• 제목/요약/키워드: Q Factor

검색결과 1,369건 처리시간 0.029초

무선 시스템용 FBAR 듀플렉서 특성 개선 연구 (A Study on Improvement of FBAR Duplexer for Wireless Systems)

  • 이은규;최형림
    • 한국전기전자재료학회논문지
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    • 제23권5호
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    • pp.388-396
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    • 2010
  • In this study, we propose characteristics improvement methods according to via hole plating method for FBAR Duplexer with bandwidth($T_x4: 1850 MHz ~ 1910 MHz, $R_x$:1930 MHz ~ 1990 MHz) which is used for wireless systems. Also, we designed and fabricated $3.8{\times}3.8{\times}1.8mm$ size microminiature FBAR Duplexer based on this proposal. First of all, in this study, we fabricated pentagon shape resonators by different size to make filter combination, and their quality factor(Q) are 687 with 6.6% of ${k_{eff}}^2$. Using this resonators, we designed $3{\times}2$ Type $T_x$ filter and $3{\times}4$ Type $R_x$ filter. The transmission line, which works as phase shifter, is designed with 210 ${\mu}m$ in width and 18 mm in length Stripline type. Inductor, which is used for matching component, is designed with width of 75 ${\mu}m$, a technically achievable minimum width. And adopted plating method of filling via hole with conductive epoxy for improved grounding and thermal conductivity. Using these configuration with all of the matching component values, we found Duplexer characteristics of -1.57 dB ~ -1.73 dB in insertion loss, -56 dB in attenuation at 1850 MHz ~ 1910 MHz of $T_x$ band. Also, found -2.71 dB ~ -3.23 dB in insertion loss, -58 dB in attenuation at 1930 MHz ~ 1990 MHz of $R_x$ band.

고체형 정밀 공진 자이로스코프를 위한 이차 PLL 루프필터 기반 위상제어루프 설계 (Phase Control Loop Design based on Second Order PLL Loop Filter for Solid Type High Q-factor Resonant Gyroscope)

  • 박상준;용기력;이영재;성상경
    • 제어로봇시스템학회논문지
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    • 제18권6호
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    • pp.546-554
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    • 2012
  • This paper suggests a design method of an improved phase control loop for tracking resonant frequency of solid type precision resonant gyroscope. In general, a low cost MEMS gyroscope adapts the automatic gain control loops by taking a velocity feedback configuration. This control technique for controlling the resonance amplitude shows a stable performance. But in terms of resonant frequency tracking, this technique shows an unreliable performance due to phase errors because the AGC method cannot provide an active phase control capability. For the resonance control loop design of a solid type precision resonant gyroscope, this paper presents a phase domain control loop based on linear PLL (Phase Locked Loop). In particular, phase control loop is exploited using a higher order PLL loop filter by extending the first order active PI (Proportion-Integral) filter. For the verification of the proposed loop design, a hemispherical resonant gyroscope is considered. Numerical simulation result demonstrates that the control loop shows a robust performance against initial resonant frequency gap between resonator and voltage control oscillator. Also it is verified that the designed loop achieves a stable oscillation even under the initial frequency gap condition of about 25 Hz, which amounts to about 1% of the natural frequency of a conventional resonant gyroscope.

진행모드 해석을 이용한 유전체 공진기 대역통과 필터의 결합 특성 개선에 관한 연구 (A Study on the Coupling Performance Improvement of Cylindrical DR Bandpass Filter using Travelling Wave Mode Analysis)

  • 이원희;박장원;양재혁;허정;이재훈;이상영
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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    • pp.125-129
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    • 2000
  • In this paper, We designed and fabricated C-band bandpass filter using dielectric resonators. From waveguide cutoff frequency which applied the region between adjacent dielectric resonators, the height of cavity is determined. The cavity's diameter is determined to the twice of dielectric resonator's diameter considering the conductor loss. The resonant frequency of the DR-cavity is calculated with travelling wave mode analysis. Conventionally, circular cylindrical dielectric resonator is analysed by Cohn's model which use the evanescent mode in the region between dielectric resonator wall and circular cavity wall, which is an approximated method. The external quality factor, Q$_{ex}$ has found with simulation result using Ansoft's Maxwell simulation tool. The designed filter using dielectric resonators with dielectric constant of 45 has the passband center at 5.065GHz. The bandpass filter using dielectric resonators have about 1dB insertion loss. 20MHz bandwidth and more than 30dB attenuation at f$_{0}$$\pm$15MHz.z.z.

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한국 중년 여성의 패션이미지 유형에 따른 디자인 요소와 특성 (Fashion Image Types and Design Factors for Middle-aged Korean Women)

  • 정수인;김영인
    • 복식
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    • 제64권5호
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    • pp.91-107
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    • 2014
  • This purpose of this study is to analyze the pursuit of current fashion trends and fashion image types of middle-aged women in Korea. This study attempted to investigate the standards and properties of these different types of fashion images. The overall characteristics of middle-aged women and the concepts of personal image and fashion image were investigated through literature research. Survey and analysis based on Q methodology was conducted. Factors of personal image, fashion image and components of fashion image were analyzed by collecting information from in-depth workshops and focus group interview of an expert group. The results of this study are as follows: 1) The main factors influencing the current fashion image of women in their forties and fifties in Korea are classified into six types. 2) The elements of fashion image that Korean women in their 40s and 50s pursue are divide into four types. 3) Each type can be recognized by specific fashion image components and colors. 4) This shows that middle-aged Korean women are highly conscious of how others perceive them and have a desire to not stand out from others. It also shows that they are very active in pursuing fashion and following trends, which is the image of an active and dignified woman. This study provides the framework that enables sorting of the fashion images types that middle-aged Korean women want to pursue. The results from analyzing the factors can be used to recognize specific fashion images, and can be used in the planning and designing of fashion items for middle-aged Korean women.

The Effect of Growth Hormone on mRNA Expression of the GABAB1 Receptor Subunit and GH/IGF Axis Genes in a Mouse Model of Prader-Willi Syndrome

  • Lee, Jin Young;Jin, Dong-Kyu
    • Journal of mucopolysaccharidosis and rare diseases
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    • 제1권2호
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    • pp.54-59
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    • 2015
  • Purpose: Growth hormone (GH) therapy substantially improves several cognitive functions in PWS. However, the molecular mechanisms underlying the beneficial effects of GH on cognition remain unclear in PWS. In this study, we investigated the effects of recombinant human GH on the gene expression of GABAB receptor subunits and GH/insulin-like growth factor (IGF) axis genes in the brain regions of PWS-mimicking mice (Snord116del). Methods: Snord116del mice were injected subcutaneously with 1.0 mg/kg GH or saline, once daily for 7 days. The collected brain tissues were analyzed for mRNA content using quantitative PCR (qPCR) in the cerebellum, hippocampus, and cerebral cortex. Results: GH increased the mRNA expression level of the $GABA_{B1}$ receptor subunit ($GABA_{BR1}$) and IGF-1R in the cerebellum. Furthermore, a significant positive correlation was found between the level of $GABA_{BR1}$ mRNA and the expression of the IGF-1R transcript. GH also induced an increase in the mRNA expression of IGF-2 and IGF-2R in the cerebellum. Conclusion: These data indicate that GH may provide beneficial effects on cognitive function through its influences on the expression of $GABA_{BR1}$ and GH/IGF-1 axis genes in PWS patients.

Computational Drug Discovery Approach Based on Nuclear Factor-κB Pathway Dynamics

  • Nam, Ky-Youb;Oh, Won-Seok;Kim, Chul;Song, Mi-Young;Joung, Jong-Young;Kim, Sun-Young;Park, Jae-Seong;Gang, Sin-Moon;Cho, Young-Uk;No, Kyoung-Tai
    • Bulletin of the Korean Chemical Society
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    • 제32권12호
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    • pp.4397-4402
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    • 2011
  • The NF-${\kappa}B$ system of transcription factors plays a crucial role in inflammatory diseases, making it an important drug target. We combined quantitative structure activity relationships for predicting the activity of new compounds and quantitative dynamic models for the NF-${\kappa}B$ network with intracellular concentration models. GFA-MLR QSAR analysis was employed to determine the optimal QSAR equation. To validate the predictability of the $IKK{\beta}$ QSAR model for an external set of inhibitors, a set of ordinary differential equations and mass action kinetics were used for modeling the NF-${\kappa}B$ dynamic system. The reaction parameters were obtained from previously reported research. In the IKKb QSAR model, good cross-validated $q^2$ (0.782) and conventional $r^2$ (0.808) values demonstrated the correlation between the descriptors and each of their activities and reliably predicted the $IKK{\beta}$ activities. Using a developed simulation model of the NF-${\kappa}B$ signaling pathway, we demonstrated differences in $I{\kappa}B$ mRNA expression between normal and different inhibitory states. When the inhibition efficiency increased, inhibitor 1 (PS-1145) led to long-term oscillations. The combined computational modeling and NF-${\kappa}B$ dynamic simulations can be used to understand the inhibition mechanisms and thereby result in the design of mechanism-based inhibitors.

양혈음가미방(養血飮加味方) 추출물의 발모효과에 대한 실험적 연구 (The Experimental Studies of YangHyulEum Gami-Bang Extracts on the Hair Growth Effect)

  • 홍지희;정현아
    • 한방안이비인후피부과학회지
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    • 제29권3호
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    • pp.74-94
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    • 2016
  • Objectives : YangHyulEum Gami-Bang(YHEG) is a hair care extracts which is composed of fourteen plant extracts used in oriental medicine. The purpose of this study is to investigate the effect of YangHyulEum Gami-Bang(YHEG) on the alopecia and hair growth.Methods & Results : The herbal extracts from YangHyulEum Gami-Bang(YHEG) was tested using in vivo and in vitro test models. 1. The YHEG extracts showed effect on the DNA proliferation of the hair dermal papilla cells measured by [3H]thymidine incorporation. 2. YHEG showed promoting on the expression of growth factors such as IGF-1, KGF-1 and inhibiting on the expression of inhibitory hair growth factor such as TGF-β1, BMP-2 estimated by qPCR. 3. The YHEG extracts showed effect on the activation of β-catenin in the dermal papilla cells. 4. YHEG showed inhibitory effects of NO synthesis at 0.2% concentrations. 5. YHEG showed effects in the expression of IL-1β, TNF-α, IL-6, COX-2 and iNOS gene in the LPS stimulated RAW 264.7 cells. 6. The hair growth index of the YHEG extracts ranked at over 2 when compared to control group which was ranked at 0. 7. The hair follicle number, length and size of the experimental group were remarkably higher than the control group in the histological observation.Conclusions : These results suggest that YangHyulEum Gami-Bang(YHEG) has hair growth promoting activity and it can be used as a potent treatment agent for preventing hair loss and stimulating hair growth for treatment of alopecia.

조혈모세포 이식을 받은 소아 환자에서 cyclosporine의 집단 약동학 분석 (Population Pharmacokinetics of Cyclosporine after Hematopoietic Stem Cell Transplantation in Pediatric Patients)

  • 조소연;강원구;이정;김재연;안숙희;곽혜선
    • 한국임상약학회지
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    • 제28권1호
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    • pp.24-29
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    • 2018
  • Background: Cyclosporine is an immunosuppressive agent used to treat and prevent graft versus host reaction (GVHR)-a complication associated with stem cell transplantation. This study aimed to develop a population pharmacokinetic model of cyclosporine and investigate factors affecting cyclosporine clearance in pediatric hematopoietic stem cell transplant patients. Methods: A total of 650 cyclosporine concentrations recorded in 65 patients who underwent hematopoietic stem cell transplantation were used. Data including age, sex, weight, height, body surface area (BSA), type of disease, chemotherapy before stem cell transplantation, type of donor, serum creatinine levels, total bilirubin concentration, hematocrit value, and type of concomitant anti-fungal agents and methylprednisolone used were retrospectively collected. Data related to cyclosporine dosage, administration time, and blood concentration were also collected. All data were analyzed using the non-linear mixed effect model; a two-compartment model with first-order elimination was used. Results: The population pharmacokinetic model of cyclosporine using the NONMEM program was as follows: $CL(L/h)=5.9{\times}(BSA/1.2)^{0.9}$, V2 (L) = 54.5, Q (L/h) = 3.5, V3 (L) = 1080.0, $k_a(h^{-1})=0.000377$. BSA was selected as a covariate of cyclosporine clearance, which increased with an increase in BSA. Conclusion: A population pharmacokinetic model for Korean pediatric hematopoietic stem cell transplant patients was developed, and the important factor affecting cyclosporine clearance was found to be BSA. The model might contribute to the development of the most appropriate dosing regimen for cyclosporine. Further studies on population pharmacokinetics should be carried out, prospectively targeting pediatric patients.

MOCVD Deposition of AlN Thin Film for Packaging Materials

  • Chang-Kyu, Ahna;Seung-Chul Choi;Seong-Hoon Cho;Sung-Hwan Han;Je-Hong Kyoung
    • 한국마이크로전자및패키징학회:학술대회논문집
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    • 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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    • pp.118-118
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    • 2000
  • New single-source precursor, [AlCI3:NH2tBu] was synthesized for AlN thin f film processing with AICI3 (Aluminum Chloride) and tBuNH2 (tert-butylamine). AlN thin films for packaging aspplication were deposited on sapphire substrate by a atmosph하ie-pressure MOCVD. In most of other study methyl-based AI precursors w were used for source, But herein Aluminum Chloride was used for as AI source i in order to prevent the carbon contamination in the films and stabilize the p precursor. New precursor showed the very high gas vapor pressure so it allowed to m make the film under atmospheric-pressure and get the high purified film. High q quality AlN thin film was obtained at 700 to $900^{\circ}C$. The new precursor was p purified by a sublimation technique and help to fabricate high purity film. It s showed high vapor pressure, which is able to a critieal factor for the high purity a and atmospheric CVD of AlN. High Quality AIN thin film was obtained at $700-900^{\circ}C$. The AIN film was characterized by RBS

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자아탄력-자아통제 수준에 따른 청소년의 기질 및 성격 특성 (Temperament and Character Traits of Adolescents by Ego Resilience and Ego Control Level)

  • 전영순;김태호;황순택;권은정;임목옥
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • 제23권1호
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    • pp.14-22
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    • 2012
  • Objectives : The purpose of present study is to identify the differences between temperament and character traits among adolescents classified by ego resilience and ego control level. Methods : A Junior Temperament and Character Inventory (TCI) was performed on participants, and a California Child Q-Test (CCQ) was tested for by the parents of the adolescent participants. Results : The result of the factor analysis and discriminant analysis show that the participants are classified into three different groups based on CCQ score and item response patterns. The three groups are named the ego resilience group, the undercontrolled group, and the overcontrolled group. The ego resilience group indicates that they have a high level of interest and curiosity but yet they are not easily tempered. Moreover, they behave proactively with a reasonable level of responsibility in order to improve themselves. In contrast, among the undercontrolled group, it is observed that, although the group shows even higher level of interest, curiosity and honesty, they are careless, more impulsive, and have a lack of delayed gratification and shame. Conclusions : The overcontrolled group shows that they are the most cautious and reflective group among the three but also show emotional instability such as strong criticism and passive-aggressiveness. In this study, implications and limitations are discussed.