• Title/Summary/Keyword: Lee Ja Hyeon

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열처리에 따른 SiO2/ZrO2 적층 감지막을 이용한 EIS소자의 pH 감지 특성 평가

  • Gu, Ja-Gyeong;Jang, Hyeon-Jun;Jeong, Hong-Bae;Lee, Yeong-Hui;Jo, Won-Ju
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.239-239
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    • 2011
  • 최근에 감지막의 pH 감지특성을 평가하기 위해 electrolyte insulator semiconductor (EIS) 구조가 유용하게 이용되고 있다. EIS는 CMOS공정과 호환이 가능하고 구조가 간단하며 pH 변화에 반응속도가 빠르다는 장점을 가지고 있다. EIS 구조를 갖는 pH 센서의 동작 메커니즘은 pH 용액의 수소이온이 감지막의 표면에서 표면전위를 변화시키는 것에 기인한다. pH 감지막으로는 높은 유전율과 안정성이 뛰어난 high-k 물질이 많이 연구되고 있다. 그 중 high-k 물질인 ZrO2은 낮은 열전도도, 산성에서 알칼리성 영역까지의 넓은 화학안정성을 가지며 낮은 열 팽창성, 높은 유전상수 등 우수한 특성을 가지고 있다. 본 실험은 SiO2/ZrO2를 적층한 EIS 소자를 제작하여 열처리에 따른 전기적 특성과 pH 감지 특성을 평가해 보았다. EIS 적층막으로 사용된 SiO2는 실리콘과 high-k 감지막 사이의 계면상태를 양호하게 유지시키기 위한 완충막으로 성장되었다. 후속열처리는 rapid thermal annealing (RTA) 시스템을 이용하여 750$^{\circ}C$, 850$^{\circ}C$, 950$^{\circ}C$로 H2/N2 분위기에서 30초 동안 실시하였다. RTA 열처리 온도가 증가할수록 높은 pH 감지특성이 보였으며 hysteresis 현상과 drift 효과와 같은 non ideal 효과에 강한 immunity가 있는 것을 확인하였다. 결론적으로 SiO2/ZrO2 적층구조를 갖는 EIS는 RTA 950$^{\circ}C$ 열처리를 실시하였을 때 우수한 EIS pH 센서를 제작할 수 있을 것으로 기대된다.

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The Clinical Study of Muscle Energy Techniques(MET) in Elector Spinae Muscle on Low Back Pain Patients-Through Meridian Electromyography (요통환자의 근에너지 기법 시술 전과 후의 척추기립근 변화-경근전도를 통해)

  • Choi, Jin-Seo;Ahn, Jae-Min;Kim, Choo-Young;Lee, Jae-Hun;Park, Dong-Su;Jeong, Su-Hyeon;Kim, Soon-Joong
    • Journal of Korean Medicine Rehabilitation
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    • v.23 no.1
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    • pp.15-23
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    • 2013
  • Objectives : To evaluate the clinical utility of MET in elector spinae muscle on low back pain patients. Methods : We compared electrical activity between a before MET and a after MET in elector spinae muscle on low back pain patients in same group(n=30) in dynamic flexion-reextension state during five seconds. We analyzed amplitudes and areas of electrical activity and asymmetry index(AI). Results : 1. After MET in elector spinae muscle on low back pain patients were significantly decreased in Visual Analogue Scale(VAS) than before MET in elector spinae muscle on low back pain patients(p<0.05). 2. After MET in elector spinae muscle on low back pain patients were lower electrical activity than before MET in elector spinae muscle on low back pain patients but it is not a pointless observation(p<0.05). 3. AI of the after MET in elector spinae muscle on low back pain patients significantly decreased compared with before MET in elector spinae muscle on low back pain patients(p<0.05). Conclusions : According to above results, there is clinical effect MET on low back pain patients.

Compact Triple-Mode Resonator and Triple-Mode Filter Design (소형의 삼중 모드 공진기와 삼중 모드 필터 설계)

  • Lee, Ja-Hyeon;Lim, Yeong-Seog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.4
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    • pp.447-452
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    • 2011
  • In this paper, we present a compact triple-mode resonator. The resonator itself can provide three transmission poles and one transmission zero. The resonance condition of each mode is analyzed theoretically, and the transmission zero is generated by open stub. Using this proposed resonator, a compact three pole bandpass filter for 2.4 GHz WLAN application with one transmission zero is designed and fabricated. The fabricated triple-mode filter shows 3 dB bandwidth of 15.8 % with the center frequency 2.4 GHz and less then 1.17 dB in 2.4~2.5 GHz passband. The size of fabricated triple-mode filter including the feed lines is 15.9 mm${\times}$9.7 mm and very compact compared with previous reported triple-mode filter.

Performance Analysis for MIMO Multi-user system employing selection of transmit antennas, constellations and powers allocation (전송 안테나 및 성상도 선택과 전력 할당을 적용한 MIMO 다중 사용자 시스템의 성능분석)

  • Yoo Hyun;Kim JinSu;Hwang HyeonChyeol;Kim BaekHyun;Lee HyungKi;Kwak KyungSup
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.9 s.339
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    • pp.41-48
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    • 2005
  • In this paper, we suggest the scheme combining long-term feedback and short-term feedback in MIMO multi-user system and analyze its system performance. At the beginning of communication, long-term feedback is fed back to transmitter such as the number of active antennas, constellations, and transmission powers which are determined to satisfy the given target symbol error and target data rate for each user. After this, short-term feedback of active antenna index is fed back periodically Simulation results show the proposed scheme outperforms better than long-term feedback or short-term feedback information scheme.

Compact Dual-Band Bandpass Filter Using Two Dual-Mode Resonators (두 개의 이중 모드 공진기를 이용한 소형 이중 대역 통과 필터)

  • Kim, Kyoung-Keun;Lee, Ja-Hyeon;Lim, Yeong-Seog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.12
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    • pp.1447-1453
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    • 2010
  • In this paper, the design and the fabrication of dual-band bandpass filter using two dual-mode resonators is presented. Dual-mode resonator using a short stub is miniaturized by inter-digital capacitor and stepped impedance. Two dual mode resonators are designed to have different resonant frequencies, one for the lower passband and the other for the upper passband. Transmission zero is positioned at low or high rejection bands with a sharp skirt characteristic. Dual-band operation can be achieved using dual feeding structure. For WLAN, the proposed filter at 2.45/5.25 GHz is designed and fabricated. The size of the filter is as compact as 1$10.83\;mm{\times}5.3\;mm$.

Application of spherical coordinate system to facial asymmetry analysis in mandibular prognathism patients

  • Yoon, Suk-Ja;Wang, Rui-Feng;Hwang, Hyeon-Shik;Kang, Byung-Cheol;Lee, Jae-Seo;Palomo, Juan Martin
    • Imaging Science in Dentistry
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    • v.41 no.3
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    • pp.95-100
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    • 2011
  • Purpose : The purpose of this study was to compare asymmetric mandibular prognathism individuals with symmetric mandibular prognathism individuals using a new alternate spherical coordinate system. Materials and Methods : This study consisted of 47 computed tomographic images of patients with mandibular prognathism. The patients were classified into symmetric and asymmetric groups. Mandibular and ramal lines were analyzed using an alternate spherical coordinate system. The length as well as midsagittal and coronal inclination angle of the lines was obtained. The bilateral differences of the spherical coordinates of the facial lines were statistically analyzed in the groups. Results : There were significant differences between the groups in bilateral difference of the length and midsagittal inclination angle of the lines (p<0.05). The bilateral difference of the length and midsagittal inclination angle of the lines has significant correlation with chin deviation (p<0.05). Conclusion : The new alternate spherical coordinate system was able to effectively evaluate facial lines. The bilateral difference of lengths and midsagittal inclination of the facial lines might contribute to the facial asymmetry in mandibular prognathism individuals.

A Study on the Factors affecting Cyber-Career-Counseling-Activation based on Structural Equation Model(SEM) (구조방정식 모형을 이용한 사이버진로상담 활성화 영향요인에 관한 연구)

  • Lee, Young-Ja;Baek, Hyeon-Gi
    • Journal of Digital Contents Society
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    • v.9 no.3
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    • pp.379-388
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    • 2008
  • This paper is to redefine the concept of Cyber Career Counseling Activation(=C-C-C-A) and verify the effects of the factors affecting the C-C-C-A at Korean academic high school level in Kyunggi Province. In this research, we hypothesize that the three independent variables increase the effects of Cyber Career Counseling Activation.. To discuss the hypothesis, we analyzed survey data of 322 students who had taken Cyber Career Counseling in December 2007 based on Structural Equation Model. The results are as follows: First, the three crucial factors(Expanding C-C-C Opportunities, Improving C-C-C Service, Establishing C-C-C Service System) increase the C-C-C-A effectiveness. Second, as a result of Confirmatory Factor Analysis(CFA), the goodness of fit indices(GFI, AGFI, CFI, RMSEA) demonstrate statistical significance and fitness of the C-C-C-A Model. Therefore, the outcomes show that the three factors are the significant ones of Cyber Career Counseling Activation Model.

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A Study on Influencing Factors in Health-promoting Lifestyle of Adolescents (청소년의 건강증진 생활양식과 관련요인연구)

  • Park In Sook;Joo Hyeon Ok;Lee Hwa Ja
    • Child Health Nursing Research
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    • v.3 no.2
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    • pp.154-168
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    • 1997
  • The purpose of this study were to define the degree of performance in health promoting lifestyle and to identify the variable related to performance in health promoting lifestyle of adolescents. The subjects of this study were 469 adolescents in the 4 high schools. The sample data were collected using a purposive sampling method from July 1 to July 27. The collected data were analysed by using descriptive statistics, Pearson's correlation coefficients, and stepwise multiple regression with SPSS PC+ program. The results of this research were as follows. First, The means of performance in the health promoting lifestyle of adolescents revealed total 2.478 ; harmonious relationships 3.045, regular diet 2.236, professional health management 1.332, sanitary life 2.910, self regulation 2.558, emotional support 2.696, healthy diet 2.408, rest and sleep 2.651, exercise and activity 2.491, self actualization 2.466, diet control 2.408. The factor with the highest degree of performance was the harmonious relationships, whereas the one with the lowest degrees was the professional health management. Second, the relationship between the degree of performance in health promoting lifestyle and its related variable were as follows. (1) Performance in the health promoting lifestyle was significantly correlated with self esteem, self efficacy, health conception, perceived health status, mother's health promoting lifestyle, mother's health conception. (2) The most important factor that affects performance in the health promoting lifestyle of adolescents was self esteem. The combination of self esteem, health conception, mother's health promoting lifestyle, self efficacy, perceived health status accounted for 45.2% of the variance in health promoting lifestyle of adolescents.

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Biological Properties of Different Types and Parts of the Dandelions: Comparisons of Anti-Oxidative, Immune Cell Proliferative and Tumor Cell Growth Inhibitory Activities

  • Lee, Sung-Hyeon;Park, Jae-Bok;Park, Hong-Ju;Cho, Soo-Muk;Park, Young-Ja;Sin, Jeong-Im
    • Preventive Nutrition and Food Science
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    • v.10 no.2
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    • pp.172-178
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    • 2005
  • Dandelions have been reported to have medicinal properties and bioactive components that impact human health. However, the precise biological properties of dandelions and the parts of the plants possessing bioactive components remain uncertain. In this study, we evaluated 3 different types of dandelions based on their cultivation origin (Songpa, Uiryung, and native Uiryung types) as well as their 4 different plant parts (leaf, flower, root, skin). Each sample was extracted with $80\%$ methanol and then compared for the biological activities (anti-oxidative, immune cell proliferative and tumor cell growth inhibitory activities). All 3 types of dandelions possessed a degree of biological functions including the hydroxyl radical scavenger activity, immune cell proliferative activity and tumor cell growth inhibitory activity. However, there was no significant difference in these activities between the 3 dandelion types. Leaves of all three dandelion types showed the highest levels of all biological activities. To a lesser degree, the flower and root parts displayed biological activities. In the skin parts, anti-oxidative activity was also detected only at higher doses of dandelion extracts. Heating the dandelion leaf extract did not affect the biological activity, suggesting a heat-stable nature of the biological compounds. Taken together, these collective data suggest that dandelions, in particular their leaves, possess a high concentration of heat-resistant biological compounds, which are responsible for anti-oxidative, immune cell proliferative and tumor cell growth-inhibitory activities.

Design of Multi-Layer Dual-Band Bandpass Filter Using Aperture-Coupling (개구 결합을 이용한 적층형 이중 대역 대역 통과 여파기 설계)

  • Shin, Bong-Geol;Lee, Ja-Hyeon;Lim, Yeong-Seog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.5
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    • pp.598-605
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    • 2012
  • In this paper, a multi-layer dual-band bandpass filter using aperture-coupling is proposed. Two coupling paths are formed with the two apertures which exist between two dual-mode resonators. The coupling coefficients can be adjusted without changing the shape of resonators. The bandwidth of the second passband can be adjusted without affecting the bandwidth of the first passband using the size of an aperture between stubs of the dual-mode resonator. The aperture coupling mechanism is theoretically analysed. The dual-mode bandpass filter for the 2.4 GHz WLAN, 3.5 GHz WiMax was designed and fabricated. The fabricated filter shows centered 2.45 GHz and 3.5 GHz with 9 % and 8 % of the bandwidth.