• Title/Summary/Keyword: directionality

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The Study of Interference Cancellation between DSRC and ETC with Adaptive Array Antenna (적응 배열 안테나를 이용한 DSRC와 ETC 상호간 간섭 제거에 관한 연구)

  • 정재승;이병섭
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.7
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    • pp.1147-1155
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    • 2000
  • The installation of wireless communication system for various services of ITS at 5.8 GHz generates mutual interference. The representative example, the sharing of frequency between DSRC system and ETC system is a cause of communication error or disturbance both sides or one side owing to mutual interference. As a solution, a Shield Plate, Antenna Directionality, Power Control is proposed, but these are not perfect solution, because a RSU doesn't have the information of position of interferer. This paper applies an adaptive array antenna which makes a gain for desired users, makes a null for interferer, to up-link, down-link of DSRC and ETC system. The analysis of BER performance shows the effect of reduced interference about 20 dB.

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The Effect of Geometrical Structure on the Moisture Transport Properties of Nonwoven Batting Materials (부직포 충전재의 구조적 특성이 수분전달 특성에 미치는 영향-단층구조와 이층구조 부직포의 비교-)

  • 김희숙;나미희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.6
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    • pp.810-818
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    • 2000
  • The purpose of this study was to analyze the effect of geometrical structure on the moisture transport properties of nonwoven batting materials. Two types of nonwovens were used such as single and double layered nonwovens. Steady and dynamic state water vapor transport properties were measured by absorption, evaporation and cobaltous chloride method respectively. The results of this study were as follows: 1) Geometrical structure affected water vapor evaporation, but there were no differences between single and double layered nonwovens in moisture absorption. Thickness and air permeability were influencing factor on water vapor transport rate. 2) Directionality of double layered nonwoven was observed both in steady and dynamic state moisture transport. There were differences between upper and lower layer of double layered nonwoven both in moisture absorption rate and color change by cobaltous chloride method. 3) In dynamic state of water vapor transport rate, single layered nonwoven reached more rapidly at the established relative humidity. It was confirmed that geometrical structure affected water vapor evaporation and hydrophilicity of fiber affected moisture absorption because there were much more water vapor transport rate by evaporation than absorption within the same period of time.

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A Study on the Optimal Magnet for ECR (ECR 용 최적 마그네트에 관한 연구)

  • Kim, Y.T.;Kim, Y.J.;Kim, K.S.;Lee, Y.J.;Son, M.H.
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.649-652
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    • 1992
  • ECR(Electron Cyclotron Resonance) occure at ${\omega}_c$=${\omega}$, ${\omega}_c$:electron cycltron frequency, ${\omega}$:electromagnetic wave frequency. ECR system have several merit, 1) power transefer efficiency 2) low neutral gas pressure (below 1 mTorr) 3) high plasma density($10^{12}$ $cm^{-3}$). It is applicated variously in the field of semiconductor and new materials as the manufacturing equipment. Magnetic field in ECR system contruct resonance layer (${\omega}$=2.45GHz, $B_z$=875 Gauss) and control plasma. Plasma is almost generated at resonance layer. If the distance between substrate and resonance layer is short, uniformity of plasma is related with profile of resonance layer. Plasma have the property "Cold in Field", so directonality of magnetic field is one of the control factors of anisotropic etching. In this study, we calculate B field and flux line distribution, optimize geometry and submagnet current and improve of magnetic field directionality (99.9%) near substrate. For the purpose of calculation, vector potential A(r,z) and magnetic field B(r,z), green function and numerical integration is used. Object function for submagnet optimization is magnetic field directionality on the substrate and Powell method is used as optimization skim.

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ROI Based Real Time Image Stitching Using the Directionality of the Image (영상의 방향성을 이용한 ROI 기반 실시간 파노라마 영상 정합)

  • Nam, Ki-Hun;Choi, Se-Jin
    • Journal of IKEEE
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    • v.20 no.4
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    • pp.420-423
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    • 2016
  • In this paper, we proposed an implementation of panoramic image stitching that operates in real time at the embedded environment by applying ROI based PROSAC algorithm using the directionality of the image. The conventional panoramic image stitching applies SURF or SIFT algorithm which contains unnecessary computation and a lots of data to detect feature points. In this paper, we use the direction of the input image and we proposed the method of reducing the unnecessary computation by using ROI. We use a gyro sensor and an acceleration sensor. Output data from gyro and acceleration sensors can be calibrated by complementary filter. The calibration does not affect the operating time of the proposed image stitching algorithm in embedded environment. Therefore, it is possible to operate in real-time.

Mobile Performance Evaluation of Mecanum Wheeled Omni-directional Mobile Robot (메카넘휠 기반의 전방향 이동로봇 주행성능 평가)

  • Chu, Baeksuk;Sung, Young Whee
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.4
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    • pp.374-379
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    • 2014
  • Mobile robots with omni-directional wheels can generate instant omni-directional motion without requiring extra space to change the direction of the body. Therefore, they are capable of moving in an arbitrary direction under any orientation even in narrow aisles or tight areas. In this research, an omni-directional mobile robot based on Mecanum wheels was developed to achieve omni-directionality. A CompactRIO embedded real-time controller and C series motion and I/O modules were employed in the control system design. Ultrasonic sensors installed on the front and lateral sides were utilized to measure the distance between the mobile robot and the side wall of a workspace. Through intensive experiments, a performance evaluation of the mobile robot was conducted to confirm its feasibility for industrial purposes. Mobility, omni-directionality, climbing capacity, and tracking performance of a squared trajectory were selected as performance indices to assess the omni-directional mobile robot.

Concept based Design-Art - Focused on the Transition Process from Fine Art and Design to Concept based Design-Art - (개념 중심의 디자인아트 - 순수미술, 디자인으로부터 개념 중심의 디자인아트로의 이행 과정을 중심으로 -)

  • Kang, Hyun-Dae;Kim, So-Hyun
    • Journal of the Korea Furniture Society
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    • v.26 no.2
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    • pp.112-121
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    • 2015
  • Concept based Design-Art is a flow formed while focusing on works not dividing boundaries with concept on top in a transition to content-centered communication methods from medium-centered communication methods so far dividing design genres. This movement begins in a try to create upper-level concepts before works and products come into being in pure art and design respectively. This thesis draws out the definition of Concept based Design-Art through its researches, diagnoses directionality of Concept based Design-Art by analyzing Concept based Design-Artists' works and considers their social duties and roles. Outcome of this study will help working authors, designers, and Design-Artists grasp the changing phases of design and art, establish their own directionality, and predict how the Concept based Design-Art market will change in the years ahead. Besides, it will be a good reference by which for them to build their own 'concept,' consider their relationship to the society and check where they are.

Implementation of Statistical Significance and Practical Significance Using Research Hypothesis and Statistical Hypothesis in the Six Sigma Projects (식스시그마 프로젝트에서 연구가설과 통계가설에 의한 통계적 유의성 및 실무적 유의성의 적용방안)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.15 no.1
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    • pp.283-292
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    • 2013
  • This paper aims to propose a new steps of hypothesis testing using analysis process and improvement process in the six sigma DMAIC. The six sigma implementation models proposed in this paper consist of six steps. The first step is to establish a research hypothesis by specification directionality and FBP(Falsibility By Popper). The second step is to translate the research hypothesis such as RHAT(Research Hypothesis Absent Type) and RHPT(Research Hypothesis Present Type) into statistical hypothesis such as $H_0$(Null Hypothesis) and $H_1$(Alternative Hypothesis). The third step is to implement statistical hypothesis testing by PBC(Proof By Contradiction) and proper sample size. The fourth step is to interpret the result of statistical hypothesis test. The fifth step is to establish the best conditions of product and process conditions by experimental optimization and interval estimation. The sixth step is to draw a conclusion by considering practical significance and statistical significance. Important for both quality practitioners and academicians, case analysis on six sigma projects with implementation guidelines are provided.

A Study on Directionally Weighted Filter Algorithm in Impulse Noise Environments (임펄스 잡음환경에서 방향성을 고려한 가중치 필터 알고리즘에 관한 연구)

  • Long, Xu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.7
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    • pp.1734-1739
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    • 2014
  • Currently, with the rapid development of the digital age, multimedia-related image devices become popular. However, images are susceptible to corruption in processing image data due to the impulse noise and active researches have been conducted to restore these images. This paper, in order to restore the damaged images in impulse noise environments, suggested an image restoration algorithm which applies weights depending on spatial distance between directionality and pixel by focusing on damaged pixels. Additionally, this algorithm was compared with existing methods by using the PSNR (peak signal to noise ratio) as the objective standard to judge whether there were improved effects.

Improvement of Proton Beam Quality from the High-intensity Short Pulse Laser Interaction with a Micro-structured Target

  • Seo, Ju-Tae;Yoo, Seung-Hoon;Pae, Ki-Hong;Hahn, Sang-June
    • Journal of the Optical Society of Korea
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    • v.13 no.1
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    • pp.22-27
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    • 2009
  • Target design study to improve the quality of an accelerated proton beam from the interaction of a high-intensity short pulse laser with an overdense plasma slab has been accomplished by using a two-dimensional, fully electromagnetic and relativistic particle-in-cell (PIC) simulation. The target consists of a thin core part and a thick peripheral part of equivalent plasma densities, while the ratio of the radius of the core part to the laser spot size, and the position of the peripheral part relative to the fixed core part were varied. The positive effects of this core-peripheral target structure could be expected from the knowledge of the typical target normal sheath acceleration (TNSA) mechanism in a laser-plasma interaction, and were apparently evidenced from the comparison with the case of a conventional simple planar target and the case of the transversal size reduction of the simple planar target. Improvements of the beam qualities including the collimation, the forward directionality, and the beam divergence were verified by detailed analysis of relativistic momentum, angular directionality, and the spatial density map of the accelerated protons.

Pile Contact Depth Effects in Rubbed Polyimide(PI) Films

  • Kim, Gi-Jeong;Gwon, Hyeok-Min;Lee, Sang-Mun;Lee, Cheol-Gu;Gwak, Mu-Seon;Kim, Bong-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.398-398
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    • 2010
  • To determine the molecular directionality of PI chains depending on rubbing condition, we measured the angle resolved near edge X-ray absorption fine structure (NEXAFS) spectra at C K-edge of the rubbed PI films. Twisted nematic mode PI (PI-TN) and in plane switching mode PI (PI-IPS) were introduced to examine the effect of rubbing conditions on the chain directionality. The average tilt angle a of the PI molecules was estimated through the measured intensity change of $C=C\;{\pi}^*$ in NEXAFS C K-edge spectrum by controlling the stage speed and the pile contact depth. After rubbing, the irregular molecular direction changed to a regular direction with a molecular tilt angle of $51.2^{\circ}$ for PI-TN and $49.6^{\circ}$ for PI-IPS at the rubbing condition of the roll speed of 1000 rpm, stage speed of 50 mm/sec, and file contact depth of 0.3 mm. The molecular tilt angle $\alpha$ was linearly decreased in the PI-TN and PI-IPS samples with increasing depth of the pile contact.

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