• Title/Summary/Keyword: Large target

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FPGA-Based Real-Time Multi-Scale Infrared Target Detection on Sky Background

  • Kim, Hun-Ki;Jang, Kyung-Hyun
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.11
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    • pp.31-38
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    • 2016
  • In this paper, we propose multi-scale infrared target detection algorithm with varied filter size using integral image. Filter based target detection is widely used for small target detection, but it doesn't suit for large target detection depending on the filter size. When there are multi-scale targets on the sky background, detection filter with small filter size can not detect the whole shape of the large targe. In contrast, detection filter with large filter size doesn't suit for small target detection, but also it requires a large amount of processing time. The proposed algorithm integrates the filtering results of varied filter size for the detection of small and large targets. The proposed algorithm has good performance for both small and large target detection. Furthermore, the proposed algorithm requires a less processing time, since it use the integral image to make the mean images with different filter sizes for subtraction between the original image and the respective mean image. In addition, we propose the implementation of real-time embedded system using FPGA.

Halo interactions in the Horizon run 4 simulation

  • L'Huillier, Benjamin;Park, Changbom;Kim, Juhan
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.46-46
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    • 2014
  • Interactions such as mergers and flybys play a fundamental role in shaping galaxy morphology. We used the Horizon Run 4 cosmological N-body simulations to study the frequency and the type of halo interactions as a function of the environment, the separation p, the mass ratio q, and the target halo mass. We defined targets as haloes more massive than 10^11 Msun/h, and a target is interacting if it is located within the virial radius of a neighbour halo more massive than 0.4 times the target mass. We find that the interaction rate as a function of time has a universal shape for different halo mass and large-scale density, with an increase and saturation. Larger density yield steeper slopes and larger final interaction rates, while larger masses saturate later. Most interactions happen at large-scale density contrast ${\delta}$ about 10^3, regardless of the redshift. We also report the existence of two modes of interactions in the (p,q) plane, reflecting the nature (satellite or main halo) of the target halo. These two trends strongly evolve with redshift, target mass, and large-scale density. Interacting pairs have similar spins parameters and aligned spins, with radial trajectories, and prograde encounters for non-radial trajectories. The satellite trajectories become less and less radial as time proceed. This effect is stronger for higher-mass target, but independent of the large-scale density.

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Cooling Performance Analysis of Water-Cooled Large Area Magnetron Sputtering System (대면적 마그네트론 스퍼터링 증착장비의 수냉시스템 방열성능 해석)

  • Kim, Kyoung-Jin
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.2
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    • pp.111-116
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    • 2010
  • In a large area magnetron sputtering system, which is under the influence of high heat load from the plasma, it is necessary to use the effective water cooling in order to maintain the proper deposition performance and the economic use of target materials. A series of three-dimensional numerical simulations are carried out on the simplified model of the large area magnetron sputtering system with the cooling plate that includes the U-shaped water channel. The analysis is focused on the effects of water channel geometry, cooling water flowrate, thermal conductivity of target material, and the degree of target erosion on the cooling performance of cooling plate, which is represented by the temperature distribution of target material.

Fish length dependance of acoustic target strength for large yellow croaker (부세에 대한 음향반사강도의 체장 의존성)

  • 강희영;이대재
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.3
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    • pp.239-248
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    • 2003
  • This paper was conducted as an attempt in order to construct the data bank of target strength for acoustic estimation of fish length in the coastal waters of Korea. The fish length dependence of acoustic target strength for 13 large yellow croakers (Pseudosciaena crocea) at 75 kHz was investigated and the prediction of the target strength by using the Kirchhoff-Ray Mode model (KRM model) was compared with target strength measurements. The results obtained are summarized as follows; 1. In the averaged target strength pattern for 13 large yellow croakers the maximum target strength was -35.13 dB at $-13.35^{\circ}$ on a tilted angle. 2. The relationship between fork length(L, cm) and averaged target strength(TS, dB) was expressed as follows; TS=23. 76log (L) -73.45 (r=0.47) TS=20log(L) -67.35 From this result, the conversion coefficient was -73.45 dB and 6.1 dB lower than the coefficient -67.35 dB where the value of the slope of the regression equation is forced to be 20. 3. Averaged target strength and a length conversion coefficient derived from a target strength histogram for 13 large yellow croakers of mean length 25.59 cm were -41.23 dB, -69.72 dB, respectively. 4. In the range of $$2;{\ll} L (fish length /{\lambda}(wave length);{\ll}40$$, the prediction of the averaged target strength by the KRM model increased gradually with the increasing of $L/{\lambda}$ and was lower than the measured target strength.

Policy for planned placement of sensor nodes in large scale wireless sensor network

  • Sharma, Vikrant;Patel, R.B;Bhadauria, HS;Prasad, D
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.3213-3230
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    • 2016
  • Sensor node (SN) is a crucial part in any remote monitoring system. It is a device designed to monitor the particular changes taking place in its environs. Wireless sensor network (WSN) is a system formed by the set of wirelessly connected SNs placed at different geographical locations within a target region. Precise placement of SNs is appreciated, as it affects the efficiency and effectiveness of any WSN. The manual placement of SNs is only feasible for small scale regions. The task of SN placement becomes tedious, when the size of a target region is extremely large and manually unreachable. In this research article, an automated mechanism for fast and precise deployment of SNs in a large scale target region has been proposed. It uses an assembly of rotating cannons to launch the SNs from a moving carrier helicopter. The entire system is synchronized such that the launched SNs accurately land on the pre-computed desired locations (DLs). Simulation results show that the proposed model offers a simple, time efficient and effective technique to place SNs in a large scale target region.

Specific Detection of DNA Using Quantum Dots and Magnetic Beads for Large Volume Samples

  • Kim, Yeon-Seok;Kim, Byoung-Chan;Lee, Jin-Hyung;Kim, Jung-Bae;Gu, Man-Bock
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.5
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    • pp.449-454
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    • 2006
  • Here we present a sensitive DNA detection protocol using quantum dots (QDs) and magnetic beads (MBs) for large volume samples. In this study, QDs, conjugated with streptavidin, were used to produce fluorescent signals while magnetic beads (MBs) were used to isolate and concentrate the signals. The presence of target DNAs leads to the sandwich hybridization between the functionalized QDs, the target DNAs and the MBs. In fact, the QDs-MBs complex, which is bound using the target DNA, can be isolated and then concentrated. The binding of the QDs to the surface of the MBs was confirmed by confocal microscopy and Cd elemental analysis. It was found that the fluorescent intensity was proportional to concentration of the target DNA, while the presence of non-complementary DNA produced no significant fluorescent signal. In addition, the presence of low copies of target DNAs such as 0.5 pM in large volume samples up to 40mL was successfully detected by using a magnet-assisted concentration protocol which consequently results in the enhancement of the sensitivity more than 100-fold.

Study on the Enhancement of the Uniform Contact Technology for Large Scale Imprinting with the Design of Vacuum Gripping Pad (진공척 흡착패드 형태에 따른 대면적 임프린팅 균일 접촉 향상 연구)

  • Jang, Si-Youl
    • Tribology and Lubricants
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    • v.24 no.6
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    • pp.326-331
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    • 2008
  • The contact surfaces between mold and target should be in parallel for a proper imprinting process. However, large size of contacting area makes it difficult for both mating surfaces (mold and target planes) to be in all uniform contact with the expected precision level in terms of thickness and position. This is caused by the waviness of mold and target although it is very small relative to the area scale. The gripping force for both mold and target by the vacuum chuck is other major effect to interrupt the uniform contact, which must be avoided in imprinting mechanism. In this study, the cause of non-conformal contact mechanism between mold and target is investigated with the consideration of deformation due to the vacuum gripping for the size $470{\times}370\;mm^2$ LCD panel.

Large eddy simulation of flow over a wooded building complex

  • Rehm, R.G.;McGrattan, K.B.;Baum, H.R.
    • Wind and Structures
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    • v.5 no.2_3_4
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    • pp.291-300
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    • 2002
  • An efficient large eddy simulation algorithm is used to compute surface pressure distributions on an eleven story (target) building on the NIST campus. Local meteorology, neighboring buildings, topography and large vegetation (trees) all play an important part in determining the flows and therefore the pressures experienced by the target. The wind profile imposed at the upstream surface of the computational domain follows a power law with an exponent representing a suburban terrain. This profile accounts for the flow retardation due to friction from the surface of the earth, but does not include fluctuations that would naturally occur in this flow. The effect of neighboring buildings on the time dependent surface pressures experienced by the target is examined. Comparison of the pressure fluctuations on the single target building alone with those on the target building in situ show that, owing to vortices shed by the upstream buildings, fluctuations are larger when such buildings are present. Even when buildings are lateral to or behind the target, the pressure disturbances generate significantly different flows around this building. A simple grid-free mathematical model of a tree is presented in which the trunk and the branches are each represented by a collection of spherical particles strung together like beads on a string. The drag from the tree, determined as the sum of the drags of the component particles, produces an oscillatory, spreading wake of slower fluid, suggesting that the behavior of trees as wind breakers can be modeled usefully.

Scattering Model for Electrical-Large Target Employing MLFMA and Radar Imaging Formation

  • Wu, Xia;Jin, Yaqiu
    • Journal of electromagnetic engineering and science
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    • v.10 no.3
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    • pp.166-170
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    • 2010
  • To numerically calculate electromagnetic scattering from the electrical-large three-dimensional(3D) objects, the high-frequency approaches have been usually applied, but the accuracy and feasibility of these geometrical and physical optics(GO-PO) approaches, to some extent, are remained to be improved. In this paper, a new framework is developed for calculation of the near-field scattering field of an electrical-large 3D target by using a multilevel fast multipole algorithm(MLFMA) and generation of radar images by using a fast back-projection(FBP) algorithm. The MPI(Message Passing Interface) parallel computing is carried out to multiply the calculation efficiency greatly. Finally, a simple example of perfectly electrical conducting(PEC) patch and a canonical case of Fighting Falcon F-16 are presented.

Effects of Pretreatment for Controlling Internal Water Transport Direction on Moisture Content Profile and Drying Defects in Large-Cross-Section Red Pine Round Timber during Kiln Drying

  • Bat-Uchral BATJARGAL;Taekyeong LEE;Myungsik CHO;Chang-Jin LEE;Hwanmyeong YEO
    • Journal of the Korean Wood Science and Technology
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    • v.51 no.6
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    • pp.493-508
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    • 2023
  • Round timber materials of 600 mm length, cut from large-cross-section round timber of red pine (Pinus densiflora S. et Z.) of 450 mm width and 4.2 m length, were prepared as the target of kiln drying in this study. After treating the target materials through end sealing (ES), end sealing - kerfing (ES-K), lateral sealing - end sealing - boring (LS-ES-B), or lateral sealing - partial end sealing (LS-PES), the effects of the treatment on the incidence of drying defects were determined. The target materials with exposed lateral surface and sealed cross surface were steamed at the initial temperature of 65℃ above the official pest control temperature of 56℃, followed by kiln drying toward the final temperature of 75℃. The target materials with sealed lateral surfaces, on the other hand, were dried at the initial temperature of 90℃ at almost the maximum temperature of conventional kiln drying, as there is no risk of early check formation caused by surface moisture evaporation. The final temperature was set at approximately 100℃. The drying time, taken for the target materials with initial moisture content of 70%-80% to reach the target moisture content of 19%, varied across treatment conditions. The measured drying time was 1,146 hours (approximately 48 days) for the timber with sealed cross surface and 745 hours (approximately 31 days) for the timber with sealed lateral surface, until the moisture content reached the target level. The formation of surface checks could not be prevented in the control and ES groups, but a definite preventive effect was obtained for the LS-ES-B and LS-PES groups.