• Title/Summary/Keyword: target transfer function

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Design of a Linear Mass Excitation System for Simulating Wind-induced Responses of a Building Structure (풍하중 구현 및 내풍특성 평가를 위한 선형질량 가진시스템 설계)

  • Park, Eun-Churn;Lee, Sang-Hyun;Min, Kyung-Won;Kang, Kyung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.661-668
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    • 2007
  • In this paper, excitation systems using linear mass shaker (LMS) are presented in order to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop function are used such that the error between the wind and actuator induced responses is minimized by preventing the actuator from exciting unexpected modal response and initial transient response. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

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Design of Projection Optical System for Target Imaging Simulator with Long Exit Pupil Distance

  • Xueyuan Cao;Lingyun Wang;Guangxi Li;Ru Zheng
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.745-754
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    • 2023
  • In order to test the recognition ability and accuracy of a target imaging simulator under the irradiation of solar stray light in a laboratory environment, it needs to be fixed on a five-axis turntable during a hardware-in-the-loop simulation test, so the optical system of the simulator should have a long exit pupil distance. This article adopts a secondary imaging method to design a projection optical system suitable for thin-film-transistor liquid crystal displays. The exit pupil distance of the entire optical system is 1,000 mm, and the final optimization results in the 400 nm-850 nm band show that the modulation transfer function (MTF) of the optical system is greater than 0.8 at the cutoff frequency of 72 lp/mm, and the distortion of each field of view of the system is less than 0.04%. Combined with the design results of the optical system, TracePro software was used to model the optical system, and the simulation of the target imaging simulator at the magnitude of -1 to +6 Mv was analyzed and verified. The magnitude error is less than 0.2 Mv, and the irradiance uniformity of the exit pupil surface is greater than 90%, which meets the requirements of the target imaging simulator.

Control of Age-Dependent Population Systems

  • Mimura, A.;Kubo, S.;Kunimatsu, N.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.433-438
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    • 2004
  • In this paper, we at first describe the linear age-dependent population system. In addition, we introduce the nonlinear population system. Using these age-dependent population systems, we evaluate the stability of these age-dependent population systems and determine the optimal birth rates that realize a target distribution which relaxes an aging population. In this paper, we focus on Japan's population and we use the amount of demographic statistics of Japan in year 2000.

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Image Blurring Estimation and Calibration with a Joint Transform Correlator

  • Jeong, Man Ho
    • Journal of the Optical Society of Korea
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    • v.18 no.5
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    • pp.472-476
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    • 2014
  • The Joint Transform Correlator (JTC) has been the most suitable technique for real time optical pattern recognition and target tracking applications. This paper proposes a new application of the JTC system for an analysis of the blurring effect of the optical images caused by a defocused lens. We present the relation between the correlation peak, optical transfer function (OTF), and the amount of blurring caused by focusing error. Moreover, we show a possibility of calibrating the blurred image by simply measuring the correlation peak.

Evaluation of Resolution of UAV-Image Using Circular Target (Circular target을 이용한 무인항공영상의 해상도 평가)

  • Lee, Jae-One;Sung, Sang-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.474-480
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    • 2019
  • We propose a method to evaluate a Modulation Transfer Function (MTF) using a circular target. In addition, a MATLAB GUI-based resolution analysis tool was developed to enhance the reliability of UAV image quality and the efficiency of the work. For this purpose, images were taken with an FC-6310 during flights at altitudes of 80 m, 120 m, and 150 m and by an iXM-100 at altitudes of 150 m, 200 m, and 400 m. The MTFs of UAV images were compared with traditional photogrammetry by measuring and analyzing MTFs on images taken by the UltraCAM Eagle Mark-2 sensor at a flight altitude of 1000 m. The results show that ${\sigma}MTF$ of the FC-6310 were 0.431(80 m), 0.524(120 m), and 0.699(150 m), and those of the iXM-100 were 0.332(150 m), 0.393(200 m), and 0.631(400 m), respectively. At the altitude of 150 m, the image quality of the iXM-100, which has a high-performance camera, was very high, and the effect of the camera performance on the image quality was confirmed. In addition, the ${\sigma}MTF$ of the UltraCAM Eagle Mark-2 was 0.711 due to the high flight altitude. This was the worst value among all UAV images. However, the ${\sigma}MTF$ of the FC-6310 at 150-m altitude was 0.699, which is almost the same as that of a manned aerial image.

The Role of Membranes and Intracellular Binding Proteins in Cytoplasmic Transport of Hydrophobic Molecules : Fatty Acid Binding Proteins and Long Chain Fatty Acids (세포내 소수성 물질 이동에서 막과 세포내 결합단백질의 역살 : 지방산 결합 단밸직과 장쇄 지방산)

  • 김혜경
    • Journal of Nutrition and Health
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    • v.30 no.6
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    • pp.658-668
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    • 1997
  • Path of a small hydrophobic molecule through the aqueous cytoplasma is not linear. Partition may favor membrane binding by several orders of magnitude : thus significant membrane association will markedly decrease the cytosolic transport rate. The presence of high concentration of soluble binding proteins for these hydrophobic molecules would compete with membrane association and thereby increase transport rate. For long chain fatty acid molecules, a family of cytosolic binding proteins collectively known as the fatty acid binding proteins(FABP), are thought to act as intracellular transport proteins. This paper examines the mechanism of transfer of fluorescent antyroyloxy-labeled fatty acids(AOFA) from purified FABPs to phosholipid membranes. With the exception of the liver FABP, AOFA is transferred from FABP by collisional interaction of the protein with a acceptor membrane. The rate of transfer increased markedly when membranes contain anionic phospholipids. This suggests that positively charged residues on the surface of the FABP may interact with the membranes. Neutralization of the surface lysine residues of adipocyte FABP decreased fatty acid transfer rate, and transfer was found to proceed via aqueous diffusion rather than collisional interaction. Site specific mutagenesis has further shown that the helix-turn-helix domain of the FABP is critical for interaction with anionic acceptor membranes. Thus cytosolic FABP may function in intracellular transport of fatty acid to decrease their membranes association as well as to target fatty acid to specific subcellular sites of utilization.

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Pathophysiological Role of S-Nitrosylation and Transnitrosylation Depending on S-Nitrosoglutathione Levels Regulated by S-Nitrosoglutathione Reductase

  • Choi, Min Sik
    • Biomolecules & Therapeutics
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    • v.26 no.6
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    • pp.533-538
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    • 2018
  • Nitric oxide (NO) mediates various physiological and pathological processes, including cell proliferation, differentiation, and inflammation. Protein S-nitrosylation (SNO), a NO-mediated reversible protein modification, leads to changes in the activity and function of target proteins. Recent findings on protein-protein transnitrosylation reactions (transfer of an NO group from one protein to another) have unveiled the mechanism of NO modulation of specific signaling pathways. The intracellular level of S-nitrosoglutathione (GSNO), a major reactive NO species, is controlled by GSNO reductase (GSNOR), a major regulator of NO/SNO signaling. Increasing number of GSNOR-related studies have shown the important role that denitrosylation plays in cellular NO/SNO homeostasis and human pathophysiology. This review introduces recent evidence of GSNO-mediated NO/SNO signaling depending on GSNOR expression or activity. In addition, the applicability of GSNOR as a target for drug therapy will be discussed in this review.

MTF Measuring Equipment of Optical System for LCD Substrate Inspection (LCD 기판 검사 광학계의 MTF 측정장치 제작)

  • Hong, Sung-Mok;Kim, Hee-Nam;Jo, Jae-Heung;Lee, Yun-Woo;Lee, Hoi-Youn;Yang, Ho-Soon;Lee, In-Won;Jung, Jin-Ho
    • Korean Journal of Optics and Photonics
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    • v.18 no.1
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    • pp.37-43
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    • 2007
  • We developed the equipment to measure the MTF(modulation transfer function) of an optical system for automatically inspecting the surface condition of an LCD substrate. We have made an object generator with USAF(United States Air Force) targets of three bar patterns and an integrating sphere, and an image analyzer with a 2 dimensional CCD(charge coupled device) and a relay lens. The MTF of the lens under test was obtained by correcting the measured CTF(contrast transfer function) which is the ratio of the contrast in the image of the USAF target to the contrast in the object. We have measured an optical system of F/13.65 (2.6x), the MTF are 30.6 % tangential plane and 26.1 % sagittal plane at 62.5 1p/mm.

Design of Variable F-number and Triple Magnification Infrared Optical System (가변 F/수 삼중 배율 적외선 광학계 설계 연구)

  • Jeong, Yumee
    • Korean Journal of Optics and Photonics
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    • v.32 no.4
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    • pp.153-162
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    • 2021
  • In this article, the design of a variable F-number and triple magnification infrared optical system is described. That is a two-in-one optical system that combines an infrared search and track (IRST) system and an electro-optical tracking system (EOTS), where an afocal optical system is added to the IRST optical system designed already. The performance target is determined by analyzing system performance, and then the specification in the optical system design is calculated. This optical system contains a warm stop making it possible that one optics has two different F/# by cutting the size of aperture, and that is designed to suit this optics. The system satisfies the requirement such as a modulation transfer function (MTF). For operational assessment, the movement of the focusing lens group is analyzed over the change of temperature and target distance. By using this optical system, it is possible to develop equipment having two functions, infrared searching and electro-optical tracking.

Quality Evaluation of UAV Images Using Resolution Target (해상도 타겟을 이용한 무인항공영상의 품질 평가)

  • LEE, Jae-One;SUNG, Sang-Min
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.1
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    • pp.103-113
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    • 2019
  • Spatial resolution is still one of the most important parameters for evaluating image quality. In this study, we propose an approach to evaluate spatial resolution and MTF(Modulation Transfer Function) using bar target and Siemens star chart as a part of quality evaluation for UAV images. To this end, images were taken with a fixed-wing eBee(Canon IXUS) at the flight height of 130m and 260m, and with a rotary-wing GD-800(SONY NEX-5N) at flight height of 130m, with a Phantom 4 pro(FC 6310) at flight height of 90m, respectively. Spatial resolution was measured on orthoimages produced from this data. Results show that the resolution measured on the Siemens star and bar target was accurately degraded in proportion to the flight height regardless of the cameras. In the words, the spatial resolution of images taken at the same altitude of 130m with the eBee(Canon IXUS) and the GD-800(SONY NEX-5N) equipped with different cameras was the same as 4.1cm, and that of the eBee(Canon IXUS) at 260m was 8.0cm. In addition, the resolution measured on the Siemens star was about 1~2cm lower than that of the bar target at every flight height. The general tendency was also found to be proportional to the flight height in the measurement of the ${\sigma}_{MTF}$ from MTF, which simultaneously represents the resolution and contrast information of the image. However, at the same altitude of 130m, the ${\sigma}_{MTF}$ of the GD-800(SONY NEX-5N) is 0.36 and the eBee(Canon IXUS) is 0.59, which shows that the GD-800(SONY NEX-5N) has better camera performance. It is expected that study results will contribute to the analysis of spatial resolution of UAV images and to improve the reliability of quality.