• Title/Summary/Keyword: 진동 수준

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An Implementation of Brain-wave DB building system for Artifacts prevention using Face Tracking (얼굴 추적 기반의 잡파 혼입 방지가 가능한 뇌파 DB구축 시스템 구현)

  • Shin, Jeong-Hoon;Kwon, Hyeong-Oh
    • Journal of the Institute of Convergence Signal Processing
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    • v.10 no.1
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    • pp.40-48
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    • 2009
  • Leading of the computer, IT technology has make great strides. As a information-industry-community was highly developed, user's needs to convenience about intelligence and humanization of interface is being increase today. Nowadays, researches with are related to BCI are progress put the application-technology development first in importance eliminating research about fountainhead technology with DB construction. These problems are due to a BCI-related research studies have not overcome the initial level, and not toward a systematic study. Brain wave are collected from subjects is a signal that the signal is appropriate and necessary in the experiment is difficult to distinguish. In addition, brain wave that it's not necessary to collect the experiment, serious eyes flicker, facial and body movements of an EMG and electrodes attached to the state, noise, vibration, etc. It is hard to collect accurate brain wave was caused by mixing disturbance wave in experiment on the environment. This movement, and the experiment of subject impact on the environment due to the mixing disturbance wave can cause that lowering cognitive and decline of efficiency when embodied BCI system. Therefore, in this paper, we propose an accurate and efficient brain-wave DB building system that more exactness and cognitive basis studies when embodied BCI system with brain-wave. For the minimize about brain wave DB with mixing disturbance, we propose a DB building method using an automatic control and prevent unnecessary action, put to use the subjects face tracking.

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A Process Optimization of HVOF on ALBC3 by Experiments Design (실험계획법을 이용한 ALBC3에 대한 고속화염용사의 최적 공정 설계)

  • Kim, Young-Moon;Lim, Byung-Chul;Kim, Min-Tae;Park, Sang-Heup
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.448-453
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    • 2016
  • Erosion and abrasion caused by cavitation damage occur in fluid equipment, such as ships or impellers. Similarly, the equipment damage from noise and vibration can shorten its life. This study analyzed the importance of the parameter characteristics of the process optimization of HVOF (High Velocity Oxygen Fuel spraying), which is generally used in a variety of industries for enhancing the resistibility from the cavitation phenomenon. The surface of the ALBC3 substrate was coated with an amorphous powder as a filler metal according to the experimental design using the Taguchi method, and then the characteristics with each parameter were analyzed using a porosity measurement test. The optimal process conditions was a combustion pressure of 80psi, coating distance of 270mm, gun speed of 200mm/s, and powder feed rate of 25g/min as a result of the HVOF coating by applying the experimental design. The combustion pressure, coating distance and powder feed rate were more than 25% and indicated a similar contribution rate, but the contribution rate of the gun speed was 19%, which was slightly less than the others. The contribution rate with each parameter was only slightly significant. On the other hand, all four parameters were found to be important in the contribution rate aspects of the HVOF coating process.

Analysis of the railway noise prediction result using Schall03 in noise mapping (소음지도 작성 시의 Schall03에 의한 철도소음 예측결과 분석)

  • Koh, Hyoin;Jang, Jinwon;Jang, Seungho;Hong, Jiyoung
    • Journal of Environmental Impact Assessment
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    • v.25 no.3
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    • pp.175-189
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    • 2016
  • The guideline for railway noise mapping is notificated in the administration law for noise/vibration which is announced by the ministry of environment, Korea. Here input parameters for the railway sound sources are proposed for each prediction models. In case of the application of the vehicle characteristics it is suggested to choose "0(%)" for the disc brake parameter. However new trains have been in revenue service since the announcement of the guideline, an investigation of the effect of the input parameters of the foreign railway prediction models on the prediction results of korean railway systems are needed. In this paper the sound prediction results are analyzed with a focus on the input parameters such as disc brake percentage, rail roughness, rail joints. Schall03 is used for the railway noise prediction which has been using most frequently in Korea. The results are shown and discussed.

The Availability of Automobile Catalytic Convert of Copper Based on the DFT Calculations of Cu-NO Complexes (Cu-NO 복합체에 대한 DFT 계산에 따른 Cu의 자동차 촉매변환기 적합성)

  • Ha, Kwanga;Lee, Min-Joo
    • Journal of the Korean Chemical Society
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    • v.62 no.5
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    • pp.358-363
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    • 2018
  • The purpose of this study is to show the possibility of using Cu catalyst in removal of $NO_x$ from automobile exhaust which is regarded as the primary source of fine dust PM2.5. The energy and the bond lengths of the three possible structures of Cu-NO complex, which is formed by binding NO molecule to Cu, and the changes in IR and Raman spectra are calculated using MPW1PW91 method on the level of 6-311(+)G(d,p) of basis sets with Gaussian 09 program. As a result, the enthalpy of formation of the Cu-NO complexes are obtained as ${\Delta}H=104.89$, 91.98, -127.48 kJ/mol for the linear, bent, and bridging forms of them, respectively. And the bond lengths between N and O in NO complexes, which becomes longer than NO molecule, indicates that O is easily reduced from Cu-NO. In addition, the Cu-NO complexes using Cu catalyst can be easily measured by infrared or Raman spectroscopy because in the IR and Raman spectra of the NO and Cu-NO complexes the positon and the intensity of bands are definitely different in each vibration mode.

Finite Element Analysis for Evaluation of Viscous and Eccentricity Effects on Fluid Added Mass and Damping (유체 부가질량 및 감쇠 결정시 점성 및 편심 영향에 대한 유한요소해석)

  • 구경회;이재한
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.2
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    • pp.21-27
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    • 2003
  • In general, simple fluid added mass method is used for the seismic and vibration analysis of the immersed structure to consider the fluid-structure interaction effect. Actually, the structural response of the immersed structure can be affected by both the fluid added mass and damping caused by the fluid viscosity. These variables appeared as a consistent matrix form with the coupling terms. In this paper, finite element formula for the inviscid fluid case and viscous fluid case are derived from the linearized Navier Stoke's equations. Using the finite element program developed in this paper, the analyses of fluid added mass and damping for the hexagon core structure of the liquid metal reactor are carried out to investigate the effect of fluid viscosity with variation of the fluid gap and Reynolds number. From the analysis results, it is verified that the viscosity significantly affects the fluid added mass and damping as the fluid gap size decrease. From the analysis results of eccentricity effect on the fluid added mass and damping of the concentric cylinders, the fluid added mass increase as the eccentricity increases, however the fluid damping increases only when the eccentricity is very severe.

Evaluation of Isolation Mechanism of Teflon or Steel Slag-Type Seismic Foundation Isolation Systems (테프론 또는 제강슬래그를 활용한 기초형 지진격리장치의 면진 메카니즘 평가)

  • Son, Su Won;Kang, In-Gu;Pouyan, Bagheri;Kim, Jin Man
    • Journal of the Korean Geotechnical Society
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    • v.34 no.1
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    • pp.5-16
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    • 2018
  • In this study, seismic performance of geotechnical seismic isolation system capable of primary seismic isolation in the ground was evaluated. 1-G shaking table test was used to assess the performance of Teflon or steel slag as geotechnical seismic isolation systems installed beneath superstructure foundation. Response acceleration and response spectra were analyzed considering different input motions. The results were compared with those of fixed foundation structure without seismic isolation system. The steel slag-type seismic isolation system showed significant reduction in acceleration. The teflon-type seismic isolation system did not show significant effects on acceleration reduction in low-to-moderate seismicity condition, but it did show better effects in case of strong seismic condition. As input motion was transferred to the upper mass, the response spectrum of the fixed foundation structure was amplified in the short period range. In contrast, the response spectrum of the structure with seismic isolation using teflon or steel slag amplified in the long period range. It is found that the change of periodicity and the friction characteristics between isolation materials and foundations affected acceleration reduction.

Effects of Joint Mobilization Techniques on the Joint Receptors (관절 가동운동이 관절 감수기에 미치는 영향)

  • Kim, Suhn-Yeop
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.2 no.1
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    • pp.9-19
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    • 1996
  • Type I, II, III are regarded as "true" joint receptors, type IV is considered a class of pain receptor. Type I, II and III mechanoreceptors, via static and dynamic input, signal joint position, intraarticular pressure changes, and the direction, amplitude, and velocity of joint movements. Type I mechanoreceptor subserve both static and dynamic physiologic functions. Type I are found primarily in the stratum fibrosum of the joint capsule and ligaments. Type I receptors have a low threshold for activation and are allow to adapt to changes altering their firing frequency. Type II receptors have a low threshold for activation. These dynamic receptors respond to joint movement. Type II receptors are thus termed rapidly adapting. Type II joint receptors are located at the junction of the synovial membrane and fibrosum of the joint capsule and intraarticular and extraarticular fat pads. Type III receptors have been found in collateral ligaments of the joints of the extremities. Morphologically similar to Golgi tendon organ. These dynamic receptors have a high threshold to stimulation and are slowly adating. Type IV receptors possess free nerve ending that have been found in joint capsule and fat pads. They are not normally active, but respond to extreme mechanical deformation of the joint as well as to direct chemical or mechanical irritation. Small amplitude oscillatory and distraction movements(joint mobilization) techniques are used to stimulate the mechanoreceptors that may inhibit the transmission of nociceptors stimuli at the spinal cord or brain stem levels.

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Analysis of Seismic Performance of Modular Containment Structure for Small Modular Reactor (소형 원자로용 모듈화 격납구조의 내진성능 분석)

  • Park, Woo-Ryong;Yhim, Sung-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.409-416
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    • 2020
  • The seismic performance of a containment structure should be secured to maintain the structural soundness of a containment structure under various earthquakes that occur globally. Therefore, an analysis of the seismic performance of a modular containment structure for a small modular reactor is also required. To analyze the seismic performance of modular containment, FEM models with contact surfaces between the modules and tendon were prepared and the modal and seismic analyses were performed. The displacement, stress, and gap size of modular containment under earthquake wave were analyzed. The effects of the tendon force, friction coefficient, and earthquake wave on the seismic performance were analyzed. The seismic performance of monolithic containment was also analyzed for comparison. In the 1st and 2nd natural modes, which most likely affect, the modular containment showed horizontal dynamic behavior, which is similar to monolithic containment, because of the combined effects of the tendon force and friction force between modules. When the combined effect is sufficient, the seismic performance of the modular containment is secured over a certain level. An additional increase in seismic performance is expected when some material with a larger friction coefficient is adopted on the contact surface.

A Study on the Wireless Ship Motion Measurement System Using AHRS (AHRS를 이용한 무선 선체 운동 측정 시스템에 관한 연구)

  • Kim, Dae-Hae;Lee, Sang-Min;Kong, Gil-Young
    • Journal of Navigation and Port Research
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    • v.37 no.6
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    • pp.575-580
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    • 2013
  • The IMU(Inertial Measurement Unit) which is the expensive equipment has been used as a special limited area, usually in measurement of posture of applying to the areas of ship, submarine, aircraft and military equipment application. However, in the current situation, MEMS AHRS technology can replace the high-priced IMU in MEMS AHRS selected application field. In this paper, wireless hull motion measurement system was suggested for measuring key elements of ship's movement such as rolling, pitching and yawing using gyro, acceleration and magnetic sensors of AHRS. In order to reduce the error such as instantaneous acceleration, effects and vibration of geomagnetic, we have adopted the sensors equipped with Kalman filtering. The Wireless hull motion measurement system using AHRS sensors was tested in actual ship and it could easily be applied in limited installation circumstances of the ship. In the future, this system can be useful in the navigation safety and marine accident analysis by using with ship equipment such as INS or VDR in the maritime.

Development of Automatic Calibration System for PC-Based Pure Tone Audiometer (PC 기반 순음청력검사기를 위한 자동보정시스템 개발)

  • Kim, Jin-Dong;Kang, Deok-Hun;Song, Bok-Deuk;Lee, Il-Woo;Kong, Soo-Keun;Kwon, Soon-Bok;Jeon, Gye-Rok;Shin, Bum-Joo;Wang, Soo-Geun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.7
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    • pp.2586-2594
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    • 2010
  • A pure tone audiometer should be able to produce both pure tone and masking noise with exact sound pressure level and frequency. For such purpose, it is unavoidable to periodically calibrates pure tone audiometer. However, manual acoustic calibration requires not only attention but also long time. It is possible to execute automatically calibration using software if it is PC-based pure tone audiometer. In this paper, we describe auto-calibration software for PC-based pure tone audiometer and dedicated sound level meter which has been implemented upon PC by us. To verify auto-calibration module, we examine whether output of PC-based audiometer calibrated through auto-calibration of this paper satisfies RETSPL of IEC or not.