• Title/Summary/Keyword: thermal extraction

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Infrared Visual Inertial Odometry via Gaussian Mixture Model Approximation of Thermal Image Histogram (열화상 이미지 히스토그램의 가우시안 혼합 모델 근사를 통한 열화상-관성 센서 오도메트리)

  • Jaeho Shin;Myung-Hwan Jeon;Ayoung Kim
    • The Journal of Korea Robotics Society
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    • v.18 no.3
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    • pp.260-270
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    • 2023
  • We introduce a novel Visual Inertial Odometry (VIO) algorithm designed to improve the performance of thermal-inertial odometry. Thermal infrared image, though advantageous for feature extraction in low-light conditions, typically suffers from a high noise level and significant information loss during the 8-bit conversion. Our algorithm overcomes these limitations by approximating a 14-bit raw pixel histogram into a Gaussian mixture model. The conversion method effectively emphasizes image regions where texture for visual tracking is abundant while reduces unnecessary background information. We incorporate the robust learning-based feature extraction and matching methods, SuperPoint and SuperGlue, and zero velocity detection module to further reduce the uncertainty of visual odometry. Tested across various datasets, the proposed algorithm shows improved performance compared to other state-of-the-art VIO algorithms, paving the way for robust thermal-inertial odometry.

Reduced-Scale Experiments of the Partial Smoke Extraction System in Tunnel Fires (풀화재를 이용한 터널화재 부분배연 모델실험)

  • Lee, Eui-Ju;Yoo, Yong-Ho
    • Fire Science and Engineering
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    • v.20 no.4 s.64
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    • pp.58-64
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    • 2006
  • Smoke extraction in tunnel fire is investigated experimently with thermal model. The object is a immersed tunnel, of which the partial extraction system exists between the tubes. The model tunnel is measured 12 m long, 0.5 m wide and 0.35 m high. The fire is simulated to pool fire and the size corresponds to full scale fire of 5 MW based on Froude modeling. The performance of partial extraction system is determined under two ventilations, natural and longitudinal ones. The results show that compared with longitudinal ventilation, the smoke extraction efficiency of natural ventilation is increased about 30% because of smoke stratification in tunnel. Also the efficiency is identical to the iso-thermal model. The results will be help for activation of the ventilation system in emergency such as in the event of tunnel fires.

Determination of Palladium in Water Samples Using Cloud Point Extraction Coupled with Laser Thermal Lens Spectrometry

  • Han, Quan;Huo, Yanyan;Yang, Na;Yang, Xiaohui;Zhai, Yunhui;Zhang, Qianyun
    • Journal of the Korean Chemical Society
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    • v.59 no.5
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    • pp.407-412
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    • 2015
  • A preconcentration procedure for determination of palladium by laser thermal lens spectrometry (TLS) is proposed. It is based on cloud point extraction of palladium(II) ions as 2-(3,5-dichloro-2-pyridylazo)-5-dimethylaminoaniline (3,5-diCl-PADMA) complexes using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The effects of various experimental conditions such as pH, concentration of ligand and surfactant, equilibration temperature and time on cloud point extraction were studied. Under the optimized conditions, the calibration graph was linear in the range of 0.15~6 ng mL−1, and the detection limit was 0.04 ng mL−1 with an enrichment factor of 22. The sensitivity was enhanced by 846 times when compared with the conventional spectrophotometric method. The recovery of palladium was in the range of 96.6%~104.0%. The proposed method was applied to the determination of palladium in water samples.

ICA based Thermal Source Extraction and Thermal Distortion Compensation for Machine Tools

  • Lee, Dong-Soo;Park, Jin-Young;Park, Doo-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.91.2-91
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    • 2002
  • $\textbullet$ Machine tools $\textbullet$ Thermal distortion compensation $\textbullet$ Independent component analysis $\textbullet$ Temperature variable reduction $\textbullet$ Thermal distortion modeling $\textbullet$ Hardware Implementation $\textbullet$ Experiments

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Power Line Extraction based on thermal Image (열영상 기반의 전력선검출)

  • Kim, Dong-Wook
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.3
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    • pp.245-250
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    • 2010
  • In this paper, an efficient extraction technique of power lines is proposed. Power line extraction technique is used to operate unmanned autonomous vehicles. To achieve the extraction of power lines, an angle space segmentation and grouping method of Hough transform are developed. In simulation results for the proposed algorithm, our algorithm shows a good detection results in experiments for several aerial images which contain different line components.

A study of thermolysis of irradiated diamide-containing extraction systems with nitric acid

  • Srvortsov, I.V.;Belova, E.V.;Sokolov, I.P.;Rodin, A.V.;Stefanovsky, S.V.;Mysoedov, B.F.
    • Nuclear Engineering and Technology
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    • v.50 no.8
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    • pp.1421-1425
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    • 2018
  • The dynamics of gas release at thermal oxidation of extraction systems on the basis of diamides of dicarbonic acids in fluorinated sulphones with 14 mol/L $HNO_3$ was investigated. The effect of preirradiation of the mixtures with accelerated electrons on the kinetics of their thermolysis was determined. The mixtures were heated in an autoclave at temperatures of 170 and $200^{\circ}C$ and irradiated using an electron accelerator to absorbed doses of 0.1, 0.5, and 1.0 MGy. It has been shown that no conditions for autocatalytic oxidation at thermolysis of extraction mixtures irradiated up to a dose of 1 MGy were developed.

Thermal Properties of Granite for Installation of Underground Heat Exchanger (지중 열교환기 설계를 위한 화강암의 열물성 연구)

  • Kim, Jong-Chan;Lee, Young-Min;Koo, Min-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.456-459
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    • 2007
  • Thermal conductivities (TC) of 57 Jurassic muscovitic granite samples (KIGAM) and 149 porphyritic granite samples (Yeonki: BE-2, BE-3) were measured with LFA-447. Ranges of TC values are $2.429{\sim}3.878$ W/mK (KIGAM), $2.220{\sim}3.767$ W/mK (Yeonki, BE-2) and $2.019{\sim}3.990$ W/mK (Yeonki, BE-3); arithmetic means are 2.924 W/mK (KIGAM), 2.907 W/mK (Yeonki, BE-2), and 2.881 W/mK (Yeonki, BE-3), respectively. In this study, harmonic mean values were calculated to estimate the average value of TC. Harmonic mean values are 2.883 W/mK (KIGAM), 2.886 W/mK (Yeonki, BE-2), and 2.866 W/mK (Yeonki, BE-3), respectively. Heat extraction rates of a borehole heat exchanger strongly depend on TC values. Heat-extraction rates from re values are expected to be a little lower than 84 W/m in all sites. However, considering ground water flow, it is expected that actual heat extraction rate would be higher than the expected value.

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Study on the Preparation of Alumina Powders used os a Rubber Filler with a Microwave Extraction System (마이크로파에 의한 고무용 충전제로서의 Alumina Powder의 제조에 관한 연구)

  • Park, Chan-Young;Hwang, Eun-Hee;Han, Seong-Kee
    • Elastomers and Composites
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    • v.33 no.3
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    • pp.201-209
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    • 1998
  • Alumina powders used as a filler in rubber compounding was extracted from kaolin in $H_2SO_4$ solution employing conventional thermal and microwave energy resources. Maximum degrees of alumina extraction from kaolin were 72.8% at $80^{\circ}C$, 1M $H_2SO_4$, and 180min in the conventional thermal extraction process and were 99.0% at $90^{\circ}C$, 1M $H_2SO_4$,, and 60min in the microwave extraction one, respectively. The samples synthesized in both processes were analyzed by means of TG/DTA, XRD, SEM, Atomic Emission Spectroscopy, and BET method. Studies are presently under way to unravel the basic interaction mechanisms between microwave and alumina power for high rates of alumina extraction from kaolin in the microwave ex-traction process.

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Hybrid feature extraction of multimodal images for face recognition

  • Cheema, Usman;Moon, Seungbin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2018.10a
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    • pp.880-881
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    • 2018
  • Recently technological advancements have allowed visible, infrared and thermal imaging systems to be readily available for security and access control. Increasing applications of facial recognition for security and access control leads to emerging spoofing methodologies. To overcome these challenges of occlusion, replay attack and disguise, researches have proposed using multiple imaging modalities. Using infrared and thermal modalities alongside visible imaging helps to overcome the shortcomings of visible imaging. In this paper we review and propose hybrid feature extraction methods to combine data from multiple imaging systems simultaneously.