• Journal of IKEEE
• /
• v.24 no.2
• /
• pp.654-660
• /
• 2020

Through the output of brain waves during muscle operation, this paper checks whether it is possible to find characteristic vectors of brain waves that are capable of dividing left and right movements by extracting brain waves in specific areas of muscle signal output that include the motion of the left and right muscles or the will of the user within EEG signals, where uncertainties exist considerably. A typical surface EMG and noninvasive brain wave extraction method does not exist to distinguish whether the signal is a motion through the degree of ionization by internal neurotransmitter and the magnitude of electrical conductivity. In the case of joint and motor control through normal robot control systems or electrical signals, signals that can be controlled by the transmission and feedback control of specific signals can be identified. However, the human body lacks evidence to find the exact protocols between the brain and the muscles. Therefore, in this paper, efficiency is verified by utilizing the results of application of CSP (Common Spatial Pattern) filter to verify that the left-hand and right-hand signals can be extracted through brainwave analysis when the subject's behavior is performed. In addition, we propose ways to obtain data through experimental design for verification, to verify the change in results with or without filter application, and to increase the accuracy of the classification.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1330-1336
• /
• 2007

The purpose of the study was to verify deduction of each coefficient necessary to analysis on micro-pressure waves and reliability of the analysis result. The tunnel running train model testing device used in the test was manufactured by scale of 1:60 and the study used a train model with ten cars long according to specifications of KTX model. The study applied tunnels with cross sections of $107.9m^3\;and\;95.1m^3$ and applied tunnel extensions with 1km, 0.75km and 0.5km. Also, the study tested train speed by changing it into 275, 300, 325 and 350km/h. The test device was a hydraulic launch system composed of a train model, a hydraulic launcher, a tunnel model and a brake. The study measured speed of a model trainby a speed sensor installed in the point of each 1.2m from the front of tunnel entrance and a pithead of tunnel exit and measured pressure change of internal tunnel continuously by installing pressure sensors in the entrance part of tunnel, in the middle part of tunnel and in the exit part of tunnel. As the result of the measurement, it was known that pressure slope of pressure wave happened in the entrance part of tunnel was increased by a nonlinear effect while spreading the tunnel or its pressure slope was reduced by diffusion. Also, the study compared and analyzed micro-pressure waves happened in the exit part of the tunnel by installing each kind of hoods in the entrance part of the tunnel to prevent reduction of micro-pressure waves.

• Korean Journal of Acupuncture
• /
• v.28 no.1
• /
• pp.23-37
• /
• 2011

Objectives : The pulse diagnosis is an important method in Oriental Medicine. The aim of this study is to measure the similarity of the diagnosis by a traditional method using doctor's hand for feeling of pulse and by pulse diagnosis apparatus using Hwang-Je (HJ) pulse analyser, Hui-Su (HS) pulse analyser on Chon, Kwan and Chuk. Methods : Four korean medical doctors and HJ pulse analyser, HS pulse analyser have measured the speed (遲數), the size (微細弱緩大), and the depth (浮沈) of pulse waves of 23 volunteers. First, four korean medical doctors measured pulse waves of volunteers. And then, the pulse waves of volunteers were measured by HJ pulse analyser, HS pulse analyser. This was performed on the right Chon, Kwan and Chuk. Results : The traditional method and the HJ pulse analyser method had the 60.9% matches on the values of the pulse speed condition, the HS pulse analyser method had the 78.3% matches on the values of the pulse speed condition. The traditional method and the HJ pulse analyser method had the 56.5% (Chon), 65.2% (Kwan), 78.3% (Chuk) matches on the values of the pulse size condition, the HS pulse analyser method had the 65.2% (Chon), 13.0% (Kwan), 39.1% (Chuk) matches on the values of the pulse size condition. The traditional method and the HJ pulse analyser method had the 43.5% (Chon), 26.1% (Kwan), 47.8% (Chuk) matches on the values of the pulse depth condition, the HS pulse analyser method had the 45.5% (Chon), 30.4% (Kwan), 36.8% (Chuk) matches on the values of the pulse depth condition. Conclusions : According to these results, we suggest that the pulse analyser is necessary to develope for its high similarities with the traditional pulse diagnosis.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.9
• /
• pp.414-420
• /
• 2005

A method for partial discharge diagnosis based on UHF narrow band type for GIS has been developed and calibrated. In generally, PD cannot be directly measured under on-line condition, but we can indirectly measure the electromagnetic wave made by PD using the high-frequency antenna. Compared with VHF band, electromagnetic waves of UHF band have a low influence for external noise in high-voltage substation. Therefore, we can detect the real abnormality with several pC in GIS using UHF narrow-band type method. For the case of no internal VHF sensor for GIS of the domestic substation, it has applied to use the external UHF sensor attached in spacer in GIS of existing substation. In this paper, we firstly described the technique of partial discharge measurement using frequency analysis and phase analysis in UHF band. Secondly, we presented the results of sensitivity test, the relationship of dBm-pC and diagnosis result of the cause of PD source by phase analysis. And then, we report the diagnosis result of partial discharge on the real GIS in domestic substation. These results make above method applicable for measurement of quantity and cause of PD for real operation GIS in high-voltage substation.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.19 no.5
• /
• pp.333-339
• /
• 1999

It is well recognized that ultrasonic technique is one of the most common and reliable nondestructive evaluation techniques for quantitative estimation of defects in structures. For the quantitative and accurate estimation of internal defects. the characteristics of scattered ultrasonic wavefields must be understood. In this study. the scattered near-field and far-field due to a circular cavity embedded in infinite media subjected to incident SH-waves were calculated by the boundary element method. The frequency response of the scattered ultrasonic far-field was transformed into the time-domain signal by obtaining its inverse Fourier transform. It was found that the amplitude of time-domain signal decreases and its time delay increases as the distance between the detecting point of ultrasonic scattered field and the center of internal cavity increases.

• Journal of Ocean Engineering and Technology
• /
• v.19 no.6 s.67
• /
• pp.35-43
• /
• 2005

Recently, various-shaped coastal structures have been studied and developed. Among them, the submerged breakwater became generally known as a more effective structure than other structures, bemuse it not only serves its original function, but also has the ability to preserve the coastal environment. Most previous investigations have been focused on the wave deformation and energy dissipation due to submerged breakwater, but less interest was given to their internal properties and dynamic behavior of the seabed foundation under wave loadings. In this study, a direct numerical simulation (DNS) is newly proposed to study the dynamic interaction between a permeable submerged breakwater aver a sand seabed and nonlinear waves, including wave breaking. The accuracy of the model is checked by comparing the numerical solution with the existing experimental data related to wave $\cdot$ permeable submerged breakwater $\cdot$ seabed interaction, and showed fairly nice agreement between them. From the numerical results, based on the newly proposed numerical model, the properties of the wave-induced pore water pressure and the flow in the seabed foundation are studied. In relation to their internal properties, the stability oj the permeable submerged breakwater is discussed.

• The Journal of Internal Korean Medicine
• /
• v.29 no.1
• /
• pp.117-129
• /
• 2008

Background & Objective : Naeso-san(NSS) has been used for the treatment of functional dyspepsia, regarded as a gastric dysmotility disease. A main cause of gastric dysmotility is antral dilatation or antroduodenal uncoordination. Therefore, we investigated the effect of NSS on gastric motility and its mechanism of action, as well as the morphologic changes in antral dilatated rats. Methods : Antral dilatated rats were induced by wrapping a nonabsorbable rubber ring(D:6mm, W:4mm, T:1mm) around the 1st portion of the duodenum for 8 weeks. Then morphologic changes were investigated and compared with normal intact rats before and after 8 weeks. Gastric emptying was measured by administration of normal saline(NS) or NSS in normal intact and antral dilatated rats. In another series of experiments to evaluate the mechanism of NSS under delayed conditions, normal intact rats were treated with atropine sulfate(1mg/kg, s.c.), quinpirole HCl(0.3mg/kg, i.p.), $NAME(N^{G}-nitro-L-arginine$ methyl ester, 75mg/kg, s.c.) and cisplatin(10mg/kg, i.p.), respectively. The myoelectrical activity of the gastric smooth muscle was recorded in normal intact and antral dilatated rats. The contractile waves were measured for 30 minutes before and after administration of each solution(NS, NSS). Results : Body weight gain of antral dilatated rats was significantly lower than that of the controls. Futhermore, we found the thickness of the mucosal and muscular layers and surface area of the stomach increased significantly compared with controls. NSS 278㎎/㎏ improved gastric emptying more than normal saline or NSS 93mg/kg in normal intact(p=0.026) and antral dilatated rats(p=0.03). NSS enhanced gastric emptying significantly in the NAME treated group(p=0.002). NSS 278mg/kg increased the significant postprandial dominant power than that of NS in normal intact rats, whereas there was no statistical significance in antral dilatated rats. Conclusions : NSS stimulates gastric motility through the cholinergic pathway. We expect that pathologic model with antral dilatation can be used as an exprimental tool which is similar to dyspepsia and NSS would be effective especially in dysmotility-like functional dyspepsia with antral dilatation or impaired reservoir functions such as gastric adaptive relaxation.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.2
• /
• pp.53-65
• /
• 2008

This paper proposes the qualitative method for planning the operation of multi-AUVs with environmental disturbances, which is considered to be a very difficult task. In this paper we use an extension collision map as a collision free motion planner. The tool was originally developed for the multiple ground vehicles with no internal/external disturbance. In order to apply the method to a water environment where there are tides and waves, and currents, we analyze the path deviation error of AUVs caused by external disturbances. And we calculate safety margin for the collision avoidance on the extension collision map. Finally, the simulation result proves that the suggested method in this paper make multi-AUVs navigate to the goal point effectively with no collision among them.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.237.2-237.2
• /
• 2010

Although oscillating water column type wave energy devices are nearing the stage of commercial exploitation, there is still much to be learnt about many facets of their hydrodynamic performance. The techniques of Computational Fluid Dynamics (CFD) are applied to simulate a wave energy conversion device in free surface such as waves. This research uses the commercially available ANSYS CFX computational fluid dynamics flow solver to model a complete oscillating water column system with savonius turbine incorporated at the rear bottom of the OWC chamber in a three dimensional numerical wave tank. The purpose of the present study is to investigate the effect of an average wave condition on the performance and internal flow of a newly developed direct drive turbine (DDT) model for wave energy conversion numerically. The effects of blade angle and front lip shape on the hydrodynamic efficiency are investigated. The results indicated that the developed models are suitable to analyze the water flow characteristics both in the chamber and in the turbine. For the turbine, the numerical results of torque were compared for the all cases. The results of the testing have also illustrated that simple changes to the front wall aperture shape can provide marked improvements in the efficiency of energy capture for OWC type devices.

• Smart Structures and Systems
• /
• v.21 no.6
• /
• pp.751-759
• /
• 2018

Glass fibre reinforced polymers (GFRP) are widely exploited in many industrial branches. Due to this Structural Health Monitoring systems containing embedded fibre optics sensors are applied. One of the problems that can influence on composite element durability is water contamination that can be introduced into material structure during manufacturing. Such inclusion can be a damage origin significantly decreasing mechanical properties of an element. A non-destructive method that can be applied for inspection of an internal structure of elements is THz spectroscopy. It can be used for identifications of material discontinuities that results in changes of absorption, refractive index or scattering of propagating THz waves. The limitations of THz propagation through water makes this technique a promising solution for detection of a water inclusion. The paper presents an application of THz spectroscopy for detection and localisation of a water drop inclusion embedded in a GFRP material between two fibre optics with fibre Bragg grating sensors. The proposed filtering method allowed to determine a 3D shape of the water drop.