• Journal of Korean Society for Atmospheric Environment
• /
• v.22 no.2
• /
• pp.191-199
• /
• 2006

Animal feedstuff handling is one of the major fugitive dust sources in the port of Incheon. For the effective control of fugitive dusts emitting from the port of Incheon, dust control facilities with bag filter systems should be designed properly considering the characteristic of the fugitive dusts including those from animal feedstuffs. The ultimate goal of this study is thus to develop the optimum fugitive dust control system which will be applicable for the renovation of the port. As the first step to achieve this longstanding goal, filtration characteristics of soybean shell, the largest dust sources in the port, were investigated with the specially designed filter testing apparatus for this study. The variables tested for the experiments included filter materials, dust concentrations, relative humidities, and filtration velocities. Also, the filtration characteristics of the other animal feedstuffs such as sunflower seed shell, tapioca, and palm shell were investigated to determine $K_2$ as a function of filtration velocity. The information on $K_2$ will be used to design the optimum bag filter systems for animal feedstuffs handling in the port.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.7
• /
• pp.58-64
• /
• 2009

In this paper, an inspection mechanism based on laser scattering has been developed for the surface evaluation of infrared cut-off filters, and optimum conditions of laser scattering are determined using the design of experiment. First of all, attributes and influence factors of laser scattering are investigated and then a laser scattering inspection mechanism is newly designed based on analyses of laser scattering parameters. Also, Taguchi method, one of experimental designs, is used for the optimum condition selection of laser scattering parameters and the optimum condition is determined in order to maximize the detection capability of surface defects. Experiments show that the proposed method is useful in a consistent and effective defect detection and can be applied to surface evaluation processes in manufacturing.

• The Journal of Engineering Geology
• /
• v.29 no.4
• /
• pp.509-529
• /
• 2019

This study performs to evaluate the role of filter material at alluvial well for intake of riverbank filtration and the applicability and improvement effect of dual filter well. To achieve this objective, dual filter intake well and single filter intake well were installed with different filter conditions at riverbank free surface aquifer in soil layer then we evaluated filter material condition, permeability, optimum yield and well efficiency according to yield in drawdown test. As a results, we assumed forming dual filter layer minimizes sudden speed changes at boundary between aquifer and filter layer by cushioning of groundwater flow. This suppresses warm current then intake groundwater efficiently, therefore it seems decreasing peripheral groundwater level changes in spite of higher intake water amount than single filter intake well. Furthermore, we confirmed by test, installing dual filter improves permeability, optimum yield and well efficiency. The result will be used by combining with former study to set up standard of design/construction of dual filter intake well at alluvial aquifer layer. Furthermore, we expect this result will be used to prove application effect of dual filter intake well compared to single filter one and radial collector well which are mainly applied on riverbank filtration.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.34D no.6
• /
• pp.65-74
• /
• 1997

In this paper, SA-multiplexed filter is designed using SA (simulated ananealing) to recognize music notation patterns varying in size, shape, position and having considerably many similar shapes for optical pattern recognition system. This filter has correlation resutls at wanted location and can identify same class, classify similar class for scale-varianted or rotation-varianted music notation patterns havng learning process. Also, the optimum filter is oriented to analyze on the similar discrimination at acquired position using SA and enhances optical diffractive efficiency as well as peak beam intensity. Compared with POF *(phase only filter), cosine-BPOF(cosine-binary phase only filter), that has excellent discrimination capability even if the different rate is 0.1% quantitatively.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.4
• /
• pp.938-946
• /
• 1996

Hierarchical subband codec has been widely promoted in the field of data compression/decompression because of their simplicity and modular nature. Over the past years, the study has received great attention to the perfect reconstruction (PR)system which perfectly recovers the original input signal at the reconstructed output. However, in the actual subband codec system, the signals that passed through the analysis filter bank are quantized before transmission to the receiver side and reconstructed by the synthesis filter bank. Thus the PR system is impossible and the quantization effects must be carefully considered in the system design such that the system recovers the reconstructed output as possible to the the original input signal with minimum quantization error.In this paper, we propose an optimum hierarchical subband codec structure in the presence of quantizer. The optimality criteria of the code is given to the deign of the hierarchical analysis/synthesis subband filter bank and the quantizer that minimize then output mean square error due to the quantizer in the codec. Specific opti-mum design esamples are shown with level-1, level-2 hierarchical structure. The optimal designs are verified by computer simulation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.2 s.93
• /
• pp.120-127
• /
• 2005

The design method of the transversal filter using continuously cascaded directional couplers is presented. The coupler can be treated for a continuously varying nonuniform coupled transmission line. The design method is based on the optimum extraction of desired coupling factor by the control of null positions which are inherent to the coupling spectra pattern. In the optimization process, the improved Woodward-Lawson sampling method is applied to easily synthesize the distributed delay and weighting elements for transversal filter properties. For application, the microstrip transversal filter is fabricated and optimum dielectric overlay is introduced for the mode phase velocity compensation for non-TEM coupler nodes by using SDA(Spectral Domain Approach). Experiment results confirm the validity of the proposed method.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.3
• /
• pp.338-347
• /
• 2005

Horizontal-Flow Roughing Filtration (HRF) is one of altemative pretreatment methods e.g. prior to Slow Sand Filtration (SSF). However, some of its limitations are that the effluent quality drops drastically at higher turbidity (>200 NTU) and at higher filtration rate (>1 m/h). To overcome these drawbacks, we suggested Direct Horizontal-Flow Roughing Filtration (DHRF), which is a modified system of Horizontal-Flow Roughing (HRF) by addition of low dose of coagulant prior to filtration. In this study to optimize the DHRF configuration, a conceptual and mathematical model for the coarse compartment has been developed in analogy with multi-plate settlers. Data from simple column settling test can be used in the model to predict the filter performance. Furthermore, the model developed herein has been validated by successive experiments carried out. The conventional column settling test has been found to be an handy and useful to predict the performance of DHRF for different raw water characteristics (e.g. coagulated or uncoagulated water, different presence of organic matter, etc.) and different inital process conditions (e.g. coagulant dose, mixing time and intensity, etc.). An optimum filter design for the coarse compartment (grain size 20mm) has been found to be of 3 m/h filtration rate with filter length of 4-4.5 m.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.2389-2391
• /
• 2000

To design high quality products at low cost is one of very important tasks for engineers. Design optimization for performances can be one solution in this task. There is the robust design which has been proved effectively in many fields of engineering design. In this paper, the concept of robust design is introduced and combined to the fuzzy optimization method and the fuzzy logic system method with non-singleton. These methods are applied for data analysis to get optimum parameters and to reduce experiments. The optimum parameter set points are obtained by the proposed methods. These methods are applied to a filter circuit, a part of the audio circuit of mobile radio transceiver. The simulation results are compared each other. The new methods reduce and predict the effect of parameter variation sources

• Journal of Advanced Marine Engineering and Technology
• /
• v.27 no.6
• /
• pp.767-775
• /
• 2003

This paper considers the method of elimination harmonics in AC/DC converters, There are few practical methods to reduce the harmonics in AC/DC converters, particularly in filter design and control strategy. In this paper, a harmonic elimination methods are proposed, which includes hybrid PWM control strategy. These methods achieve precise output control along with the optimum performance simultaneously. The control method in this paper is developed to eliminate a fixed number of harmonics in AC to DC converter. The higher order harmonics can be easily eliminated by using filter proposed in this paper. The validity of these methods is confirmed experimentally.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.4
• /
• pp.84-91
• /
• 1996

Input filter for satellite communication transponder is the interface between the antenna and the receiver. It is used to provide the selection of the uplink signals with minimum insertion loss and to prevent downlink signals form reaching the LNA. This paper is intended to provide a description of the input filter for KOREASAT communication transponder. Included are description for the electrical and mechanical design and the requirments of environmental test. In expecting the electrical performine the optimum electrical configuration ot meet all requirements are performed. Mechanical requirements are charactersed by several constraints for weight, size of the filter and its type of input output interface. The standardized environmental tests are performed to confirm satisfactory performance of the filter with respect to the requirements of vibration and thermal vacuum shocks.