• Title/Summary/Keyword: Primary frequency control

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Optimal Design of CEDM considering the Dynamic Characteristics (제어봉 구동장치의 동적 특성을 고려한 최적설계)

  • 김인용;진춘언
    • Computational Structural Engineering
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    • v.10 no.3
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    • pp.225-231
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    • 1997
  • The dynamic characteristics of Control Element Drive Mechanism(CEDM) for Korea Standard Nuclear Power Plant are studied with the CEDM modeled as a secondary mass in a simplified two degree of freedom system, while the reactor vessel as a primary mass. The optimal .mu.-f curve is developed to reduce the response amplitudes of both primary and secondary masses. In order to improve a design it is proposed that the natural frequency ratio, f, should be converged to 0.93, the mass ratio, .mu., should not be reduced, and the result should be converged to the optimal .mu.-f curve. Optimal design for CEDM components has been carried out and the response amplitude ratios of reactor are reduced 10.5 - 19.7% while those of CEDM are reduced 6.3 - 3.4%.

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Contactless Power Transfer System using Voltage Phase (전압위상을 이용한 무접점 전원공급 시스템에 관한 연구)

  • Yu, Joo-Hee;Kim, Choon-Sam
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.3
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    • pp.219-226
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    • 2011
  • As the existing contactless power transfer system(CPTS) is adopting the principle of contactless transformer enables to supply power in contactless way using RFID(radio frequency identification)/ID communication method between primary and secondary sides of contactless transformer and detect the alien load. Such CPTS requires the circuit that generates ID in addition, and the ID identification and control generated from the secondary side is performed at the primary side, which cuases complexity of the circuit. Therefore, this study suggested the CPTS using voltage phase, and In order to verify the validity of this study, 3[W] class CPTS shall be designed, and the simulation and test of CPTS using current and voltage phases shall be carried out.

A Study on Maternal Verbal Control Pattens and Children's Recognition against those (어머니의 언어통제유형과 그에 대한 아동의 인지 연구)

  • 이희자
    • Journal of the Korean Home Economics Association
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    • v.30 no.4
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    • pp.231-247
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    • 1992
  • A Study on Maternal Verbal Control Patterns and Children's Recognition against those. The primary objective of the material presented in this dissertation is the analysis of the maternal verbal control patterns. The major focus is given to the differences between maternal verbal control patterns and children's recognition against those. The purspoe of this study were; 1) to investigate the maternal verbal control patterns recognized by children according to their family and personal surroundings; 2) to investigate the verbal control patterns in mother's response according to the differences of family and personal surroundings; 3) to find the differences between children's recognition and maternal verbal control patterns; 4) How the maternal verbal control patterns recognized by children are? The materials of this study were 81(37; boys, 44; girl)) from kindergarten in Seou. The sample of age used in this study was 5 to 7 years old. The test about maternal verbal environment used the question sheet for reaction between mother and children by Gumperz. The kids got interviews with same questions as mothers with question sheet. The statistical tools used is the analysis of the data were frequency, crosstab, and t-test. The result of the study were summarized as follows; 1) The maternal verbal control patterns recognized by children had differences according to whether living with grand-parent or not. Living with grand-parent are more person-oriented than without grand-parent group. 2) The maternal verbal control patterns of mother response show the differences within mother's academic background, present situation of child, and parent's expection to child. The imperative verbal control pattern was more frequently used of low academic background who just fraduate the middle or high school. The personal verbal control pattern was more frequently used of high educational background's like university graduate or more educated group. 3) The differences between maternal verbal control patterns with children's recognition and with mother response is that mother responseis more person-oriented than children's. 4) The imperative verbal control pattern used command, verbal purnishment, and physical purnishment. the status-oriented verbal control pattern used univesal positional appeals and limited positional appeals. The person-oriented verbal control pattern used child-oriented cognitive affective appeals.

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Genotoxicity of low-dose Glyphosate by Sister Chromatid Exchange (자매염색분체교환을 통한 글라이포세이트 유전독성)

  • Lee, Sang Hoon;Kim, Sung Jin;Choi, Woo Ik;Jin, Sang Chan;Choi, In Jang;Lee, Jae Ho
    • Journal of The Korean Society of Clinical Toxicology
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    • v.12 no.1
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    • pp.8-13
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    • 2014
  • Purpose: Glyphosate (N-phosphonomethyl glycine) is widely used as an herbicide for weed control in rural areas. It is also readily available for suicide attempts. Glyphosate has high toxicity and negatively affects the human body. The aim of this investigation was to study the genotoxicity of a low-concentration of glyphosate through sister chromatid exchange (SCE) in human blood lymphocytes in vitro. Methods: Primary lymphocyte cultures were obtained from blood samples of 11 males and seven females who had been exposed to glyphosate (0, 100, 200, and 300 ng/mL). The frequency of SCEs was examined and statistical analysis was performed. Results: All doses of glyphosate induced a significant dose-dependent increase in SCE frequency compared with the control group (P<0.001). In particular, the SCE frequency for exposure to low-dose glyphosate was significantly higher in females than in males. Conclusion: According to the result of this study, even a low-dose of glyphosate may damage DNA and females are more vulnerable to glyphosate.

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ST-Segment Analysis of ECG Using Polynomial Approximation (다항식 근사를 이용한 심전도의 ST-Segment 분석)

  • Jeong, Gu-Young;Yu, Kee-Ho;Kwon, Tae-Kyu;Lee, Seong-Cheol
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.8
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    • pp.691-697
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    • 2002
  • Myocardial ischemia is a disorder of cardiac function caused by insuficient blood flow to the muscle tissue of the heart. We can diagnose myocardial ischemia by observing the change of ST-segment, but this change is temporary. Our primary purpose is to detect the temporary change of the 57-segment automatically In the signal processing, the wavelet transform decomposes the ECG(electrocardiogram) signal into high and low frequency components using wavelet function. Recomposing the high frequency bands including QRS complex, we can detect QRS complex more easily. Amplitude comparison method is adopted to detect QRS complex. Reducing the effect of noise to the minimum, we grouped ECG by 5 data and compared the amplitude of maximum value. To recognize the ECG .signal pattern, we adopted the polynomial approximation partially and statistical method. The polynomial approximation makes possible to compare some ECG signal with different frequency and sampling period. The ECG signal is divided into small parts based on QRS complex, and then, each part is approximated to the polynomials. After removing the distorted ECG by calculating the difference between the orignal ECG and the approximated ECG for polynomial, we compared the approximated ECG pattern with the database, and we detected and classified abnormality of ECG.

A New Parallel Method for Narrowband Active Noise Control (협대역 능동 소음 제어를 위한 새로운 병렬 기법)

  • Kim, Seong-Woo;Park, Young-Cheol;Seo, Young-Soo;Youn, Dae Hee
    • The Journal of the Acoustical Society of Korea
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    • v.33 no.6
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    • pp.375-382
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    • 2014
  • In many practical active noise control applications, the primary noise contains multiple closely-spaced harmonics. A narrowband ANC system consists of adaptive filters excited by a composite reference signal, which is the set or sum of sinusoids. This paper analyzes and shows that the convergence speeds of the direct form, parallel form, and simplified parallel form narrowband ANC systems are affected by the fundamental frequency and frequency separation between two adjacent sinusoids in the reference signal. This paper also proposes the new simplified parallel form narrowband ANC system whose convergence speed is independent on the frequency of the reference signal. Computer simulations are conducted to verify the analysis presented in the paper and to compare the proposed narrowband ANC system with the conventional narrowband ANC system.

Apo-1/Fas (CD95) Gene Polymorphism in Korean Knee Osteoarthritis Patients (한국인 무릎 골 관절염 환자들의 임상 양상과 Apo-1/Fas (CD95) 유전자 다형성과의 상관관계에 관한 연구)

  • Hong, Seung-Jae;Yang, Hyung-In;Yim, Sung-Vin;Chung, Joo-Ho;Jung, Young-Ok;Kim, Ho-Youn
    • IMMUNE NETWORK
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    • v.3 no.2
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    • pp.145-149
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    • 2003
  • Background: Apoptosis has been implicated in pathogenesis of various disease. Apo-1/Fas (CD95) is one of the main pathway of apoptosis. To examine the possible relationship between Apo-1/Fas (CD95) and primary knee osteoarthritis, MvaI restriction length polymorphism (RFLP) in human Apo-1/Fas (CD95) gene was assessed. Methods: Genotype and allele frequencies in promoter region in the Apo-1/Fas (CD95) gene were studied by PCR-RFLP in 226 Korean controls and 148 Korean patients with primary knee osteoarthritis. Results: No statistically significant difference in the genotypic distribution and allelic frequencies was found between the control and the knee oateoarthritis patients. But in the severe grade (grade 3, 4) Kellgren-Lawrence score patients, the frequency of $MvaI^*1$ (G) allele was significantly decreased (P=0.0392) and the of $MvaI^*2$ (A) allele frequency was significantly increased (P=0.0473) compared to the normal controls. Conclusion: Apo-1/Fas (CD95) gene polymorphism is a part a determinant factor of severity in knee osteoarthritis, the patients with $MvaI^*2$ (A) allele is more severe radiologic progression. Further substantiation studies are needed in larger patient samples and various other apoptosis related genes to elucidate the mechanism of osteoarthritis, including the Fas ligand gene analysis.

Cyclin D1 Gene G870A Variants and Primary Brain Tumors

  • Zeybek, Umit;Yaylim, Ilhan;Ozkan, Nazli Ezgi;Korkmaz, Gurbet;Turan, Saime;Kafadar, Didem;Cacina, Canan;Kafadar, Ali Metin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.7
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    • pp.4101-4106
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    • 2013
  • Alterations of cyclin D1, one of the main regulators of the cell cycle, are known to be involved in various cancers. The CCDN1 G870A polymorphism causes production of a truncated variant with a shorter half-life and thus thought to impact the regulatory effect of CCDN1. The aim of the present study was to contribute to existing results to help to determine the prognostic value of this specific gene variant and evaluate the role of CCDN1 G870A polymorphism in brain cancer susceptibility. A Turkish study group including 99 patients with primary brain tumors and 155 healthy controls were examined. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. The CCDN1 genotype frequencies in meningioma, glioma and control cases were not significantly different (p>0.05). No significant association was detected according to clinical parameters or tumor characteristics; however, a higher frequency of AG genotype was recorded within patients with astrocytic or oligoastrocytic tumors. A significant association between AG genotype and gliobilastoma multiforme (GBM) was recorded within the patients with glial tumors (p value=0.048 OR: 1.87 CI% 1.010-3.463). According to tumor characteristics, no statistically significant difference was detected within astrocytic, oligoasltrocytic tumors and oligodentrioglias. However, patients with astrocytic astrocytic or oligoastrocytic tumors showed a higher frequency of AG genotype (50%) when compared to those with oligodendrioglial tumors (27.3%). Our results indicate a possible relation between GBM formation and CCDN1 genotype.

Isolated Bidirectional CLLC Resonant Converter using Digital Control for LVDC Distribution System (디지털로 제어되는 저압 직류 배전용 절연형 양방향 CLLC 공진형 컨버터)

  • Jung, Jee-Hoon;Kim, Ho-Sung;Ryu, Myung-Hyo;Kim, Jong-Hyun;Kim, Tae-Jin;Baek, Ju-Won
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.379-380
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    • 2012
  • A bidirectional full-bridge CLLC resonant converter using a digital control method is proposed for a LVDC power distribution system. This converter can operate under high power conversion efficiency since the CLLC resonant network has soft switching capability for primary switches and output rectifiers. In addition, the power conversion efficiency of any directions is exactly the same as each other because of the symmetric structure of the converter. Intelligent digital control methods are proposed to regulate output voltage under any power flow directions. A 5kW prototype converter was designed for a high-frequency galvanic isolation of 380V dc buses using a digital signal processor to verify the performance of the proposed topology and algorithms.

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Multi-spectral adaptive vibration suppression of two-path active mounting systems with multi-NLMS algorithms

  • Yang Qiu;Dongwoo Hong;Byeongil Kim
    • Smart Structures and Systems
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    • v.32 no.6
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    • pp.393-402
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    • 2023
  • Recently, hybrid and electric vehicles have been actively developed to replace internal combustion engine (ICE) vehicles. However, their vibrations and noise with complex spectra cause discomfort to drivers. To reduce the vibrations transmitted through primary excitation sources such as powertrains, structural changes have been introduced. However, the interference among different parts is a limitation. Thus, active mounting systems based on smart materials have been actively investigated to overcome these limitations. This study focuses on diminishing the source movement when a structure with two active mounting systems is excited to a single sinusoidal and a multi-frequency signal, which were investigated for source movement reduction. The overall structure was modeled based on the lumped parameter method. Active vibration control was implemented based on the modeled structure, and a multi-normalization least mean square (NLMS) algorithm was used to obtain the control input for the active mounting system. Furthermore, the performance of the NLMS algorithm was compared with that of the quantification method to demonstrate the performance of active vibration control. The results demonstrate that the vibration attenuation performance of the source component was improved.