• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.927-932
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• 2010

Estimation methods of motion intention from bio-signal present challenges in man machine interaction(MMI) to offer user's command to machine without control of any devices. Measurements of meaningful bio-signals that contain the motion intention and motion estimation methods from bio-signal are important issues for accurate and safe interaction. This paper proposes a novel motion estimation sensor based on a geometrical muscle changes, and a motion estimation method using the sensor. For estimation of the motion, we measure the circumference change of the muscle which is proportional to muscle activation level using a flexible piezoelectric cable (pMAS, piezo muscle activation sensor), designed in band type. The pMAS measures variations of the cable band that originate from circumference changes of muscle bundles. Moreover, we estimate the elbow motion by applying the sensor to upper limb with least square method. The proposed sensor and prediction method are simple to use so that they can be used to motion prediction device and methods in rehabilitation and sports fields.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.263-268
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• 2015

The purpose of this study was to investigate anti-melanogenesis effects of mulberry seed extracts (MSE). MSE inhibited melanogenesis in melan-a cells at $10{\mu}g/mL$ without cytotoxicity. Also, MSE decreased tyrosinase, tyrosinase-related protein-1 (TRP-1) protein expression in the melan-a cells. To identify the signaling pathway of MSE, the ability of MSE to influence extracellular signal-regulated protein kinase (ERK) activation was investigated. MSE induced ERK protein expression in a dose-dependent manner. In addition, MSE presented inhibition of the body pigmentation in vivo zebrafish model. These results suggest that MSE may be an effective anti-melanogenesis agent regulating the expression of ERK protein and melanogenic enzymes.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.149-150
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• 2006

In this paper, design, simulation, fabrication method, and measured results of a digital frequency discriminator(DFD) operating in E, F, and G band are introduced. We describe the direct conversion scheme(DCS) with microwave integrated-circuit(MIC) developed for the small-area and high-speed system. When the input signal is the pulse with a pulse width of 100 ns, accuracy of frequencies measured by the DFD has 1.335 MHz RMS at no noise and 2.64 MHz RMS at signal-to-noise(S/N) ratio within 3 dB in E, F, and G band, which nearly satisfy the specification of 2.5 MHz RMS.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.4
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• pp.64-69
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• 2021

In the developed NMR hyperpolarization techniques, Signal amplification by reversible exchange (SABRE) technique is thought to be a promising method to overcome the low sensitivity of bio-NMR/MRI. Most experiments using SABRE have been done in methanol, which is biologically harmful solvent. Therefore, more biological friendly solvent, such as ethanol can be more appropriate solvent to be applicable in bio-NMR and MRI. As the proof of concept, successful hyperpolarization on pyridine via SABRE is carried out in ethanol and its enhancement factor is calculated to be more than 150 folds. To investigate more about its possibility of hyperpolarization in different alcohol solvents, methanol and propanol are used for SABRE in the same condition. The overall polarization trend in different external magnetic field is similar but its polarization number is decreased with higher molecular weight solvents (the order from methanol to propanol). This result indicates that the efficiency of SABRE is different from solvent system despite its same functional group and similar properties. Higher para-hydrogen concentration, higher partial pressure of para-hydrogen, and deuterated solvent can increase the hyperpolarization in any solvents. With these series of successful SABRE results, future studies on SABRE in more biofriendly environment, on more various solvent systems, and with more substrates are needed and it will be the firm basis for applying the SABRE system on the future bio-NMR/MRI.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.57-62
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• 2015

The wet brakes used on a forklift often produce noise upon engagement. The elimination or reduction of this squeal noise is an important task for the improvement of the comfort of those operating these machines. In this paper, a test rig was developed for the testing of brake noise, and the squeal noise was measured with this apparatus. Automatic transmission fluid and grooves in the material of the friction-plate pad were found to be the main factors causing squeal noise. In order to identify the characteristics of this type of noise, signal analyses of the noise were conducted using different frequency spectra. The experimental results showed that the viscosity of the automatic transmission fluid and the groove pattern on the friction-plate pad largely affected the reduction of the wet brake squeal noise made by an industrial forklift.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.1
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• pp.50-57
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• 2004

The aim of this study is to collect driver's psychophysiological signal under various road condition and to select and quantify psychophysiological variables for diagnosis of road-driver compatibility. A 4x4 vehicle with measuring devices was developed to collect driver's psychophysiological signal and collected driver's psychophysiological signal under various road conditions. The collected data were analyzed by the temporal pattern of signal overtime. Thirteen bio-signals with consistent pattern were selected and quantified in terms of slope and amplitude of the signal. These quantified values could be used as a part of tool to diagnose the road-driver compatibility.

• Journal of radiological science and technology
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• v.39 no.1
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• pp.35-42
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• 2016

Room-temperature operating CdZnTe(CZT) material is an innovative radiation detector which could reduce the patient dose to one-tenth level of conventional CT (Computed Tomography) and mammography system. The pixel and pixel pitch in the imaging device determine the conversion efficiency of incident X-or gamma-ray and the cross-talk of signal, that is, image quality of detector system. The weighting potential is the virtual potential determined by the position and geometry of electrode. The weighting potential obtained by computer-based simulation in solving Poisson equation with proper boundaries condition. The pixel was optimized by considering the CIE (charge induced efficiency) and the signal cross-talk in CT detector system. The pixel pitch was 1-mm and the detector thickness was 2-mm in the simulation. The optimized pixel size and inter-pixel distance for maximizing the CIE and minimizing the signal cross-talk is about $750{\mu}m$ and $125{\mu}m$, respectively.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.294-301
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• 2017

This paper presents a low power ${\Sigma}{\Delta}$ modulator for an implantable chip to acquire a bio-signal such as EEG, DBS, and EMG. In order to reduce a power consumption of the proposed fourth order modulator, two op-amps utilized for the first two integrators are reconfigured to drive the second two integrators. The KT/C noise reduction circuit in the first two integrators is employed to enhance SNR of the modulator. The proposed circuit was fabricated in a 0.18 um CMOS n-well 1 poly 6 metal process with the active chip core area of $900um{\times}800um$ and the power consumption of 830 uW. Measurement results were demonstrated to be SNDR of 76 dB, DR of 77 dB, ENOB of 12.3 bit at the input frequency of 250 Hz and the clock frequency of 256 kHz. FOM1 and FOM2 were measured to be 41 pJ/step and 142.4 dB, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.1 s.244
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• pp.1-7
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• 2006

A system for the electrical bio signal detection for a microchip is proposed. Gold nanoparticles were selected for the system for their bio-compatibility and potential for higher sensitivity with large surface areas. For the estimation of the conductivity of gold nanoparticles, microchips with interdigitated microelectrodes of 3,5,7 and $9\;{\mu}m$ spacing were fabricated. In addition, a simulation program was developed to estimate the electrical resistance of the fabricated microchip. The results of conduction simulation for the nanoparticles show good agreements with experimental data, which validate the proposed system.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.263-266
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• 1997

The purpose of this paper is the development of Integrated Bio-signal Management System. (IBMS) using the network. IBMS is the system to manage the medical signals that measured from the each independent medical measurement system module. Each has a LAN Card. We developed the Network Application using Socket Library. Also, we developed the Graphic User Interface software for IBMS using Visual C++ on Windows 95.