• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1163-1169
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• 2023

In this study, the flow characteristics of the filter system were analyzed due to the effect of the density of the filter in the triple filter system. Flow analysis was performed as a flow passing through a porous medium. The flow characteristics of each filter system were analyzed by arranging filters with different densities in the forward flow flow and the reverse flow. The arrangement order of the triple filters was excellent in the case of forward fluid flow and in the case of higher density from the inside to the outside filter. In the reverse flow filter system, the performance of the system was the best in the case of reverse order filter arrangement. As a result of the analysis, Case II, which showed a pressure drop rate of 5.65% for forward flow, was the best in the reverse direction with a pressure drop rate of 14.25%. Considering reverse and forward flows, it was found that the optimal filter arrangement was most effective when the intermediate filter was the densest, and the inner or outer filter was less dense.

• Journal of the Korea society of information convergence
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• v.5 no.2
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• pp.101-108
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• 2012

In the present paper, it removed the low frequency noise under 1Hz which get up base wandering from the various noise which is included in ECG signals. It used wavelet filter, FIR filter and Adaptive FIR filter and compared the efficiency of the filter. The set condition of 3 kind filters which are the comparative object is the next contents. Used wavelet case, used generating functions db7 and after decomposition, the low frequency of 8 phases (cA8) replaced at 0. FIR filter case, filter coefficient set 1400, cutoff frequency (${\omega}$) set 0.002. Adaptive FIR filter case, collecting coefficients (${\mu}$) with 0.005. The comparative result from the output wave shape and FT spectrum, wavelet is excellent in base wandering removals compared FIR filter and Adaptive FIR filter. And SNR comparisons, wavelet filter(44.16) is high compare with other two filters(25.19 and 15.94).

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.206-213
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• 2009

The study is to measure a variation of exposed dose on genital glands (ovary, testis) which are exposed to radiation during the defecography to diagnosis domain according to use of filters and to look into its utility. whose results are as follows: The measured values of dose were the left ovary 23.4mGy, the right ovary 7.5mGy, the testis 10.3mGy in case of not using filter at all, the left ovary 22.4mGy the right ovary 7.0mGy, the testis 9.5mGy in case of using an additional filter only, the left ovary 26.7mGy, the right ovary 8.4mGy, the testis 11.5mGy in case of using a defeco filter only and the left ovary 20.5mGy, the right ovary 6.2mGy, the testis 7.5mGy in case of using both an additional filter and a defeco filter, respectively. When comparing with the value in case of not using filter at all, the dose to the left ovary decreased by 10%, the dose to right ovary by 5% and the testis by 8% respectively in case of using an additional filter only. While the dose to the left ovary increased by 33%, the dose to right ovary by 9% and the testis by 12% respectively gonad a defeco filter only. And in case of using both an additional filter and a defeco filter, the dose to the left ovary decreased by 29%, the dose to right ovary by 13% and the testis by 28% respectively. In other words, the dose increased in case of using a defeco filter only while the dose decreased markedly on the rest conditions such as using an additional filter only, using a defeco filter only and using both an additional filter and a defeco filter.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.74-79
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• 2021

This study focuses on designing a filter case using a water pump for application in eDNA filtering systems. Filter cases, channel type and net type were designed based on the flow field and made using a 3D printer for metal. Flow analysis was conducted for each filter case, and the results were consistent with the pressure experiment results. Furthermore, the water sampling performance test showed that the channel-type filter case exhibited a high flow rate and low pressure through the filter. The eDNA extraction experiment showed that the channel type exhibited improved capture ability compared to the net type.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.702-710
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• 2008

In this paper, the observability of the INS/GPS integrated system for a land vehicle is analyzed on measurements and different filters with respect to the measurements are designed. In the stationary case, it is shown that horizontal accelerometer biases and vertical attitude errors and gyro biases are unobservable. An 8-state filter is designed based on the observability analysis. When GPS signal is available, a 15-state filter is used with position and velocity measurements. To estimate the INS errors even in the case that GPS signal is blocked a filter is designed in consideration of the non-holonomic constraints of a land vehicle. In this case, the horizontal position and velocity errors and vertical attitude error are unobservable. However, a 12-state filter including the velocity states is designed to estimate the accelerometer biases. When GPS signal recovers, a 9-state filter is used excluding the sensor biases. This paper presents a multi-dimensional filter that switches the four filters according to the usable measurements and maneuver environments. A simulation is carried out to verify the performance of the proposed filter.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.377-380
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• 2002

When it calculates the optimum price of filter coefficient, the many operation quantity is necessary. Is like that the real-time control is difficult and the hardware embodiment expense is big. The case which does not know advance information of input signal or the case where the statistical nature changes with change of surroundings environment is necessary the adaptive filter. Every hour to change a coefficient automatically and system in order to reach to the condition of optimum oneself, the fact that is the adaptive filter. When it does not the quality of input signal or it does not know the environment of surroundings every hour changing, it does not emit not to be, in order to collect, the fact that is the adaptive filter. The case of the Acoustic Echo Canceler does thousands filter coefficients in necessity. It reduces a many calculation quantity to respect, it uses the IIR filter from hour territory. Also it uses the block adaptive filter which has a block input signal and a block output signal. The former there is a weak point where the stability discrimination is always demanded. Consequently, The block adaptive filter is researched plentifully. This dissertation planned the block MADF adaptive filter used to MADf algorithm.

• Journal of Broadcast Engineering
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• v.16 no.4
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• pp.624-634
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• 2011

Recently, the JCT-VC is developing the next generation video coding standard that is called HEVC. HEVC has adopted many coding technologies increasing coding efficiency. For chroma interpolation, DCT-based interpolation filter showing better performance than the linear filter in H.264/AVC was adopted in HEVC. In this paper, a combined filter that utilizes the FIR filter and the linear filter in H.264/AVC is proposed to increase coding efficiency. When the proposed method is compared with DCT-based interpolation filter, the experimental results for various sequences show that the average BD-rate improvements on chroma U and V components are 0.9% and 1.1%, respectively, in the high efficiency case of random access structure, those on U and V components are 1.1% and 1.1%, respectively, in the low complexity case of random access structure, those on U and V components are 0.9% and 1.4%, respectively, in the high efficiency case of low delay structure, and those on U and V components are 1.8% and 1.8%, respectively, in the low complexity case of low delay structure.

• International Journal of Control, Automation, and Systems
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• v.1 no.4
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• pp.520-526
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• 2003

In the case of a strapdown inertial navigation system (SDINS) with sizeable attitude errors, the uncertainty caused by linearization of the system degrades the performance of the filter. In this paper, a robust filter and various error models for the uncertainty are presented. The analytical characteristics of the proposed filter are also investigated. The results show that the filter does not require the statistical property of the system disturbance and that the region of the estimation error depends on a freedom parameter in the worst case. Then, the uncertainty of the SDINS is derived. Depending on the choice of the reference frame and the attitude error state, several error models are presented. Finally, various in-flight alignment methods are proposed by combining the robust filter with the error models. Simulation results demonstrate that the proposed filter effectively improves the performance.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.378-381
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• 2014

We studied the pasteurization effect of the microorganism involved in the water, using ion-exchanging filter made of the Radiation Induced Grafted Polymerization. This ion-exchanging filter is made by the graft polymerization of GMA, after irradiation of electron beam to the non-woven filter. Then, we made the ion-exchanging filter (EtA, DEA, SS) applying ion-exchanging base to the GMA filter. As a result, the density of the ion-exchanging base is shown as 2.38 mol/kg in case of EtA, 1.79 mol/kg in case of DEA and 0.75 mol/kg in case of SS. Through this filter made by this method, we measured the pasteurization power of E. coli. We found very high elimination rate such as log 4.65 in case of SS-dial filter, which is higher as 3.00 times in comparison with EtA, and 1.10 times in comparison with DEA. This data show the result is very excellent comparing with 3,000 CFU/ml. of city water treatment basis.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.3
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• pp.163-168
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• 2000

The problems of mixed $H_2/H_{\infty}$ filtering design fer continuous and discrete time linear systems with time delay are investigated. The main purpose is to design a stable mixed $H_2/H_{\infty}$ filter which minimizes the H$_2$Performance measure satisfying a prescribed H$_{\infty}$ norm bound on the closed loop system in continuous-time case and discrete-time case, respectively. The sufficient conditions of existence of filter, the mixed $H_2/H_{\infty}$ filter design method, and the upper bound of performance measure are proposed by LMI(linear matrix inequality) techniques in terms of all finding variables. Also, we present optimization problems in order to get the optimal mixed $H_2/H_{\infty}$ filter in continuous and discrete time case, respectively.