• Title/Summary/Keyword: four point method

Search Result 959, Processing Time 0.028 seconds

An EEG Classifier Representing Subject's Characteristics for Brain-Computer Interface (뇌-컴퓨터 인터페이스를 위한 개인의 특성을 반영하는 뇌파 분류기)

  • Kim, Do-Yeon;Lee, Kwang-Hyung;Hwang, Min-Cheol
    • Journal of KIISE:Software and Applications
    • /
    • v.27 no.1
    • /
    • pp.24-32
    • /
    • 2000
  • BCI(Brain-Computer Interface) is studied to control the machines with brain. In this study, an EEG(Electroencephalography) signal classification model is proposed. The model gets EEG pattern from each subject's brain and extracts characteristic features. The model discriminates the EEG patterns by using those extracted characteristic features of each subject. The proposed method classifies each pair of the given tasks and combines the results to give the final result. Four tasks such as rest, movement, mental-arithmetic calculation and point-fixing were used in the experiment. Over 90% of the trials, the model yielded successful results. The model exploits characteristic features of the subjects and the weight table that was produced after training. The analysis results of the model such as its high success rates and short processing time show that it can be used in a real-time brain-computer interface system.

  • PDF

Fabrication of Y-TZP/Ce-TZP Multilayer Composites Using Slip Casting(II) (슬립주입에 의한 Y - TZP/Ce-TZP 다층 복합체의 제조(II))

  • Kim, Min-Ju;Lee, Yun-Bok;Kim, Yeong-U;Jeon, Byeong-Se;Park, Hong-Chae
    • Korean Journal of Materials Research
    • /
    • v.10 no.10
    • /
    • pp.677-683
    • /
    • 2000
  • Three- and five-layer 3Y-YZP/12Ce- TZP composites prepared by a slip casting method have been char­acterized in terms of mechanical properties. The fracture strength of mutilayer c$\alpha$nposites determined in a diametral compression test was 327~534 MPa. Although the indentation strength of the materials was generally reduced with i increasing Vickers indentation load up to 300 N, the damage resistance of multilayer composites was superior com­pared to monolithic layer TZP material. The four-point bend strength of the layered material remained at the values of 620~674 MPa after indentation with a load of 49 N, while that of the monolithic TZP material was 129~339 MPa. The microindentation toughness of the multilayer material was $7.7~13.1\;MPa{\cdot}m^{1/2}$.

  • PDF

A Study on Development of Performance Indicators for Korean Public Libraries (공공도서관의 성과지표 개발에 관한 연구)

  • Kim, Gyu-Hwan;Nam, Young-Joon
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.42 no.4
    • /
    • pp.113-139
    • /
    • 2008
  • Under rapidly changing circumstances, public libraries are required to evaluate the performance with an integrated point of view to cope with a variety of changes. In other words, it is necessary to develop integrated library performance appraisal indicators which are both quantitative and qualitative. Recently, ISO and IFLA attempt to adopt an integrated performance evaluation system based on the Balanced Scorecard(BSC). Therefore, this study defines four aspects of the library appraisal including input, process, output and outcome, and suggests a new library appraisal system and indicators of each appraisal aspect. In the concrete, appraisal aspects were derived from ISO appraisal system, and an appraisal system and indicators were presented based on the comparison and analysis of the ones respectively used inside and outside of Korea. Finally, this study proposes the method of suitability evaluation of those performance indicators by librarians and professors in Korea.

A Study of Solving Maze Escape Problem through Robots' Cooperation (로봇협동을 통한 미로탈출 문제해결 방안)

  • Hong, Ki-Cheon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.11
    • /
    • pp.4167-4173
    • /
    • 2010
  • ICT education guidelines revised in 2005 reinforce computer science elements such as algorithm, data structure, and programming covering all schools. It means that goal of computer education is improving problem-solving abilities not using of commercial software. So this paper suggests problem-solving method of maze escape through robots' cooperation in an effort of learning these elements. Problems robots should solve are first-search and role-exchange. First-search problem is that first robot searches maze and send informations about maze to the second robot in real time. Role-exchange problem is that first robot searches maze, but loses its function at any point. At this time second robot takes a role of first robot and performs first robot's missions to the end. To solve these two problems, it goes through four steps; problem analysis, algorithm description, flowchart and programming. Additional effects of our suggestion are chance of cooperation among students and use of queue in data structure. Further researches are use of more generalized mazes, application to real field and a talented curriculum.

A Study on the Correlationship between Wearable ECG and Clinical ECG Measurements (웨어러블 심전도 측정과 임상 심전도 측정과의 상관관계에 대한 연구)

  • Lee, Kang-Hwi;Lee, Seong-Su;Kim, Sang-Min;Lee, Hyeok-Jae;Min, Kyoung-Jin;Kang, Hyun-Kyu;Lee, Joo-Hyeon;Kwak, Hwy-Kuen;Ko, Yun-Soo;Lee, Jeong-Whan
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.67 no.12
    • /
    • pp.1690-1698
    • /
    • 2018
  • Recent advances in ICT technology have transformed many of our daily lives and attracted a lot of attention to personal health. Heart beat measurement that reflects cardiac activities has been used in various fields such as exercise evaluation and psychological state evaluation for a long time, but its utilization method is limited due to its differentiation from clinical electrocardiogram. Therefore, in this study, we could observe the change of the measured signal according to the change of the distance and the position of the measuring electrodes which are non-standard electrode configuration. Based on the electric dipole model of the heart, correlation with clinical electrocardiogram could be confirmed by synthesizing multiple surface potentials measured with a shorter electrode distance than standard one. From the electromagnetic point of view, the distance between the measuring electrodes corresponds to the distance that the electric potential by the cardiac electric dipole moves, and the electric potential measured at the body surface is proportional to the moving distance of the electric potential. Therefore, it is preferable to make the distance between electrodes as long as possible, and to position the measuring electrode close to the ventricle rather than the atrium. In addition, it was found that standard electrocardiographic waveforms could be synthesized by using arithmetic sum of multiple measuring electrodes due to the relationship of electrical dipole vectors, which is obtained by dividing and positioning a plurality of measuring electrodes on a reference electrode line, such as Lead-I, Lead-II direction. Also, we obtained a significant Pearson correlation coefficient ($r=0.9113{\pm}0.0169$) as a result of synthetic experiments on four subjects.

Simulation based Target Geometry Determination Method for Extrinsic Calibration of Multiple 2D Laser Scanning System (다중 2D 레이저 스캐너 시스템의 외부 표정요소 캘리브레이션을 위한 시뮬레이션 기반 표적 배치 결정 기법)

  • Ju, Sungha;Yoon, Sanghyun;Park, Sangyoon;Heo, Joon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.36 no.6
    • /
    • pp.443-449
    • /
    • 2018
  • Acquiring indoor point cloud, using SLAM (Simultaneous Localization and Mapping) based mobile mapping system, is an element progress for development of as-build BIM (Building Information Model) for the maintenance of the building. In this research we proposed a simulation-based target geometry determination for extrinsic calibration of multiple 2D laser scanning mobile system. Four different types of calibration sites were designed: (1) circle type; (2) rectangle type; (3) double circle type; and (4) double rectangle type. Based on the measurement values obtained from each simulated calibration site geometry, least squares solution based extrinsic calibration was derived. As a result, the rectangle type geometry is most suitable for extrinsic calibration of this system. Also, correlation values between extrinsic calibration parameters were high, and calibration results were distinct according to the calibration sites.

Service model development and importance analysis using shared economic service - As a specialization center for mail service (공공서비스의 공유경제 서비스모델 도입 위한 중요요인 분석 -우체국 서비스를 중심으로)

  • Park, Sung Hwan;Leem, Choon Seong
    • Journal of the Korea Convergence Society
    • /
    • v.10 no.5
    • /
    • pp.181-188
    • /
    • 2019
  • People can easily use a shared economic service system based on ICT technology. Most of the shared economic services are provided by private companies, and discussion on public goods is insufficient. If we look at the current shared economic service from the point of view of courier service, $\ddot{U}ber^{\prime}s$ system can be an alternative. The post office courier service uses ICT technology but differs from the service of the shared economy. This study uses Delphi analyzer method and AHP methodology to derive important factors in introducing shared economic system. As a result, socioeconomic characteristics were found to be the most important in the upper tier, and the shared economic platform, sharing of idle resources, popularization of smartphone, and increase of e - commerce were the four important factors in the lower tier. In order to maximize efficiency, which is the essence of the shared economy, the necessity of introduction into the shared economic system and important factors in the introduction of public goods are presented.

IR Absorption Property in NaNo-thick Nickel Cobalt Composite Silicides (나노급 두께의 Ni50Co50 복합 실리사이드의 적외선 흡수 특성 연구)

  • Song, Oh Sung;Kim, Jong Ryul;Choi, Young Youn
    • Korean Journal of Metals and Materials
    • /
    • v.46 no.2
    • /
    • pp.88-96
    • /
    • 2008
  • Thermal evaporated 10 nm-$Ni_{50}Co_{50}$/(70 nm-poly)Si films were deposited to examine the energy saving properties of silicides formed by rapid thermal annealing at temperature ranging from 500 to $1,100^{\circ}C$ for 40 seconds. Thermal evaporated 10 nm-Ni/(70 nm-poly)Si films were also deposited as a reference using the same method for depositing the 10 nm-$Ni_{50}Co_{50}$/(70 nm-poly)Si films. A four-point probe was used to examine the sheet resistance. Transmission electron microscopy (TEM) and X-ray diffraction XRD were used to determine cross sectional microstructure and phase changes, respectively. UV-VIS-NIR and FT-IR (Fourier transform infrared spectroscopy) were used to examine the near-infrared (NIR) and middle-infrared (MIR) absorbance. TEM analysis confirmed that the uniform nickel-cobalt composite silicide layers approximately 21 to 55 nm in thickness had formed on the single and polycrystalline silicon substrates as well as on the 25 to 100 nm thick nickel silicide layers. In particular, nickel-cobalt composite silicides showed a low sheet resistance, even after rapid annealing at $1,100^{\circ}C$. Nickel-cobalt composite silicide and nickel silicide films on the single silicon substrates showed similar absorbance in the near-IR region, while those on the polycrystalline silicon substrates showed excellent absorbance until the 1,750 nm region. Silicides on polycrystalline substrates showed high absorbance in the middle IR region. Nickel-cobalt composite silicides on the poly-Si substrates annealed at $1,000^{\circ}C$ superior IR absorption on both NIR and MIR region. These results suggest that the newly proposed $Ni_{50}Co_{50}$ composite silicides may be suitable for applications of IR absorption coatings.

A Study on the Information Continuum Model: Preliminary Analysis to Establish the Relationship Between Records and Information (정보 컨티뉴엄 모델에 관한 연구: 기록과 정보 간의 관계 정립을 위한 예비적 분석)

  • Kim, Myoung-hun
    • Journal of Korean Society of Archives and Records Management
    • /
    • v.22 no.3
    • /
    • pp.21-36
    • /
    • 2022
  • This study intends to analyze the information continuum model as part of establishing the relationship between records and information. The information continuum is a theoretical system designed to establish a new information concept from the record-keeping point of view based on the record continuum. It provides a conceptual framework that can identify the elements for information management that exist in record-keeping. Accordingly, in Chapter 2, the background and process of the information continuum development, which followed after the record continuum development, were reviewed. Then, the concept of information established by borrowing information science theory was examined in relation to the record continuum. In Chapter 3, the conceptual structure of the information continuum and the purpose and method of information utilization were considered. Afterward, the four dimensions and attributes that structurally schematize the elements for information management in record-keeping were analyzed. Based on this analysis, Chapter 4 tried to present the meaning and limitations of the information continuum.

Sensory Evaluation of Friction and Viscosity Rendering with a Wearable 4 Degrees of Freedom Force Feedback Device Composed of Pneumatic Artificial Muscles and Magnetorheological Fluid Clutches

  • Okui, Manabu;Tanaka, Toshinari;Onozuka, Yuki;Nakamura, Taro
    • Journal of Drive and Control
    • /
    • v.18 no.4
    • /
    • pp.77-83
    • /
    • 2021
  • With the progress in virtual reality technology, various virtual objects can be displayed using head-mounted displays (HMD). However, force feedback sensations such as pushing against a virtual object are not possible with an HMD only. Focusing on force feedback, desktop-type devices are generally used, but the user cannot move in a virtual space because such devices are fixed on a desk. With a wearable force feedback device, users can move around while experiencing force feedback. Therefore, the authors have developed a wearable force feedback device using a magnetorheological fluid clutch and pneumatic rubber artificial muscle, aiming at presenting the elasticity, friction, and viscosity of an object. To date, we have developed a wearable four-degree-of-freedom (4-DOF) force feedback device and have quantitatively evaluated that it can present commanded elastic, frictional, and viscous forces to the end effector. However, sensory evaluation with a human has not been performed. In this paper, therefore, we conduct a sensory evaluation of the proposed method. In the experiment, frictional and viscous forces are rendered in a virtual space using a 4-DOF force feedback device. Subjects are asked to answer questions on a 1- to 7-point scale, from 1 (not at all) to 4 (neither) to 7 (strongly). The Wilcoxon signed rank test was used for all data, and answer 4 (neither) was used as compared standard data. The experimental results confirmed that the user could feel the presence or absence of viscous and frictional forces. However, the magnitude of those forces was not sensed correctly.