• Mass Spectrometry Letters
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• v.8 no.1
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• pp.8-13
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• 2017

Analysis of quinidine for fish tissues using single drop microextraction (SDME) coupled with atmospheric pressure matrix assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) are reported. Optimization conditions; such as extraction solvent, extraction time, pH of the aqueous solution, salt additions (NaCl), stirring rate, matrix type and concentration are investigated. Linear dynamic range (${\mu}M$), limit of detection, relative recovery%, and enrichment factor are 0.08-9.2, 0.05, $94.8{\pm}3.1-98.5{\pm}3.3%$, $4.34{\pm}0.28-4.40{\pm}0.30$, respectively. SDME-AP-MALDI-MS shows good intraday and interday reproducibility.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.652_653
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• 2009

주어진 조건 하에서 의도하는 기간 동안 요구된 기능을 적절하게 수행하기 위해서는 제품의 신뢰성 확보가 무엇보다도 중요하다. 신뢰성 확보를 위해서는 제품의 안전성 및 내구성에 대한 고려가 충분히 이루어져야 한다. 고빈도 개폐를 목적으로 사용되는 전자기 접촉기 또한 제품의 안전성 및 성능의 신뢰성이 중요한 제품이라 할 수 있다. 그래서 이를 검증하기 위한 전자기 접촉기의 부하개폐동작성능에 대한 평가가 중요한 시험항목으로 부각되고 있다. 그리고 개폐특성을 평가하기 위한 부하는 규정된 과도회복전압특성을 얻을 수 있도록 조정되어야 한다. 본 논문에서는 부하측 중성점 접지 방식의 부하 회로 조정방법을 사용하여 전자기 접촉기의 개폐성능을 평가하기 위한 과도회복전압의 진동주파수와 진폭율의 특성을 고찰하였다.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2310-2318
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• 2018

Critical conduction mode (CRM) operation is more efficient than continuous conduction mode (CCM) operation at low power levels because of the valley switching of switches and elimination of the reverse recovery losses of boost diodes. When using a sensorless digital control method, an error occurs between the actual and the estimated current. Because of the error, it operates as CCM or discontinuous conduction mode (DCM) during CRM operation and also has an adverse effect on THD of input current. In this paper, a current sensorless technique is presented in an inverter system using a bridgeless boosted power factor correction converter, and a compensation method is proposed to reduce CRM calculation error. The validity of the proposed method is verified by simulation and experiment.

• Journal of the Korean Society of School Health
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• v.15 no.2
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• pp.167-182
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• 2002

The purpose of this study was to examine the factors related to adolescence' post-sexual assault attitudes and behaviors. 906 students from 5girls high schools completed self-reported questionnaires. Independent variables are sexual attitudes, rape myth acceptance, perceived importance of sexuality education, parent sexuality education, parent closeness, parent superintendence, family functioning and socioeconomic variables. The data were analyzed by Factor Analysis, Correlation Analysis, Stepwise Multiple Regression Analysis using SPSS program. The significant influencing factors were home sexuality education, perceived necessity & importance of sexuality education, parent closeness, parent superintendence, family functioning, grade, vocational school, rape myth(rapists are mentally ill, dating partner would not be rapist. rapists are stranger), sexual attitudes(sexual permissiveness, gender equality, family planning, STDs & prostitution, marriage and divorce and abortion), and dating experience. Examination of barriers to post-sexual assault coping behaviors and attitudes is critical component of victim recovery and rape prevention. This study would gives basic information to the effective prevention and coping program development related to sexual assault.

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.2
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• pp.1-10
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• 2003

The Rheological properties are important factors in printing process. Specially, emulsification phenomenon is a very important factor that decides the quality of printing products in lithography. In this paper, I investigated the flow characteristics depending on calcium carbonate concentration for emulsified inks. By applying the data of this paper, I which to predict quality of printing product in practical printing process.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1140-1146
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• 2013

Bioelectrochemical systems (BESs) have been suggested as a new technology for wastewater treatment while accomplishing energy and chemical generation. This study describes the performance of BESs based on mixed culture that are capable of reducing carbon dioxide to acetate. The cathode potential was a critical factor that affected the performance of the BESs. The rate of acetate production increased as the electrode potential became more negative, from 0.38 mM $d^{-1}$ (-900 mV vs. Ag/AgCl) to 2.35 mM $d^{-1}$ (-1,100 mV), while the electron recovery efficiency of carbon dioxide reduction to acetate increased from 53.6% to 89.5%. The microbial population was dominated by relatives of Acetobacterium woodii when a methanogenic inhibitor was added to the BESs initially.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.4
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• pp.181-186
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• 2006

This study was undertaken to evaluate whether peroxisome proliferator-activated-receptor-gamma $(PPAR-{\gamma})$ agonist-rosiglitazone (ROSI) induces postischemic functional recovery in Langendorf heart model. Hearts isolated from normal rats were subjected to 20 min of normoxia or 25 min zero-flow ischemia followed by 50 min reperfusion. In this acute protocol, ROSI $(20\;{\mu}g/ml)$ administered 10 min before ischemia had no effect on hemodynamic cardiac function, but had protective effect on lipid peroxidation in in vitro experiments. In chronic protocol in which ROSI was given by daily gavage (4 mg/kg) for three consecutive days, ROSI could not prevent the hemodynamic alteration on cardiac performance, but has protective effect on the activity of superoxide dismutase (SOD). There was no significant difference in the contents of reduced glutathione (GSH) and catalase activity between ischemia-reperfusion (IR) and ROSI treated IR hearts. Although ROSI had no effect on hemodynamic factor, it had effect on antioxidant activity. Our results indicate that ROSI provides partial beneficial effects by inhibiting lipid peroxidation and/or recovering normal level of SOD activity in the ischemic reperfused heart.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2191-2192
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• 2006

이 논문에서는 자기에너지 회생 스위치(MERS)를 이용한 3상 유도전동기의 역률개선을 목표로 한다. 기존의 MERS는 단상의 유도성 부하에 대해서는 간단한 제어방법을 통하여 역률을 개선시키는 효과가 있는 스위치로 알려져 있다. 이러한 스위치의 기능을 응용하여 논문에서는 실제 전철 등의 구동시스템에서 사용하는 3상 유도전동기 부하를 가진 시스템에 MERS를 적용시켰을 때 어떠한 이점들이 발생 하는지를 제안한다. 시뮬레이션을 위해 실제로 사용되는 3상 유도전동기와 이를 구동시키기 위한 컨버터와 인버터가 포함된 모터 구동 회로를 직접 구성하였다.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.559-560
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• 2006

이 논문에서는 자기에너지 회생 스위치(MERS)를 이용한 3상 유도전동기의 역률개선을 목표로 한다. 기존의 MERS는 단상의 유도성 부하에 대해서는 간단한 제어방법을 통하여 역률을 개선시키는 효과가 있는 스위치로 알려져 있다. 이러한 스위치의 기능을 응용하여 논문에서는 실제 전철 등의 구동시스템에서 사용하는 3상 유도전동기 부하를 가진 시스템에 MERS를 적용시켰을 때 어떠한 이점들이 발생하는지를 제안한다. 시뮬레이션을 위해 실제로 사용되는 3상 유도전동기와 이를 구동시키기 위한 컨버터와 인버터가 포함된 모터 구동 회로를 직접 구성하였다.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.90-95
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• 2015

This paper describes IEC 61727 standard of Photovoltaic (PV) systems -Characteristics of the utility interface. IEC 61727 standard tests include utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1) voltage, current and frequency, 2) normal voltage operating range, 3) flicker, 4) DC injection, 5) normal frequency operating range, 6) harmonics and 7) waveform distortion, 8) power factor of PV inverter. Also personnel safety and equipment protection part includes test items 1)loss of utility voltage, 2)over/under voltage and frequency, 3)Islanding protection, 4)response to utility recovery, 5)earthing, 6)short circuit protection, 7)Isolation and switching of PV inverter. In this paper, each item of IEC 61727 standard test is studied and analyzed and finally full tested by PV inverter performance function.