• Title/Summary/Keyword: orientation target

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Electrical Characteristics of PZT Thin film Deposited by Rf-magnetron Sputtering as Pb Excess Content of Target (Rf-sputtering법으로 증착한 PZT박막의 타겟의 Pb 함량에 따른 전기적 특성에 관한 연구)

  • Lee, Kyu-Il;Kang, Hyun-Il;Park, Young;Park, Ki-Yub;Song, Joon-Tae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.3
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    • pp.186-189
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    • 2003
  • The role of excess Pb about the crystallization behavior and electrical properties in b(Zr$\sub$0.52/Ti$\sub$0.48/)O3(PZT) thin films has not been precisely defined. In this work, the effect of excess Pb content on the ferroelectric properties of these films was investigated. To analyze the effect, PZT films containing various amounts of excess Pb were Prepared. PZT thin films were deposited on the Pt/Ti bottom electrode by rf magnetron sputtering method and then they were crystallized by rapid thermal annealing (RTA). The experiment showed that all PZT films indicated perovskite polycrystalline structure with preferred orientation (111) and no pyrochlore phase was observed. As higher excess Pb was included, the films showed that value of leakage current shift from 2.03${\times}$10$\^$-6/ to 6.63 ${\times}$ 10$\^$-8/A/cm$^2$ at 100kV/cm, and value of remanent polarization shift from 8.587 ${\mu}$C /cm$^2$ to 4.256 ${\mu}$C/ cm$^2$. Electrical properties of PZT thin film affected by Pb excess content of target were explained to be caused of defect among space charges and defect grain boundaries.

Implementing Dynamic Obstacle Avoidance of Autonomous Multi-Mobile Robot System (자율 다개체 모바일 로봇 시스템의 동적 장애물 회피 구현)

  • Kim, Dong W.;Yi, Cho-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.1
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    • pp.11-19
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    • 2013
  • For an autonomous multi-mobile robot system, path planning and collision avoidance are important functions used to perform a given task collaboratively and cooperatively. This study considers these important and challenging problems. The proposed approach is based on a potential field method and fuzzy logic system. First, a global path planner selects the paths of the robots that minimize the cost function from each robot to its own target using a potential field. Then, a local path planner modifies the path and orientation from the global planner to avoid collisions with static and dynamic obstacles using a fuzzy logic system. In this paper, each robot independently selects its destination and considers other robots as dynamic obstacles, and there is no need to predict the motion of obstacles. This process continues until the corresponding target of each robot is found. To test this method, an autonomous multi-mobile robot simulator (AMMRS) is developed, and both simulation-based and experimental results are given. The results show that the path planning and collision avoidance strategies are effective and useful for multi-mobile robot systems.

A Study on Mechanical Properties Evaluation of Fiber-reinforced Plastic Cellular Injection-molded Specimens for the Development of High-strength Lightweight MHEV Battery Housing Molding Technology (고강성 경량 MHEV 배터리 하우징 성형기술개발을 위한 섬유강화 플라스틱 발포 사출 시험편의 기계적 물성평가에 관한 연구)

  • Eui-Chul Jeong;Yong-Dae Kim;Jeong-Won Lee;Sung-Hee Lee
    • Design & Manufacturing
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    • v.17 no.3
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    • pp.55-60
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    • 2023
  • The fiber-reinforced plastics and cellular injection molding process can be used to efficiently reduce the weight of battery housing components of mild hybrid electronic vehicles(MHEV) made of metal. However, the fiber orientation of fiber-reinforced plastics and the growth of foaming cells are intertwined during the injection molding process, so it is difficult to predict the mechanical properties of products in the design process. Therefore, it is necessary to evaluate the mechanical properties of the materials prior to the efficient stiffness design of the target product. In this study, a study was conducted to evaluated the mechanical properties of fiber reinforced cellular injection-molded specimens. Two types of fiber-reinforced plastics that can be used in the target product were evaluated for changes in tensile properties of cellular injection-molded specimens depending on the foaming ratio and position from the injection gate. The PP and PA66 specimens showed a decrease of tensile modulus and strength of approximately 30% and 17% depending on the foaming ratio, respectively. Also, the tensile strength decreased approximately 26% and 17% depending on the position from the injection gate, respectively. As a result, it was confirmed that the PP specimens have a significantly mechanical property degradation compared to the PA66 specimens depending on the foaming ratio and position.

Low Temperature Processing of $SrBi_2Ta_2O_9$ Thin Films

  • Choelhwyi Bae;Lee, Jeon-Kook;Park, Dongkyun;Jung, Hyung-Jin
    • The Korean Journal of Ceramics
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    • v.6 no.2
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    • pp.110-115
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    • 2000
  • $SrBi_2Ta_2O_9$ thin films were deposited at room temperature on the usual (111) oriented Pt bottom electrodes using r.f. magnetron sputtering, and then post-annealed at 650-$800^{\circ}C$ for 30min in oxygen flow. Low temperature processing which shows the preferred oriented SBT thin films was obtained by controlling the sputtering pressure and/or Sr content in target. The orientation and grain growth behavior of SBT thin films were dependent on Sr contents in films. With increasing the excess Bi content up to 50% in SBT thin films, it was possible to lower the onset temperature of grain growth. The c-axis preferred oriented SBT thin films were well-grown under the condition of low post-annealing($650^{\circ}C$) by lowering post-annealing pressure. After $10^{11}$ switching cycles, no polarization degradation was observed in both preferred oriented SBT capacitors.

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The Effect of Elementary Students' Usage of Smartphone, Computer and TV on Academic Attitude (초등학생의 스마트폰, 컴퓨터, TV 사용이 학습태도에 미치는 영향)

  • Park, Suk-Kyue;Lee, Eun-Young
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.2
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    • pp.576-588
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    • 2015
  • This study analyzed the influences of elementary students' usage of smartphone, computer and TV on academic attitude. Of the subjects residing in the U city to target of 10 elementary schools from the fourth grade to sixth grade, 865 students were sampled. This research made a frequency analysis and reliability analysis of the obtained date using SPSS 21.0 program were used. Research results are as follows. First, in the smartphone, computer and TV usage status of elementary school, smartphone, computer and TV were used the high frequency with which almost every commonly used, was found to be necessary to take advantage of the time to less than one hour a day, mostly alone, it has been found that a lot of online games, videos and SNS. Second, the use of smartphone, computer and TV were showed a significant effect on all sub-variables of open, self-concept, initiative, responsibility, learning enthusiasm, future orientation, creativity, self-assessment.

Assessment of a smartphone-based monitoring system and its application

  • Ahn, Hoyong;Choi, Chuluong;Yu, Yeon
    • Korean Journal of Remote Sensing
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    • v.30 no.3
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    • pp.383-397
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    • 2014
  • Information technology advances are allowing conventional surveillance systems to be combined with mobile communication technologies, creating ubiquitous monitoring systems. This paper proposes monitoring system that uses smart camera technology. We discuss the dependence of interior orientation parameters on calibration target sheets and compare the accuracy of a three-dimensional monitoring system with camera location calculated by space resectioning using a Digital Surface Model (DSM) generated from stereo images. A monitoring housing is designed to protect a camera from various weather conditions and to provide the camera for power generated from solar panel. A smart camera is installed in the monitoring housing. The smart camera is operated and controlled through an Android application. At last the accuracy of a three-dimensional monitoring system is evaluated using a DSM. The proposed system was then tested against a DSM created from ground control points determined by Global Positioning Systems (GPSs) and light detection and ranging data. The standard deviation of the differences between DSMs are less than 0.12 m. Therefore the monitoring system is appropriate for extracting the information of objects' position and deformation as well as monitoring them. Through incorporation of components, such as camera housing, a solar power supply, the smart camera the system can be used as a ubiquitous monitoring system.

Effects of Doping Concentration on the Properties of Ga-doped ZnO Thin Films Prepared by RF Magnetron Sputtering (Ga의 도핑농도에 따른 ZnO 박막의 특성)

  • Kim, Hyoung Min;Ma, Dae Young;Park, Ki Cheol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.12
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    • pp.984-989
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    • 2012
  • We have investigated the structural, electrical and optical properties of Ga-doped ZnO (GZO) thin films prepared by RF magnetron sputtering with laboratory-made ZnO targets containing 1, 3, 5, 7 wt% of $Ga_2O_3$ powder as a doping source. The GZO thin films show the typical crystallographic orientation with c-axis regardless of $Ga_2O_3$ content in the targets. The $3,000{\AA}$ thick GZO thin films with the lowest resistivity of $7{\times}10^{-4}{\Omega}{\cdot}cm$ are obtained by using the GZO ($Ga_2O_3$= 5 wt%) target. Optical transmittance of all films shows higher than 80% at the visible region. The optical energy band gap for GZO films increases as the carrier concentration ($n_e$) in the film increases.

Effect of RF Power on SnO Thin Films Obtained by Sputtering (스퍼터링에 의해 제조된 SnO 박막의 RF 파워에 따른 특성 연구)

  • Um, Joseph;Roh, Byeong-Min;Kim, Sungdong;Kim, Sarah Eunkyung
    • Journal of the Korean Ceramic Society
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    • v.49 no.5
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    • pp.399-403
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    • 2012
  • SnO thin films were fabricated by rf reactive sputtering on borosilicate substrates with an Sn target and Ar/$O_2$ gas mixture. The effect of rf power on the structural, electrical, and optical properties of SnO thin films was investigated with XRD, AFM, SEM, Hall effect measurements, and UV-Vis spectrometer. As a plasma power increased the crystallinity with a preferred orientation of SnO thin films was improved and the grain size slightly increased. However the grains were coalesced and excessively irregular in shape. The electrical conductivity of SnO thin films demonstrated a relatively low p-type conductivity of 0.024 $(Wcm)^{-1}$ at a higher power condition. Lastly, SnO thin films had poor optical transmittance in the visible range as a plasma power increased.

Alignment System for Display Panel using Edge Feature (에지 특징을 이용한 디스플레이 패널 설비의 얼라인 시스템)

  • Lee, HoHun;Lee, DaeJong;Chun, MyungGeun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.3
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    • pp.260-265
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    • 2015
  • This paper proposes a alignment system using edge feature. An alignment system obtains the position and orientation of printed circuit board(PCB) or liquid crystal display(LCD) panel through the fiducial marks. Thus, it is the indicator of the system performance how accurate we detect the positions of the fiducial marks in the target image. Edges have the geometrical characteristics such as positions, lengths, and shapes. These features are suitable for finding the marks and have the advantages of lighting variations, model occlusion, as well as variations in scale and angle. The performance of the proposed system is validated through the alignment experiment using an display panel alignment system included X, Y axis, and rotatable stage.

Computer Integrated Surgical Robot System for Spinal Fusion

  • Kim Sungmin;Chung Goo Bong;Oh Se Min;Yi Byung-Ju;Kim Whee Kuk;Park Jong Il;Kim Young Soo
    • Journal of Biomedical Engineering Research
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    • v.26 no.5
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    • pp.265-270
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    • 2005
  • A new Computer Integrated Surgical Robot system is composed of a surgical robot, a surgical planning system, and an optical tracking system. The system plays roles of an assisting surgeon and taking the place of surgeons for inserting a pedicle screw in spinal fusion. Compared to pure surgical navigation systems as well as conventional methods for spinal fusion, it is able to achieve better accuracy through compensating for the portending movement of the surgical target area. Furthermore, the robot can position and guide needles, drills, and other surgical instruments or conducts drilling/screwing directly. Preoperatively, the desired entry point, orientation, and depth of surgical tools for pedicle screw insertion are determined by the surgical planning system based on CT/MR images. Intra-operatively, position information on surgical instruments and targeted surgical areas is obtained from the navigation system. Two exemplary experiments employing the developed image-guided surgical robot system are conducted.