• Title/Summary/Keyword: optical filter

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NORTH ECLIPTIC POLE WIDE SURVEY

  • Lee, Hyung Mok;Kim, Seong Jin;NEP-Wide Team, NEP-Wide Team
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.129-134
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    • 2012
  • The North Ecliptic Pole (NEP) Wide survey covered about 5.4 $deg^2$, a nearly circular area centered on the NEP, using nine passbands of InfraRed Camera (IRC). We present the photometric properties of the data sets, and the nature of the sources detected in this field. The number of detected sources varied according to the filter band: with about 109,000 sources in the NIR, about 20,000 sources in the MIR-S, and about 16,000 sources seen in the MIR-L channel. The $5{\sigma}$ detection limits are about 21 mag in the NIR and 19.5 - 18.5 mag in the MIR bands in terms of the AB magnitude. 50% completeness levels are about 19.8 mag at $3{\mu}m$, 18.6 mag at $9{\mu}m$, and 18 mag at $18{\mu}m$ band (in AB magnitude), respectively. In order to validate the detected sources, all of them are confirmed by matching tests with those in other bands. The 'star-like' sources, defined by the high stellarity and magnitude cut from the optical ancillary data, appear statistically to have a high probability of being stars. The nature of the various types of extragalactic sources in this field are discussed using the color-color diagrams of the NIR and MIR bands with the redshift tracks of galaxies providing useful guidelines.

Adaptive Color Snake Model for Real-Time Object Tracking

  • Seo, Kap-Ho;Jang, Byung-Gi;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.740-745
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    • 2003
  • Motion tracking and object segmentation are the most fundamental and critical problems in vision tasks suck as motion analysis. An active contour model, snake, was developed as a useful segmenting and tracking tool for rigid or non-rigid objects. Snake is designed no the basis of snake energies. Segmenting and tracking can be executed successfully by energy minimization. In this research, two new paradigms for segmentation and tracking are suggested. First, because the conventional method uses only intensity information, it is difficult to separate an object from its complex background. Therefore, a new energy and design schemes should be proposed for the better segmentation of objects. Second, conventional snake can be applied in situations where the change between images is small. If a fast moving object exists in successive images, conventional snake will not operate well because the moving object may have large differences in its position or shape, between successive images. Snakes's nodes may also fall into the local minima in their motion to the new positions of the target object in the succeeding image. For robust tracking, the condensation algorithm was adopted to control the parameters of the proposed snake model called "adaptive color snake model(SCSM)". The effectiveness of the ACSM is verified by appropriate simulations and experiments.

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Liveness Detection of Fingerprints Using Correlation Filters (상관 필터를 이용한 위조 지문 검출 방법)

  • Choi, Hee-Seung;Choi, Kyung-Taek;Kim, Jai-Hie
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.355-358
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    • 2005
  • Fingerprint recognition systems are the most widely used in biometrics for personal authentication. As they become more familiar, the security weaknesses of fingerprint sensors are becoming better known. In this paper, we propose a liveness detection method that applies correlation filter to the fingerprint recognition systems. The physiological characteristic of sweat pore, observed only in live people, is used as a measure to classify 'live' fingers from 'spoof' fingers. Previous works show that detection of sweat pores and perspiration patterns in fingerprint images can be used as an anti-spoofing measure. These methods don't consider the characteristic of pores in each individual. We construct the correlation filters of each individual which are composed of their pore information. We make the final decision about the "livens" of fingerprint using correlation output. The proposed algorithm was applied to a data set of 110 live, 110 spoof fingerprint images from optical fingerprint scanner and achieved classification rate of 80%.

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Implementation of Wireless Multiple Integrated Laser Engagement System using ZigBee-based Persinal Area Network (ZigBee기반 개인영역망을 사용한 무선 다중 통합 레이저 교전 시스템의 구현)

  • Ki, Hyeon-Cheol
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.85-90
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    • 2014
  • We realized a wireless multiple integrated laser engagement system composed of personal area network using Zigbee. The wireless laser detector had function of analog signal processor, decoder and wireless communication. However, it should consume low power and be small and light in order to be attached to a soldier's body. The decoder was realized in software to be small and light. We induced low power consumption as reducing the load of system using a narrow band optical filter. The fabricated wireless laser detector functioned well in optically noisy environment. Although the communication to the player unit through the wireless personal area network was dependent on the attachment place it was perfectly worked with transmission power of -40.2dBm or more.

Damage Analysis of CCD Image Sensor Irradiated by Continuous Wave Laser (연속발진 레이저에 의한 CCD 영상센서의 손상 분석)

  • Yoon, Sunghee;Jhang, Kyung-Young;Shin, Wan-Soon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.6
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    • pp.690-697
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    • 2016
  • EOIS(electro-optical imaging system) is the main target of the laser weapon. Specially, the image sensor will be vulnerable because EOIS focuses the incident laser beam onto the image sensor. Accordingly, the laser-induced damage of the image sensor needs to be identified for the counter-measure against the laser attack. In this study, the laser-induced damage of the CCD image sensor irradiated by the CW(continuous wave) NIR(near infrared) laser was experimentally investigated and mechanisms of those damage occurrences were analyzed. In the experiment, the near infrared CW fiber laser was used as a laser source. As the fluence, which is the product of the irradiance and the irradiation time, increased, the permanent damages such as discoloration and breakdown appeared sequentially. The discoloration occurred when the color filter was damaged and then the breakdown occurred when the photodiode and substrate were damaged. From the experimental results, LIDTs(laser-induced damage thresholds) of damages were roughly determined.

Comparative Behavior Analysis in Love Model with Same and Different Time Delay (동일 시간 지연과 서로 다른 시간 지연을 갖는 사랑모델에서의 비교 거동 해석)

  • Huang, Linyun;Ba, Young-Chul
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.3
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    • pp.210-216
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    • 2015
  • It is well known that the structure of brain and consciousness of human have a phenomena of complex system. The human emotion have a many kind. The love is one of human emotion, which have been studied in sociology and psychology as a matter of great interested thing. In this paper, we consider a same and different time delay in love equation of Romeo and Juliet. We represent a behavior of love as a time series and phase portrait, and analyze the difference of behaviors between a same and different time delay.

CQUEAN II System Design: New Auto-guiding System

  • Choi, Nahyun;Lee, Hye-In;Pak, Soojong;Ji, Tae-Geun;Jeong, Byeongjoon;Bae, Min K.;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.83.2-83.2
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    • 2013
  • Camera for QUasars in EArly uNiverse (CQUEAN) is an optical CCD camera developed by the Center for the Exploration of the Origin of the Universe (CEOU). In 2010 August, CQUEAN was attached on the 2.1m Otto Struve Telescope at the McDonald Observatory in Texas, USA. As the main purpose of CQUEAN is detecting the Lyman breaks of redshift ~5 quasars, it is sensitive to near-infrared wavelengths (0.7-1.0 ${\mu}m$). For the auto-guiding system, it is using a rotating guide arm to find guide stars on the Cassegrain off-axis focus of the telescope. We plan to upgrade a new filter wheel system consists of a series of narrow band filters. We will install this independent auto-guiding units on the finder scope, which makes rooms on the Cassegrain focal plane of the main telescope. In this presentation we present the system architecture of the CQUEAN Auto-guiding Package (CAP).

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Pool Combustion of Iso-Propanol Fuel including IPA and PCBs in different Type Vessels

  • An Suk-Heon
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.1
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    • pp.102-108
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    • 2006
  • On the refutation demanded for a control of various toxic substances. PCBs(poly chlorinated biphenyl) has a fatal poisonous matter in the ecosystem and the environmental pollution as it Is a kind of stable chemical substance. Especially, the gross Product of PCBs is estimated at about one million tonnage all over the world. However it is kept on storing in untreated state, then has a deterioration by the Prolonged storage and a risk of overflowing. Therefore, this research examined the fundamental characteristics of combustion and emission for the target of using the IPA (iso-propyl alcohol) solution as a part of PCBs control. IPA was filled to three kinds of Vessel, i.e. Vessel I, II, and III, and then was investigated as follows combustion shape, flame temperature. mass burning velocity, and PM(Particulate matter). A radial thermometer and a C-A thermocouple measured the flame temperature, and the optical extinction method by using He-Ne laser and the filter weight method used in the PM measurement. As a result, with an increasing of L/S ratio, the flame length become shorter and the burning velocity is more rapid, but the particulate matters is higher. It is supposed that the air flow rate is high on Vessel. and then the combustion is Promoted in the surface area of the upstream zone. The future works plan to investigate the characteristics with an using of the mixing of IPA and PCBs

Temperature Field Measurement of Non-Isothermal Jet Flow Using LIF Technique (레이저형광여기(LIF)를 이용한 비등온 제트유동의 온도장 측정)

  • Yoon, Jong-Hwan;Lee, Sang-Joon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.10
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    • pp.1399-1408
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    • 2000
  • A 2-dimensional temperature field measurement technique using PLIF (Planar Laser Induced Fluorescence) was developed and it was applied to an axisymmetric buoyant jet. Rhodamine B was used as a fluorescent dye. Laser light sheet illuminated a two-dimensional cross section of the jet. The intensity variations of LIF signal from Rhodamine B molecules scattered by the laser light were captured with an optical filter and a CCD camera. The spatial variations of temperature field of buoyant jet were derived using the calibration data between the LIF signal and real temperature. The measured results show that the turbulent jet is more efficient in mixing compared to the transition and laminar jet flows. As the initial flow condition varies from laminar to turbulent flow, the entrainment from ambient fluid increases and temperature decay along the jet center axis becomes larger. In addition to the mean temperature field, the spatial distributions of temperature fluctuations were measured by the PLIF technique and the result shows the shear layer development from the jet nozzle exit.

Effects of thermal aging on variations in paper color (강제열화에 따른 종이의 색상변화)

  • Kim, Sun-Kyung;Choi, Eun-Yeon;Lee, Yong-Kyu;Cho, Byoung-Uk
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2011.04a
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    • pp.235-241
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    • 2011
  • Effects of thermal aging on color variations of various papers were evaluated. With thermal aging, most of papers showed a special trend in $a^*$-$b^*$ plane: $a^*$ (red-green) values of the samples were reduced at beginning and after a turning point it was increased while $b^*$ (blue-yellow) was kept increased (yellowing of paper). In case of filter paper which consists of chemical pulps, the changes in $a^*$ value was occurred late compared with other samples. In case of the copy paper with optical brightening agent, the turning point in $a^*$ was not observed while a constant increase in $b^*$ was observed. In case of color paper, no specific trends in $a^*$-$b^*$ were found.

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