• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.80-87
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• 1999

According to the fact that algae, which is usually used as a biosorbent, contains chlorophyll, we used the chlorophyll as an adsorbent. In this study, chlorophyll is immobilized by agar, which was made of platan, oak, ginkgo and pine. We investigated the removing capacity of biosorbents to toxic heavy metals (Pb, CU, Cd, Zn) in the single ion solution. Then the experimental parameters were pH, reaction time and concentration of heavy metal ions.The optimum conditions for the adsorption of heavy metals were as follows : pH range was 4~5, reaction time was 40mon, and the highest ratio of the removing rate was 50~70 ppm. The order of the amount of Pb, Cu and Cd removed was specified as oak > ginkgo > pine > platan in these conditions and as pine > ginkgo > oak > platan at Zn. Fro the results of the desorption experiments, we found that the heavy metal with the highest ratio of desorption in the single ion adsorbent was Cu.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.45-52
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• 1999

In this thesis, a packer is proposed and designed for removing the bottle-neck effect and easy signal processing using a new algorithm with the operation frequency of 54MHz. To verify the performance of the proposed packer, DCT coefficient encoding block with ROM table using a combinational logic is designed and its output data are used the input data of the packer. Circuits in this thesis are designed by using VHDL code and its modeling and simulation are performed by SYNOPSYS tool using $0.65{\mu}m$ rule.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.3
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• pp.205-212
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• 2002

The catalytic combustion of benzene, toluene and xylene over Pt-based catalyst was investigated in a fixed bed flow reactor system with atmospheric pressure to recycle the waste industrial catalyst for the processes of removing volatile organic compounds. According to the pretreatment condition, the properties of the waste Pt-based catalyst were characterized by XRD (X-ray diffraction) and BET (Brunauer-Emmett-Toller). In the carte of air pretreatment, 20$0^{\circ}C$ was found to be optimal, and increasing pretreatment temperature resulted in the reduction of the catalytic activity. When Pt-based catalyst pretreated at 20$0^{\circ}C$ by alto was retreated by hydrogen, the catalytic activity increased by increasing treatment temperature. In the case of HNO$_3$aqueous solution pretreatment, the catalytic activity decreased by increasing the concentration of HNO$_3$aqueous solution. The catalytic activity was seen to observe the following sequence : benzene > toluene > xylene.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.41-48
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• 2017

It is necessary to develop an LED traffic light lens having a snow removal function capable of clearly providing a traffic signal to the driver even when a traffic light is blurred due to heavy snow and wind in the winter season. This study is focused on the research and development of the traffic light lens in the process of developing the LED traffic light with the snow removal function. In the developed traffic light lens, instead of attaching the film heater, the coated nichrome wire was wound into a coil shape and inserted directly into the groove in the lens. The developed heater system facilitates the insertion of the heating wire with high elasticity into a curved lens and can provide a sufficient heat without deformation of the PC lens. The proposed traffic lights were tested in various external environments and the test results showed that complete snow removal is possible without tunnel effect.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.162-165
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• 2000

This paper presents the analysis of the effect which DC offsets produced in the direct-conversion receiver system under the AWGN circumstance exercise on the system performance. Then, as a method which improve the system performance by removing the DC offsets, we proposed the plan which can copes with the time variant DC offsets occurrences according to taking accumulation and average through the loop signals which DC offsets are produced.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.205-208
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• 2012

Nowadays GPU (Graphic Process Unit) is not only used to show and render some images, but also for another computation. In this paper, we tried to use GPU to do some morphology operations to remove skull from axial MRI images. This skull removing process is an important step in brain segmentation because we would like to work with the brain only, without any skull on it. The result shows that simple morphology operations to remove skull has been successfully applied on MRI images, but there are still many parts that can be develop to get better images.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.34-39
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• 1996

There is much recent interests in applying membrane separation technologies, especially for organic liquid and vapor separation or removing dissolved organics from water. Pervaporation separation can separate azeotropic mixtures and mixtures close to boiling point, and it has a potential for energy saving process instead of distillation. Removal of chlorinated oraganics from water is other measure application for pervaporation separation. Contaminated pollutant must be removed from water, and a pervaporation can effectively remove the pollutant. Air pollution by organic vapor recently became serious enviromncntal problem, and removing organic vapor from air is important application of the membrane technology.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.398-401
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• 2001

This paper presents rough cutting pat고 drilling. This method has differences from conventional method which uses boundary curve by intersecting object to machine and each cutting plane. Die-cavity shape is drilled in z-map, we select various tool and remove much material in the short time. as a result, this method raise productivity. The major challenges in die-cavity pocketing include : 1)finding an inscribed circle for removing material of unmachined regions, 2) selecting optimal tool and efficiently arranging tool, 3) generating offset surface of shape, 4) determining machined width according to the selected tool, 5) detecting and removing unmachined regions, and 6) linking PJE(path-joining element). Conventional machining method calling contour-map is compared with drilling method using Z-map, for finding efficiency in the view of productivity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1269-1275
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• 2002

This paper presents a new method for removing reaching phase in variable structure control systems using Bell type switching function. By proposed method, during the entire control process reaching phase is removed. For effective speed control of trapezoidal type brushless DC motor, a time varying switching function based speed controller is developed as illustration.

• ETRI Journal
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• v.34 no.4
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• pp.564-571
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• 2012

This paper presents an algorithm for removing high-density impulsive noise that generates some serious distortions in edge regions of an image. Although many works have been presented to reduce edge distortions, these existing methods cannot sufficiently restore distorted edges in images with large amounts of impulsive noise. To solve this problem, this paper proposes a method using connected lines extracted from a binarized image, which segments an image into uniform and edge regions. For uniform regions, the existing simple adaptive median filter is applied to remove impulsive noise, and, for edge regions, a prediction filter and a line-weighted median filter using the connected lines are proposed. Simulation results show that the proposed method provides much better performance in restoring distorted edges than existing methods provide. When noise content is more than 20 percent, existing algorithms result in severe edge distortions, while the proposed algorithm can reconstruct edge regions similar to those of the original image.