• 전력전자학회:학술대회논문집
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• 전력전자학회 2020년도 전력전자학술대회
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• pp.381-382
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• 2020

In the battery energy storage system, battery cells are connected in series to increase the operating voltage. Due to the difference in characteristics, the performance degradation of cells is dissimilar. This paper proposes an online DC internal impedance estimation for battery cells in the series string using a matrix-switched capacitor converter, which is already verified as useful for the series balancing of the cells. The simulation in the hardware in the loop test rig shows good accuracy and the feasibility of the proposed method.

• 대한한방내과학회지
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• 제25권2호
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• pp.298-306
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• 2004

Objective : The main purpose of this study was to determine if Rehmanniae Radix has significant effects on lung fibrosis. Materials and Methods : C57BL/6J mice were devided into three groups. These were the normal group, which were not treated, the control group, given Intratracheal instillation(IT) of Bleomycin, the sample group, given IT of bleomycin and water-extracted Rehmanniae Radix. Animals were sacrificed 14 days after IT treatment. Lung fibrosis was evaluated by analysis of bronchoalveolar larvage(BAL) total WBC, percentage of macrophage, lymphocyte and neutrophil. This was done histologically by semiquantitative histological index(SHT) of lung tissue. Results : The sample group in coparison with control group showed a decrease in the BAL, total WBC, lower percentage of lymphocyte and neutrophil(p<0.05) and correspondingly a lower percentage of macrophage(p<0.01). The Sample group showed a significant decrease of collagen accumulation with respect to the control group in SHI of lung tissue(p<0.01). INF-${\gamma}$ and IL-4 levels in BALF of mice significantly decreased in the control group(p<0.05). Conclusions : Results suggest that Rehmanniae Radix has an anti-imflamatory effect and anti-fibrotic effect on the lungs through decrease of IL-4 and total WBC count for not only macrophage, but also lymphocyte and neutrophil. The degradation of INF-${\gamma}$ calls for research beyond the scope of this study.

• 대한한방내과학회지
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• 제25권4호
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• pp.274-288
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• 2004

Objectives : This study was designed to evaluate the effect on cytotoxicity of Bojungikki-tang(BIT) in human lung cancer H460 cells. Methods : BIT-induced cell death was confirmed as apoptosis characterized by chromatin condensation and increase of the $sub-G_1$, DNA content. It was tested whether the water extract of BIT affects the cell cycle regulators such as, p2l/Cipl, p27/Kipl, cyclin $B_1$. Results : The data showed that treatment of BIT decreased the viability of H460 cells in a dose-dependent manner. p2l/Cip1 is gradually decreased by the addition of the cells with BIT extract. Interestingly, p27/Kip1 is not detected for 24 hr after the addition of BIT extract, however, after 24 hr, p27/Kipl markedly increased. In addition, cyclin $B_1$, decreased in a time dependent manner after the addition of the water extract. The activation of caspase -3 protease was further confirmed by degradation of procaspase-8 protease andpoly(ADP-ribose) polymerase(P ARP) by BIT in H460 cells. Moreover, BIT induced the increase of Bak expression. Conclusion : These results suggest that the extract of BIT exerts anticancer effects to induce the death of human lung cancer H460 cells via down regulation of cell cycle regulators such as p2l/Cip1, and cyclin B1 or up regulation of cell cycle regulators such as p27/Kip1. Moerover results suggest that BIT induces an apoptosis in H460 cells via activation of intrinsic caspase cascades.

• 대한한방내과학회지
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• 제22권1호
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• pp.39-44
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• 2001

Objective : This experimental study was carried out to investigate the effects of Persicae Semen(PS) and Caesalpiniae Lignum(CL) on the intravascular coagulation which is considered as thrombosis. Methods : Rats were pretreated orally with PS and CL extracts(PS: 8.45mg/100g, CL: 4.4mg/100g), and 1 hour later, to induce thrombosis, were given an endotoxin(0.01mg/100g) injection into the caudal vein. After 4hours we collected blood by cardiac puncture and measured the platelet count, the prothrombin time, the level of fibrinogen and the FDP(fibrinogen degradation product). Results : PS and CL supressed the decrease of the Platelet count and the prolongation of prothrombin time. In these factors, both groups showed significant effect. Both groups supressed the decrease of the fibrinogen level and the increase of the FDP level. But, only the PS group showed a significant effect on the fibrinogen level, and only the Cle CL group showed a significant effect on FDP level. Conclusions : PS had significant effects on the platelet count, the prothrombin time, and the FDP level. CL had significant effects on the platelet count, the prothrombin time, and the fibrinogen level. Therefore, PerSicae Semen and Caesalpiniae Lignum seem to be applicable to treating the diseases related to thrombosis.

• Journal of electromagnetic engineering and science
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• 제17권3호
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• pp.138-146
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• 2017

A phase-locked dielectric resonator oscillator (PLDRO) is an essential component of millimeter-wave communication, in which phase noise is critical for satisfactory performance. The general structure of a PLDRO typically includes a dual loop of digital phase-locked loop (PLL) and analog PLL. A dual-loop PLDRO structure is generally used. The digital PLL generates an internal voltage controlled crystal oscillator (VCXO) frequency locked to an external reference frequency, and the analog PLL loop generates a DRO frequency locked to an internal VCXO frequency. A dual loop is used to ease the phase-locked frequency by using an internal VCXO. However, some of the output frequencies in each PLL structure worsen the phase noise because of the N divider ratio increase in the digital phase-locked loop integrated circuit. This study examines the design aspects of an interconnected PLL structure. In the proposed structure, the voltage tuning; which uses a varactor diode for the phase tracking of VCXO to match with the external reference) port of the VCXO in the digital PLL is controlled by one output port of the frequency divider in the analog PLL. We compare the proposed scheme with a typical PLDRO in terms of phase noise to show that the proposed structure has no performance degradation.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.78-81
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• 1995

In imaging the samples or human internal organs in a tube shape, general RF-probe types (that encircles a sample or places on top of the sample) are usually unsuitable for the internal imaging due to the degradation of signal-to-noise ratios(SNR's). In the present study the inside-out probes for Magnetic Resonance Imaging (MRI) have been constructed in the three different shapes such as an anti-solenoidal, a saddle and a dual surface types which are positioned as close to the area as possible by putting the probe inside the tubelike sample to improve filling factor. RF-field distributions have also been calculated depending upon the geometrical changes of anti-solenoid probes. Moreover, the performance of the inside-out probes has been checked by measuring SNR's of the images acquired. The inside-out probes constructed in this study produced better SNR's and rf-field uniformity in the area close to the probes in comparing with any other commercial probes. There is a high possibility that the constructed probes in the present study are applicable to the diagnosis of human bodies.

• 대한한의학방제학회지
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• 제16권2호
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• pp.101-114
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• 2008

Objective : The purpose of this study was to investigate the anti-inflammatory effects of Hwagae-san extract(HGSE) on the peritoneal macrophage. Methods : To evaluate anti-inflammatory effects of HGSE, We measured cytokines(interleukin-6; IL-6, interleukin-12; IL-12, tumor necrosis factor-${\alpha}$; TNF-${\alpha}$) and nitric oxide(NO) production in lipopolysaccharide(LPS)-induced macrophages. Furthermore, We examined molecular mechanism using western blot and also LPS-induced endotoxin shock. Results : 1. HGSE did not have any cytotoxic effect in the peritoneal macrophages. 2. HGSE reduced LPS-induced IL-6, TNF-${\alpha}$, IL-12 and NO production in peritoneal macrophages. 3. HGSE inhibited the activation of extracelluar signal-regulated kinase(ERK), C-Jun NH2-terminal kinase(JNK) but not of p38, degradation of IkB-${\alpha}$ in the LPS-stimulated peritoneal macrophages. 4. HGSE inhibited the production of TNF-$\alpha$, IL-6 and IL-12 in serum after LPS injection. Conclusion : These results suggest that HGSE may inhibit the production of TNF-${\alpha}$, IL-6, and IL-12 through inhibition of ERK and JNK activation, and that HGSE may be beneficial for inflammatory diseases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2377-2379
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• 1999

In order to analyze failure rates of underground transmission power cable systems in Korea, the survey has been performed for the failure cases of cables, joints, and terminations in CV, OF and POF cable systems which occurred from 1983 to 1998. During 16 years, the failure cases due to trips of the systems were 47 among the total 108 cases, These 47 cases could be divided into internal reasons(manufacture/installation, corrosion and degradation) of 16 cases and external reasons (external mechanical damages, lightning, fire. etc.) of 31 cases. For the 154 kV cable systems during 12 years from 1987 to 1998, total failure rate was 0.0057 [case/100C-km/year] and internal reason failure rate was 0.0020 [case/100C-km/Year], which is similar to those of foreign countries. Also, the many cases of internal reason failures occurred in the early stage after the operations due to incorrect installations. This implies that the installation process is very important and some diagnostic tests such as PD measurement are needed besides after laying test.

• 대한한의학회지
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• 제26권1호
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• pp.18-25
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• 2005

Objective & Methods: We examined the effects of Platycodi radix on the process of lipopolysaccharide (LPS)-induced nuclear factor $NF-{\kappa}Bp65$ and inhibitory $(I)-{\kappa}B{\alpha}$ alteration in RAW 264.7 cells and acute lung injury in rats. Results: Immunoblot analysis showed that LPS-induced degradation of $I-{\kappa}B{\alpha}$ in RAW 264.7 was inhibited by pretreatment of Platycodi radix. The total cells of bronchoalveolar lavage fluid by LPS challenge markedly decreased in the Platycodi radix pretreatment rats. Platycodi radix pretreatment also caused a decline in neutrophils infiltration into interstitium of the lung. In the alveolar macrophages and neutrophils, decreased $NF-{\kappa}Bp65$ and inducible nitric oxide synthase and increased $I-{\kappa}B{\alpha}$ immunoreaction were detected in Platycodi radix pretreated rats compared with LPS alone treated ones. Conclusion : It may be concluded that Platycodi radix attenuates the development of LPS-induced inflammation by reduction of $NF-{\kappa}Bp65$ activation and neutrophil-mediated acute lung injury. Platycodi radix would be useful as a therapeutic agent for endotoxin-induced lung disease.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.237-239
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• 2018

This paper proposes an on-line estimation algorithm of internal resistance of Li-ion battery based on the recursive least squares method to prevent the overvoltage and undervoltage casing degradation of life cycle of battery. An equivalent circuit model with single time constant is adopted, and under assumptions that the terminal voltage, current and SOC are measured accurately, the discrete time based nonlinear equation of the model can be converted to the linear equation which can be applied to recursive least squares method. Since the coefficients of the discrete time linear equation can be expressed by the parameters of the equivalent circuit model, it is shown that an internal resistance (Ri) can be estimated in real time using the least square method.