• Smart Structures and Systems
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• v.22 no.1
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• pp.57-70
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• 2018

For the long-term structural health monitoring of civil structures, the effect of ambient temperature variation has been regarded as one of the critical issues. In this study, a principal component analysis (PCA)-based algorithm is proposed to filter out temperature effects on electromechanical impedance (EMI) monitoring of prestressed tendon anchorages. Firstly, the EMI monitoring via a piezoelectric interface device is described for prestress-loss detection in the tendon anchorage system. Secondly, the PCA-based temperature filtering algorithm tailored to the EMI monitoring of the prestressed tendon anchorage is outlined. The proposed algorithm utilizes the damage-sensitive features obtained from sub-ranges of the EMI data to establish the PCA-based filter model. Finally, the feasibility of the PCA-based algorithm is experimentally evaluated by distinguishing temperature changes from prestress-loss events in a prestressed concrete girder. The accuracy of the prestress-loss detection results is discussed with respect to the EMI features before and after the temperature filtering.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.589-598
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• 1995

Filtering rates of Crassostrea gigas were experimentally investigated with reference to effects of water temperature and size. Absorptiometric determinations of filtering rates with oysters being fed diatom Chaetoceros calcirtans were carried out in a closed system. Optical density of 675nm in path length 100mm cell used as the indication of food particles absorption was appeared directly In proportion with the concentration of diatom pigment $chlorophyll-\alpha$. In the closed system where $C_0$ is $OD_{675}$ at initial time 0, $C_t$, at time t, and Z is the decreasing coefficient of OD as meaning of instantaneous removal speed, then $C_t=C_0{\cdot} e^{-2t}$, $Z=In(C_t/C_0)/t$. On the assumption that the filtering rate is constant, then removal rate per unit time (d) is $d=-e^{-z}$. If t is used to time unit of hour (hr), the filtering rate (FR) in I/hr is given by $FR=V{\cdot}d=V(1-e^{-z})$, where V is the water volume (I) of the experimental vessel. Filtering rate increased as exponential function with increasing temperature while not over critical limit. The critical temperature for filtering rate was assumed to be between $28^{\circ}C$ and $29^{\circ}C$. And the weight exponent for filtering rate is 0.223. The model formula derived from the results as FR, $Ihr^{-1}$ = $Exp(0.208{\cdot}T-4.324){\cdot} (DW)^{0.223}$ (T<29 $^{\circ}C)$ where T is water temperature $(^{\circ}C

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.4
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• pp.361-367
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• 1995

This study has been carried out to investigate the filteration performance of Electrostatically Stimulated Fabric Filter(ESFF) at high temperature condition. The electric field was maintained parallel to the fabric surface. The benefits of ESFF are lower residual pressure drop, improvement of fine particle removal efficiency and increasing reduced rate of pressure drop during a filteration cycle, stable operation at higher filtering velocities. According to the variance of filtering velocities and dust loadings, the results are summarized as follows; By imposing an electric field on the filter, the reduced rate of pressure drop was 7.sim.18% at room temperature, and when filtering velocity was 1.8m/min and dust loading was 1g/m$^{3}$, the value of reduced rate of pressure drop was shown the highest. Under the electric field around the filter, the reduced rate of pressure drop was 10.sim.35% at high temperature, and when filtering velocity was 1.8m/min and dust loading was 1g/m$^{3}$, the value of reduced rate of pressure drop was shown the highest. Most of all, at high temperature, the value of reduced rate of pressure drop was resulted to 25%. Also the collecting efficiency was shown clearly improved. By the SEM photo analysis, the number of penetrated particles at the Conventional Fabric Filter was approximately two times that of Electrostatically Stimulated Fabric Filter.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1269-1271
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• 2009

We had proposed fast thermal stress estimation methodology for the components on system board when the system is stationary within specific ambient air temperature. Now, we will propose one efficient thermal stress estimation methodology, block adaptive filtering methodology, for the FPD electronic system board which is enclosed by mechanical cover.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1250-1259
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• 2007

Bambusae Caulis in Liquamen(BCL) has been commonly prescribed for stroke patients in the traditional Oriental medicine. So this study is aims to investigate the anti-apoptotic and neuroprotective effects of Bambusae Caulis in Liquamen(BCL) manufactured by different production process on the focal ischemia induced by intraluminal filament insertion in rats. The focal ischemia was induced by intraluminal filament insertion into middle cerebral artery. The animals were divided into four groups (n=15 in each group). The ischemia induced and not treated group : Control group, the ischemia induced and oral medication of the three kinds of BCL : BCL-A group, BCL-B group, BCL-C group. BCL-A was produced by heating at a low temperature$(250^{\circ} C)$ in electric kiln and filtering. BCL-B was produced by heating at a high temperature$(900^{\circ} C{\sim}1,000^{\circ}C)$ in yellow earth kiln and refining and filtering. BCL-C was produced by heating at a low temperature$(400^{\circ} C)$ yellow earth kiln and no refining and filtering. The anti-apoptotic and neuroprotective effects of the oral medication of BCL were observed by Bax, BCL-2, cytochrome c, mGluR5, cresyl violet and ChAT-stain. Our study suggests that BCl-A(was produced by heating at a low temperature in electric kiln and filtering) and BCL-C(was produced by heating at a low temperature in yellow earth kiln and no refining and filtering) show anti-apoptotic and neuroprotective effects on the focal ischemia induced by intraluminal filament insertion in rats and BCL-C is more effective than BCL-A.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.272-277
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• 1998

Filtering rates of two farming ascidians Styela clava and S. plicata, and of a farming mussel Mytilus edulis were experimentally investigated with reference to effects of water temperature and size. Absorptiometric determinations of filtering rates were carried out in a closed system with experimental animals being decreased indicate dyes neutral red. Optical density (OD) of 440 nm in path length 22 mm cell used as the indication of food particles absorption was appeared directly in proportion with the concentration of neutral red dyes. The filtering rate F is calculated by Kim's equation $F\;=\;V(1-e^{-z})$, where V is the water volume ($\ell$) in the experimental jar, and Z is the decreasing coefficient of OD as meaning of instantaneous removal speed as In $C_t\;=\;In\;C_{o}-Z{\cdot}t$, in this formula $C_t$ is OD at the time t. Filtering rate of S. clava increased as exponential function with increasing temperature while not over critical limit, and the critical temperature for filtering rate was assumed to be between $28^{\circ}C$ and $29^{\circ}C$. In case of S. plicata, the critical temperature was to be below $13^{\circ}C$, and through the temperature range $15\~25^{\circ}C$ appeared a little difference in level even though with significant. M. edulis was not appear any significant effects by water temperature less than $29^{\circ}C$. The model formula derived from the results is as below, where F is filtering rate (${\ell}/hr/animal$), T is water temperature ($^{\circ}C$), and DW is dry meat weight (g) of experimental animal. $$S.\;Clava;\;F\;=\;e xp\;(0.119\;T-4.540)\;(DW)^{0.6745},\;T<29^{\circ}C$$) $$S.\;plicata;\;F\;=\;e xp\;(A_t)\;(DW)^{0.5675},\;(13^{\circ}C $$[A_t =-8.56+0.6805\;T-0.0153\;T^2]$$ $$M.\;edulis;\;F\;=\;0.3844\;(DW)^{0.4952},\;<29^{\circ}C$$)

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.113-120
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• 2000

This study has developed a new liquid crystal calibration technique using Neural networks with median filtering and applied this technique to heat transfer measurements. To verify the validity of this new measurement technique, the local Nusselt numbers on a flat plate surface subjected to an axisymmetric impinging jet were measured and compared with the results by the conventional Hue-temperature calibration technique under the same conditions. Because the Neural networks predict the non-linear relations between temperatures and corresponding R, G, B values, Neural networks-median filtering calibration technique can utilize a much wider color band in the experiment than the Hue-temperature calibration technique, resulting in a significant reduction in the experimental time.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.10
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• pp.1014-1022
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• 2014

In mechatronic systems using electric signals to drive control systems, driving signals including the frequency band of the unwanted signals, such as resonant frequencies and noise frequencies, can affect the accuracy of the controlled system and can cause serious damage to the system due to the resonance phenomenon of the mechatronic system. An LOS (Line of Sight) control unit is used to automatically rotate the gimbal system with a video imaging system generally mounted on modern aerial vehicles. However, it still suffers from natural frequency variation problems due to variations of operational temperature. To prevent degradation in performance, this paper proposes an adaptive filtering technique based on real-time noise analysis and adaptive notch-filtering for LOS control systems, and verifies how our proposed method maintains the LOS stabilization performance. Additionally, this filtering technique can be applied to the image noise filtering of the video imaging system. It is designed to reduce image noises generated by switching circuits or power sources. The details of design procedures of the proposed filtering technique and the experiments for the performance verification are described in this paper.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.446-451
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• 2015

Recently, researches on sensor-based U-health applications that provide personal health information such as blood pressure, body temperature, and glucose, have actively been studied. The health information obtained via sensors, however, may have accuracy problems so that they can not be used unprocessed. This paper proposes a sensor abstraction layer for enhancing the accuracy of sensor readings from biomedical sensors that interact with smart phones. This layer recognizes sensor types and converts sensor readings into a form as specified in ISO/IEEE 11073 Personal Health Standard. When necessary, not only a filtering method that eliminates outlier values from sensor readings but also a summarization method that transforms them into more suitable forms, can also be applied. An android-based development board is used for the evaluation of proposed sensor abstraction layer. The results obtained by applying filtering and summarization show improved accuracy over unprocessed sensor readings of the body temperature and heartbeat sensors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.1
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• pp.89-94
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• 2003

As ship's fuel oil recently becomes viscous and the amount of sludge increases, many researches and studies are underway to process the sludge onboard the ship and to recycle it as a fuel for ship's boiler. Of many researches, especially ultrasonic emulsifier to break the particle of sludge into fine pieces is recognized as a most possible recycling device. In this regards, the author investigates the property change of sludge's temperature and pressure at the early stage of the study of ultrasonic emulsifier. This study can be used as a useful dora to determine the proper temperature and pressure to inject the processed sludge in the boiler injector and the results can also be comparable dora with the experimental data by ultrasonic emulsifier. In addition, the results will be a fundamental data to study the filtering efficiency of the sludge particle broken by temperature and pressure. It is expected that this study ultimately play a role to prevent marine oil pollution as the sludge is recycled onboard the ship and used as a fuel for boiler.