• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.695-697
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• 2013

본 논문에서는 MOSFET을 사용하여 IC내부의 온도를 측정해 전압을 출력으로 나타내는 온도감지회로를 제안하였다. 제안한 온도감지회로는 CMOS공정에서 구현하기 위해 MOSFET을 이용한 두 개의 전류미러 회로를 이용하여 설계하였고, 다양한 어플리케이션에 적용 가능하도록 하였다. 온도감지회로는 온도감지모드, 절전모드 두 가지 동작을 하며 각각의 모드 시뮬레이션 결과 온도감지모드에서는 $0^{\circ}C{\sim}125^{\circ}C$까지 스윕했을 때 출력전압이 0V에서 1.2V까지 측정되었고, 절전모드에서는 출력전류가 100pA 이하로 흐르는 것을 확인 할 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.438-440
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• 2018

심정지(Cardiac arrest)는 원인과 관계없이 심장의 박동이 정지되어 발생하는 일련의 상태를 말한다. 심장질환에 의한 심정지는 매년 우리나라 3대 사망원인에 포함되며 예측이 불가하다. 심정지 발생시 환자의 생명을 구하기 위한 유일한방법 중 하나는 심폐소생술이며 이 술기를 통하여 순환을 유지시킬 수 있다. 시각으로 받아들여진 정보는 시신경을 통하여 뇌로 전달되며, 그중 거울은 자신의 움직임과 자신의 형태를 볼 수 있게 하고, 교정과 분석이 가능하여 다양하게 활용 할 수 있다. 이에 거울을 활용한 시각적 정보에 따른 가슴압박의 질을 비교하였다. 연구결과 거울 사용에 따라 가슴압박의 평균 깊이가 유의한 차이가 있었고($48.93{\pm}6.76$, $53.86{\pm}4.56$, <0.001), 압박 대 이완 비율에도 차이를 보였다($0.87{\pm}0.13$, $0.96{\pm}0.10$, <0.002). 또한 자세를 의식하는 정도에서도 유의한 차이를 보였다($4.93{\pm}0.85$, $8.14{\pm}1.38$, <0.001).

• 대한전자공학회논문지SD
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• 제44권7호통권361호
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• pp.37-44
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• 2007

GSM 셀룰러폰을 위한 저전압 고선형 바이폴라 OTA와 이룡 이용한 IF bandpass filter(BPF)를 제안하였다. OTA는 저전압 선형 transconductor, translinear 전류이득 셀, 그리고 3개의 전류 미러로 구성 되어있다. BPF는 2개의 동일한 2차 BPF를 직렬 연결한 형태인데, 2차 BPF는 저항과 커패시터 그리고 2개의 OTA와 커패시터로 된 ground simulated inductor로 구성되어 있다. 8GHz bipolar transistor-array를 사용한 SPICE 시뮬레이션에서는 1mS의 transconductance의 OTA가 ${\pm}2%$ 이하의 선형 오차와 ${\pm}2\;V$에서 ${\pm}0.65\;V$이상의 선형범위를 가짐을 보여준다. transconductor의 온도계수는 $-90ppm/^{\circ}C$이하이다. BPF는 중심 주파수는 $85MHz\;Q$값은 80이 되도록 설계하였다. 중심주파수에서의 온도계수는 $-182ppm/^{\circ}C$이고, BPF의 소비전력은 128mW 이다.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2394-2398
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• 2013

Nicotine is the main component of environmental tobacco smoke, and its presence in indoor air is widely used as a secondhand-smoke indicator. Environmental tobacco smoke is a major source of indoor air pollution, but sufficient investigation of the uncertainty of its measurement, which mirrors the reliability of nicotine measurement, has not been performed. We calculated the uncertainty of measurement of indoor air nicotine concentration at low, medium, and high concentrations of 11.3798, 10.1977, $98.3768{\mu}g/m^3$, respectively, and we employed the Guide to the Expression of Uncertainty in Measurements (GUM), proposed by the International Organization for Standardization (ISO). The factors considered in determining the uncertainty were uncertainty of the calibration curve (calibration curve and repeated measurements), desorption efficiency, extraction volume, and sampling airflow (accuracy and acceptable limits of flowmeter). The measurement uncertainty was highest at low concentrations; the expanded measurement uncertainty is $0.9435{\mu}g/m^3$ and is represented as a relative uncertainty of 63.38%. At medium and high (concentrations, the relative uncertainty was 13.1% and 9.1%, respectively. The uncertainty of the calibration curve was largest for low indoor nicotine concentrations. To increase reliability of measurement in assessing the effect of secondhand smoke, measures such as increasing the sample injection rate ($1{\mu}L$ or more), increasing sampling volume to increase collected nicotine, and using gas chromatography-mass spectrometry (GC/MS) or GC/MS/MS, which has a lower quantitation threshold, rather than gas chromatography with nitrogen phosphorous detector, should be considered.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.287-293
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• 2004

A numerical simulation is presented for investigating the effects of pressure ratio of $D_2$ injector to supersonic nozzle on the population inversion in the DF chemical laser cavity, while a lasing concurrently takes place. The laser beam is generated between the mirrors in the cavity and it is important to obtain stronger population inversion and more uniform distribution of the excited molecules in the laser cavity in order to produce high power laser beam with good quality. In this study, these phenomena are investigated by means of analyzing the distributions of the DF excited molecules and the F atom used as an oxidant, while simultaneously estimating the maximum small signal and saturated gains and power in the DF chemical laser cavity. For the numerical solution, an 11-species (including DF molecules in various excited states of energies), 32-step chemistry model is adopted for the chemical reaction of the DF chemical laser system. The results are discussed by comparison with two $D_2$injector pressure cases; 192 torr and 388.64 torr. Major results reveal that in the resonator, stronger population inversions occur in the all transitions except DF(1)-DF(0), when the $D_2$injection pressure is lower. But, the higher $D_2$injection pressure provides a favorable condition for DF(1)-DF(0) transition to generate the higher power laser beam. In other words, as the pressure of $D_2$injector increases, the maximum small signal gain in the $V_{1-0}$ transition, which is in charge of generating most of laser power, becomes higher. Therefore, the total laser beam power becomes higher.r.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제9권9호
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• pp.267-280
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• 2020

거울은 일반적으로 아말감으로 코팅된 물리적 반사 표면으로 거울 앞의 상을 선명하게 반사한다. 이것은 언제 어디서나 사용이 가능하며 사용자의 얼굴이나 외모를 확인하기 위한 필수적인 도구이다. 현대 소프트웨어 기술의 출현으로 사람들은 실시간 처리, Microservice 및 머신 러닝이 적용된 편의성과 지능성을 통해 거울 반사 기능을 향상시킬 수 있다. 본 논문에서는 거울로써 실시간 반영과 동시에 사용자 맞춤 정보 조회, 공공 정보 조회, 외모를 통한 나이와 감정 탐지 등의 기능을 가진 디지털 거울 시스템 개발을 제안한다. 더불어, 본 시스템은 터치 기반, 음성 인식 기반, 제스처 기반의 Multi-Modal 사용자 인터페이스를 제공한다. 본 논문에서는 이 시스템에 대한 디자인을 제시하고 현재 기술을 이용하여 실시간 거울 반영과 동시에 유용한 정보 제공 및 지능형 머신 러닝 기술을 제공하는 구현 방법을 제안한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.148-149
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• 2007

We present the design and fabrication prcoess of a two-axis tilting micromirror device driven by the electrostatic vertical comb actuator. A high aspect-ratio comb actuator is fabricated by multiple DRIE process in order to achieve large scan angle. The proposed fabrication process enables a mirror to be fabricated on the wafer-scale. By bonding a double-side polished (DSP) wafer and a silicon-on-insulator (SOI) wafer together, all actuators on the wafer are completely hidden under the reflectors. Nickel lines are embedded on a Pyrex wafer for the electrical access to numerous electrodes of mirrors. An anodic bonding step is implemented to contact electrical lines with ail electrodes on the wafer at a time. The mechanical angle of a fabricated mirror has been measured to be 1.9 degree and 1.6 degree, respectively, in the two orthogonal axes under driving voltages of 100 V. Also, a $8{\times}8$ array of micromirrors with high fill-factor of 70 % is fabricated by the same fabrication process.

• Journal of Welding and Joining
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• 제26권5호
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• pp.74-78
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• 2008

The laser welding of the car body and components has been spread in the automotive industry. The Nd:YAG laser welding system could be used in 3D welding with robot. However, this system cannot efficiently reduce the welding cycle time according to various welding sequences because the robot's moving time is same that of the resistant spot welding system. But the remote welding system with high power $CO_2$ laser and scanner makes it possible welding cycle time much faster than the robot laser welding system. In the $CO_2$ laser remote welding system, laser beam can be rapidly transferred to a workpiece by moving mirrors of scanner system. So, it makes reducing the cycle time of welding process and shaping various welding patterns easily. Therefore, in this paper, the characteristic of weld strength according to patterns of weld bead on $CO_2$ laser welding was investigated. Also, the relationship between shape of weld bead and value of tensile load was studied. Finally, the optimum remote welding condition for car bumper was investigated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.763-764
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• 2013

A three-dimensional image capturing device and its signal processing algorithm and apparatus are presented. Three dimensional information is one of emerging differentiators that provides consumers with more realistic and immersive experiences in user interface, game, 3D-virtual reality, and 3D display. It has the depth information of a scene together with conventional color image so that full-information of real life that human eyes experience can be captured, recorded and reproduced. 20 Mega-Hertz-switching high speed image shutter device for 3D image capturing and its application to system prototype are presented[1,2]. For 3D image capturing, the system utilizes Time-of-Flight (TOF) principle by means of 20MHz high-speed micro-optical image modulator, so called 'optical resonator'. The high speed image modulation is obtained using the electro-optic operation of the multi-layer stacked structure having diffractive mirrors and optical resonance cavity which maximizes the magnitude of optical modulation[3,4]. The optical resonator is specially designed and fabricated realizing low resistance-capacitance cell structures having small RC-time constant. The optical shutter is positioned in front of a standard high resolution CMOS image sensor and modulates the IR image reflected from the object to capture a depth image (Figure 1). Suggested novel optical resonator enables capturing of a full HD depth image with depth accuracy of mm-scale, which is the largest depth image resolution among the-state-of-the-arts, which have been limited up to VGA. The 3D camera prototype realizes color/depth concurrent sensing optical architecture to capture 14Mp color and full HD depth images, simultaneously (Figure 2,3). The resulting high definition color/depth image and its capturing device have crucial impact on 3D business eco-system in IT industry especially as 3D image sensing means in the fields of 3D camera, gesture recognition, user interface, and 3D display. This paper presents MEMS-based optical resonator design, fabrication, 3D camera system prototype and signal processing algorithms.

• 한국축산식품학회지
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• 제32권4호
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• pp.414-427
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• 2012

Carcass characteristics and meat quality traits as a function of endpoint months of slaughter age (26 vs 32 mon) and chiller ageing (1 vs 10 d) were evaluated for m. longissmus of 26 Hanwoo steers fed with commercial diets including whole crop barley silage. Totally twenty six Hanwoo steers for 6 mon of age that were fed until 26 mon of age constituted the short term-fed group and fed until 32 mon of age constituted long-term fed group. Carcasses were chilled for 24 h and were graded. Strip loin samples were divided into two age groups (1 d and 10 d). Long-term feeding increased carcass weight, rib-eye area, yield grade, marbling score, firmness and quality grade of the meat. The feeding for 32 mon produced tender, juicy meat (p<0.01) with lower cooking loss and higher rating score (p<0.05) than short term feeding, while other quality traits were not influenced by the length of feeding. Intramuscular fat content and oxidative stability (TBARS value) were significantly (p<0.05) higher in beef from long-term feeding however the length of feeding did not alter the fatty acid composition. Chiller aging reduced instrumental tenderness (WBSF value), improved color, sensory tenderness, acceptability and rating of beef. The results of the present study mirrors that Hanwoo steers until 32 mon of age overall improved carcass traits and palatability compared to that for 26 mon. However, from the viewpoints of economical and environmental aspects, cost of the additional feeding for 6 mon for value-adding of eating quality was relatively high and the effects in turn were limited.