• 한국자기학회지
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• 제19권2호
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• pp.52-56
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• 2009

[CoFe/Cu/CoFe]/IrMn 다층박막에 대하여 자유층 CoFe 두께에 따른 상호교환결합력, 교환결합세기, 보자력, 자기저항비, 자장감 응도 등의 자기저항 특성을 관찰하였다. IrMn 층을 통해 유도된 강자성체/비자성체/강자성체 구조인 CoFe(t)/Cu($25\;{\AA}$)/CoFe($60\;{\AA}$)/IrMn($80\;{\AA}$) 다층박막은 자유층 CoFe 두께 $30\;{\AA}$일 때 작은 보자력과 높은 자장감응도를 유지하는 연자성 특성을 보였다. 반면에 자유층 CoFe 두께 $90\;{\AA}$일 때 큰 보자력과 낮은 자장감응도를 보였다. 양호한 연자성 특성을 갖은 $2{\times}8{\mu}m^2$ 크기의 CoFe($30\;{\AA}$)/Cu($25\;{\AA}$)/CoFe($60\;{\AA}$)]/IrMn($80\;{\AA}$) 스핀밸브 소자를 제작하였다. 길이방향의 센싱전류와 폭방향의 고정층의 용이축 방향을 택하여 2 단자법으로 측정한 소자의 연자성 자기저항 특성인 자기저항비와 자장감응도는 각각 3.0%와 0.3%/Oe 이었다.

• 천문학회보
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• 제40권1호
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• pp.72.3-72.3
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• 2015

We present the mid-infrared (MIR) luminosity function (LF) of local (z < 0.3) star forming (SF) galaxies based on the AKARI's NEP-Wide Survey data. We utilized a combination of the NEP-Wide point source catalogue containing a large number (114,000) of infrared (IR) sources distributed over the wide (5.4 sq. deg) field and spectroscopic redshift (z) data for 1790 selected targets obtained by optical follow-up surveys with MMT/Hectospec and WIYN/Hydra. The AKARI's continuous $2{\sim}24{\mu}m$ wavelength coverage and the spectroscopic redshifts for sample galaxies enable us to derive accurate spectral energy distributions (SEDs) in the mid-infrared. We carried out SED-fit analysis and employed 1/Vmax method to derive the mid-IR (e.g., $8{\mu}m$, $12{\mu}m$, and $15{\mu}m$ rest-frame) luminosity functions. Our results for local galaxies from the NEP region generally consistent with various previous works for other fields over wide luminosity ranges. The comparison with the results of the NEP-Deep data implies the luminosity evolution from higher redshifts towards the present epoch. We attempted to fit our derived LFs to the double power-laws and present the resulting power indices. We also examined the correlation between mid-IR luminosity and total IR luminosity.

• 전자공학회논문지
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• 제49권9호
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• pp.49-54
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• 2012

본 논문에서는 IR-UWB 레이더 신호의 크기와 도달시간을 결합한 새로운 방법의 호흡속도추정 방법을 제안한다. 특히 이 논문에서는 분석을 통해서 인체의 흔들림이 호흡속도추정에 왜곡을 일으키지 않음을 증명한다. 분석을 바탕으로 레이더 신호의 크기 정보 신호와 도달시간 정보 신호의 컨볼루션 방법을 제안한다. 하드웨어 실험을 통한 분석을 통해서 호흡속도성분의 추출 능력이 기존의 추정 방법에 비해서 10dB 이상 향상됨을 보인다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권4호
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• pp.246-253
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• 2016

Infrared (IR) imaging has been researched for various applications such as surveillance. IR radiation has the capability to detect thermal characteristics of objects under low-light conditions. However, automatic segmentation for finding the object of interest would be challenging since the IR detector often provides the low spatial and contrast resolution image without color and texture information. Another hindrance is that the image can be degraded by noise and clutters. This paper proposes multi-level segmentation for extracting regions of interest (ROIs) and objects of interest (OOIs) in the IR scene. Each level of the multi-level segmentation is composed of a k-means clustering algorithm, an expectation-maximization (EM) algorithm, and a decision process. The k-means clustering initializes the parameters of the Gaussian mixture model (GMM), and the EM algorithm estimates those parameters iteratively. During the multi-level segmentation, the area extracted at one level becomes the input to the next level segmentation. Thus, the segmentation is consecutively performed narrowing the area to be processed. The foreground objects are individually extracted from the final ROI windows. In the experiments, the effectiveness of the proposed method is demonstrated using several IR images, in which human subjects are captured at a long distance. The average probability of error is shown to be lower than that obtained from other conventional methods such as Gonzalez, Otsu, k-means, and EM methods.

• 천문학논총
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• 제32권1호
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• pp.355-357
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• 2017

For future space IR missions, such as SPICA, it is crucial to establish an experimental method for evaluating the performance of mid-IR detectors. In particular, the wavelength dependence of the sensitivity is important but difficult to be measured properly. We are now preparing a testing system for mid-IR Si:As/Si:Sb detectors on SPICA. We have designed a cryogenic optical system in which IR signal light from a pinhole is collimated, passed through an optical filter, and focused onto a detector. With this system, we can measure the photoresponse of the detector for various IR light using optical filters with different wavelength properties. We have fabricated aluminum mirrors which are adopted to minimize thermal distortion effects and evaluated the surface figure errors. The total wavefront error of the optical system is $1.3{\mu}m$ RMS, which is small enough for the target wavelengths ($20-37{\mu}m$) of SPICA. The point spread function measured at a room temperature is consistent with that predicted by the simulation. We report the optical performance of the system at cryogenic temperatures.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.908-912
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• 2014

Microgratings whose diffracted field at a fixed angle generate IR spectra of $SF_6$ or $NH_3$ were fabricated by MEMS techniques for the purpose of IR correlation spectroscopy. Each micrograting was composed of 1441 reflecting lines in the area of $19.2{\times}19.2mm^2$. The depth profile of the line elements was determined with a gradient searching method that was described in our previous publication (J. Mod. Opt. 2013, 60, 324-330), and was discretized into 16 levels between 0 and $6.90{\mu}m$. The diffraction field from a given depth profile was calculated with Fraunhofer equation. The fabricated microgratings showed errors in the depth and the width within acceptable ranges. As the result, the diffracted IR spectrum of each micrograting matched well with its target reference spectrum within spectral resolution of our optical setup.

• 한국전기전자재료학회논문지
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• 제13권8호
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• pp.694-699
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• 2000

S $r_{0.9}$/B $i_{2.1}$/T $a_{2}$/ $O_{9}$ solutions was synthesized by MOD (metalorganic decomposition) method. SBT thin films with 2000$\AA$ thickness were prepared on Ir $O_2$/ $SiO_2$/Si and Pt/Ti/ $SiO_2$/Si substrates using the spin coating process and then investigated the dielectric and electrical properties of them. In the case of using Ir $O_2$bottom electrode the hysteresis loop was saturated at lower temperature than Pt/Ti electrode but the breakdown phenomenon was occurred at low voltage because of the rough surface morphology and porous microstructure of SBT thin films. As the results of the fatigue and imprint characteristics related to the lifetime and reliability of devices after 10$^{10}$ cycles the fatigue rates were about 10% at the Ir $O_2$and Pt/Ti bottom electrodes. Both SBT thin films with Ir $O_2$ and with Pt/Ti bottom electrodes show a slight tendency to imprint after 10$^{9}$ cycles but do not lead to a failure.e.e.

• 한국안전학회지
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• 제37권6호
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• pp.25-31
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• 2022

In this study, the spill and leak system is developed to provide real-time remote monitoring of industrial complexes where chemical accidents have been occurring every year. The spill and leak monitoring system uses IR-RCD equipment mounted on a 70m-high steel tower to detect chemical substances, thereby detecting chemical accidents such as leaks, fires, and explosions in real time. If IR-RCD equipment can actually detect chemical substances at a long distance, accurate and rapid initial response can be expected. Therefore, in order to confirm that IR-RCD equipment can detect chemical leakage accidents occurring at a long distance, acetone was selected as the experimental substance and a detection experiment was designed. The experiment was conducted using the acetone pool evaporation method at the wharf which was located 1.5 km away from IR-RCD equipment, and it was confirmed whether IR-RCD equipment could detect acetone in real time through the control monitor.

• 전자공학회논문지
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• 제53권11호
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• pp.73-81
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• 2016

일반적으로 적외선 열화상 영상은 가시광선 영상보다 약한 선명도를 가지며, 디테일 정보도 거의 없다. 그래서 종래 영상확대 알고리즘 방법으로 적외선 영상을 확대할 경우 가시광 영상에 비해 효과적이지 않다. 이런 문제점을 해결하기 위해 본 논문은 입력 적외선 영상을 ADRC 기반 초고해상도 기법으로 일차적으로 확대하고, 대응하는 가시광선 영상과 융합하는 방법을 제안한다. 제안하는 알고리즘은 크게 확대 과정과 융합 과정으로 나뉜다. 먼저 입력된 적외선 영상을 ADRC 기반의 초고해상도 알고리즘으로 확대한다. 사전의 학습과정에서 고해상도 영상들에 소위 pre-emphasis를 적용한 후 학습을 함으로써 선명도 향상을 꾀했다. 융합 과정에서는 먼저 입력 IR영상과 대응하는 가시광선 영상에서 고주파 정보를 추출하고, IR영상의 복잡도에 따라 적응적으로 상기 추출된 고주파 정보를 합성하는 방식으로 최종적인 확대 적외선 영상이 얻어진다. 모의 실험 결과 제안 알고리즘은 최신 SR기법 중 하나인 A+기법보다 JNB수치가 평균 0.2184만큼 높은 우수한 정량적 결과를 보인다. 뿐만 아니라 주관적 화질에서도 상당한 우위를 보인다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.320-323
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• 2007

The vacuum sealing method is adopted to minimize the residual impurity gas by enhancing a base vacuum level, and the resultant changes in the reset, address, and sustain discharge characteristics, such as a firing voltage, IR emission, and ICCD image, were examined in comparison with the conventional sealing method in the 42-in. AC-PDP. In the PDP cells fabricated by the vacuum sealing method, the ICCD observation illustrates that the discharge is initiated and extinguished very fast and its IR emission intensity is high.