• The Korean journal of internal medicine
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• 제33권6호
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• pp.1234-1240
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• 2018

Background/Aims: Red blood cell distribution width (RDW) is a value representing the heterogeneity in the size of red blood cell, and it is usually used in distinguishing types of anaemia. Recently, it was reported that it could reflect the burden of inflammation in diverse diseases and their prognosis. Hence, in this study, we investigated whether RDW may contribute to discriminating adult onset Still's disease (AOSD) from sepsis in serious febrile patients within 24 hours after hospitalization. Methods: We reviewed the medical records and enrolled 21 AOSD patients, 27 sepsis patients and 30 matched healthy controls. We collected at least two laboratory results of variables including RDW within 24 hours after hospitalization, and we calculated their mean values. Results: Sepsis patients showed the significantly increased median white blood cell count, compared to AOSD patients ($14,390.0/mm^3$ vs. $12,390.0/mm^3$, p = 0.010). The median RDW in sepsis patients was higher than that in AOSD patients (15.0% vs. 13.3%, p = 0.001), and furthermore, the median RDW in both patient-groups was significantly higher than that in healthy controls. In contrast, the median ferritin level in sepsis patients was lower than that in AOSD patients (544.0 mg/dL vs. 3,756.6 mg/dL, p = 0.001). In multivariate analysis, RDW ${\geq}14.8%$ (odds ratio, 17.549) and ferritin < 2,251.0 mg/dL (odds ratio, 32.414) independently suggested sepsis more than AOSD in patients initially presenting with fever requiring hospitalization. Conclusions: RDW might be a rapid and helpful marker for a differential diagnosis between AOSD from sepsis at an early phase.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.416-416
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• 2011

태양전지의 고효율화를 위해, 생성된 전자와 전공을 전극에서 효과적으로 수집하는 방법에 대한 연구가 많이 진행되고 있다. 태양전지 전면전극은 빛의 조사에 의해 생성된 전자를 수집하는 매체로써 finger width가 넓어질수록, 전자를 수집하기 쉬워진다. 하지만 finger width가 넓어짐에 따라, shadowing loss 증가에 의해 단락전류 밀도가 감소하여 태양전지 효율이 저하 될 수 있다. 본 연구에서는 스크린 프린팅에 의해 형성된 전면전극의 finger width를 기존의 $80{\mu}m$에서 $50{\mu}m$로 변경하고, double printing에 의해 finger height를 높이는 방법으로 태양전지의 효율을 향상 시키고자 하였다. 그 결과, 전극패턴 50에서는 전극패턴 80보다 0.47 단락전류밀도가 증가하였고, 효율(efficiency)은 0.16%가 증가하는 것을 확인할 수 있었다.

• 전력전자학회논문지
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• 제27권6호
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• pp.526-534
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• 2022

The modular multilevel converter (MMC) has been widely applied to various industrial areas because of its various advantages and structural characteristics. Therefore, many methods for synthesizing the output voltage of MMC have been studied. Among these methods, phase-shifted pulse width modulation (PSPWM) is frequently used in MMC systems because it has diverse merits, such as excellent output qualities even with a small number of cells and uniform power distribution among cells. In this study, the total harmonic distortion (THD) of the output voltage is analyzed in accordance with the number of cells in one arm of a single-delta bridge cell MMC in order to compare PSPWM methods in terms of the THD of the output voltage. The physical characteristics of the triangle and sawtooth carrier waves used for the PSPWM and the mathematical modeling of output voltage are introduced. Then, the obtained results are verified through real-time simulation of a 1 MW single-delta bridge cell MMC system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.991-992
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• 2010

• 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.

• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.753-756
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• 2015

Background: Red cell distribution width (RDW) is one of the standard parameters with blood cell counts. Much previous research has indicated that it increases in cases of systemic inflammation or cardiametabolic incident. However, information on the relation of RDW with solid tumors causing systemic inflammation is limited. In the present research, we examined the relation of RDW with malignant and benign lesions of the colon. Materials and Methods: 115 patients with colon polyps (group 1), and 30 with colon cancer (group 2) who were diagnosed histopathologically in our clinic between January 2010-January 2013 were scanned retrospectively. Patients with anemia, hematologic diseases and active inflammation were excluded. RDW, mean corpuscular volume (MCV), hemoglobin (Hgb) and platelet (Plt) measurements were recorded and their relations with the malignant and benign lesions of the colon were examined. Results: Both groups were similar in age and gender distribution. RDW values of patients with colon cancer were significantly higher than the patients with colon polyp (p=0,01). No significant differences were detected between the two groups in terms of MCV and Plt values (p>0,05). Conclusions: RDW can be used as an early warning biomarker for solid colon tumors. Further prospective research is required on the relations of cheap and easily measured RDW parameters with colon malignancies.

• 한국통신학회논문지
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• 제42권2호
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• pp.374-382
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• 2017

본 논문에서는 주파수 대역 0.8-6GHz를 포함하는 2단 2-암 시누어스 안테나를 제안하였다. 제안한 안테나는 전체 반경 60mm중 1단 반경 50mm까지는 8개의 셀을 자기 상보구조(셀의 각 폭을 $90^{\circ}$)로 설계하고 2단은 폭 10mm사이에 비 자기상보 구조로 0.5개의 셀 각 폭을 $720^{\circ}$로 구성하였다. 측정 결과, 동일한 제원과 반경을 사용한 기존의 1단 2-암 시누어스 안테나는 반사손실 -10dB가 약 0.878GHz에서부터 발생하였지만, 제안한 안테나는 반사손실 -10dB이 0.807GHz 부터 발생하여, 시누어스 안테나의 소형화의 가능성을 제시하였다.

• 대한전자공학회논문지TC
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• 제49권2호
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• pp.56-66
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• 2012

단위 셀의 길이를 고정시키고 단위 셀의 폭과 via를 변화시켜 수평방향 방사가 억제되고 전방방향 방사가 증가하여 방사특성이 향상되는 inductive loaded 패치 안테나에 대하여 연구하였다. Inductive loaded 전송선을 구성하는 단위 셀의 구조 파라미터인 via 반경과 단위 셀 패치의 면적에 따라 분산 특성을 살펴보았다. 수평방향의 방사를 억제시키기 위해 inductive loaded 패치 안테나의 유효유전상수를 1과 가깝게 만드는 via의 반경과 단위 셀 패치의 폭을 결정하는 방법을 체계적으로 설명하였다. 5 GHz에서 동작하는 $5{\times}1$ inductive loaded 패치 안테나를 설계하여 방사특성을 전산모의한 결과 유효유전상수가 1보다 다소작을 때 E-평면 방향 수평 방사가 약 -15 dBi 이하로 크게 억제됨을 확인하였다.

• 한국정밀공학회지
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• 제25권5호
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• pp.96-102
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• 2008

Manufacturing of printed electronics using printing technology has begun to get into the hot issue in many ways due to the low cost effectiveness to existing semi-conductor process. This technology, with low cost and high productivity, can make it possible to produce printed electronics such as TFT, solar cell, RFID Tag, printed battery, and so on. In this study, apparatus of gravure-offset printing are developed for fine line-width/gap printing and the results obtained from the apparatus shows that it is possible to make around 20 micro-meter line-width/gap printing patterns. The roll-to-roll printing system for fine line-width printing based on primary experiment is presented. The printing results obtained from the system shows around 30 micro-meter line-width/gap printing patterns.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권2호
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• pp.156-163
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• 2008

We proposed a new $p^+/n^+$ gate locally-separated-channel (LSC) bulk FinFET which has vertically formed oxide region in the center of fin body, and device characteristics were optimized and compared with that of normal channel (NC) FinFET. Key device characteristics were investigated by changing length of $n^+$ poly-Si gate ($L_s$), the material filling the trench, and the width and length of the trench at a given gate length ($L_g$). Using 3-dimensional simulations, we confirmed that short-channel effects were properly suppressed although the fin width was the same as that of NC device. The LSC device having the trench non-overlapped with the source/drain diffusion region showed excellent $I_{off}$ suitable for sub-50 nm DRAM cell transistors. Design of the LSC devices were performed to get reasonable $L_s/L_g$ and channel fin width ($W_{cfin}$) at given $L_gs$ of 30 nm, 40 nm, and 50 nm.