• Title/Summary/Keyword: differential image

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Development of a Data Reduction Algorithm for Optical Wide Field Patrol (OWL) II: Improving Measurement of Lengths of Detected Streaks

  • Park, Sun-Youp;Choi, Jin;Roh, Dong-Goo;Park, Maru;Jo, Jung Hyun;Yim, Hong-Suh;Park, Young-Sik;Bae, Young-Ho;Park, Jang-Hyun;Moon, Hong-Kyu;Choi, Young-Jun;Cho, Sungki;Choi, Eun-Jung
    • Journal of Astronomy and Space Sciences
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    • v.33 no.3
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    • pp.221-227
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    • 2016
  • As described in the previous paper (Park et al. 2013), the detector subsystem of optical wide-field patrol (OWL) provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time) data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.

Characteristics of Symmetric-Shape Parts Shearing on Micro NCT (마이크로 NCT에 의한 대칭형상구멍의 전단특성)

  • Hong N. P.;Kim B. H.;Chang I. B.;Kim H. Y.;Oh S. I.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.02a
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    • pp.285-291
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    • 2002
  • The shearing process for the sheet metal is normally used in the precision elements such as a frame of TFT-LCD or lead frame of If chips. In these precision elements, the burr formation prevents the system assembly and needs the additional burr removing process. In this paper, we developed the small size NC punching system which has an aligning kinematics between the rectangular shaped punch and die. The punch is driven by an ai cylinder and the sheet metal is moving on the X-Y table system which is driven by two stewing motors. The microprocessor control the whole system and communicate with the monitoring PC by RS232C serial communication protocol. The graphic user interface program in PC monitors nil control the punching system. The cross shaped joint hinge supports the punching die and positioned by two differential screws, whose are installed in perpendicular directions. The aligning between the punch and die is performed using the sheets of half thickness(0.1mm Brass) of the real process for the frame of the TFT-LCD. Using half thickness Brass, the burr formation is magnified and we can decide the aligning direction more easily then using the real thickness(0.2mm) Aluminum. In this paper, the aligning results are measured manually using the SEM photographs and we hope to make the automated aligning procedures using some kinds of image processing techniques.

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Computer Aided Diagnosis Applications for the Differential Diagnosis of Infarction: Apply on Brain CT Image (뇌경색 감별진단을 위한 컴퓨터보조진단 응용: Brain CT Images 적용)

  • Park, Hyong-Hu;Cho, Mun-Joo;Im, In-Chul;Lee, Jin-Soo
    • Journal of the Korean Society of Radiology
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    • v.10 no.8
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    • pp.645-652
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    • 2016
  • In this study, based on the analysis of texture feature values of statistical properties. And we examined the normal and the applicability of the computer-aided diagnosis of cerebral infarction in the brain computed tomography images. The experiment was analyzed to evaluate the ROC curve recognition rate of disease using six parameters representing the feature values of the texture. As a result, it showed average mean 88%, variance 92%, relative smoothness 94%, uniformity of 88%, a high disease recognition rate of entropy 84%. However, it showed a slightly lower disease recognition rate and 58% for skewness. In the analysis using ROC curve, the area under the curve for each parameter indicates 0.886 (p = 0.0001) or more, resulted in a meaningful recognition of the disease. Further, to determine the cut-off values for each parameter are determined to be the prediction of disease through the computer-aided diagnosis.

A Literature Review for an Emotion Evaluation Protocols Based on Skin Temperature for Home Appliances (피부온을 기반으로 한 가전제품의 감성 평가 프로토콜 수립을 위한 문헌 조사)

  • Jeon, Eun-Jin;Lee, Seung-hoon;Kim, Hee-Eun;You, Hee-Cheon
    • Fashion & Textile Research Journal
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    • v.22 no.2
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    • pp.240-249
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    • 2020
  • This study reviews studies that used skin temperature in order to establish an emotion evaluation protocol based on skin temperature for home appliances. A survey of skin temperature evaluation papers was conducted by the following five stages: (1) keyword search, (2) title screening, (3) abstract screening, (4) full paper screening, and (5) relevance evaluation. Selected papers were reviewed for: purpose, recruitment criteria of participants, the number of participants, apparatus, procedure, measures, analysis methods, and major findings. Thermistor sensors and thermography are used for the measurement of skin temperature. Skin temperature sensors are attached to 4 - 10 locations on the body and their mean of skin temperature is calculated by Ramanatan's 4-point or Hardy & Dubois's 7-point method. Semantic differential (SD) method and thermography measuring facial surface temperature have been used for emotion evaluation. The SD method provides a set of adjective pairs related to a product and evaluates changes in emotion from the use of the product. The range of facial surface analyzed is defined in the thermal image and temperature changes before and after the evaluation are analyzed. The evaluation items of home appliances include form, color, material, aesthetics, satisfaction, novelty, convenience, pleasantness, and excellence. Many existing emotion studies using skin temperature do not apply physiological and psychological methods. This study provides basic data to establish a skin temperature and emotion evaluation protocol by examining literature for skin temperature and evaluation of sensitivity.

Protein Expression of Mouse Uterus in Post-Implantation

  • Kim, Hong-Rye;Han, Rong-Xun;Kim, Myung-Youn;Diao, Yunfei;Park, Chang-Sik;Jin, Dong-Il
    • Reproductive and Developmental Biology
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    • v.33 no.4
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    • pp.237-242
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    • 2009
  • Pregnancy is a unique event in which a fetus develops in the uterus despite being genetically and immunologically different from the mother, and the underlying mechanisms remain poorly understood. To analyze the differential gene expression profiles in nonpregnant and 7 days post coitus (dpc) pregnant uterus of mice, we performed a global proteomic study by 2-D gel electrophoresis (2-DE) and MALDI-TOF-MS. The uterine proteins were separated using 2-DE, Approximately 1,000 spots were detected on staining with Coomassie brilliant blue. An image analysis using Melanie III (Swiss Institute for Bioinformatics) was performed to detect variations in protein spots between pregnant and nonpregnant uterus. Twenty-one spots were identified as differentially expressed proteins, of which 10 were up-regulated proteins such as alpha-fetoprotein, chloride intracellular channel 1, transgelin, heat-shock protein beta-1, and carbonic anhydrase II, while 11 were down-regulated proteins such as X-box binding protein, glutathione S-transferase omega 1, olfactory receptor Olfr204, and metalloproteinase-disintegrin domain containing protein TECADAM. Most of the identified proteins appeared to be related with catabolism, cell growth, metabolism, regulation, cell protection, protein repair, or protection. Our results uncovered key proteins of mouse uterus involved in pregnancy.

Visual Preference Evaluation on Forest Working Systems' Characteristics for Forest Scenic Beauty Management (산림풍치자원관리(山林風致資源管理)를 위한 산림시업특성별(山林施業特性別) 시각선호도(視覺選好度) 평가(評價))

  • Song, Hyung Sop
    • Journal of Korean Society of Forest Science
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    • v.88 no.3
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    • pp.309-319
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    • 1999
  • This study was conducted to get forest scenic beauty management information toward forest working systems; characteristics in Larix forest stands. 35 different alternatives were simulated to visualize on basis of actual forest working methods. The options were illustrated as photos produced by computer software. Each alternatives were evaluated by 3 groups with total 593 respondents after reliability test. Visual preference evaluation was used 1 - 10 point rating scale. The ratings were scaled using SBE analysis program of RMRATE. To compare the relationship of visual preference and image scale, Spatial images of 13 thinning alternatives were measured by Semantic differential scale. In general, the respondents preferred refreshing and ordering forest stand after forest working to natural forest stand before forest working. Visual preference decreased with the increasing intensity of bare ground area and slash area in forest stand. And also, visual preference was high related to tree density, clear length of stem, and ground vegetation. Farm line of small clear cutting area was preferred straight line to curve line. Visual preferences were significant differences in certain socioeconomic variables of the respondents. Results indicate how to conduct forest working system for forest scenic beauty management.

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AUTO-GUIDING SYSTEM FOR CQUEAN (CAMERA FOR QUASARS IN EARLY UNIVERSE)

  • Kim, Eun-Bin;Park, Won-Kee;Jeong, Hyeon-Ju;Kim, Jin-Young;Kuehne, John;Kim, Dong-Han;Kim, Han-Geun;Odoms, Peter S.;Chang, Seung-Hyuk;Im, Myung-Shin;Pak, Soo-Jong
    • Journal of The Korean Astronomical Society
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    • v.44 no.4
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    • pp.115-123
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    • 2011
  • To perform imaging observations of optically red objects such as high redshift quasars and brown dwarfs, the Center for the Exploration of the Origin of the Universe (CEOU) recently developed an optical CCD camera, Camera for QUasars in EArly uNiverse (CQUEAN), which is sensitive at 0.7-1.1 ${\mu}m$. To enable observations with long exposures, we develop an auto-guiding system for CQUEAN. This system consists of an off-axis mirror, a baffle, a CCD camera, a motor and a differential decelerator. To increase the number of available guiding stars, we design a rotating mechanism for the off-axis guiding camera. The guiding field can be scanned along the 10 arcmin ring offset from the optical axis of the telescope. Combined with the auto-guiding software of the McDonald Observatory, we confirm that a stable image can be obtained with an exposure time as long as 1200 seconds.

A Real Time Flame and Smoke Detection Algorithm Based on Conditional Test in YCbCr Color Model and Adaptive Differential Image (YCbCr 컬러 모델에서의 조건 검사와 적응적 차영상을 이용한 화염 및 연기 검출 알고리즘)

  • Lee, Doo-Hee;Yoo, Jae-Wook;Lee, Kang-Hee;Kim, Yoon
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.5
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    • pp.57-65
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    • 2010
  • In this paper, we propose a new real-time algorithm detecting the flame and smoke in digital CCTV images. Because the forest fire causes the enormous human life and damage of property, the early management according to the early sensing is very important. The proposed algorithm for monitoring forest fire is classified into the flame sensing and detection of smoke. The flame sensing algorithm detects a flame through the conditional test at YCbCr color model from the single frame. For the detection of smoke, firstly the background range is set by using differences between current picture and the average picture among the adjacent frames in the weighted value, and the pixels which get out of this range and have a gray-scale are detected in the smoke area. Because the proposed flame sensing algorithm is stronger than the existing algorithms in the change of the illuminance according to the quantity of sunshine, and the smoke detection algorithm senses the pixel of a gray-scale with the smoke considering the amount of change for unit time, the effective early forest fire detection is possible. The experimental results indicate that the proposed algorithm provides better performance than existing algorithms.

Differential Absorption Analysis of Nonmagnetic Material in the Phantom using Dual CT

  • Kim, Ki-Youl;Lee, Hae-Kag;Cho, Jae-Hwan
    • Journal of Magnetics
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    • v.21 no.2
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    • pp.286-292
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    • 2016
  • This study evaluates the change of computer tomography (CT) number in the case of the metal artifact reduction (MAR) algorithm, using the phantom. The images were obtained from dual CT using a gammex 467 tissue characterization phantom, which is similar to human tissues. The test method was performed by dividing pre and post MAR algorithm and measured CT values of nonmagnetic materials within the phantom. In addition, the changes of CT values for each material were compared and analyzed after measuring CT values up to 140 keV, using the spectral HU curve followed by CT scan. As a result, in the cases of N rod (trabecular bone) and E rod (trabecular bone), the CT numbers decreased as keV increasing but were constant above 90 keV. In the cases of I rod (dense bone) and K rod (dense bone), the CT numbers also decreased as keV increased but were uniform above 90 keV. The CT numbers from 40 keV to 140 keV were consistent in the cases of J rod (liver), D rod (liver), L rod (muscle), and F rod (muscle). For A rod (adipose), G rod (adipose), B rod (breast) and O rod (breast), the CT numbers increased as keV increased but were constant after 90 keV. The CT numbers from 40 keV to 140 keV were consistent in the cases of C rod (lung (exhale)), P rod (lung (exhale)), M rod (lung (inhale)) and H rod (lung (exhale)). Conclusively, because dual CT exhibits no changes in image quality and is able to analyze nonmagnetic materials by measuring the CT values of various materials, it will be used in the future as a useful tool for the diagnosis of lesions.

Comparison of Image Uniformity with Photon Counting and Conventional Scintillation Single-Photon Emission Computed Tomography System: A Monte Carlo Simulation Study

  • Kim, Ho Chul;Kim, Hee-Joung;Kim, Kyuseok;Lee, Min-Hee;Lee, Youngjin
    • Nuclear Engineering and Technology
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    • v.49 no.4
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    • pp.776-780
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    • 2017
  • To avoid imaging artifacts and interpretation mistakes, an improvement of the uniformity in gamma camera systems is a very important point. We can expect excellent uniformity using cadmium zinc telluride (CZT) photon counting detector (PCD) because of the direct conversion of the gamma rays energy into electrons. In addition, the uniformity performance such as integral uniformity (IU), differential uniformity (DU), scatter fraction (SF), and contrast-to-noise ratio (CNR) varies according to the energy window setting. In this study, we compared a PCD and conventional scintillation detector with respect to the energy windows (5%, 10%, 15%, and 20%) using a $^{99m}Tc$ gamma source with a Geant4 Application for Tomography Emission simulation tool. The gamma camera systems used in this work are a CZT PCD and NaI(Tl) conventional scintillation detector with a 1-mm thickness. According to the results, although the IU and DU results were improved with the energy window, the SF and CNR results deteriorated with the energy window. In particular, the uniformity for the PCD was higher than that of the conventional scintillation detector in all cases. In conclusion, our results demonstrated that the uniformity of the CZT PCD was higher than that of the conventional scintillation detector.