 독립적으로 인가함과 동시에 여러 망막신경절세포의 흥분파를 기록하였다. 이후 오프라인에서 망막신경절세포의 파형을 추출하고 ON-cell, OFF-cell, ON/OFF-cell로 분류한 후 개개의 망막신경절세포의 감수야를 WATLAB을 이용하여 구현하여 보았다. 이런 방식으로 재구성된 ON-cell과 OFF-cell의 감수야의 예를 제시한다.

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A Study On the Cooling Effect of the Floating Horizontal Solar Cell

  • Jae-hyuk Lee
    • International journal of advanced smart convergence
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    • 제12권2호
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    • pp.182-186
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    • 2023
  • In this study, we measured the power and temperature of the floating horizontal solar cell in a coastal lagoon and compared with those of ground solar cell and water platform solar cell. Because the bottom surface of the floating horizontal solar cell was contacting the water, cooling effect was expected stronger than other cells. As a result of the measurement, the power of floating horizontal cell was 11.7% higher than that of the ground cell and 15% higher than that of the water platform cell. During the measurement, it was observed that water waves were continuously flowed on the top surface of floating horizontal cell by the wind, and it could be assumed that the cooling effect occurred not only on the bottom surface of the cell but also on the top surface. In order to analyze the cooling effect and power increasing of the horizontal cell in the wave situation, we measured power and temperature of the cell while generating artificial waves in a laboratory equipped with Zenon lamp as a solar simulator. At the height of thewater surface, the power of the cell with waves was 3.7% higherthan without waves and temperature was 4.6℃ lower. At 1 cm and 2 cm below the watersurface, power of the cell with waves was decreased by 14% and 11% than without waves while temperature was same . At 3 cm below the water surface, there was no effect of waves.

가감소합향원(加減蘇合香元) 향기액이 세포활성에 미치는 영향과 항산화효과에 관한 연구 (The Effect of GagamSohabhwang-won(Jiajiansuhexiang-yuan) Essential Oil on Cell Activity and Anti Oxidation)

  • 윤여국;김근우;구병수
    • 동의신경정신과학회지
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    • 제20권3호
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    • pp.1-13
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    • 2009
  • Objectives : The glial cell, located in between the blood vessel and nerve cell, takes charge of the cell support, nutrition supply, elimination of body waste, and cell action. GagamSohabhwangwon(GGSH), a chinese traditional medicinal prescription has been used orally for the treatment of seizures, infantile, convulsion, stroke and so forth. This paper examines the effect of the GagamSohabhwangwon(GGSH) essential oil on cell activity and anti oxidation. Methods : MTT assay methods were employed to measure the cell activity based on the amount of the GagamSohabhwangwon(GGSH) essential oil by using primarily cultivated glial cell. In addition, this paper measured a viability of the glial cell after a protein active retarder control to confirm the multiplication of the cell and examined the cell extinction by the active oxygen, an extinction shielding effect with different amount of the GagamSohabhwangwon(GGSH) essential oil to observe anti oxidation. Furthermore, this paper measured a viability of the cell and phosphorylation(phosphorylation) of the protein which affects the multiplication of the glial cell. Results : When controlling the amount of the GagamSohabhwangwon(GGSH), there was a multiplication effect of the primary glial cell, the multiplication of the cell was dependent on the density of the GagamSohabhwangwon. The multiplication power of the primary glial cell was suppressed by PKA inhibiter (H89). In compliance with the active oxygen the extinction of the primary glial cell was dependent on the density of the GagamSohabhwangwon, there was a shielding effect of the cell extinction when GagamSohabhwangwon(GGSH) was preprocessed. When inducing the multiplication of the primary glial cell, phosphorylation of the Akt, BDNF, CREB, ERK and ERM were increased. Conclusions: Based on the results, GagamSohabhwangwon essential oil will have the effect which activates the nervous system cell and protects the cell through anti oxidation.

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권삼(拳蔘)의 항암효과에 대한 연구 (Studies of the Anti-cancer Effects of Bistortae Rhizoma)

  • 김준범;한효상;이영종
    • 동의생리병리학회지
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    • 제23권5호
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    • pp.1139-1144
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    • 2009
  • This study was purposed to research the anti-cancer effects of Bistortae Rhizoma. A total extract of Bistortae Rhizoma decoction was prepared. By measuring the cell proliferation, apoptosis, morphology and cytokine level from the extracts, the influence on HepG2 cell, SNU-1 cell and A549 cell was compared. The Bistortae Rhizoma decoction extract did not control HepG2 cell proliferation but controlled SNU-1 cell and A549 cell proliferation. In particular, the inhibitory effect on SNU-1 cell proliferation was highest. The Bistortae Rhizoma decoction extract showed to increase the apoptosis of the HepG2 ceil, SNU-1 cell and A549 cell in a dose-dependent manner. In particular, the promotion effect of the apoptosis was highest in SNU-1 cell. Among the various fraction extracts of the Bistortae Rhizoma decoction, n-BuOH extraction showed the greatest increase of the apoptosis of the HepG2 cell. The Bistortae Rhizoma decoction extract decreased dose-dependently the secretion of the TGF-$\beta$ in the HepG2 cell, SNU-1 cell and A549 cell and increased the secretion of the TNF-$\alpha$ and the IFN-$\gamma$. These results suggest that the total extract of Bistortae Rhizoma decoction has anti-cancer effect against SNU-1 cell and A549 cell.

Microfluidic Control for Biological Cell Orientation

  • Namkung, Young-Woo;Park, Jung-Yul;Kim, Byung-Kyu;Park, Jong-Oh;Kim, Jin-Oh
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.2457-2460
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    • 2003
  • There is a great demand to manipulate biological cell autonomously since biologist should spend much time to obtain skillful manipulation techniques. For this purpose, we propose a cell chip to control, carry, fix and locate the cell. In this paper, we focus on the cell rotator to rotate individual biological cell based on a micro fluidics technology. The cell rotator consists of injection hole and rotation well to rotate a biological cell properly. Under the variation of flow rate in injection hole, the angular velocity of a biological cell is evaluated to find the feasibility of the proposed rotation method. As a practical experiment, Zebrafish egg is employed. Based on this research, we find the possibility of non-contact rotation way that can highly reduce the damage of the biological cell during manipulation. To realize an autonomous biological cell manipulation, a cell chip with manipulation well and micro channel in this research will be utilized effectively in near future.

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Load Cell Noise 제거를 위한 Digital Load Cell 에 대한 연구 (A study on a digital load cell for the removal of load cell noise)

  • 이영진;이흥호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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    • pp.562-564
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    • 2002
  • Noise reduction and a simplification of a precision measurement system has been performed by changing analog output mode of a load cell into digital output mode. Usually, analog output signal of a few $\mu V$ from a load cell are amplified by amp and acquired by A/D converter. If the distance from a load cell to a DAS(Data Acquisition System) increases, more noise signals are mixed. So, a microprocessor has been integrated into a load cell so that the amplification and A/D conversion of output signals could be done in close proximity to the lode cell for the reduction in mixing of noise. Obtained data from the load cell like this manner are transferred to a computer with digital values(of TTL level). To simplify the configuration of a multi-channel DAS, RS-485 communication system has used for data transfer.

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