• Journal of Power Electronics
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• v.16 no.5
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• pp.1716-1724
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• 2016

This paper proposes both an active-switched quasi-Z-source inverter (AS-qZSI) and an extended active-switched qZSI (EAS-qZSI), which are based on the classic qZSI. The proposed AS-qZSI adds only one active switch and one diode to the classic qZSI for increasing the voltage boost capability. Compared with other topologies based on the switched-inductor/capacitor qZSI, the proposed AS-qZSI requires fewer passive components in the impedance network under the same boost capability. Additionally, the proposed EAS-qZSI is designed by adding one inductor and three diodes to the AS-qZSI, which offers enhanced boost capability and lower voltage stress across the switches. The performances of the two proposed topologies are verified by simulation and experimental results obtained from a prototype with a 32-bit DSP built in a laboratory.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.3
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• pp.311-320
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• 2008

In this paper, a new variable active inductor using a conventional grounded active inductor with feedback variable LC-resonator is proposed. The grounded active inductor is realized by the gyrator-C topology and the variable LC-resonator is realized by the low-Q spiral inductor and varactor. This variable LC-resonator can compensate the degradation of Q-factor due to parasitic capacitance of a transistor, and the frequency range with high Q-factor is adjustable by resonance frequency adjustment of LC-resonator. The fabricated variable active inductor with Magnachip $0.18{\mu}m$ CMOS process shows that high-Q frequency range can be adjusted according to varactor control voltage from 4.66 GHz to 5.45 GHz and Q-factor is higher than 50 in the operating frequency ranges. The measured inductance at 4.9GHz can be controlled from 4.12 nH to 5.97 nH by control voltage.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.431-446
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• 2022

In this study, the characteristics of the experiences and perceptions of vulnerable adolescents on the school environment were explored and categorized, and of which the meanings were confirmed. For this purpose, Q methodology was used, and 94 Q samples were extracted by analyzing pre-interviews, literature analysis, and media search contents to form a Q population. Q classification was performed on the subjects. The schools belonging to the sample P are 7 high schools in Seoul and 4 high schools in Gyeonggi-do. As a result of analyzing the data collected in Q sorting using QUANL-PC program, a Q analysis program, it was classified into 4 types. Type 1 is 'a conformal and moeling type', and Type 2 is 'negative and defiant type', Type 3 is 'passive and helpless type' and Type 4 is 'progressive and struggling type'. Through this study, it is expected that this study will be able to understand the experiences and perceptions of the school environment of underprivileged adolescents, and to obtain the necessary clues for realistic support strategies for them.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.209-215
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• 2015

Colorectal carcinoma is one of the four major cancers in Korea, and it shows the tendency of increase every year due to economic development and changes to western styles. Accordingly, various diagnostic methods are needed and so comparative genomic hybridization (CGH) was performed. Deletion was detected on 5q (10%), 10q (17%), 17p (40%), 18p (23%), 18q (47%), 22q (23%), and higher deletion loci were 18q (12/30, 47%), 17p (12/30, 40%), and 22q (7/30, 23%). Amplification was shown on chromosomes 6pq (10%), 7p (17%), 7q (33%), 8q (13%), 9pq (10%), 12q (17%), 13q (37%), 20p (23%), and 20q (57%) respectively. The highest amplification was detected on chromosomes 20q (17/30, 57%), 13q (11/30, 37%), and 7q (10/30, 33%). The genetic change pattern with the locus of colorectal carcinoma was shown mean 3.1 (amplification 1.7, deletion 1.4) on the right colorectal carcinoma, while rectal carcinoma appeared high mean 6.3 (amplification 3.7, deletion 2.6) (p<0.001). The genetic change pattern with lymphatic gland metastasis, mean 3.5 (amplification 2.2, deletion 1.3) from "no metastasis" group, while high mean 6.3 (amplification 3.5, deletion 2.8) from metastasis group (p<0.003). The genetic change pattern with disease stages appeared mean 3.5 (amplification 2.1, deletion 1.4) from I-II stages, while high mean 6.0 (amplification 3.4, deletion 2.6) from III-IV stages (p<0.006). No significance was observed in comparing histological classification and serum CEA increased groups.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.82-83
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• 2000

굴절율이 외부보다 큰 실린더 (cylinder)나 스피어 (sphere)는 경계면에서의 전반사에 의해 손실이 매우 적은 high-Q 공진기가 될 수 있음이 잘 알려져 있다. 크기가 수 십 $mu extrm{m}$ 되는 실린더나 스피어에서의 공명모드는 편광(TM, TE), 모드 수 (mode number) n, 모드 순서 (mode order) l에 의해 정의되고 WGM (whispering gallery mode)라고도 불리워진다$^{(1)}$ . 모드 수n 이 클수록 모드 순서 l이 작을수록 공명모드의 Q 값은 큰 경향을 가진다. 액체 방울이나 액체 제트와 같이 열적 섭동에 민감한 마이크로 공진기 (micro-cavity)의 경우 Q값이 $10^{7}$ 정도로 제약되나, 실리카 마이크로 스피어 (micro-sphere)와 같은 고체 구에서 측정된 Q값은 약 $101^{10}$ 정도로 손실이 매우 적은 공진기가 될 수 있다$^{(2)}$ . 이와 같은 마이크로 공진기 특성을 이용하여 다양한 형태의 마이크로 공진기 레이저 대한 연구가 진행되어 왔다. 색소가 첨가된 고체구, 액체 방울, 액체 제트 등에서 기본적인 실험이 이루어졌고 반도체마이크로 스피어 구조에서 WGM 레이저$^{(3)}$ , polymer disc laser$^{(4)}$ , 광양자테 (photonic quantum ring)$^{(5)}$ 특성 연구 등이 실용가능성을 목표로 진행되고 있다. (중략)

• Journal of Plant Biology
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• v.37 no.1
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• pp.37-42
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• 1994

Correlative changes between photosynthetic O2 exchange rates and room temperature Chl fluorescence were investigated in wheat (Triticum aestivum L.) chloroplasts treated with high temperature for 5 min. With increasing treatment temperature, photosynthetic O2 evolution rate mediated by PSII was decreased, showing 50% inhibition at 38$^{\circ}C$ (I50). But PSI activity measured by O2 uptake rates was stimulated as a function of increasing temperature. Dark level fluorescence (Fo)-temperature (T) analysis showed that fluorescence rising temperature (Tr), critical temperature (Tc), and peak temperature (Tp) was 38, 43, and 52$^{\circ}C$, respectively. Quenching analysis of Chl fluorescence showed that both the oxidized fraction of plastoquinone (qQ) and degree of thylakoid membrane energization (qNP) increased up to 4$0^{\circ}C$ and then declined dramatically. These results suggest that Tr is correlated with temperature showing a 50% of inhibition of photosynthesis and under mild high temperature stress, qNP is worth regarding as indicator for heat-induced damage of photosynthesis.

• Journal of electromagnetic engineering and science
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• v.14 no.1
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• pp.9-14
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• 2014

This paper discusses the resonant characteristics, such as the resonant frequencies and Q factors, as well as tuning methods of the resonant frequency of the triple-mode dielectric resonators, for their possible application to compact bandpass filters for mobile communication systems. The resonators include spheres and cylindrical rods that can be applied to compact bandpass filters. These high Q ceramic resonators can replace the conventional coaxial type resonators, which are large sized and also have relatively low Q values. Both simulated and measured results show that the Q values of the sphere and rod reach 27,000 and 24,000, respectively. Decoupling of degenerate modes is also briefly discussed.

• Honam Mathematical Journal
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• v.35 no.3
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• pp.395-406
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• 2013

Generalized paper folding sequences $X^n_p$ and $(X_pY_q)^n$ where $X,Y{\in}\{R,L,U,D\}$, and $n,p,q{\in}\mathbb{N}$, and with $p,q{\geq}2$ are classified in this paper. We show that all generalized paper folding sequences $X^n_p$ are classified into one type if we classify generalize paper folding sequences along with the numbers of downwards and upwards. In addition, we investigate the numbers of downwards and upwards in $(X_pY_q)^n$ and prove that all generalized paper folding sequences $(X_pY_q)^n$ are classified into two types.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.368-375
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• 2000

For safety reason ATS(Automatic Train Stop) system is being used, which is a kind of communication system with a feedback amplifier and a transformer on the train and wayside coils. The coils are highly resonant LC circuits, also have very high Q(Quality) factors. The Q factors of wayside ATS coils are to be maintained high enough for the amplifier to operate reliably. In this paper a novel Q measurement system is proposed. The system measures the resonant frequency and the bandwidth of the ATS coils, by controlling the phase difference between the transformer and the coil using digital PLL(Phase Locked Loop). The overall configuration and algorithms of the proposed system and the digital PLL control schemes are presented in details. The experimental waveforms are shown to verify the system performances.

• Journal of the Korea Convergence Society
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• v.10 no.5
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• pp.249-256
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• 2019

This study started from the question of what is the perception of high school students' college of management, 'business school', which is the demand of university education. Especially, for the analysis, the Q methodology was used to typify the recognition. 30 high school students classified 30 selected Q-statements into 9points standard. As a result of analysis, three types were defined. emphasized 'overall management', 'business', and 'money management'. So, we called "Type of Overall Business Interest". emphasized 'money management' 'Member Management'. So, we called "Type of Management Money and Member". And emphasized 'business', 'marketing' and 'sales'. So, we called "Type of Business Recognition". In addition, we found a hypothesis that high school students' perception of the business line would be different according to the characteristics of the respondents.