• Title/Summary/Keyword: Spatial Differentiation

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Analytic simulator and image generator of multiple-scattering Compton camera for prompt gamma ray imaging

  • Kim, Soo Mee
    • Biomedical Engineering Letters
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    • v.8 no.4
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    • pp.383-392
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    • 2018
  • For prompt gamma ray imaging for biomedical applications and environmental radiation monitoring, we propose herein a multiple-scattering Compton camera (MSCC). MSCC consists of three or more semiconductor layers with good energy resolution, and has potential for simultaneous detection and differentiation of multiple radio-isotopes based on the measured energies, as well as three-dimensional (3D) imaging of the radio-isotope distribution. In this study, we developed an analytic simulator and a 3D image generator for a MSCC, including the physical models of the radiation source emission and detection processes that can be utilized for geometry and performance prediction prior to the construction of a real system. The analytic simulator for a MSCC records coincidence detections of successive interactions in multiple detector layers. In the successive interaction processes, the emission direction of the incident gamma ray, the scattering angle, and the changed traveling path after the Compton scattering interaction in each detector, were determined by a conical surface uniform random number generator (RNG), and by a Klein-Nishina RNG. The 3D image generator has two functions: the recovery of the initial source energy spectrum and the 3D spatial distribution of the source. We evaluated the analytic simulator and image generator with two different energetic point radiation sources (Cs-137 and Co-60) and with an MSCC comprising three detector layers. The recovered initial energies of the incident radiations were well differentiated from the generated MSCC events. Correspondingly, we could obtain a multi-tracer image that combined the two differentiated images. The developed analytic simulator in this study emulated the randomness of the detection process of a multiple-scattering Compton camera, including the inherent degradation factors of the detectors, such as the limited spatial and energy resolutions. The Doppler-broadening effect owing to the momentum distribution of electrons in Compton scattering was not considered in the detection process because most interested isotopes for biomedical and environmental applications have high energies that are less sensitive to Doppler broadening. The analytic simulator and image generator for MSCC can be utilized to determine the optimal geometrical parameters, such as the distances between detectors and detector size, thus affecting the imaging performance of the Compton camera prior to the development of a real system.

A Study on the Role and Characteristics of Middle Space in Museum of Seoul National University based on the Concept of Sequential Exhibition Space (연속적 전시공간 개념으로 본 서울대 뮤지엄 내 연결 공간의 역할과 특성에 관한 연구)

  • Hwang, Joon-Ho;Cho, Jeong-Sik
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.5
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    • pp.73-83
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    • 2019
  • The purpose of this study is to analyze the spatial transformational patterns according to the spectator and the exhibition environment and to examine the role of 'the middle space' organically linking the exhibition space with MoA which is a representative example of 'sequential exhibition space'. The concept of sequential exhibition space in MoA is applied not only to building but also to extended continental concepts including neighborhood. MoA's exhibition space consists of the library area and the exhibition area. In particular, the spaces of library area perform a complex function as a quasi-exhibition space, and the exhibition spaces have variable spatial transformation through an associated structure of the library area and the educational area. The types of exhibition space those constitute the sequential exhibition space of MoA appear as 'Room type', 'Free plan type', and 'Gallery type'. Each exhibition space maintains independence, but it is changed according to the situation of exhibition. The flow is based on the spiral induction around the central void space, but with selective circulation considering the visitors. Therefore, through the transformation of the exhibition area and the division of the flow, the whole museum space appears as the area differentiation.

An Analytical Study on Space Configuration in After-School Care Class for Elementary School - Focused on Guidelines of Emementary School Care Classes - (초등돌봄교실 공간구성특징에 관한 분석연구 - 초등 돌봄교실 길라잡이를 중심으로 -)

  • Kim, Sora
    • Journal of the Korean Institute of Educational Facilities
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    • v.28 no.6
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    • pp.3-13
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    • 2021
  • Introduced in 2004 as an 'After-School Academy' policy, the 'After-School Care Class' has become a universal program for elementary schools over time. While the concept of public education service has expanded and changed in various ways including educational welfare, the physical environment of the care classroom has undergone fixed changes within the uniform classroom structure of a standardized school space. The purpose of this study is to identify spatial characteristics of care classroom through chasing and analysing changes in the care class space configuration from 2004 to the present. The findings are as follows. The plan of the early care classroom wasn't much different from the existing common classroom, and it was only in 2007 that the kitchen and floor heating appeared for the first time.From the 2015 standard plan, prominent differentiation of the space between learning activities and resting area was shown, but the spatial characteristics are nothing more than a division that utilizes ready-made furniture. A distinctive feature of the 2018 Seoul care classes are diversity. In the case of the care exclusive classrooms, the division between the support space and the main activity space became more clear using furniture integrated open walls and various floor levels. In the case of a shift classrooms that is used together with common classrooms, it is characterized by flexibility that allows dramatically different classroom configurations for each time period by using a convertible furnishing space.

Reduction of Quantization Noise in Block-Based Video Coding Using Wavelet Transform (블록기반 동영상 부호화에서의 웨이브렛 변환을 이용한 양자화 잡음 제거)

  • 문기웅;장익훈;김남철
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.155-158
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    • 2000
  • In this paper, the quantization noise in block-based video coding is analyzed, and a post-processing method based on the analysis is presented for reducing the quantization noise by using a wavelet transform(WT). In the proposed method, the quantization noise is considered as the sum of a blocking noise expressed as a deterministic profile and the random remainder noise. Each noise is removed in a viewpoint of image restoration using a 1-D WT, which yields a regularized differentiation. The blocking noise first is reduced by weakening the strength of each blocking noise component that appears as an impulse in the first scale wavelet domain. The impulse strength estimation is performed using median filter, quantization parameter(QP), and local activity. The remainder noise, which is considered as a white noise at non-edge pixels, then is reduced by soft-thresholding. The experimental results show that the proposed method yields better performance in terms if subjective quality as well as PSNR performance over VM post-filter in MPEG-4 for all test sequences of various compression ratios. We also present a fast post-processing in spatial domain equivalent to that in wavelet domain for real-time application.

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Selective Gene Express Profiles in Rat Uterus during Estrus Cycle

  • Kim, Do-Rim;Yu, Seong-Jin;Kim, Jee-Yun;Youm, Mi-Young;Lee, Chae-Kwan;Kang, Sung-Goo
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 2003.10a
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    • pp.70-70
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    • 2003
  • The uterus undergoes dynamic changes during the cycle and displays many features typical of developmental process. In order to be prepared for implantation, endometrium undergoes predictable, sequential phases of proliferation and secretory changes. The uterus during estrus cycle synthesize a complex of signaling molecules with specific spatial and temporal modes of expression and which are critical for cell proliferation and differentiation. The purpose of this investigation was to use cDNA microarrays to evaluate the expression of genes of rat uterus in estrus cycle. Animals were sacrificed on proestrus, estrus, metestrus, diestrus. Differential gene expression profiles were revealed(growth-related c-myc reponsive protein RCL, heat shock 47-kDa protein (HSP47), cytochrome c oxidase polypeptide Vlc2 (COX6C2), calreticulin (CALR)). Reverse transcription polymerase chain reaction (RT-PCR) was used to validate the relative expression pattern. Using this approach, we found several genes whose expression in rat uterus was altered with estrus cycle. Our long-term goal is to determine the role of these differentially expressed genes during estrus cycle. This study was supported by through the Biohealth Products Research Center(BPRC), Inje University.

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A Study on the Expression of a Trance Aesthetic Consciousness of Continuity in Contemporary Fashion (현대 패션에 나타난 연속성의 트랜스 미의식에 관한 연구)

  • Yang, Hee-Young;Lee, Kyung-Hee
    • Journal of the Korean Society of Costume
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    • v.58 no.8
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    • pp.74-90
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    • 2008
  • Since the late of 20th Century, philosophy, art, and aesthetics have attention to the movement of object that persue the dynamics and qualitative change, not existing fixed and quantitative object. Qualitative continuity, including discontinuity of specific spot and surface that occurs sudden change, is distinct characteristics considered in contemporary logo civilization, which combines and disperses according as various purpose among the different elements and objects. Therefore, I studied about the characteristics of qualitative continuity that creates the change and the differentiation continuously through the "formative characteristics of the continuity expressed in contemporary fashion" of my preceding paper. This paper is the following study of above mentioned paper, and Investigates about aesthetic consciousness leading to the various change. This is intends to consider the trans-aesthetic consciousness that accepts dynamic movement and change the different object and reforms new relationship continuously. This studies' conclusion is as follows; 1) sublimity-Infinity, de-constructive, excessive 2) jouissance - functional, structural 3) paradox-perceptual, spatial. A study about the trans-aesthetic consciousness would help to offer philosophical basis, and make a change building aesthetic foundation in explaining various relationship like as phenomenon of the retro, neo, post, fusion expressed since the late of 20th Century.

Composition, Structure and Some Distribution Features of Fouling Community in the Water Intake Tunnel of Vladivostok Heat and Power Plant

  • Moshchenko Alexander V.;Zvyagintsev Alexander Yu.
    • Ocean and Polar Research
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    • v.26 no.4
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    • pp.619-633
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    • 2004
  • The composition, structure and some of the features of spatial distribution of fouling communities in the cooling system tunnels of Heat and Power Station Vladivostok City were determined. Three groups of animals, possessing features expressive of topological differentiation as well as categorical differences based on dominant and subdominant species, were clearly distinguished in the fouling community of the water intake tunnel. These are Jassa marmorata on the tunnel vault, Balanus rostratus on the walls, and Mytilus trossulus on the bottom. The group from the tunnel vault should be clearly related to 'physically controlled' communities, whereas the groups from the walls and bottom, being also physically controlled, show many of the features of 'biologically balanced' communities. Thermal treatment of tunnels, performed in summertime, is grossly inefficient, since mytilids continue to settle in September-November as well. In order to prevent intensive settlement of Mytilus trossulus larvae it is recommended that the water intake tunnels integral to the cooling system be placed deeper than 15m.

A COMPARISON OF OBJECTED-ORIENTED AND PIXELBASED CLASSIFICATION METHODS FOR FUEL TYPE MAP USING HYPERION IMAGERY

  • Yoon, Yeo-Sang;Kim, Yong-Seung
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.297-300
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    • 2006
  • The knowledge of fuel load and composition is important for planning and managing the fire hazard and risk. However, fuel mapping is extremely difficult because fuel properties vary at spatial scales, change depending on the seasonal situations and are affected by the surrounding environment. Remote sensing has potential of reduction the uncertainty in mapping fuels and offers the best approach for improving our abilities. This paper compared the results of object-oriented classification to a pixel-based classification for fuel type map derived from Hyperion hyperspectral data that could be enable to provide this information and allow a differentiation of material due to their typical spectra. Our methodological approach for fuel type map is characterized by the result of the spectral mixture analysis (SMA) that can used to model the spectral variability in multi- or hyperspectral images and to relate the results to the physical abundance of surface constitutes represented by the spectral endmembers. Object-oriented approach was based on segment based endmember selection, while pixel-based method used standard SMA. To validate and compare, we used true-color high resolution orthoimagery

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Endocytic Regulation of EGFR Signaling

  • Chung, Byung-Min
    • Interdisciplinary Bio Central
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    • v.4 no.2
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    • pp.3.1-3.7
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    • 2012
  • Epidermal growth factor receptor (EGFR) is a member of the ErbB family (ErbB1-4) of receptor tyrosine kinases (RTKs). EGFR controls numerous physiological functions, including cell proliferation, migration, differentiation and survival. Importantly, aberrant signaling by EGFR has been linked to human cancers in which EGFR and its various ligands are frequently overexpressed or mutated. EGFR coordinates activation of multiple downstream factors and is subject of various regulatory processes as it mediates biology of the cell it resides in. Therefore, many studies have been devoted to understanding EGFR biology and targeting the protein for the goal of controlling tumor in clinical settings. Endocytic regulation of EGFR offers a promising area for targeting EGFR activity. Upon ligand binding, the activated receptor undergoes endocytosis and becomes degraded in lysosome, thereby terminating the signal. En route to lysosome, the receptor becomes engaged in activating various signaling pathways including PI-3K, MAPK and Src, and endocytosis may offer both spatial and temporal regulation of downstream target activation. Therefore, endocytosis is an important regulator of EGFR signaling, and increasing emphasis is being placed on endocytosis in terms of cancer treatment and understanding of the disease. In this review, EGFR signaling pathway and its intricate regulation by endocytosis will be discussed.

3D Depth Measurement System-based Nonliniar Trail Recognition for Mobile Robots (3 차원 거리 측정 장치 기반 이동로봇용 비선형 도로 인식)

  • Kim, Jong-Man;Kim, Won-Sop;Shin, Dong-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.517-518
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    • 2007
  • A method to recognize unpaved road region using a 3D depth measurement system is proposed for mobile robots. For autonomous maneuvering of mobile robots, recognition of obstacles or recognition of road region is the essential task. In this paper, the 3D depth measurement system which is composed of a rotating mirror, a line laser and mono-camera is employed to detect depth, where the laser light is reflected by the mirror and projected to the scene objects whose locations are to be determined. The obtained depth information is converted into an image. Such depth images of the road region represent even and plane while that of off-road region is irregular or textured. Therefore, the problem falls into a texture identification problem. Road region is detected employing a simple spatial differentiation technique to detect the plain textured area. Identification results of the diverse situation of Nonlinear trail are included in this paper.

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