• The Transactions of the Korean Institute of Power Electronics
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• 제13권3호
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• pp.206-212
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• 2008

This paper proposes the PLL(Phase-Locked Loop) algorithm by a new FFT(Fast Fourier Transform) in a grid-connected PV PCS(Photovoltaics Power Conditionning System). The grid-connected inverter that is applied in a new renewable energy field needs the grid phase information for synchronism. Unlike the PLL which is normally used by three phase D-Q conversion, the preposed PLL algorithm using FFT has non-gain tuning and the powerful noise elimination by the characteristics of FFT. Both simulation and experimental result show that proposed algorithm has the good capacity.

• Proceedings of the KIEE Conference
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.756-757
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• 2008

Interior permanent magnet synchronous motor (IPMSM) which has high power density is usually applied to traction motor for hybrid electric vehicle. In order to analyze characteristics of IPMSM, d- and q-axis equivalent circuit analysis is generally used. However, the line current of IPMSM calculated by d- and q-axis equivalent circuit analysis differ from measured value. This error is mainly appeared under the flux weakening control. In order to reduce the error between calculated and measured line current, no-load linkage flux which is calculated with considering saturation of magnetic core and armature reaction is applied to characteristic analysis. The result of line current calculated by the method dealt with in this paper is verified by comparison with experimental results.

• Journal of Power Electronics
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• 제16권6호
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• pp.2294-2305
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• 2016

The introduction of a high-voltage direct-current (HVDC) system based on a modular multilevel converter (MMC) for wind farm integration has stimulated studies on methods to control this type of converter. This research article focuses on the control of the AC voltage and circulating current for a wind-farm-side MMC (WFS-MMC). After theoretical analysis, emotional learning (EL) controllers are proposed for the controls. The EL controllers are derived from the learning mechanisms of the amygdala and orbitofrontal cortex which make the WFS-MMC insensitive to variance in system parameters, power change, and fault in the grid. The d-axis and q-axis currents are respectively considered for the d-axis and q-axis voltage controls to improve the performance of AC voltage control. The practicability of the proposed control is verified under various conditions with a point-to-point MMC-HVDC system. Simulation results show that the proposed method is superior to the traditional proportional-integral controller.

• Transactions of the Korean Society of Automotive Engineers
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• 제23권1호
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• pp.25-33
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• 2015

This paper presents the d-q axis equivalent circuit model of an interior permanent magnet (IPM) which includes the iron loss resistance. The model is implemented to be able to run in real-time on the FPGA-based HIL simulator. Power electronic devices are removed from the motor control unit (MCU) and a separated controller is interfaced with the real-time simulated motor drive through a set of proper inputs and outputs. The inputs signals of the HIL simulation are the gate driver signals generated from the controller, and the outputs are the winding currents and resolver signals. This paper especially presents iron loss prediction which is introduced by means of comparing the torque calculated from d-q axis currents and the desired torque; and minimizing the torque difference. This prediction method has stable prediction algorithm to reduce torque difference at specific speed and load. Simulation results demonstrate the feasibility and effectiveness of the proposed methods.

• YAKHAK HOEJI
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• 제54권5호
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• pp.377-386
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• 2010

Single-dimensional (1-D) and two-dimensional (2-D) LC methods were utilized to separate peptides from various sources followed by MS/MS analysis. Two-dimensional ultra-high performance liquid chromatography is a useful tool for proteome analysis, providing a greater peak capacity than 1-D LC. The most popular 2-D LC approach used today for proteomic research combines strong cation exchange and reversed-phase LC. We have evaluated an alternative mode for 2-D LC of peptides using 2-D RP-RP nano UPLC Q-TOF Mass Spectrometry, employing reversed-phase columns in both separation dimensions. As control experiments, we identified 129 proteins in 1-D LC and 322 proteins in 2-D LC from E. coli extract peptides. Furthermore, we applied this method to rat primary hepatocyte and a total of 170 proteins were identified from 1-D LC, and 527 proteins were identified from all 2-D LC system. The in-depth protein profiling established by this 2-D LC MS/MS from rat primary hepatocyte could be a very useful reference for future applications in regards to drug induced liver toxicity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.607-610
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• 2003

The characteristic prediction and analysis of 3-dimensional (3-D) solenoid-type embedded inductors is investigated. The four different structures of 3-D inductor are fabricated by using low-temperature cofired ceramic (LTCC) process. The circuit model parameters of the each building block are optimized and extracted using the partial element equivalent circuit method and HSPICE circuit simulator. Based on the model parameters, predictive modeling is applied for the structures composed of the combination of the modeled building blocks. And the characteristics of test structures, such as self-resonant frequency, inductance and Q-factor, are analyzed. This approach can provide the characteristic conception of 3-D solenoid embedded inductors for structural variations.

• Biomedical Science Letters
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• 제19권2호
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• pp.153-157
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• 2013

Although culture is the gold standard method to identify mycobacteria, its use in tuberculous lymphadenitis (TBL) is limited due to formalin fixation of the submitted specimens. We evaluated the performance of quantitative real-time PCR (q-PCR) for Mycobacterium Tuberculosis (MTB) in granulomatous lymphadenitis using formalin-fixed paraffin-embedded (FFPE) tissues. From 2000 to 2010, a total number of 117 cases of lymph node samples with granulomatous inflammation which were surgically removed and fixed in formalin were studied. Hematoxylin & Eosin (H&E) and Ziehl-Neelsen-stained (ZN) slides were reviewed. qPCR using Real TB-Taq$^{(R)}$ was performed for all cases to identify Mycobacterium tuberculosis. Thirteen non-tuberculous lymphadenopathy cases were used as negative control. Cervical lymph nodes were more frequently affected (60%, 70/117) than other sites. ZN stain for acid fast bacilli was positive in 19 (16.24%) cases. qPCR for tuberculosis was positive in 92 (78.63%) cases. Caseous necrosis was found in 103 (88.03%) cases. While the ZN stain and qPCR were both negative in all control cases, the qPCR showed a significantly higher positive rate (78.63% vs. 16.24%) compared to ZN stain in histologically diagnosed TBL. Quantitative real-time PCR proves to be more sensitive than ZN stain for diagnosis of tuberculous lymphadenitis.

• Journal of Korean Society for Quality Management
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• 제43권3호
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• pp.273-288
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• 2015

Purpose: In this study, we apply environmental stress screening (ESS) to battle management system (BMS) of a tank and use the ESS profile based on production process data, guided by MIL-HDBK-781/344/2164. Methods: To optimize ESS Profile of the BMS of a tank, we estimate ESS model parameters (e.g., defect density, screening strength) using primary production failure reporting and corrective action system (FRACAS) data of military supply contract firm. Results: First, we collect the Primary production FRACAS data of military supply contract firm. Second, we compute curve fitting approach to find patent defect density and latent defect density using FRACAS data. Third, we solve the equation of Defect Density(patent defect density + latent defect density)($D_{IN}$) and Screening Strength(SS) Using second step data. As a result of analysis according to the order, we calculate $D_{IN}$(Temperature stress case : 74.02, Vibration stress : 10.252) and : SS(Temperature stress case : 0.4632, Vibration stress : 0.4142) and confirm the Condition II-D based on MIL-HDBK-344. According to Condition II-D, it is necessary to modify existing ESS profile through decreasing the $D_{IN}$ and increasing the SS. Conclusion: Identification of defect causes through ESS approach reduce defect densities for production. It provides feedback to a lessons-learned data base to avoid similar problems on next generation tank BMS.

• Journal of the Society of Cosmetic Scientists of Korea
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• 제34권1호
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• pp.51-55
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• 2008

Although phthalates aren't used as an cosmetic ingredient, some cosmetics especially nail lacquer, hair spray, and perfume still have phthalates. This is mainly caused by contamination and carryover during manufacturing process, so analysis of phthalates in those cosmetics has became a very important thing for quality-assurance(Q.A). The main phthalates under debate are diethyl phthalate(DEP), dibutyl phthalate(DBP), and bis(2-ethylhexyl) phthalate (DEHP) in domestic market. Gas chromatography-mass spectrometry(GC-MS) coupled with solvent extraction and concentration has been used for ppm level and sub ppm level analysis of phthalates. It requires much time and cost to use mass spectrometric detector and to prepare the test solution. Moreover analysis of phthalates at low concentrations is difficult because of contamination which results in wrong analytical results. In the present study, we showed a simple method using gas chromatography-flame ionization detector(GC-FID) which has fast analysis time, minimum use of solvent, reduced sample preparation steps for minimizing contamination and quantitative range of $2{\sim}50{\mu}g/g(ppm)$ in products. Consequently, this method will be proper for Q.A analysis in related companies.

• Economic and Environmental Geology
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• 제17권3호
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• pp.163-169
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• 1984

A linear inversion of heat flow values using heat production data with reliable value is studied in this work. To evaluate 2-D problem, a thin vertical sheet model is considered. Making use of a relation based on potential theory, a new relation between $q_{rad}$ and $A_0$ is derived. The forward calculations with noise and without noise are shown. The inversion of random search is comparable to that of ridge regression method. The agreements between the computed and best fit after inversion suggest the importance of random search method in the inversion technique.