위성 통신 시스템을 위한 Ka-band 이득제어 CMOS 저잡음 증폭기

임혜민,정하연,이재용,박성규,박창근,Im, Hyemin,Jung, Hayeon,Lee, Jaeyong,Park, Sungkyu,Park, Changkun 한국정보통신학회 2019 한국정보통신학회논문지 Vol.23 No.8

본 논문에서는 CMOS 65-nm 공정을 이용하여 위성 통신 시스템에서 Ka-band를 지원하기 위한 저잡음 증폭기를 설계하였다. 제안된 저잡음 증폭기는 고이득 모드와 저이득 모드로 구성되어있으며, 입력신호의 크기에 따라 이득을 제어하도록 설계하였다. 전력소모를 줄이기 위해 회로 전체의 공급전압을 1 V 이하로 제한하였으며, 인버터 구조의 이득제어 회로에 대해 기술하였다. 제작된 회로의 크기를 줄이기 위해 3D EM 시뮬레이터를 사용하였으며, 패드를 포함하며 $0.33mm^2$의 면적을 갖는다. 제작된 증폭기는 3 dB 대역폭에서 -7 dB의 이득제어 범위를 가지며 반사계수는 고이득 모드에서 -6 dB, 저이득 모드에서 -15 dB 미만으로 측정되었다. In this paper, we design a low noise amplifier to support ka-band satellite communication systems using 65-nm RFCMOS process. The proposed low noise amplifier is designed with high-gain mode and low-gain mode, and is designed to control the gain according to the magnitude of the input signal. In order to reduce the power consumption, the supply voltage of the entire circuit is limited to 1 V or less. We proposed the gain control circuit that consists of the inverter structure. The 3D EM simulator is used to reduce the size of the circuit. The size of the designed amplifier including pad is $0.33mm^2$. The fabricated amplifier has a -7 dB gain control range in 3 dB bandwidth and the reflection coefficient is less than -6 dB in high gain mode and less than -15 dB in low gain mode.

Growth and Physiological Responses of Quercus acutissima Seedling under Drought Stress

임혜민,강준원,이솔지,이현석,이위영 한국육종학회 2017 Plant Breeding and Biotechnology Vol.5 No.4

In this study, Quercus acutissima seedlings were subjected to drought for 30 days then analyzed to determine their response to water deficit. The growth phenotype, chlorophyll fluorescence response, fresh weight, dry weight, photosynthetic pigment levels, soluble sugar content, and malondialdehyde (MDA) were measured to evaluate the effects of drought on plant growth and physiology. The growth phenotype was observed by infrared (IR) digital thermal imaging after 30 days of drought treatment. The maximum, average, and minimum temperatures of drought-treated plant leaves were 1-2°C higher than those of the control. In contrast, the fresh and dry weights of the dehydrated leaves were generally lower than those of the control. There were no significant differences between treatments in terms of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid levels. Nevertheless, for the drought treatment, the Fv/Fm and Fv/Fo ratios (chlorophyll fluorescence response) were lower than those for the control. Therefore, photosynthetic activity was lower in the dehydrated plants than the control. The drought-stressed Q. acutissima S0536 had lower soluble sugar (glucose and fructose) and higher MDA levels than the controls. These findings may explain the early growth and physiological responses of Q. acutissima to dehydration and facilitate the selection of drought-resistant tree families.

고분자 가소제가 포함된 나노 섬유 분리막 기반의 이차전지용 고분자 전해질

임혜민,안현준,김수환,윤지현,임두현 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.0

다공성 Co₃O₄/RuO₂ 복합체 합성 및 전기화학적 특성

임혜민,류광선,Lim, Hye-Min,Ryu, Kwang-Sun 한국재료학회 2012 한국재료학회지 Vol.22 No.3

We synthesized porous $Co_3O_4/RuO_2$ composite using the soft template method. Cetyl trimethyl ammonium bromide (CTAB) was used to make micell as a cation surfactant. The precipitation of cobalt ion and ruthenium ion for making porosity in particles was induced by $OH^-$ ion. The porous $Co_3O_4/RuO_2$ composite was completely synthesiszed after anealing until $250^{\circ}C$ at $3^{\circ}C$/min. From the XRD ananysis, we were able to determine that the porous $Co_3O_4$/RuO2 composite was comprised of nanoparticles with low crystallinity. The shape or structure of the porous $Co_3O_4/RuO_2$ composite was studied by FE-SEM and FE-TEM. The size of the porous $Co_3O_4/RuO_2$ composite was 20~40 nm. From the FE-TEM, we were able to determine that porous cavities were formed in the composite particles. The electrochemical performance of the porous $Co_3O_4/RuO_2$ composite was measured by CV and charge-discharge methods. The specific capacitances, determined through cyclic voltammetry (CV) measurement, were ~51, ~47, ~42, and ~33 F/g at 5, 10, 20, and 50 mV/sec scan rates, respectively. The specific capacitance through charge-discharge measurement was ~63 F/g in the range of 0.0~1.0 V cutoff voltage and 50 mAh/g current density.

유니세프 연말캠페인 내곁에 있어줘 (UNICEF CAMPAIGN - WITH ME)

임혜민,최규진 (사)한국인터넷전문가협회 2017 Web Korea Annual Vol.2017 No.-

에스페란자 스팔딩의 <NPR MUSIC FRONT ROW>에 나타난 신(新) 라이브 공연 연출기법

임혜민,주은총,이우창 글로벌문화콘텐츠학회 2016 글로벌문화콘텐츠학회 학술대회 Vol.2016 No.2

기존 라이브 공연은 흔히 악기 세션들과 가수가 정해진 자리에서 노래를 부르거나, 춤을 추거나, 더 나아가서는 홀로그램 등 시각적인 효과를 이용한다. 그런데 에스페란자 스팔딩의 라이브 공연 실황 <NPR MUSIC FRONT ROW>에서는 2016년 3월에 발매된 정규앨범 <Emily s D+ Evolution>의 수록 곡들을 바탕으로 뮤지컬 형식의 공연을 참신하게 연출하였다. 본 논문은 기존의 라이브 공연에서 벗어나 새로운 공연 연출의 가능성을 열어보고자 한다.

PGB: BERT 프루닝을 위한 순서 변경 규칙 및 그룹화

임혜민,최동완 한국정보과학회 2023 정보과학회논문지 Vol.50 No.6

최근 사전 학습된 트랜스포머 계열의 모델은 자연어 처리, 이미지 인식 등 다양한 인공지능 분야에서 활발히 사용되고 있다. 그러나 해당 모델들은 수십억 개의 파라미터를 가지고 있어 추론 시에 상당한 연산량을 필요로 하며 자원이 제한된 환경에서 사용하기에는 많은 제약이 따른다. 이러한 문제들을 해결하기 위해 본 논문은 트랜스포머 모델에 대한 그룹화 기반의 새로운 구조화된 프루닝 방법인 PGB(Permutation Grouped BERT pruning)를 제안한다. 제안된 방법은 자원 제약 조건에 따라 최적의 어텐션 순서를 변경하는 방법을 찾고, 모델의 정보 손실을 최소화하기 위해 헤드의 중요도를 기반으로 불필요한 헤드에 대해 프루닝한다. 다양한 비교 실험을 통해 사전 학습된 BERT 모델에 대한 기존의 구조화된 프루닝 방법보다 본 논문에서 제안한 방법이 추론 속도 및 정확도 손실 측면에서 더 우수한 성능을 보임을 확인한다.

A Low-Loss On-Chip Transformer Using an Auxiliary Primary Part (APP) for CMOS Power Amplifier Applications

임혜민,박창근 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.2

We propose a low-loss on-chip transformer using an auxiliary primary part (APP) for an output matchingnetwork for fully integrated CMOS power amplifiers. The APP is designed using a fifth metal layer while theprimary and secondary parts are designed using a sixth metal layer with a width smaller than that of theprimary and secondary parts of the transformer to minimize the substrate loss and the parasitic capacitancebetween the primary and secondary parts. By adapting the APP in the on-chip transformer, we obtain animproved maximum available gain value without the need for any additional chip area. The feasibility of theproposed APP structure is successfully verified.

출생 체중 1 kg 미만의 초 극소 저 체중 출생아에서 침습성 진균 감염증에 대한 Fluconazole 예방 요법의 효과 분석

임혜민,양사미,박윤희,한혜원,곽혜선,김재연 한국병원약사회 2014 病院藥師會誌 Vol.31 No.4

Background : An invasive fungal infection (IFI) is an important cause of morbidityand mortality in preterm infants with immature immune systems. In the present study, we evaluatedthe efficacy in preventing IFI and adverse effects of prophylactic fluconazole in extremelylow birth weight infants (ELBWIs). Methods : From January 2010 to July 2012, we conducted a chart review in a total of 106preterm infants with a birth weight less than 1 kg that were hospitalized in the neonatal intensivecare unit (NICU) of the Asan medical center. In May 2011, an unit policy on fluconazole prophylaxishad been implemented (3 mg/kg twice a week intravenous infusion) and we classified thestudy population into two groups; control group (admitted before the introduction of fluconazoleprophylaxis, n=71) and study group (admitted after the introduction of fluconazole prophylaxis,n=35). The incidence of IFI and the strains of infection were investigated and other outcome variables including mortality, morbidity, and adverse effects of fluconazole were also collected. Results : The incidence of IFI was 2.9% in the study group versus 19.7% in the control group(p<0.05). Logistic regression revealed that fluconazole prophylaxis significantly decreased therates of IFI (Odds ratio 0.082, p<0.05). There was no difference in the incidence of cholestasisbetween two groups and there was no evidence of hepatotoxicity of fluconazole. Conclusion : The prophylactic administration of fluconazole in ELBWIs revealed its effectivenessin preventing IFI without significant adverse effects.

대학생의 열등감과 관계적 공격성의 관계에서 의도귀인의 매개효과

임혜민,최지영 한국인간발달학회 2019 人間發達硏究 Vol.26 No.3

The purpose of this study is to explore whether intention attribution plays a mediating role in the relationship between inferiority feelings and relational aggression in university students. For this purpose, intention attribution was set as a mediator in the relationship between inferiority feelings and relational aggression, and verification using a structural equation model was conducted. The subjects of this study were 330 students enrolled in six universities in Daejeon Metropolitan City and Chungcheongnam-do in Korea. Questionnaire surveys using the inferiority symptom scale, relational aggression scale, and intention attribution scale were untilized in this study. The analysis methods were descriptive statistics, a correlation analysis, a confirmatory factor analysis, the structural equation model and bootstrapping. The results of this study are as follows. First, the relationships among inferiority feelings, relational aggression, and intention attribution were significantly correlated with each other. Second, as a result of examining whether the mediating effect of intention attributed to inferiority feelings and relational aggression, intention attribution was found to be partially mediated in the relationship between inferiority feelings and relational aggression. In other words, inferiority feelings had a direct effect on relational aggression, while having an indirect effect through intention attribution. These results suggest that higher levels of inferiority feelings in university students are linked to a stronger tendency to feel intention or hostility toward others' behavior, which again leads to relational aggression. This study is meaningful in that it presents empirical research results pertaining to the prevention and reduction of relational aggression through educational intervention in cognitive and emotional aspects including inferiority feelings and intention attribution by means of counseling for university students.