• Title/Summary/Keyword: Dark field image

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Daylighting of Underground Parking Lots in Apartment Housings by Field Survey and Performance Evaluation (공동주택 지하주차장의 자연채광 실태 및 채광성능 평가)

  • Chung, Yu-Gun;Kim, Jeong-Tai
    • KIEAE Journal
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    • v.2 no.2
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    • pp.39-44
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    • 2002
  • Recently, underground spaces can be usually applied to the alternative of land use for parking. However, lack of window and natural light are among the most cited drawbacks associated with dark image of underground. If underground parking lots are designed to be positive and safe environment for people, openings for daylighting will play a significant role. The natural light and unobstructed view to outdoor are main elements to create optimal underground parking lots. This paper focuses on investigating the actual day lighting conditions and evaluating the day lighting performance of openings as potential lighting resources. For the study, the field measurements and Questionnaire surveys are conducted. And then, the day lighting performance of underground parking lots based on opening geometry and orientation are evaluated by scaled model experiments. As results, the feelings of safety and orientation of underground parking lots are improved by openings for day lighting regardless of the sizes. The required illuminances (daylight factor 0.5%) for underground parking lots can be satisfied in the skylight opening ratio of 4% or more.

A Deep Convolutional Neural Network approach to Large Scale Structure

  • Sabiu, Cristiano G.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.53.3-53.3
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    • 2019
  • Recent work by Ravanbakhsh et al. (2017), Mathuriya et al. (2018) showed that convolutional neural networks (CNN) can be trained to predict cosmological parameters from the visual shape of the large scale structure, i.e. the filaments, clusters and voids of the cosmic density field. These preliminary works used the dark matter density field at redshift zero. We build upon these works by considering realistic mock galaxy catalogues that mimic true observations. We construct light-cones that span the redshift range appropriate for current and near future cosmological surveys such as LSST, EUCLID, WFIRST etc. In summary, we propose a novel multi-image input CNN to track the evolution in the morphology of large scale structures over cosmic time to constrain cosmology and the expansion history of the Universe.

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Development of Automated Surface Inspection System using the Computer V (컴퓨터 비젼을 이용한 표면결함검사장치 개발)

  • Lee, Jong-Hak;Jung, Jin-Yang
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.668-670
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    • 1999
  • We have developed a automatic surface inspection system for cold Rolled strips in steel making process for several years. We have experienced the various kinds of surface inspection systems, including linear CCD camera type and the laser type inspection system which was installed in cold rolled strips production lines. But, we did not satisfied with these inspection systems owing to insufficient detection and classification rate, real time processing performance and limited line speed of real production lines. In order to increase detection and computing power, we have used the Dark Field illumination with Infra_Red LED, Bright Field illumination with Xenon Lamp, Parallel Computing Processor with Area typed CCD camera and full software based image processing technique for the ease up_grading and maintenance. In this paper, we introduced the automatic inspection system and real time image processing technique using the Object Detection, Defect Detection, Classification algorithms. As a result of experiment, under the situation of the high speed processed line(max 1000 meter per minute) defect detection is above 90% for all occurred defects in real line, defect name classification rate is about 80% for most frequently occurred 8 defect, and defect grade classification rate is 84% for name classified defect.

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Background-noise Reduction for Fourier Ptychographic Microscopy Based on an Improved Thresholding Method

  • Hou, Lexin;Wang, Hexin;Wang, Junhua;Xu, Min
    • Current Optics and Photonics
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    • v.2 no.2
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    • pp.165-171
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    • 2018
  • Fourier ptychographic microscopy (FPM) is a recently proposed computational imaging method that achieves both high resolution (HR) and wide field of view. In the FPM framework, a series of low-resolution (LR) images at different illumination angles is used for high-resolution image reconstruction. On the basis of previous research, image noise can significantly degrade the FPM reconstruction result. Since the captured LR images contain a lot of dark-field images with low signal-to-noise ratio, it is very important to apply a noise-reduction process to the FPM raw dataset. However, the thresholding method commonly used for the FPM data preprocessing cannot separate signals from background noise effectively. In this work, we propose an improved thresholding method that provides a reliable background-noise threshold for noise reduction. Experimental results show that the proposed method is more efficient and robust than the conventional thresholding method.

A Study on the Improvement of Aquaculture Security System to Insure the Lawful Evidence of Theft (도적행위의 법적증거확보를 위한 양식장 보안 시스템 개선에 관한 연구)

  • Yim, Jeong-Bin;Nam, Taek-Keun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.13 no.4
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    • pp.55-63
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    • 2007
  • The Group Digital Surveillance System for Fishery Safety and Security (GDSS-F2S) is to provide the target tracking information and the target identification information in order to secure an huge aquaculture farm-field from a thief. The two information, however, is not enough to indict the thief due to the lack of lawful evidences for the crime actions. To overcome this problem, we consider the target image information as one of solutions after discussion with the effective countermeasure tools for the crime actions with scenario-based analysis according to the geological feature of aquaculture farm-field. To capture the real-time image for the trespassing targets in the aquaculture farm-field area, we developed the image capture system which is consists of ultra sensitive CCD(Charge-Coupled Device) camera with 0.0001 Lux and supplementary devices. As results from the field tests for GDSS-F2S with image capture system, the high definite images of the vehicle number plate and shape, person's actions and features are obtainable not only day time but also very dark night without moon light. Thus it is cleary known that the improved GDSS-F2S with image capture system can provide much enough lawful evidences for the crime actions of targets.

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Study on Characteristic difference of Semiconductor Radiation Detectors fabricated with a wet coating process

  • Choi, Chi-Won;Cho, Sung-Ho;Yun, Min-Suk;Kang, Sang-Sik;Park, Ji-Koon;Nam, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.192-193
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    • 2006
  • The wet coating process could easily be made from large area film with printing paste mixed with semiconductor and binder material at room temperature. Semiconductor film fabricated about 25mm thickness was evaluated by field emissions-canning electron microscopy (FE-SEM). X-ray performance data such as dark current, sensitivity and signal to noise ratio (SNR) were evaluated. The $Hgl_2$ semiconductor was shown in much lower dark current than the others, but the best sensitivity. In this paper, reactivity and combination character of semiconductor and binder material that affect electrical and X-ray detection properties would prove out though experimental results.

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Characterizing Overlap Area of KOMPSAT-3 (다목적실용위성 3호 Overlap 영역의 특성분석)

  • Seo, Doo-Chun;Kim, Hee-Seob
    • Aerospace Engineering and Technology
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    • v.10 no.2
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    • pp.154-162
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    • 2011
  • The KOrea Multi-Purpose Satellite-3 (KOMPSAT-3) provides 0.7 m Ground Sample Distance (GSD) panchromatic image and 2.8 m GSD multi-spectral image data for various applications. The KOMPSAT-3 system data will be applied in the field of earth observations, covering land, sea, coastal zones, and Geographic Information Systems (GIS). In order to keep the swath width of 15km at nadir view of KOMPSAT-3, CCD consist of approximately 24,020 pixels excluding 20 dark pixels at both sides and has overlap region. Because there are no CCD-line sensors with a pixel size of $7{\mu}m$, the field of view is separated into 2 parts and imaged on 2 detectors, each with 12,080 pixels. Therefore, 2 detectors have different geometric characteristic. This paper provides image simulation for geometric characteristics analysis of overlapping area of KOMPSAT-3 using KOMPSAT-2 image data.

Design and Evaluation of a CMOS Image Sensor with Dual-CDS and Column-parallel SS-ADCs

  • Um, Bu-Yong;Kim, Jong-Ryul;Kim, Sang-Hoon;Lee, Jae-Hoon;Cheon, Jimin;Choi, Jaehyuk;Chun, Jung-Hoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.1
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    • pp.110-119
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    • 2017
  • This paper describes a CMOS image sensor (CIS) with dual correlated double sampling (CDS) and column-parallel analog-to-digital converter (ADC) and its measurement method using a field-programmable gate array (FPGA) integrated module. The CIS is composed of a $320{\times}240$ pixel array with $3.2{\mu}m{\times}3.2{\mu}m$ pixels and column-parallel 10-bit single-slope ADCs. It is fabricated in a $0.11-{\mu}m$ CIS process, and consumes 49.2 mW from 1.5 V and 3.3 V power supplies while operating at 6.25 MHz. The measured dynamic range is 53.72 dB, and the total and column fixed pattern noise in a dark condition are 0.10% and 0.029%. The maximum integral nonlinearity and the differential nonlinearity of the ADC are +1.15 / -1.74 LSB and +0.63 / -0.56 LSB, respectively.

A Research Study on Work-Man's Uniform(1) (직장 남성들의 근무복 실태조사 연구(1) -근무복 만족도와 선호도를 중심으로-)

  • 박선희;서미아
    • The Research Journal of the Costume Culture
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    • v.4 no.1
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    • pp.75-91
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    • 1996
  • The work-man's uniform should be coincident wit the image of his firm and accounted of the function according as its purpose. We made questions to 404 workers at 8 firm in our country through the questionnaire papers to know about a work-man's uniform and researched whether the satisfactory in wearing his uniform had relation with his type of business, grade, carrier, age, marriage, and monthly income. The results of this study is as follows; 1. In the uniform status of the fir, thee were many jumper styles in he design of the uniform. The color of that was more dark than bright and the materials of one was used much more chemical fiber than natural fiber. Each of the field office supplied the uniform to his work-man more frequently than the main office. All of firm payed off the uniform expense and decision of the uniform design was almost made both the firm and the labour union. 2. In he satisfaction of the uniform, the satisfaction of uniform was shown high in the design, color, materials, size and function. The highest dissatisfaction reason is as follows; it was disagreeable to concrete design in the design and dark color and keeping warm or draft was bad in the materials, the bust and pant's length was long in the size. 3. In preference of the uniform, the older of preference in the design was what the working environment and the image of firm was suitable, the characteristic uniform. The order of preference in the color was beige, blue, grey. The preference of in the materials was good to keep warm and draft. The preference in the pattern was 'no pattern' every type of business. The experts, or administrators and office workers than others preferred 'no pattern' of the uniform in the pattern.

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Estimation of Above-Ground Biomass of a Tropical Forest in Northern Borneo Using High-resolution Satellite Image

  • Phua, Mui-How;Ling, Zia-Yiing;Wong, Wilson;Korom, Alexius;Ahmad, Berhaman;Besar, Normah A.;Tsuyuki, Satoshi;Ioki, Keiko;Hoshimoto, Keigo;Hirata, Yasumasa;Saito, Hideki;Takao, Gen
    • Journal of Forest and Environmental Science
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    • v.30 no.2
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    • pp.233-242
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    • 2014
  • Estimating above-ground biomass is important in establishing an applicable methodology of Measurement, Reporting and Verification (MRV) System for Reducing Emissions from Deforestation and Forest Degradation-Plus (REDD+). We developed an estimation model of diameter at breast height (DBH) from IKONOS-2 image that led to above-ground biomass estimation (AGB). The IKONOS image was preprocessed with dark object subtraction and topographic effect correction prior to watershed segmentation for tree crown delineation. Compared to the field observation, the overall segmentation accuracy was 64%. Crown detection percent had a strong negative correlation to tree density. In addition, satellite-based crown area had the highest correlation with the field measured DBH. We then developed the DBH allometric model that explained 74% of the data variance. In average, the estimated DBH was very similar to the measured DBH as well as for AGB. Overall, this method can potentially be applied to estimate AGB over a relatively large and remote tropical forest in Northern Borneo.