• Title/Summary/Keyword: Mapping Technique

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An Investigation on the Surface Flow Characteristics of Ogive-cylinder using the Infrared Ray Thermogram 3D Mapping Technique (적외선 온도 측정 3차원 매핑 기법을 이용한 오자이브 실린더 표면 유동 특성 파악)

  • LEE, Jaeho
    • Journal of Aerospace System Engineering
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    • v.12 no.4
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    • pp.57-63
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    • 2018
  • IR thermography is a non-invasive method and used for the visualization of the surface temperature of the model. However, this technique only derives 2D results and not quantitative data. The goal of this study is to apply the 3D mapping technique for IR thermography. The wind tunnel model is an ogive-cylinder with a wind speed of 20 m/s ~ 80 m/s and the angle of attack ranging from $0^{\circ}$ to $90^{\circ}$. The real location of the model was made to correspond with the position of the IR image using the makers. Based on this result, quantitative results were obtained. The 3D mapping method was verified by comparing the separation point and the theoretical value.

Efficient Technology Mapping of FPGA Circuits Using Fuzzy Logic Technique (퍼지이론을 이용한 FPGA회로의 효율적인 테크놀로지 매핑)

  • Lee, Jun-Yong;Park, Do-Soon
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.8
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    • pp.2528-2535
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    • 2000
  • Technology mapping is a part of VLSI CAD system, where circuits in logical level are mapped into circuits in physical level. The performance of technology mapping system is evaluatecJ by the delay and area of the resulting circuits. In the sequential circuits, the delay of the circuit is decided by the maximal delay between registers. In this work, we introduce an FPGA mapping algorithm improved by retiming technique used in constructive level and iterative level, and by fuzzy logic technique. Initial circuit is mapped into an FPGA circuit by constructive manner and improved by iterative retiming. Criteria given to the initial circuit are structured hierarchically by decision-making functions of fuzzy logic. The proposed system shows better results than previous systems by the experiments with MCNC benchmarkers.

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Increasing the SLAM performance by integrating the grid-topology based hybrid map and the adaptive control method (격자위상혼합지도방식과 적응제어 알고리즘을 이용한 SLAM 성능 향상)

  • Kim, Soo-Hyun;Yang, Tae-Kyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.8
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    • pp.1605-1614
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    • 2009
  • The technique of simultaneous localization and mapping is the most important research topic in mobile robotics. In the process of building a map in its available memory, the robot memorizes environmental information on the plane of grid or topology. Several approaches about this technique have been presented so far, but most of them use mapping technique as either grid-based map or topology-based map. In this paper we propose a frame of solving the SLAM problem of linking map covering, map building, localizing, path finding and obstacle avoiding in an automatic way. Some algorithms integrating grid and topology map are considered and this make the SLAM performance faster and more stable. The proposed scheme uses an occupancy grid map in representing the environment and then formulate topological information in path finding by A${\ast}$ algorithm. The mapping process is shown and the shortest path is decided on grid based map. Then topological information such as direction, distance is calculated on simulator program then transmitted to robot hardware devices. The localization process and the dynamic obstacle avoidance can be accomplished by topological information on grid map. While mapping and moving, pose of the robot is adjusted for correct localization by implementing additional pixel based image layer and tracking some features. A laser range finer and electronic compass systems are implemented on the mobile robot and DC geared motor wheels are individually controlled by the adaptive PD control method. Simulations and experimental results show its performance and efficiency of the proposed scheme are increased.

A Design of Parallel Turbo Decoder based on Double Flow Method Using Even-Odd Cross Mapping (짝·홀 교차 사상을 이용한 Double Flow 기법 기반 병렬 터보 복호기 설계)

  • Jwa, Yu-Cheol;Rim, Chong-Suck
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.7
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    • pp.36-46
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    • 2017
  • The turbo code, an error correction code, needs a long decoding time since the same decoding process must be repeated several times in order to obtain a good BER performance. Thus, parallel processing may be used to reduce the decoding time, in which case there may be a memory contention that requires additional buffers. The QPP interleaving has been proposed to avoid such case, but there is still a possibility of memory contention when a decoder is constructed using the so-called double flow technique. In this paper, we propose an even-odd cross mapping technique to avoid memory conflicts even in decoding using the double-flow technique. This method uses the address generation characteristic of the QPP interleaving and can be used to implement the interleaving circuit between the decoding blocks and the LLR memory blocks. When the decoder implemented by applying the double flow and the proposed methods is compared with the decoder by the conventional MDF techniques, the decoding time is reduced by up to 32% with the total area increase by 8%.

Inversion of Time-domain Induced Polarization Data by Inverse Mapping (역 사상법에 의한 시간영역 유도분극 자료의 역산)

  • Cho, In-Ky;Kim, Yeon-Jung
    • Geophysics and Geophysical Exploration
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    • v.24 no.4
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    • pp.149-157
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    • 2021
  • Given that induced polarization (IP) and direct current (DC) resistivity surveys are similar in terms of data acquisition, most DC resistivity systems are equipped with a time-domain IP data acquisition function. In addition, the time-domain IP data include the DC resistivity values. As such, IP and DC resistivity data are intimately linked, and the inversion of IP data is a two-step process based on DC resistivity inversions. Nevertheless, IP surveys are rarely applied, in contrast to DC resistivity surveys, as proper inversion software is unavailable. In this study, through numerical modeling and inversion experiments, we analyze the problems with the conventional inverse mapping technique used to invert time-domain IP data. Furthermore, we propose a modified inverse mapping technique that can effectively suppress inversion artifacts. The performance of the technique is confirmed through inversions applied to synthetic IP data.

A Study on Mapping using Projection Moir Technique (투영 모아레 기법을 이용한 Mapping에 관한 연구)

  • 유복모;이성옥;유광호
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.3 no.2
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    • pp.1-10
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    • 1985
  • Moire technique is generally divided into shadow Moire Technique and Projection Moire Technique. In this paper, determinating the direction of reference planes for this system, by comparing the results of this system with those of general terrestrial photogrammetry, is an objective of this paper. For the objective, control surveying is done and the results of control surveying are compared with those of moire photograph. In this technique, it is found that though the positions of a projector and a reference grid are not moved, a desired moire contour whose the reference plane is different respectively is easily obtained by changing the pitches of a master grid and a reference grid on an object. Also it is found that when the pitches of the two grids on an object are equal, a moire contour which has the reference plane parallel to the object can be obtained.

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Increasing Spatial Resolution of Remotely Sensed Image using HNN Super-resolution Mapping Combined with a Forward Model

  • Minh, Nguyen Quang;Huong, Nguyen Thi Thu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.6_2
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    • pp.559-565
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    • 2013
  • Spatial resolution of land covers from remotely sensed images can be increased using super-resolution mapping techniques for soft-classified land cover proportions. A further development of super-resolution mapping technique is downscaling the original remotely sensed image using super-resolution mapping techniques with a forward model. In this paper, the model for increasing spatial resolution of remote sensing multispectral image is tested with real SPOT 5 imagery at 10m spatial resolution for an area in Bac Giang Province, Vietnam in order to evaluate the feasibility of application of this model to the real imagery. The soft-classified land cover proportions obtained using a fuzzy c-means classification are then used as input data for a Hopfield neural network (HNN) to predict the multispectral images at sub-pixel spatial resolution. The 10m SPOT multispectral image was improved to 5m, 3,3m and 2.5m and compared with SPOT Panchromatic image at 2.5m resolution for assessment.Visually, the resulted image is compared with a SPOT 5 panchromatic image acquired at the same time with the multispectral data. The predicted image is apparently sharper than the original coarse spatial resolution image.

A Method of Deriving an Intensity Mapping Function by Using The Variational Technique (변분법을 이용한 명암도 변환 함수 획득 방법)

  • Kim, Jun-Hyung;Noh, Chang-Kyun;Ko, Sung-Jea
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.5
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    • pp.10-15
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    • 2011
  • Histogram equalization is an effective method to enhance the contrast of the image. However, it can result in unwanted artifacts such as excessive contrast enhancement and noise amplification. These artifacts can be reduced by modifying an intensity mapping function which is generated by histogram equalization. In this paper, we present a variational approach to the modification of the intensity mapping function. We define a functional whose minimization produces a modified intensity mapping function. Experimental results show that the intensity mapping function obtained by the proposed method can enhance the contrast of the image without visual artifacts.

The Effects of Science Lessons using Mind Mapping on Science Process Skill and Science Academic Achievement (마인드 맵 활용전략 과학수업이 과학탐구능력 및 과학 학업성취도에 미치는 효과)

  • Kang, Jung-Mun;Lee, Yong-Seob
    • Journal of the Korean Society of Earth Science Education
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    • v.7 no.2
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    • pp.192-202
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    • 2014
  • The purpose of this study was to examine the effects of science lessons using mind mapping on creativity and academic achievement in science. The subjects of this study were fifth-grade students selected from four classes of an elementary school located in Busan. For ten weeks, the experimental group of 40 students were taught using the mind mapping technique. The comparative group, also of 40 students, was taught in normal classes which used a standard text-book. Children were given a test on science processing skills and academic achievement in science to measure the effects of mind mapping. The Likert scales were used to gather student's feedback on creativity and academic achievement in science. Through these procedures, the following results were obtained: First, mind mapping had a greater effect on science processing skills than the normal classes, where a text-book was used. Second, mind mapping was effective in improving the student's academic achievements in science at a greater level than the normal classes where a text-book was used. Third, after viewing results of the Student Recognition Investigation, we found that the students showed a higher level of interest in science lessons that used mind mapping, and were better able to understand the scientific theories. As a result, the elementary science class with mind mapping developed greater science processing skills and saw higher academic achievement in science. We conclude that science classes that use mind mapping have the potential to develop better science processing skills and improve academic achievement in science.